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Lais T, Lukashuk L, van de Water L, Hyde TI, Aramini M, Sankar G. Elucidation of copper environment in a Cu-Cr-Fe oxide catalyst through in situ high-resolution XANES investigation. Phys Chem Chem Phys 2021; 23:5888-5896. [PMID: 33660717 DOI: 10.1039/d0cp06468h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Copper containing materials are widely used in a range of catalytic applications. Here, we report the use of Cu K-edge high resolution XANES to determine the local site symmetry of copper ions during the thermal treatment of a Cu-Cr-Fe oxide catalyst. We exploited the Cu K-edge XANES spectral features, in particular the correlation between area under the pre-edge peak and its position to determine the local environment of Cu2+ ions. The information gained from this investigation rules out the presence of Cu2+ ions in a tetrahedral or square planar geometry, a mixture of these sites, or in a reduced oxidation state. Evidence is presented that the Cu2+ ions in the Cu-Cr-Fe oxide system are present in a distorted octahedral environment.
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Affiliation(s)
- Tahmin Lais
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Liliana Lukashuk
- Johnson Matthey, PO Box 1, Belasis Avenue, Billingham, Cleveland TS23 1LB, UK
| | - Leon van de Water
- Johnson Matthey, PO Box 1, Belasis Avenue, Billingham, Cleveland TS23 1LB, UK
| | - Timothy I Hyde
- Johnson Matthey, Blounts Court, Sonning Common, Reading, RG4 9NH, UK
| | - Matteo Aramini
- Diamond Light Source, Harwell Science & Innovation Campus, Oxfordshire OX11 0DE, UK
| | - Gopinathan Sankar
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
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2
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Drzewiecka-Antonik A, Rejmak P, Klepka M, Wolska A, Chrzanowska A, Struga M. Structure and anticancer activity of Cu(II) complexes with (bromophenyl)thiourea moiety attached to the polycyclic imide. J Inorg Biochem 2020; 212:111234. [PMID: 32927369 DOI: 10.1016/j.jinorgbio.2020.111234] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/15/2020] [Accepted: 08/16/2020] [Indexed: 11/25/2022]
Abstract
A series of nine copper complexes were synthesized by reacting 1,3-disubstituted thioureas with copper(II) chloride. The new compounds were characterized by elemental analysis, infrared, ultraviolet-visible and X-ray absorption spectroscopies as well as molecular modelling. The molecular structure of complexes in the solid state consists of two thiourea ligands chelated to the Cu(II) ion through the S and deprotonated N atoms (CuN2S2). The coordination polyhedron of metal cation in powdered samples exhibits two different geometries. Pseudo-tetrahedral structure is observed for noncentrosymmetric complexes with cis-N2S2 arrangement around Cu(II). A distorted square planar geometry is characteristic for centrosymmetric compounds with trans arrangements of chelating atoms around the central ion. All complexes after dissolving in dimethyl sulfoxide adopt a centrosymmetric coordination, while after diluting this solution with water, the reorganization of atoms around the metal cation is observed, leading to the formation of a tetrahedral compounds. Initial ligands and Cu(II) complexes were evaluated for their cytotoxicity. Two complexes with 4- and 3-bromophenyl attached to the (1,7,8,9,10-pentamethyl-3,5-dioxo-4-azatricyclo[5.2.1.02,6]dec-8-en-4-yl)thiourea moiety (Cu1, Cu3) are cytotoxic against SW480 and PC3 cells (IC50 4-19 μm), and non-cytotoxic against HaCaT cells (IC50 ≥ 84 μm), being more selective than doxorubicin and cisplatin used as references. The compounds induced apoptosis in cancer cells, however, Cu3 was estimated to be highly active inducer of late apoptosis in SW480 and PC3 cells at lower toxicity against normal cells. The likely mechanism of action of complexes is correlated with decreasing release of IL-6 in cancer cell lines.
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Affiliation(s)
| | - Paweł Rejmak
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Marcin Klepka
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Anna Wolska
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Alicja Chrzanowska
- Medical University of Warsaw, Chair and Department of Biochemistry, Banacha 1, PL-02097 Warsaw, Poland
| | - Marta Struga
- Medical University of Warsaw, Chair and Department of Biochemistry, Banacha 1, PL-02097 Warsaw, Poland
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3
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Yilmaz M, Handoko AD, Parkin IP, Sankar G. Probing the electronic and geometric structures of photoactive electrodeposited Cu2O films by X-ray absorption spectroscopy. J Catal 2020. [DOI: 10.1016/j.jcat.2020.06.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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4
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Adsorption and activation of molecular oxygen over atomic copper(I/II) site on ceria. Nat Commun 2020; 11:4008. [PMID: 32782245 PMCID: PMC7419315 DOI: 10.1038/s41467-020-17852-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 07/22/2020] [Indexed: 11/08/2022] Open
Abstract
Supported atomic metal sites have discrete molecular orbitals. Precise control over the energies of these sites is key to achieving novel reaction pathways with superior selectivity. Here, we achieve selective oxygen (O2) activation by utilising a framework of cerium (Ce) cations to reduce the energy of 3d orbitals of isolated copper (Cu) sites. Operando X-ray absorption spectroscopy, electron paramagnetic resonance and density-functional theory simulations are used to demonstrate that a [Cu(I)O2]3- site selectively adsorbs molecular O2, forming a rarely reported electrophilic η2-O2 species at 298 K. Assisted by neighbouring Ce(III) cations, η2-O2 is finally reduced to two O2-, that create two Cu-O-Ce oxo-bridges at 453 K. The isolated Cu(I)/(II) sites are ten times more active in CO oxidation than CuO clusters, showing a turnover frequency of 0.028 ± 0.003 s-1 at 373 K and 0.01 bar PCO. The unique electronic structure of [Cu(I)O2]3- site suggests its potential in selective oxidation.
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Chia L, Du YH, Palale S, Lee PS. Interaction of Copper Phthalocyanine with Nitrogen Dioxide and Ammonia Investigation Using X-ray Absorption Spectroscopy and Chemiresistive Gas Measurements. ACS OMEGA 2019; 4:10388-10395. [PMID: 31460132 PMCID: PMC6647996 DOI: 10.1021/acsomega.8b02108] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 12/04/2018] [Indexed: 05/28/2023]
Abstract
The interaction site of phthalocyanine (Pc) with nitrogen dioxide (NO2) has been characterized using different methods and found to be conflicting. By knowing the interaction site, the Pc molecule can be better customized to improve the gas sensitivity. In this article, the interaction sites of copper phthalocyanine (CuPc) with oxidizing NO2 or with reducing gas (ammonia, NH3) were identified using in situ X-ray absorption spectroscopy (XAS). The sensitivity of CuPc to sub-ppm levels of the tested gases was established in the CuPc chemoresistive gas sensors. The analyte-sensor interaction sites were identified and validated by monitoring the Cu K-edge XAS before and during gas exposure. From the X-ray absorption near-edge structure and its first derivative, a low or lack of axial coordination on the Cu metal center of CuPc is evident. Using the extended X-ray absorption fine structure with molecular orbital information of the involved molecules, the macrocycle interaction between CuPc and NO2 or NH3 was proposed to be the dominant sensing mechanism on CuPc sensors.
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Affiliation(s)
- Liping
Sharon Chia
- Research
and Technology Center (Asia Pacific), Corporate Research, Robert Bosch (SEA) Pte Ltd, 11 Bishan Street 21, 573943, Singapore
- School
of Materials Science and Engineering, Nanyang
Technological University, Singapore 639798, Singapore
| | - Yong Hua Du
- Institute
of Chemical and Engineering Sciences, Agency
for Science, Technology and Research in Singapore (A*STAR), 1 Pesek Road, Jurong
Island, 627833, Singapore
| | - Suresh Palale
- Research
and Technology Center (Asia Pacific), Corporate Research, Robert Bosch (SEA) Pte Ltd, 11 Bishan Street 21, 573943, Singapore
| | - Pooi See Lee
- School
of Materials Science and Engineering, Nanyang
Technological University, Singapore 639798, Singapore
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6
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Hao X, Han S, Zhu J, Hu Y, Chang LY, Pao CW, Chen JL, Chen JM, Haw SC. A bis-benzimidazole PMO ratiometric fluorescence sensor exhibiting AIEE and ESIPT for sensitive detection of Cu2+. RSC Adv 2019; 9:13567-13575. [PMID: 35519599 PMCID: PMC9063946 DOI: 10.1039/c9ra00892f] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/14/2019] [Indexed: 01/06/2023] Open
Abstract
A novel bis-benzimidazole organic siloxane precursor (BBM-Si) was prepared, and was combined with tetraethylorthosilicate (TEOS) as a mixed Si source. Then, bridged periodic mesoporous organosilica (BBM-PMO) spherical nanoparticles were synthesized by co-condensation using cetyltrimethylammonium bromide (CTAB) as structure directing agent. The optical properties showed that BBM qualifies as an “aggregation induced emission enhanced” (AIEE) molecule, exhibiting characteristics of excited-state intramolecular proton transfer (ESIPT), such as a large Stokes shift and dual fluorescence emission. For the BBM-PMO materials, the silica skeleton provides a rigid environment that limits molecular rotation, resulting in improved fluorescence emission. In particular, the BBM-PMOs exhibited dual emission of the enol and keto forms, achieving a ratiometric response to Cu2+ with high sensitivity and selectivity in a broad pH range. Additionally, the limit of detection was as low as 7.15 × 10−9 M in aqueous solution. The X-ray absorption near-edge spectroscopy (XANES) showed the coordination structure through the interaction between copper ions and N atoms of benzimidazole in the BBM-PMO coordinated to Cu2+. These results demonstrate that BBM-PMO hybrid materials have potential applications in the fields of bio-imaging and environmental monitoring. A novel bis-benzimidazole organic siloxane precursor (BBM-Si) was prepared, and was combined with tetraethylorthosilicate (TEOS) as a mixed Si source.![]()
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Affiliation(s)
- Xiafan Hao
- Key Lab of Colloid and Interface Chemistry
- Ministry of Education
- Shandong University
- Jinan 250100
- P. R. China
| | - Shuhua Han
- Key Lab of Colloid and Interface Chemistry
- Ministry of Education
- Shandong University
- Jinan 250100
- P. R. China
| | - Jingtao Zhu
- MOE Key Laboratory of Advanced Micro-structured Materials
- School of Physics Science and Engineering
- Tongji University
- Shanghai 200092
- P. R. China
| | - Yongfeng Hu
- Canadian Light Source 44 Innovation Boulevard Saskatoon
- Canada
| | - Lo Yueh Chang
- Institute of Functional Nano & Soft Materials (FUNSOM)
- Soochow University-Western University Centre for Synchrotron
- Radiation Research
- Suzhou 215006
- P. R. China
| | - Chih-Wen Pao
- National Synchrotron Radiation Research Center
- Hsinchu 30076
- Taiwan
| | - Jeng-Lung Chen
- National Synchrotron Radiation Research Center
- Hsinchu 30076
- Taiwan
| | - Jin-Ming Chen
- National Synchrotron Radiation Research Center
- Hsinchu 30076
- Taiwan
| | - Shu-Chih Haw
- National Synchrotron Radiation Research Center
- Hsinchu 30076
- Taiwan
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7
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Synthesis, properties and structure of copper(II) complexes of quinolyl azo derivatives of pyrazole-5-one(thione). Polyhedron 2018. [DOI: 10.1016/j.poly.2018.02.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Gaur A, Nitin Nair N, Shrivastava B, Das B, Chakrabortty M, Jha S, Bhattacharyya D. Study of distorted octahedral structure in 3d transition metal complexes using XAFS. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2017.12.067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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9
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XAFS study of bioactive Cu(II) complexes of 7-hydroxycoumarin derivatives in organic solvents. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.02.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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10
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Chutia A, Gibson EK, Farrow MR, Wells PP, Scanlon DO, Dimitratos N, Willock DJ, Catlow CRA. The adsorption of Cu on the CeO2(110) surface. Phys Chem Chem Phys 2017; 19:27191-27203. [DOI: 10.1039/c7cp04144f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A detailed density functional theory (DFT) study coupled with extended X-ray absorption fine structure (EXAFS) experiments on the geometrical and electronic properties of copper species on CeO2 surface demonstrating the effects of oxidation state and solvent environment.
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Affiliation(s)
| | - Emma K. Gibson
- UK Catalysis Hub
- RCaH
- Rutherford Appleton Laboratory
- Didcot
- UK
| | | | - Peter P. Wells
- UK Catalysis Hub
- RCaH
- Rutherford Appleton Laboratory
- Didcot
- UK
| | - David O. Scanlon
- Department of Chemistry
- University College London
- London
- UK
- Diamond Light Source Ltd
| | | | - David J. Willock
- Cardiff Catalysis Institute
- School of Chemistry
- Cardiff University
- Cardiff
- UK
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