1
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Arshad MS, Billing C, Billing DG, Guan W. Phase-Assisted Tailored Conductivity of Doped Ceria Electrolytes to Boost SOFC Performance. ACS Appl Mater Interfaces 2023; 15:39396-39407. [PMID: 37556767 PMCID: PMC10450644 DOI: 10.1021/acsami.3c08146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 07/27/2023] [Indexed: 08/11/2023]
Abstract
Efforts to lower the operating temperature of solid oxide fuel cells include producing electrolytes that are sufficiently conductive and stable below 600 °C. Doped ceria is one such electrolyte being considered. During this study, codoped ceria powders (Ce0.8Sm0.2-xMxO2-δ, M = Bi3+, Zn2+ and x = 0, 0.05, 0.1, 0.15, 0.2) were prepared via coprecipitation by the addition of sodium carbonate and annealed at 800 and 1200 °C, respectively. Poor solubility of the codopants in the ceria was observed for samples annealed at 800 °C, resulting in a mixed-phase product including stable phases of the oxides of these codopants. A second-stage partial incorporation of these codopants into the ceria lattice was observed when the annealing temperature was increased to 1200 °C, with both codopants forming cubic-type phases of their respective oxides. Materials were characterized using X-ray diffraction (XRD), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR), as well as scanning electron microscopy (SEM) for structural and morphological investigations. The oxide ion conductivity was evaluated using electrochemical impedance spectroscopy between 550 and 750 °C. Fuel cell performance tests of selected samples (annealed at 1200 °C) showed remarkable improvement in peak power densities when the test temperature was increased from 500 to 600 °C (∼720 mW/cm2 for Ce0.8Sm0.15Bi0.05O2-δ and ∼1230 mW/cm2 for Ce0.8Sm0.15Zn0.05O2-δ), indicating possible contribution from the distinct cubic-type oxide phases of the codopants in performance enhancement.
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Affiliation(s)
- Muhammad S. Arshad
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa
- Department
of Chemical Sciences, University of Johannesburg, Doornfontein, Johannesburg 2028, South Africa
- Ningbo
Institute of Material Technology and Engineering, Chinese Academy
of Sciences, Ningbo 315201, China
| | - Caren Billing
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa
| | - David G. Billing
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa
| | - Wanbing Guan
- Ningbo
Institute of Material Technology and Engineering, Chinese Academy
of Sciences, Ningbo 315201, China
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2
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Shnier A, Otieno F, Billing C, Wamwangi D, Billing DG. Robust Arduino controlled spin coater using a novel and simple gravity chuck design. HardwareX 2023; 14:e00422. [PMID: 37179702 PMCID: PMC10172839 DOI: 10.1016/j.ohx.2023.e00422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Spin coaters offer an invaluable method of thin film fabrication. Various implementations, both proprietary and open-source exist, offering vacuum and gravity samples chucks. These implementations vary in their reliability, ease-of-use, cost, and versatility. Here we present a novel easy-to-use open-source gravity-chuck type spin coater with minimal points of failure at a material cost of around 100 USD (1500 ZAR). The unique chuck design makes use of interchangeable brass plate sample masks, each specific to a sample size, these can be made with basic skills and common hand tools. In comparison, replacement chucks for commercial alternatives can cost as much as the entire spin coater we present. Open-source hardware such as this provides an example for individuals in the field on the design and development of hardware where reliability, cost, and flexibility are most important, as is the case for many institutions in developing countries.
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Affiliation(s)
- Adam Shnier
- School of Chemistry, University of Witwatersrand, Johannesburg 2050, South Africa
- DSI-NRF Centre of Excellence in Strong Materials (CoE-SM), University of Witwatersrand, Johannesburg 2050, South Africa
| | - Francis Otieno
- School of Physics, University of Witwatersrand, Johannesburg 2050, South Africa
- DSI-NRF Centre of Excellence in Strong Materials (CoE-SM), University of Witwatersrand, Johannesburg 2050, South Africa
- Department of Physics and Materials science, Maseno University Private Bag Maseno, Kenya
| | - Caren Billing
- School of Chemistry, University of Witwatersrand, Johannesburg 2050, South Africa
- DSI-NRF Centre of Excellence in Strong Materials (CoE-SM), University of Witwatersrand, Johannesburg 2050, South Africa
| | - Daniel Wamwangi
- School of Physics, University of Witwatersrand, Johannesburg 2050, South Africa
- DSI-NRF Centre of Excellence in Strong Materials (CoE-SM), University of Witwatersrand, Johannesburg 2050, South Africa
| | - David G. Billing
- School of Chemistry, University of Witwatersrand, Johannesburg 2050, South Africa
- DSI-NRF Centre of Excellence in Strong Materials (CoE-SM), University of Witwatersrand, Johannesburg 2050, South Africa
- Corresponding author at: School of Chemistry, University of Witwatersrand, Johannesburg 2050, South Africa.
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3
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Özer B, Karlsen MA, Thatcher Z, Lan L, McMahon B, Strickland PR, Westrip SP, Sang KS, Billing DG, Ravnsbæk DB, Billinge SJL. Towards a machine-readable literature: finding relevant papers based on an uploaded powder diffraction pattern. Acta Crystallogr A Found Adv 2022; 78:386-394. [PMID: 36047395 PMCID: PMC9434602 DOI: 10.1107/s2053273322007483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/21/2022] [Indexed: 02/05/2023] Open
Abstract
A prototype application for machine-readable literature is investigated. The program is called pyDataRecognition and serves as an example of a data-driven literature search, where the literature search query is an experimental data set provided by the user. The user uploads a powder pattern together with the radiation wavelength. The program compares the user data to a database of existing powder patterns associated with published papers and produces a rank ordered according to their similarity score. The program returns the digital object identifier and full reference of top-ranked papers together with a stack plot of the user data alongside the top-five database entries. The paper describes the approach and explores successes and challenges.
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Affiliation(s)
- Berrak Özer
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, 10027, USA,Correspondence e-mail: ,
| | - Martin A. Karlsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Zachary Thatcher
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, 10027, USA
| | - Ling Lan
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, 10027, USA
| | - Brian McMahon
- International Union of Crystallography, Chester, CH1 2HU, UK
| | | | | | - Koh S. Sang
- International Union of Crystallography, Chester, CH1 2HU, UK
| | - David G. Billing
- School of Chemistry, University of the Witwatersrand, Private Bag 3, PO WITS, 2050, South Africa
| | | | - Simon J. L. Billinge
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, 10027, USA,Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA,Correspondence e-mail: ,
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4
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Thiebaut M, Billing C, Naidoo D, Billing DG. The influence of the Li + addition rate during the hydrothermal synthesis of LiFePO 4 on the average and local structure. Dalton Trans 2022; 51:18176-18186. [DOI: 10.1039/d2dt01752k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In hydrothermal synthesis of LiFePO4 a slower addition of Li+ to a mixture of Fe2+ + PO43- increased Fe2+ oxidation, defects within the LiFePO4 structure and iron impurities in the product. No link was seen between Li3PO4 formation and addition rate.
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Affiliation(s)
- Michelle Thiebaut
- Molecular Science Institute, School of Chemistry, University of the Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa
- DST-NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Private Bag X3, 2050 Johannesburg, South Africa
| | - Caren Billing
- Molecular Science Institute, School of Chemistry, University of the Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa
- DST-NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Private Bag X3, 2050 Johannesburg, South Africa
| | - Deena Naidoo
- Material Physics Research Institute, School of Physics, University of the Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa
| | - David G. Billing
- Molecular Science Institute, School of Chemistry, University of the Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa
- DST-NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Private Bag X3, 2050 Johannesburg, South Africa
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5
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Thiebaut M, Billing C, Billing DG, Naidoo D. LiFePO 4 and Li + addition rate during synthesis: combining X-ray diffraction and spectroscopy techniques to determine average and local structure. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321093314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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6
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Dolla TH, Billing DG, Sheppard C, Prinsloo A, Carleschi E, Doyle BP, Pruessner K, Ndungu P. Mn substituted MnxZn1−xCo2O4 oxides synthesized by co-precipitation; effect of doping on the structural, electronic and magnetic properties. RSC Adv 2018; 8:39837-39848. [PMID: 35558230 PMCID: PMC9091321 DOI: 10.1039/c8ra08150f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/20/2018] [Indexed: 11/21/2022] Open
Abstract
Mn substituted MnxZn1−xCo2O4 (x = 0, 0.3, 0.5, 0.7, 1) oxides were synthesized by a facile co-precipitation method followed by calcination at 600 °C. The presence of manganese ions causes appreciable changes in the structural and magnetic properties of the Mn-substituted ZnCo2O4. The morphologies, structures, and electronic properties of Mn–Zn–Co oxide microspheres were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The X-ray diffraction and Fourier transform infrared spectroscopy results confirmed the formation of spinel MnxZn1−xCo2O4. It was shown that the Mn–Zn–Co oxide microspheres increase in size and become regular in shape with increasing Mn concentration with the crystal size lying in the range from 19.1 nm to 51.3 nm. Magnetization measurements were carried out using a vibrating sample magnetometer at room temperature and 10 K. The saturation magnetization is observed to increase with increasing Mn concentration from x = 0 to x = 1. Mn substituted MnxZn1−xCo2O4 (x = 0, 0.3, 0.5, 0.7, 1) oxides were synthesized by a facile co-precipitation method followed by calcination at 600 °C.![]()
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Affiliation(s)
- Tarekegn Heliso Dolla
- Energy, Sensors and Multifunctional Nanomaterials Research Group
- Department of Applied Chemistry
- University of Johannesburg
- Doornfontein Campus
- South Africa
| | - David G. Billing
- DST-NRF Centre of Excellence in Strong Materials and Molecular Sciences Institute
- School of Chemistry
- University of the Witwatersrand
- Johannesburg
- South Africa
| | - Charles Sheppard
- Chromium Research Group
- Department of Physics
- University of Johannesburg
- Auckland Park
- South Africa
| | - Aletta Prinsloo
- Chromium Research Group
- Department of Physics
- University of Johannesburg
- Auckland Park
- South Africa
| | - Emanuela Carleschi
- Department of Physics
- University of Johannesburg
- Auckland Park
- South Africa
| | - Bryan P. Doyle
- Department of Physics
- University of Johannesburg
- Auckland Park
- South Africa
| | - Karin Pruessner
- School of Chemistry and Physics
- University of KwaZulu-Natal
- Durban
- South Africa
| | - Patrick Ndungu
- Energy, Sensors and Multifunctional Nanomaterials Research Group
- Department of Applied Chemistry
- University of Johannesburg
- Doornfontein Campus
- South Africa
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7
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Otieno F, Airo M, Erasmus RM, Billing DG, Quandt A, Wamwangi D. Effect of thermal treatment on ZnO:Tb3+ nano-crystalline thin films and application for spectral conversion in inverted organic solar cells. RSC Adv 2018; 8:29274-29282. [PMID: 35547995 PMCID: PMC9084489 DOI: 10.1039/c8ra04398a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/26/2018] [Indexed: 11/21/2022] Open
Abstract
Down conversion has been applied to minimize thermalization losses in photovoltaic devices. In this study, terbium-doped ZnO (ZnO:Tb3+) thin films were deposited on ITO-coated glass, quartz and silicon substrates using the RF magnetron sputtering technique fitted with a high-purity (99.99%) Tb3+-doped ZnO target (97% ZnO, 3% Tb) for use in organic solar cells as a bi-functional layer. A systematic study of the film crystallization dynamics was carried out through elevated temperature annealing in Ar ambient. The films were characterized using grazing incidence (XRD), Rutherford backscattering spectrometry (RBS), atomic force microscopy, and UV-visible transmittance and photoluminescence measurements at an excitation wavelength of 244 nm. The tunability of size and bandgap of ZnO:Tb3+ nanocrystals with annealing exhibited quantum confinement effects, which enabled the control of emission characteristics in ZnO:Tb3+. Energy transfer of ZnO → Tb3+ (5D3–7F5) was also observed from the photoluminescence (PL) spectra. At an inter-band resonance excitation of around 300–400 nm, a typical emission band from Tb3+ was obtained. The ZnO:Tb3+ materials grown on ITO-coated glass were then used as bi-functional layers in an organic solar cell based on P3HT:PCBM blend, serving as active layers in an inverted device structure. Energy transfer through down conversion between ZnO and Tb3+ led to enhanced absorption in P3HT:PCBM in the 300–400 nm range and subsequently augmented Jsc of a Tb3+-based device by 17%. Thermal annealing of Tb doped ZnO thin films was undertaken and as proof of concept, pristine films were used as a bi-functional in inverted solar cell devices.![]()
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Affiliation(s)
- Francis Otieno
- Material Physics Research Institute
- School of Physics
- University of the Witwatersrand
- Johannesburg
- South Africa
| | - Mildred Airo
- School of Chemistry
- University of the Witwatersrand
- Republic of South Africa
| | - Rudolph M. Erasmus
- Material Physics Research Institute
- School of Physics
- University of the Witwatersrand
- Johannesburg
- South Africa
| | - David G. Billing
- School of Chemistry
- University of the Witwatersrand
- Republic of South Africa
- Materials for Energy Research Group (MERG)
- University of the Witwatersrand
| | - Alexander Quandt
- Material Physics Research Institute
- School of Physics
- University of the Witwatersrand
- Johannesburg
- South Africa
| | - Daniel Wamwangi
- Material Physics Research Institute
- School of Physics
- University of the Witwatersrand
- Johannesburg
- South Africa
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8
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Miller SF, Billing DG. A mild synthetic route to A 23+Pb 24+O 7-type mixed metal oxides. INORG NANO-MET CHEM 2017. [DOI: 10.1080/24701556.2017.1326140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Stuart F. Miller
- DST-NRF Centre of Excellence in Strong Materials and Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa
| | - David G. Billing
- DST-NRF Centre of Excellence in Strong Materials and Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa
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9
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Phaahlamohlaka TN, Kumi DO, Dlamini MW, Forbes R, Jewell LL, Billing DG, Coville NJ. Effects of Co and Ru Intimacy in Fischer–Tropsch Catalysts Using Hollow Carbon Sphere Supports: Assessment of the Hydrogen Spillover Processes. ACS Catal 2017. [DOI: 10.1021/acscatal.6b03102] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Tumelo N. Phaahlamohlaka
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa
- DST-NRF Centre of Excellence in Catalysis (c*change), Rondebosch 7701 South Africa
| | - David O. Kumi
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Mbongiseni W. Dlamini
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa
- DST-NRF Centre of Excellence in Catalysis (c*change), Rondebosch 7701 South Africa
| | - Roy Forbes
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Linda L. Jewell
- Department
of Chemical Engineering, University of South Africa, Private Bag X6, Florida 1710, South Africa
- DST-NRF Centre of Excellence in Catalysis (c*change), Rondebosch 7701 South Africa
| | - David G. Billing
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa
- DST-NRF Centre of Excellence in Strong Materials, Johannesburg 2050, South Africa
| | - Neil J. Coville
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa
- DST-NRF Centre of Excellence in Catalysis (c*change), Rondebosch 7701 South Africa
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10
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Barrett DH, Scurrell MS, Rodella CB, Diaz B, Billing DG, Franklyn PJ. Achieving nano-gold stability through rational design. Chem Sci 2016; 7:6815-6823. [PMID: 28042468 PMCID: PMC5134759 DOI: 10.1039/c6sc01597b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 07/19/2016] [Indexed: 11/21/2022] Open
Abstract
When Au is subdivided to the nanoscale its reactivity changes from an inert nature to one of incredible reactivity which is not replicated by other catalysts. When dispersed onto metal oxides such as TiO2, nano-Au has shown high reactivities for a multitude of reduction and oxidation reactions of industrial importance with potential and current uses such as, CO oxidation, NO x reduction, purification of hydrogen for fuel cells, water gas shift reactions, abatement of volatile organic compounds (VOC's) as well as pollution and emission control systems such as autocatalysts. However, many industrially important reactions and applications operate under harsh conditions where the catalyst is exposed to high temperatures and further needs to operate for extended periods of time. These conditions cause Au nanoparticle sintering whereby small, highly active clusters form large clusters which are catalytically inactive. For this reason, research into stabilizing Au nanoparticles has abounded with a goal of producing durable, thermally stable catalysts for industrial applications. Here we show a durable, thermally stable Au-TiO2 catalyst which has been developed by rational design. The catalyst exhibits a 3-dimensional, radially aligned nanorod structure, already locked into the thermodynamically stable polymorph, via a scalable and facile synthesis, with Au nanoparticles isolated on the support structure. As the Au nanoparticles are highly stable the new catalyst is able to maintain light-off for CO oxidation below 115 °C even after multiple cycles at 800 °C. This ability of the catalyst to resist multiple thermal cycles to high temperature while remaining active at low temperatures shows promise for various industrial applications. The thermal stability of the catalyst is investigated and characterized through morphological and structural studies.
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Affiliation(s)
- Dean H Barrett
- Molecular Sciences Institute , School of Chemistry , University of the Witwatersrand , Private Bag PO Wits , Braamfontein , 2050 , South Africa . ; Brazilian Synchrotron Light Laboratory (LNLS)/Brazilian Center for Research in Energy and Materials (CNPEM) , C. P. 6192 , 13083-970 , Campinas , SP , Brazil .
| | - Michael S Scurrell
- Molecular Sciences Institute , School of Chemistry , University of the Witwatersrand , Private Bag PO Wits , Braamfontein , 2050 , South Africa . ; Dept. of Civil & Chemical Engineering , University of South Africa , Johannesburg , Florida 1710 , South Africa
| | - Cristiane B Rodella
- Brazilian Synchrotron Light Laboratory (LNLS)/Brazilian Center for Research in Energy and Materials (CNPEM) , C. P. 6192 , 13083-970 , Campinas , SP , Brazil .
| | - Beatriz Diaz
- Canadian Light Source , 44 Innovation Boulevard , Saskatoon , SK S7N 2V3 , Canada
| | - David G Billing
- Molecular Sciences Institute , School of Chemistry , University of the Witwatersrand , Private Bag PO Wits , Braamfontein , 2050 , South Africa . ; DST-NRF Centre of Excellence in Strong Materials , School of Chemistry , University of the Witwatersrand , Private Bag PO Wits , Braamfontein , 2050 , South Africa
| | - Paul J Franklyn
- Molecular Sciences Institute , School of Chemistry , University of the Witwatersrand , Private Bag PO Wits , Braamfontein , 2050 , South Africa .
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11
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Grover BPC, Johnson RH, Billing DG, Weiersbye IMG, Tutu H. Mineralogy and geochemistry of efflorescent minerals on mine tailings and their potential impact on water chemistry. Environ Sci Pollut Res Int 2016; 23:7338-7348. [PMID: 26681330 DOI: 10.1007/s11356-015-5870-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 11/23/2015] [Indexed: 06/05/2023]
Abstract
In the gold mining Witwatersrand Basin of South Africa, efflorescent mineral crusts are a common occurrence on and nearby tailings dumps during the dry season. The crusts are readily soluble and generate acidic, metal- and sulphate-rich solutions on dissolution. In this study, the metal content of efflorescent crusts at an abandoned gold mine tailings dump was used to characterise surface and groundwater discharges from the site. Geochemical modelling of the pH of the solution resulting from the dissolution of the crusts was used to better understand the crusts' potential impact on water chemistry. The study involved two approaches: (i) conducting leaching experiments on oxidised and unoxidised tailings using artificial rainwater and dilute sulphuric acid and correlating the composition of crusts to these leachates and (ii) modelling the dissolution of the crusts in order to gain insight into their mineralogy and their potential impact on receiving waters. The findings suggested that there were two chemically distinct discharges from the site, namely an aluminium- and magnesium-rich surface water plume and an iron-rich groundwater plume. The first plume was observed to originate from the oxidised tailings following leaching with rainwater while the second plume originated from the underlying unoxidised tailings with leaching by sulphuric acid. Both groups of minerals forming from the respective plumes were found to significantly lower the pH of the receiving water with simulations of their dissolution found to be within 0.2 pH units of experimental values. It was observed that metals in a low abundance within the crust (for example, iron) had a stronger influence on the pH of the resulting solutions than metals in a greater abundance (aluminium or magnesium). Techniques such as powder X-ray diffraction (PXRD) and in situ mineral determination techniques such as remote sensing can effectively determine the dominant mineralogy. However, the minerals or metals incorporated through solid solution into bulk mineralogy that dominates the chemistry of the solutions upon their dissolution may occur in minor quantities that can only be predicted using chemical analysis. Their mineralogy can be predicted using geochemical modelling and can provide a set of hypothetical minerals that upon dissolution yield a solution similar to that of the actual crusts. This realisation has a bearing on decision-making such as in risk assessment and designing pollutant mitigation strategies.
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Affiliation(s)
- B P C Grover
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa
| | - R H Johnson
- SM Stoller Corporation, Grand Junction, CO, 81503, USA
| | - D G Billing
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa
| | - I M G Weiersbye
- Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - H Tutu
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa.
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12
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Abstract
Abstract We evaluated the suitability of phosphogypsum from the Lowveld region of South Africa (LSA), for the manufacturing of building materials, with reference to (1) the National Nuclear Regulator Act 47 of 1999 and (2) the radioactivity associated risks as quantified in terms of the external and internal hazard indices, the activity concentration index and the radium equivalent. The distribution of radioactive nuclides in the LSA phosphogypsum was also examined. Analyses of 19 samples of the phosphogypsum show that phosphogypsum contains lower activity concentrations of naturally occurring radioactive nuclides of uranium and thorium and their progeny than the 500 Bg/kg limit set for regulation in South Africa. The potassium-40 (40K) activity concentration was below the minimum detectable amount of 100 Bq/kg. The values obtained for external and internal hazard indices and the activity concentration index were: 2.12 0.59, 3.44 0.64 and 2.65 0.76 respectively. The calculated radium equivalent Raeq was 513 76Bq/kg. The final decision regarding phosphogypsum’s suitability for use as a building material should consider scenarios of use.
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13
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Dlamini MW, Kumi DO, Phaahlamohlaka TN, Lyadov AS, Billing DG, Jewell LL, Coville NJ. Carbon Spheres Prepared by Hydrothermal Synthesis-A Support for Bimetallic Iron Cobalt Fischer-Tropsch Catalysts. ChemCatChem 2015. [DOI: 10.1002/cctc.201500334] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Billing DG, Miller SF. Defect fluorite versuspyrochlore: the M2M' 2O 7case. Acta Crystallogr A Found Adv 2015. [DOI: 10.1107/s2053273315094875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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15
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Meyer WH, Bowen RJ, Billing DG. Tri(3-pyridyl)phosphine as Amphiphilic Ligand in the Rhodium-catalysed Hydroformylation of 1-Hexene. Zeitschrift für Naturforschung B 2014. [DOI: 10.1515/znb-2007-0306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The molecular structure of carbonylchlorobis(tri(3-pyridyl)phosphine)rhodium, 1, has been determined by X-ray diffraction methods. The N-protonated trifluoromethanesulfonate (triflate) complex 3 was synthesised as a model compound for the extraction of a rhodium complex bearing amphiphilic ligands which can allow catalyst recycling in the hydroformylation of alkenes by using their distribution behavior in organic and aqueous solvents of different pH. The high water-solubility of the employed ligand renders the recycling method as only partly successful due to insufficient extraction from the water phase into the organic phase. In the hydroformylation of 1-hexene the production of n-heptanal is slightly disfavoured when using the ligand tri(3-pyridyl)phosphine as compared to triphenylphosphine which can be ascribed to a higher amount of ligand-deficient active rhodium complexes of the less basic pyridyl phosphine ligand under CO pressure.
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Affiliation(s)
- Wolfgang H. Meyer
- School of Chemistry, University of the Witwatersrand, PO Wits 2050, Johannesburg, South Africa / Sasol Technology Research and Development, PO Box 1, Sasolburg, 1947, South Africa
| | - Richard J. Bowen
- School of Chemistry, University of the Witwatersrand, PO Wits 2050, Johannesburg, South Africa
| | - David G. Billing
- School of Chemistry, University of the Witwatersrand, PO Wits 2050, Johannesburg, South Africa
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Rayner MK, Billing DG, Coville NJ. In-situX-ray diffraction activation study on an Fe/TiO2pre-catalyst. Acta Crystallogr B Struct Sci Cryst Eng Mater 2014; 70:498-509. [DOI: 10.1107/s2052520614011238] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 05/15/2014] [Indexed: 11/10/2022]
Abstract
This study focuses on the use ofin situpowder X-ray diffraction (PXRD) and quantitative phase analysis using the Rietveld method to monitor the structural properties of a titania-supported iron (10% Fe/TiO2) pre-catalyst during calcination (oxidation) and activation (reduction) in the temperature range 25–900°C. The TiO2oxidation study revealed an increase in anatase particle size before the anatase to rutile phase transformation, lending credibility to the bridging mechanism proposed by Kimet al.[(2007),Mater. Sci. Forum,534–536, 65–68]. Pre-catalyst oxidation experiments allowed for the determination of a suitable calcination temperature (450°C) of the pre-catalyst in terms of maximum hematite concentration and appropriate particle size. These experiments also confirmed that the anatase to rutile phase transformation occurred at higher temperatures after Fe addition and that anatase was the sole donor of Ti4+ions, which are known to migrate into hematite (Gennariet al., 1998), during the formation of pseudobrookite (Fe2TiO5) at temperatures above 690°C. Using the results from the oxidation experiments, two pre-catalyst samples were calcined at different temperatures; one to represent the preferred case and one to represent a case where the pre-catalyst had been excessively heated. Samples of the excessively heated catalysts were exposed to different reducing gas atmospheres (5, 10 and 100% H2/N2) and heated in thein situPXRD reactor, so that diffraction data could be collected during the activation process. The results show that reduction with gases containing low concentrations of H2(5 and 10%) led to the formation of ilmenite (FeTiO3) and we were able to show that both anatase and rutile are consumed in the reaction. Higher concentrations of H2led to the formation of magnetite (Fe3O4) and metallic iron (Fe0). We also noted a decrease in the anatase to rutile transformation temperature under reducing atmospheres when compared with the pre-catalyst heat-treatment experiment. A reduced calcination temperature prior to reduction allowed more facile Fe reduction.
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Affiliation(s)
- Matthew K Rayner
- DST/NRF Centre of Excellence in Catalysis and Molecular Science Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits, 2050, South Africa
| | - David G Billing
- Molecular Science Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits, 2050, South Africa
| | - Neil J Coville
- DST/NRF Centre of Excellence in Catalysis and Molecular Science Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits, 2050, South Africa
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Billing DG, Katrusiak A. Non-ambient crystallography – is extreme becoming common? Acta Crystallogr B Struct Sci Cryst Eng Mater 2014; 70:399-400. [DOI: 10.1107/s2052520614012323] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Richardson RP, Billing DG. The decomposition of lead nitrate. Acta Crystallogr A 2013. [DOI: 10.1107/s0108767313095913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Billing DG. Thermoresponsive behaviour of interesting phosphate-based functional materials. Acta Crystallogr A 2013. [DOI: 10.1107/s0108767313098474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Mogodi WM, Billing DG. Thermoresponsive behaviour of CaBPO 5, SrBPO 5and H 8Mn 5O 20P 4. Acta Crystallogr A 2013. [DOI: 10.1107/s0108767313095901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Billing DG. Thermoresponsive behaviour of interesting phosphate-based functional materials. Acta Crystallogr A 2013. [DOI: 10.1107/s0108767313094920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Lemmerer A, Billing DG. Synthesis, characterization and phase transitions of the inorganic-organic layered perovskite-type hybrids [(C(n)H(2n+1)NH3)2PbI4], n = 7, 8, 9 and 10. Dalton Trans 2011; 41:1146-57. [PMID: 21853171 DOI: 10.1039/c0dt01805h] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Four inorganic-organic hybrid materials that consist of 2-D layers of corner-sharing lead(II) iodide octahedra separated by alkylammonium chains have been crystallized and characterized via single-crystal XRD (SCXRD). The four hybrids, represented by the general formula [(C(n)H(2n+1)NH(3))(2)PbI(4)] and abbreviated C(n)PbI, exhibit multiple reversible phase transitions for a narrow temperature range. The transition temperatures were determined with differential scanning calorimetry experiments. The number of transitions and the transition temperatures are dependant on the chain length; for n = 7 and 10, there are three transitions, and for n = 8 and 9, there are two transitions. Regardless of the number of transitions, all four compounds have identical lowest temperature phases, which have inorganic layers that are eclipsed, non-planar conformations of the alkyl ammonium chains and yellow-coloured crystals. The next highest temperature phase for three of the compounds (C(10)PbI goes through an intermediate phase first), has staggered inorganic layers, all-trans planar conformations of the chains and orange coloured crystals. The highest temperature phase for n = 8 and 10 has red-coloured crystals and shows a disordering of the alkylammonium chains over two positions and staggered inorganic layers. The high temperature phase of C(7)PbI retains its orange colour and has only increased thermal motion of its alkylammonium chain. The structure of the high temperature phase of C(9)PbI was not determined. The SCXRD structures of the various phases give clues to the structural changes that the compounds undergo at the phase transitions, which will now enable future studies of their optical and electronic properties to be better understood.
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Affiliation(s)
- Andreas Lemmerer
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, PO WITS 2050, South Africa
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Rademeyer M, Tsouris C, Billing DG, Lemmerer A, Charmant J. Robust motifs in 2-phenylethylammonium and related tetrahalometallates. CrystEngComm 2011. [DOI: 10.1039/c0ce00634c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Billing DG, Black RS. Structure and optical properties of natural low-dimensional semiconductors. Acta Crystallogr A 2010. [DOI: 10.1107/s0108767310094146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Black RS, Billing DG, Bartyzel A, Cukrowska EM. N,N'-Bis[(2-hydroxy-phen-yl)(phen-yl)methyl-idene]propane-1,2-diamine. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o1256-7. [PMID: 21579360 PMCID: PMC2979517 DOI: 10.1107/s1600536810015291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 04/26/2010] [Indexed: 11/11/2022]
Abstract
In the the title compound, C(29)H(26)N(2)O(2), two strong intra-molecular O-H⋯N hydrogen bonds involving the hydr-oxy and imine groups generate S(6) ring motifs. The dihedral angles between the pairs of terminal benzene rings are 89.8 (2) and 87.8 (2)°.
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Affiliation(s)
- Robert S Black
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits, 2050, South Africa
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Abstract
In the title compound, C6H7N2O2+·I3−·H2O, the triiodide anions form two-dimensional sheets along the a and c axes. These sheets are separated by the 4-nitroanilinium cations and water molecules, which form part of an extended hydrogen-bonded chain with the triiodide along the c axis, represented by the graph set C33(14). The second important hydrogen-bonding interaction is between the nitro group, the water molecule and the anilinium group, which forms an R22(6) ring and may be the reason for the deviation of the torsion angle between the benzene ring and the nitro group from 180 to 163.2 (4)°. These two strong hydrogen-bonding interactions also cause the benzene rings to pack off-centre from one another, with an edge-on-edge π–π stacking distance of 3.634 (6) Å and a centroid–centroid separation of 4.843 (2) Å.
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Affiliation(s)
- David G Billing
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private bag, PO Wits 2050, South Africa
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Black RS, Billing DG, Bartyzel A, Cukrowska E. 2,2'-[(Propane-1,3-diyldinitrilo)bis-(phenyl-methyl-idyne)]diphenol. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o1002-3. [PMID: 21580567 PMCID: PMC2983949 DOI: 10.1107/s1600536810011189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 03/24/2010] [Indexed: 05/26/2023]
Abstract
In the title molecule, C29H26N2O2, there are two strong intramolecular O—H⋯N hydrogen bonds involving the hydroxy and imine groups, forming S(6) ring motifs. The dihedral angles between adjacent phenyl rings and phenol-containing planes are 85.27 (19) and 91.38 (18)°. In the crystal structure, weak intermolecular C—H⋯O hydrogen bonds connect molecules into a two-dimensional network.
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Affiliation(s)
- Robert S Black
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits 2050, South Africa
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Lemmerer A, Billing DG. Effect of heteroatoms in the inorganic–organic layered perovskite-type hybrids [(ZCnH2nNH3)2PbI4], n = 2, 3, 4, 5, 6; Z = OH, Br and I; and [(H3NC2H4S2C2H4NH3)PbI4]. CrystEngComm 2010. [DOI: 10.1039/b917824d] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Rademeyer M, Kruger GJ, Billing DG. Crystal structures and phase transitions of long-chain n-alkylammonium bromide monohydrates. CrystEngComm 2009. [DOI: 10.1039/b817318d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Billing DG, Lemmerer A. Inorganic–organic hybrid materials incorporating primary cyclic ammonium cations: The lead bromide and chloride series. CrystEngComm 2009. [DOI: 10.1039/b819455f] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Dinesh J, Rademeyer M, Billing DG, Lemmerer A. Bis(2-methyl-4-nitro-anilinium) tetra-chloridomercurate(II). Acta Crystallogr Sect E Struct Rep Online 2008; 64:m1598. [PMID: 21581195 PMCID: PMC2960147 DOI: 10.1107/s1600536808038415] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Accepted: 11/18/2008] [Indexed: 11/17/2022]
Abstract
The title compound, (C7H9N2O2)2[HgCl4], self-assembles into cationic organic bilayers containing the 2-methyl-4-nitroanilinium cations, sandwiched between anionic inorganic layers built up by the distorted tetrahedral [HgCl4]2− groups. The organic sheets are interlinked through weak C—H⋯O hydrogen bonds, while they interact with the anionic part via strong charge-assisted N+—H⋯Cl—Hg hydrogen bonds. The [HgCl4]2− anions are bisected by a mirror plane passing through the metal and two of the chloride ions.
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Lemmerer A, Billing DG, Robinson JM. Hydrogen-bonding one-dimensional chains containing the R4(2)(8) motif in the ammonium salts 1-naphthylammonium iodide and naphthalene-1,8-diyldiammonium diiodide. Acta Crystallogr C 2008; 64:o481-4. [PMID: 18758015 DOI: 10.1107/s0108270108023561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Accepted: 07/25/2008] [Indexed: 11/10/2022] Open
Abstract
In 1-naphthylammonium iodide, C(10)H(10)N(+).I(-), and naphthalene-1,8-diyldiammonium diiodide, C(10)H(12)N(2)(2+).2I(-), the predominant hydrogen-bonding pattern can be described using the graph-set notation R(4)(2)(8). This is the first report of a structure of a diprotonated naphthalene-1,8-diyldiammonium salt.
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Affiliation(s)
- Andreas Lemmerer
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits 2050, South Africa
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Billing DG, Lemmerer A. Synthesis, characterization and phase transitions of the inorganic–organic layered perovskite-type hybrids [(CnH2n+1NH3)2PbI4] (n = 12, 14, 16 and 18). NEW J CHEM 2008. [DOI: 10.1039/b805417g] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Billing DG, Lemmerer A. Synthesis, characterization and phase transitions in the inorganic-organic layered perovskite-type hybrids [(CnH2n+1NH3)2PbI4], n = 4, 5 and 6. Acta Crystallogr B 2007; 63:735-47. [PMID: 17873443 DOI: 10.1107/s0108768107031758] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Accepted: 06/28/2007] [Indexed: 11/10/2022]
Abstract
Three inorganic-organic layered perovskite-type hybrids of the general formula [(C(n)H(2n+1)NH(3))(2)PbI(4)], n = 4, 5 and 6, display a number of reversible first-order phase transitions in the temperature range from 256 to 393 K. [(C(4)H(9)NH(3))(2)PbI(4)] has a single phase transition, [(C(5)H(11)NH(3))(2)PbI(4)] has two phase transitions and [(C(6)H(13)NH(3))(2)PbI(4)] has three phase transitions. In all three cases, the lowest-temperature phase transition is thermochromic and the crystals change colour from yellow in their lowest-temperature phase to orange in their higher-temperature phase for [(C(4)H(9)NH(3))(2)PbI(4)] and [(C(6)H(13)NH(3))(2)PbI(4)], and from orange to red for [(C(5)H(11)NH(3))(2)PbI(4)]. The structural details associated with this phase transition have been investigated via single-crystal X-ray diffraction, SC-XRD, for all three compounds.
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Affiliation(s)
- David G Billing
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa.
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Rademeyer M, Lemmerer A, Billing DG. Bis(4-aminopyridinium) hexachloridostannate(IV) and bis(p-toluidinium) hexachloridostannate(IV). Acta Crystallogr C 2007; 63:m289-92. [PMID: 17609547 DOI: 10.1107/s010827010702327x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2007] [Accepted: 05/11/2007] [Indexed: 11/10/2022] Open
Abstract
The crystal structures of the two organic-inorganic hybrids bis(4-aminopyridinium) hexachloridostannate(IV), (C(5)H(7)N(2))(2)[SnCl(6)], and bis(p-toluidinium) hexachloridostannate(IV), (C(7)H(10)N)(2)[SnCl(6)], differ in the way their cations pack in the layered structures. The Sn atom in the 4-aminopyridinium compound lies on an inversion centre.
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Affiliation(s)
- M Rademeyer
- School of Chemistry, University of KwaZulu-Natal, Pietermaritzburg Campus, Private Bag X01, Scottsville 3209, South Africa
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Lemmerer A, Billing DG, Reisinger SA. Isostructural crystal packing and hydrogen bonding in alkylammonium tin(IV) chloride compounds. Acta Crystallogr C 2007; 63:m97-m100. [PMID: 17339715 DOI: 10.1107/s0108270107004659] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Accepted: 01/29/2007] [Indexed: 11/10/2022] Open
Abstract
The three isostructural compounds butylammonium hexachloridotin(IV), pentylammonium hexachloridotin(IV) and hexylammonium hexachloridotin(IV), (C(n)H(2n+1)NH(3))(2)[SnCl(6)], with n = 4, 5 and 6, respectively, crystallize as inorganic-organic hybrids. As such, the structures consist of layers of [SnCl(6)](2-) octahedra, separated by hydrocarbon layers of interdigitated butylammonium, pentylammonium or hexylammonium cations. Corrugated layers of cations alternate with tin(IV) chloride layers. The asymmetric unit in each compound consists of an anionic component comprising one Sn and two Cl atoms on a mirror plane, and two Cl atoms in general positions; the two cations lie on another mirror plane. Application of the mirror symmetry generates octahedral coordination around the Sn atom. All compounds exhibit bifurcated and simple hydrogen-bonding interactions between the ammonium groups and the Cl atoms, with little variation in the hydrogen-bonding geometries.
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Affiliation(s)
- Andreas Lemmerer
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits 2050, South Africa
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Billing DG, Lemmerer A, Rademeyer M. Bis(1-phenylethylammonium) hexachloridostannate(IV) and bis(2-phenylethylammonium) hexachloridostannate(IV). Acta Crystallogr C 2007; 63:m101-4. [PMID: 17339700 DOI: 10.1107/s0108270107004970] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Accepted: 01/30/2007] [Indexed: 11/10/2022] Open
Abstract
The crystal structures of the two isomers bis(1-phenylethylammonium) hexachloridostannate(IV) and bis(2-phenylethylammonium) hexachloridostannate(IV), both (C(8)H(12)N)(2)[SnCl(6)], exhibit alternating organic and inorganic layers, which interact via N-H...Cl hydrogen bonding. The inorganic layer contains an extended two-dimensional hydrogen-bonded sheet. The Sn atom in the 1-phenylethylammonium salt lies on an inversion centre.
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Affiliation(s)
- David G Billing
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits 2050, South Africa
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Billing DG, Lemmerer A. Inorganic–organic hybrid materials incorporating primary cyclic ammonium cations: The lead iodide series. CrystEngComm 2007. [DOI: 10.1039/b618196a] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lemmerer A, Billing DG. Two packing motifs based upon chains of edge-sharing PbI6octahedra. Acta Crystallogr C 2006; 62:m597-601. [PMID: 17148895 DOI: 10.1107/s0108270106039746] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Accepted: 09/27/2006] [Indexed: 11/11/2022] Open
Abstract
The compounds catena-poly[p-phenylenediammonium [[diiodolead(II)]-di-mu-iodo] dihydrate], {(C6H10N2)[PbI4].2H2O}n, (I), and catena-poly[bis(3,5-dimethylanilinium) [[diiodolead(II)]-di-mu-iodo]], {(C8H12N)2[PbI4]}n, (II), crystallize as organic-inorganic hybrids. As such, the structures consist of chains of [PbI2]- units extending along the c axis in (I) and along the b axis in (II). The asymmetric unit in (I) contains one Pb atom on a site of 2/m symmetry, two I atoms and a water molecule on mirror planes, and a p-phenylenediammonium molecule that sits around a site of 2/m symmetry with the C and N atoms on a mirror plane. In (II), the Pb atom is on a twofold axis and the two I atoms are on general positions. Each Pb atom is octahedrally coordinated to six I atoms, arranged as chains of edge-sharing octahedra. Both compounds undergo hydrogen-bonding interactions between the ammonium groups and the I atoms. In addition, there are hydrogen bonds between the water molecules and the ammonium groups and halides in (I), and between the ammonium groups and the ring systems in (II).
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Affiliation(s)
- Andreas Lemmerer
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits 2050, South Africa.
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Billing DG, Lemmerer A. Poly[bis[2-(1-cyclohexenyl)ethylammonium] di-mu-iodo-diodoplumbate(II)]. Acta Crystallogr C 2006; 62:m269-71. [PMID: 16823189 DOI: 10.1107/s0108270106013953] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Accepted: 04/18/2006] [Indexed: 11/10/2022] Open
Abstract
The title compound, (C(8)H(16)N)(2)[PbI(4)], crystallizes as an inorganic-organic hybrid perovskite, adopting the unusual 2a(p) x 2a(p) superstructure. As such, the structure consists of two-dimensional sheets of corner-sharing PbI(6) octahedra in the ab plane, separated by bilayers of 2-(1-cyclohexenyl)ethylammonium cations. The ethylammonium groups are not in the plane of the cyclohexenyl rings.
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Affiliation(s)
- David G Billing
- School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits 2050, South Africa
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Billing DG, Lemmerer A. catena-Poly[bis(tert-butylammonium) [plumbate(II)-tri-μ-iodo] iodide dihydrate]. Acta Crystallogr C 2006; 62:m264-6. [PMID: 16763309 DOI: 10.1107/s0108270106016167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Accepted: 05/02/2006] [Indexed: 11/10/2022] Open
Abstract
The title compound, [(C4H12N)2[PbI3]I.2H2O]n, crystallizes as an organic-inorganic hybrid. The six-coordinate Pb atom lies on a centre of inversion and all the I atoms lie on mirror planes; the two independent cations both lie across mirror planes. The structure contains anionic chains along [100] of fused [PbI3]- units forming face-sharing octahedra. Four cations enclose channels occupied by isolated iodide ions and water molecules of hydration.
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Affiliation(s)
- David G Billing
- School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits 2050, South Africa.
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Billing DG, Lemmerer A. Octakis(3-propylammonium) octadecaiodopentaplumbate(II): a new layered stucture based on layered perovskites. Acta Crystallogr C 2006; 62:m238-40. [PMID: 16763300 DOI: 10.1107/s0108270106014417] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 04/20/2006] [Indexed: 11/11/2022] Open
Abstract
The title compound, (C3H10N)8[Pb5I18], crystallizes as an inorganic-organic hybrid. As such, the structure consists of two-dimensional sheets of corner- and face-sharing [PbI6]4- octahedra, separated by layers of 3-propylammonium cations, which hydrogen bond to the I atoms. The asymmetric unit contains six independent Pb atoms; four are on general positions and the other two are on special positions, viz. a centre of inversion and a twofold axis. The inorganic sheets show a never before seen motif.
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Affiliation(s)
- David G Billing
- School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits 2050, South Africa.
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Lemmerer A, Billing DG. Hydrogen bonding in isomorphous 2-methyl-4-nitroanilinium bromide and iodide. Acta Crystallogr C 2006; 62:o271-3. [PMID: 16679601 DOI: 10.1107/s0108270106011358] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Accepted: 03/28/2006] [Indexed: 11/10/2022] Open
Abstract
The isomorphous structures of 2-methyl-4-nitroanilinium bromide, C7H9N2O2+.Br-, and 2-methyl-4-nitroanilinium iodide, C7H9N2O2+.I-, exhibit ionic layers separated by hydrocarbon layers. The hydrocarbon layer stacks head-to-head, while in the ionic layer, the ammonium groups and halide anions interact via hydrogen bonds to form infinite chains.
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Affiliation(s)
- Andreas Lemmerer
- School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits 2050, South Africa.
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Billing DG, Lemmerer A. catena-Poly[tetrakis(3-phenylpropylammonium) [iodoplumbate(II)-tri-μ-iodo-plumbate(II)-tri-μ-iodo-iodoplumbate(II)-di-μ-iodo]]. Acta Crystallogr C 2006; 62:m174-6. [PMID: 16679574 DOI: 10.1107/s0108270106009127] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Accepted: 03/10/2006] [Indexed: 11/11/2022] Open
Abstract
The title compound, {(C9H14N)4[Pb3I10]}n, crystallizes as an organic-inorganic hybrid. As such, the structure consists of a two-dimensional inorganic layer of [Pb3I10]n(4n-) ions extending along [100]. The asymmetric unit contains two independent Pb atoms, viz. one in a general position and the other on an inversion centre. Each Pb atom is octahedrally coordinated by six iodide ions and exhibits both face- and corner-sharing with adjacent atoms in the inorganic layer. These anionic layers alternate with 3-phenylpropylammonium cations, which hydrogen bond to the iodides. Simple face-to-edge sigma-pi stacking interactions are observed between the aromatic rings that stabilize the overall three-dimensional structure. This net structure has only been observed five times previously.
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Affiliation(s)
- David G Billing
- School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits 2050, South Africa.
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Bala MD, Adeyemi OG, Billing DG, Levendis DC, Coville NJ. Quantification of steric interactions in phosphine ligands from single crystal X-ray diffraction data. Crystal structures of (η5-C5H4Me)Mo(CO)2(PR3)I (R3=PhMe2, PhEt2, Et3). J Organomet Chem 2006. [DOI: 10.1016/j.jorganchem.2005.10.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Billing DG, Lemmerer A. Synthesis and crystal structures of inorganic–organic hybrids incorporating an aromatic amine with a chiral functional group. CrystEngComm 2006. [DOI: 10.1039/b606987h] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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