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Huyen TL, Raghunath P, Lin M. Quantum chemical modeling of spontaneous reactions of N2O4 with hydrazines in CCl4 solution at low temperature. COMPUT THEOR CHEM 2020. [DOI: 10.1016/j.comptc.2020.112951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Raghunath P, Lee YP, Lin MC. Computational Chemical Kinetics for the Reaction of Criegee Intermediate CH2OO with HNO3 and Its Catalytic Conversion to OH and HCO. J Phys Chem A 2017; 121:3871-3878. [DOI: 10.1021/acs.jpca.7b02196] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. Raghunath
- Center
for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yuan-Pern Lee
- Center
for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan
- Department
of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Institute
of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - M. C. Lin
- Center
for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan
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Srinivasadesikan V, Raghunath P, Lin MC. Quantum chemical investigation on the role of Li adsorbed on anatase (101) surface nano-materials on the storage of molecular hydrogen. J Mol Model 2015; 21:142. [PMID: 25966674 DOI: 10.1007/s00894-015-2686-1] [Citation(s) in RCA: 2] [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: 10/13/2014] [Accepted: 04/27/2015] [Indexed: 10/23/2022]
Abstract
Lithiation of TiO2 has been shown to enhance the storage of hydrogen up to 5.6 wt% (Hu et al. J Am Chem Soc 128:11740-11741, 2006). The mechanism for the process is still unknown. In this work we have carried out a study on the adsorption and diffusion of Li atoms on the surface and migration into subsurface layers of anatase (101) by periodic density functional theory calculations implementing on-site Coulomb interactions (DFT+U). The model consists of 24 [TiO2] units with 11.097 × 7.655 Å(2) surface area. Adsorption energies have been calculated for different Li atoms (1-14) on the surface. A maximum of 13 Li atoms can be accommodated on the surface at two bridged O, Ti-O, and Ti atom adsorption sites, with 83 kcal mol(-1) adsorption energy for a single Li atom adsorbed between two bridged O atoms from where it can migrate into the subsurface layer with 27 kcal mol(-1) energy barrier. The predicted adsorption energies for H2 on the lithiated TiO2 (101) surface with 1-10 Li atoms revealed that the highest adsorption energies occurred on 1-Li, 5-Li, and 9-Li surfaces with 3.5, 4.4, and 7.6 kcal mol(-1), respectively. The values decrease rapidly with additional H2 co-adsorbed on the lithiated surfaces; the maximum H2 adsorption on the 9Li-TiO2(a) surface was estimated to be only 0.32 wt% under 100 atm H2 pressure at 77 K. The result of Bader charge analysis indicated that the reduction of Ti occurred depending on the Li atoms covered on the TiO2 surface.
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Affiliation(s)
- V Srinivasadesikan
- Center for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University, Hsinchu, 300, Taiwan
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Xu ZF, Raghunath P, Lin MC. Ab Initio Chemical Kinetics for the CH3 + O(3P) Reaction and Related Isomerization–Decomposition of CH3O and CH2OH Radicals. J Phys Chem A 2015; 119:7404-17. [DOI: 10.1021/acs.jpca.5b00553] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Z. F. Xu
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - P. Raghunath
- Center for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan
| | - M. C. Lin
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
- Center for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan
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Chuang CC, Lin CK, Wang TT, Srinivasadesikan V, Raghunath P, Lin MC. Computational and experimental studies on the effect of hydrogenation of Ni-doped TiO2 anatase nanoparticles for the application of water splitting. RSC Adv 2015. [DOI: 10.1039/c5ra16119c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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] Open
Abstract
The hydrogenated black Ni–TiO2 nanoparticles exhibit a much greater efficiency in water splitting producing H2 gas over those of non-hydrogenated TiO2 and Ni-doped TiO2.
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Affiliation(s)
- Chung-Ching Chuang
- Center for Interdisciplinary Molecular Science
- Department of Applied Chemistry
- National Chiao Tung University
- Hsinchu
- Taiwan 300
| | - Cheng-Kuo Lin
- Center for Interdisciplinary Molecular Science
- Department of Applied Chemistry
- National Chiao Tung University
- Hsinchu
- Taiwan 300
| | - T. T. Wang
- Center for Interdisciplinary Molecular Science
- Department of Applied Chemistry
- National Chiao Tung University
- Hsinchu
- Taiwan 300
| | - V. Srinivasadesikan
- Center for Interdisciplinary Molecular Science
- Department of Applied Chemistry
- National Chiao Tung University
- Hsinchu
- Taiwan 300
| | - P. Raghunath
- Center for Interdisciplinary Molecular Science
- Department of Applied Chemistry
- National Chiao Tung University
- Hsinchu
- Taiwan 300
| | - M. C. Lin
- Center for Interdisciplinary Molecular Science
- Department of Applied Chemistry
- National Chiao Tung University
- Hsinchu
- Taiwan 300
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Raghunath P, Lin MC. Ab initio chemical kinetics for SiH2 + Si2H6 and SiH3 + Si2H5 reactions and the related unimolecular decomposition of Si3H8 under a-Si/H CVD conditions. J Phys Chem A 2013; 117:10811-23. [PMID: 24059703 DOI: 10.1021/jp407553a] [Citation(s) in RCA: 8] [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] [Indexed: 12/26/2022]
Abstract
The kinetics and mechanisms for SiH2 + Si2H6 and SiH3 + Si2H5 reactions and the related unimolecular decomposition of Si3H8 have been investigated by ab initio molecular orbital theory based on the QCISD(T)/CBS//QCISD/6-311++G(d,p) method in conjunction with quantum statistical variational Rice-Ramsperger-Kassel-Marcus (RRKM) calculations. For the barrierless radical association processes, their variational transition states have been characterized by the CASPT2//CASSCF method. The species involved in the study are known to coexist under CVD conditions. The results show that the association reaction of SiH2 and Si2H6 producing Si3H8 occurs by insertion via its lowest-energy path forming a loose hydrogen-bonding molecular complex with 8.3 kcal/mol binding energy; the reaction is exothermic by 55.0 kcal/mol. The chemically activated Si3H8 adduct can fragment by several paths, producing SiH4 + SiH3SiH (-0.7 kcal/mol), Si(SiH3)2 + H2 (-1.4 kcal/mol), and SiH3SiH2SiH + H2 (-1.4 kcal/mol). The predicted enthalpy changes as given agree well with available thermochemical data. Three other decomposition channels of Si3H8 occurring by Si-H or Si-Si breaking were found to be highly endothermic, and the reactions take place without a well-defined barrier. The heats of formation of Si3H8, SiH2SiH, Si2H4, i-Si3H7, n-Si3H7, Si(SiH3)2, and SiH3SiH2SiH have been predicted and found to be in close agreement with those available data in the literature. The product branching rate constants for SiH2 + Si2H6 and SiH3 + Si2H5 reactions and the thermal unimolecular decomposition of Si3H8 for all low-energy paths have been calculated with multichannel variational RRKM theory covering varying P,T conditions typically employed in PECVD and Cat-CVD processes for hydrogenated amorphous silicon (a-Si/H) film growth. The results were also found to be in good agreement with available kinetic data. Our kinetic results may be employed to model and control very large-area a-Si/H film growth for a new generation of solar cell applications.
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Affiliation(s)
- P Raghunath
- Center for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University , Hsinchu 300, Taiwan
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Raju MVR, Raghunath P, Lin MC, Lin HC. An Acid–Base Controllable Hierarchical Nanostructure from a NIR-Absorbing Conjugated Polyrotaxane-Based Optical Molecular Switch. Macromolecules 2013. [DOI: 10.1021/ma401485b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
| | - P. Raghunath
- Center
for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Ming-Chang Lin
- Center
for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Hong-Cheu Lin
- Department
of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan
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Zhu RS, Raghunath P, Lin MC. Effect of Roaming Transition States upon Product Branching in the Thermal Decomposition of CH3NO2. J Phys Chem A 2013; 117:7308-13. [DOI: 10.1021/jp401148q] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R. S. Zhu
- Department of Chemistry, Emory University, Atlanta, Georgia 30322,
United States
| | - P. Raghunath
- Center for
Interdisciplinary
Molecular Science, Department of Chemistry, National Chiao Tung University, Hsinchu, Taiwan 300
| | - M. C. Lin
- Department of Chemistry, Emory University, Atlanta, Georgia 30322,
United States
- Center for
Interdisciplinary
Molecular Science, Department of Chemistry, National Chiao Tung University, Hsinchu, Taiwan 300
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Raghunath P, Huang WF, Lin MC. Quantum chemical elucidation of the mechanism for hydrogenation of TiO2 anatase crystals. J Chem Phys 2013; 138:154705. [DOI: 10.1063/1.4799800] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Raghunath P, Lin MC. Ab initio chemical kinetics for the ClOO + NO reaction: Effects of temperature and pressure on product branching formation. J Chem Phys 2012; 137:014315. [DOI: 10.1063/1.4731883] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Chen HT, Raghunath P, Lin MC. Computational investigation of O2 reduction and diffusion on 25% Sr-doped LaMnO3 cathodes in solid oxide fuel cells. Langmuir 2011; 27:6787-6793. [PMID: 21563810 DOI: 10.1021/la200193a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The oxygen reduction reaction (ORR) and diffusion mechanisms on 25% Sr-doped LaMnO(3) (LSM) cathode materials as well as their kinetic behavior have been studied by using spin-polarized density functional theory (DFT) calculations. Bader charge and frequency analyses were carried out to identify the oxidation state of adsorbed oxygen species. DFT and molecular dynamics (MD) results show that the fast O(2) adsorption/reduction process via superoxide and peroxide intermediates is energetically favorable on the Mn site rather than on the Sr site. Furthermore, the higher adsorption energies on the Mn site of the (110) surface compared to those on the (100) surface imply that the former is more efficient for O(2) reduction. Significantly, we predict that oxygen vacancies enhance O(2) reduction kinetics and that the O-ion migration through the bulk is dominant over that on the surface of the LSM cathode.
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Affiliation(s)
- Hsin-Tsung Chen
- Department of Chemistry, Chung Yuan Christian University, Chungli 32023, Taiwan.
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Huang WF, Raghunath P, Lin MC. Computational study on the reactions of H2O2 on TiO2 anatase (101) and rutile (110) surfaces. J Comput Chem 2010; 32:1065-81. [DOI: 10.1002/jcc.21686] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 08/02/2010] [Accepted: 09/03/2010] [Indexed: 11/12/2022]
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Affiliation(s)
- Ku-We Lu
- Department of Applied Chemistry, National Chiao Tung University, 1001, Ta Hsuch Road, Hsinchu 30010 Taiwan
| | - Hiroyuki Matsui
- Department of Applied Chemistry, National Chiao Tung University, 1001, Ta Hsuch Road, Hsinchu 30010 Taiwan
| | - Ching-Liang Huang
- Department of Applied Chemistry, National Chiao Tung University, 1001, Ta Hsuch Road, Hsinchu 30010 Taiwan
| | - P. Raghunath
- Department of Applied Chemistry, National Chiao Tung University, 1001, Ta Hsuch Road, Hsinchu 30010 Taiwan
| | - Niann-Shiah Wang
- Department of Applied Chemistry, National Chiao Tung University, 1001, Ta Hsuch Road, Hsinchu 30010 Taiwan
| | - M. C. Lin
- Department of Applied Chemistry, National Chiao Tung University, 1001, Ta Hsuch Road, Hsinchu 30010 Taiwan
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Affiliation(s)
- D. H. Varma
- Center for Interdisciplinary Molecular Science, Institute of Molecular Science, National Chiao Tung University, Hsinchu 300, Taiwan
| | - P. Raghunath
- Center for Interdisciplinary Molecular Science, Institute of Molecular Science, National Chiao Tung University, Hsinchu 300, Taiwan
| | - M. C. Lin
- Center for Interdisciplinary Molecular Science, Institute of Molecular Science, National Chiao Tung University, Hsinchu 300, Taiwan
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Wu SY, Raghunath P, Wu JS, Lin MC. Ab Initio Chemical Kinetic Study for Reactions of H Atoms with SiH4 and Si2H6: Comparison of Theory and Experiment. J Phys Chem A 2009; 114:633-9. [DOI: 10.1021/jp908222g] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- S. Y. Wu
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu 300, Taiwan
| | - P. Raghunath
- Center for Interdisciplinary Molecular Science, Institute of Molecular Science, National Chiao Tung University, Hsinchu 300, Taiwan
| | - J. S. Wu
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu 300, Taiwan
| | - M. C. Lin
- Center for Interdisciplinary Molecular Science, Institute of Molecular Science, National Chiao Tung University, Hsinchu 300, Taiwan
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Maiti B, Raghunath P, Karunasagar I, Karunasagar I. Cloning and expression of an outer membrane protein OmpW of Aeromonas hydrophila and study of its distribution in Aeromonas spp. J Appl Microbiol 2009; 107:1157-67. [PMID: 19426281 DOI: 10.1111/j.1365-2672.2009.04296.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS The main aims of this study were to clone and express an outer membrane protein (OMP), OmpW, of Aeromonas hydrophila and to study its distribution in Aeromonas spp. METHODS AND RESULTS The gene encoding OmpW in A. hydrophila has been cloned and expressed in Escherichia coli. Primers were designed for amplification of full-length ompW gene and used for identification of this gene in different Aeromonas spp. Of the 42 Aeromonas strains tested, all the isolates were positive by polymerase chain reaction (PCR) except one strain of Aeromonas veronii biovar veronii (VTE338). None of the other gram-negative bacteria were positive by PCR with primers specific to ompW gene of A. hydrophila. Polyclonal antibodies were raised in rabbit against the purified recombinant protein and the reaction of these antibodies was confirmed by western blotting using the purified recombinant protein and 42 Aeromonas cultures grown at various salt concentrations. CONCLUSIONS The ompW-based PCR method developed in this study was found to be 100% specific and 97% sensitive. Expression of OmpW protein of Aeromonas was found to be salt-dependant. Recombinant OmpW protein was found to be highly immunogenic in fish. SIGNIFICANCE AND IMPACT OF THE STUDY To our knowledge, this is the first report on cloning and expression of OmpW protein of A. hydrophila. Full-length ompW gene amplification by PCR can be used for the detection of Aeromonas. Recombinant OmpW protein can be useful for vaccination of fish against Aeromonas spp.
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Affiliation(s)
- B Maiti
- Department of Fishery Microbiology, Karnataka Veterinary, Animal and Fisheries Sciences University, College of Fisheries, Mangalore 575 002, India
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Bhowmick P, Khushiramani R, Raghunath P, Karunasagar I, Karunasagar I. Molecular typing of Vibrio parahaemolyticus isolated from seafood harvested along the south-west coast of India. Lett Appl Microbiol 2007; 46:198-204. [DOI: 10.1111/j.1472-765x.2007.02304.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Raghunath P, Karunasagar I, Karunasagar I. Evaluation of an alkaline phosphatase-labeled oligonucleotide probe for detection and enumeration of vibrio spp. from shrimp hatchery environment. Mol Cell Probes 2007; 21:312-5. [PMID: 17446040 DOI: 10.1016/j.mcp.2007.03.003] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 02/16/2007] [Accepted: 03/08/2007] [Indexed: 11/16/2022]
Abstract
An alkaline phosphatase (AP)-labeled genus-specific oligonucleotide probe was developed to detect and enumerate vibrios in shrimp larvae and their surrounding environment. The probe was evaluated using 35 laboratory isolates of Vibrio species and 29 isolates of non-vibrio species. The probe was specific for the Vibrio species and no cross reaction was found with the non-vibrios included in the study. The total Vibrio counts obtained by plating on thiosulfate-citrate-bile salts-sucrose agar (TCBS) and using oligonucleotide probe were compared. Total Vibrio counts obtained by probe were comparatively higher than the counts obtained by plating on TCBS agar. The difference between the counts obtained by the probe and by plating on TCBS agar ranged from 2 to 21 times. The study reveals that the use of a non-selective medium such as T1N3 agar followed by detection using a genus-specific probe would help to precisely enumerate the total Vibrio load in the aquaculture environments.
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Affiliation(s)
- P Raghunath
- Department of Fishery Microbiology, Karnataka Veterinary, Animal and Fisheries Sciences University, College of Fisheries, Mangalore 575 002, India
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Abstract
The reactions of trimethylindium (TMIn) with H2O and H2S are relevant to the chemical vapor deposition of indium oxide and indium sulfide thin films. The mechanisms and energetics of these reactions in the gas phase have been investigated by density functional theory and ab initio calculations using the CCSD(T)/[6-31G(d,p)+Lanl2dz]//B3LYP/[6-31G(d,p)+Lanl2dz] and CCSD(T)/[6-31G(d,p)+Lanl2dz] //MP2/[6-31G(d,p)+Lanl2dz] methods. The results of both methods are in good agreement for the optimized geometries and relative energies. When TMIn reacts with H2O and H2S, initial molecular complexes [(CH3)3In:OH2 (R1)] and [(CH3)3In:SH2 (R2)] are formed with 12.6 and 3.9 kcal/mol binding energies. Elimination of a CH4 molecule from each complex occurs with a similar energy barrier at TS1 (19.9 kcal/mol) and at TS3 (22.1 kcal/mol), respectively, giving stable intermediates (CH3)2InOH and (CH3)2InSH. The elimination of the second CH4 molecule from these intermediate products, however, has to overcome very high and much different barriers of 66.1 and 53.2 kcal/mol, respectively. In the case of DMIn with H2O and H2S reactions, formation of both InO and InS is exothermic by 3.1 and 30.8 kcal/mol respectively. On the basis of the predicted heats of formation of R1 and R2 at 0 K and -20.1 and 43.6 kcal/mol, the heats of formation of (CH3)2InOH, (CH3)2InSH, CH3InO, CH3InS, InO, and InS are estimated to be -20.6, 31.8, and 29.0 and 48.4, 35.5, and 58.5 kcal/mol, respectively. The values for InO and InS are in good agreement with available experimental data. A similar study on the reactions of (CH3)2In with H2O and H2S has been carried out; in these reactions CH3InOH and CH3InSH were found to be the key intermediate products.
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Affiliation(s)
- P Raghunath
- Center for Interdisciplinary Molecular Science, Institute of Molecular Science, National Chiao Tung University, Hsinchu 300, Taiwan
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Tzeng YR, Raghunath P, Chen SC, Lin MC. Computational Study of Reaction Pathways for the Formation of Indium Nitride from Trimethylindium with HN3: Comparison of the Reaction with NH3 and That on TiO2 Rutile (110) Surface. J Phys Chem A 2007; 111:6781-8. [PMID: 17388580 DOI: 10.1021/jp0690345] [Citation(s) in RCA: 9] [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] [Indexed: 11/28/2022]
Abstract
The reactions of trimethylindium (TMIn) with HN3 and NH3 are relevant to the chemical vapor deposition of indium nitride thin film. The mechanisms and energetics of these reactions in the gas phase have been investigated by density functional theory and ab initio calculations using the CCSD(T)/Lanl2dz//B3LYP/Lanl2dz and CCSD(T)/Lanl2dz//MP2/Lanl2dz methods. The results of both methods are in good agreement for the optimized geometries and relative energies. These results suggest that the reaction with HN3 forms a new stable product, dimethylindiumnitride, CH3-In=N-CH3 via another stable In(CH3)2N3 (dimethylindium azide, DMInA) intermediate. DMInA may undergo unimolecular decomposition to form CH3InNCH3 by two main possible pathways: (1) a stepwise decomposition process through N2 elimination followed by CH3 migration from In to the remaining N atom and (2) a concerted process involving the concurrent CH3 migration and N2 elimination directly giving N2+CH3InNCH3. The reaction of TMIn with NH3 forms a most stable product DMInNH2 following the initial association and CH4-elimination reaction. The required energy barrier for the elimination of the second CH4 molecule from DMInNH2 is 74.2 kcal/mol. Using these reactions, we predict the heats of formation at 0 K for all the products and finally for InN which is 123+/-1 kcal/mol predicted by the two methods. The gas-phase reaction of HN3 with TMIn is compared with that occurring on rutile TiO2 (110). The most noticeable difference is the high endothermicity of the gas-phase reaction for InN production (53 kcal/mol) and the contrasting large exothermicity (195 kcal/mol) released by the low-barrier Langmuir-Hinshelwood type processes following the adsorption of TMIn and HN3 on the surface producing a horizontally adsorbed InN(a), Ti-NIn-O(a), and other products, CH4(g)+N2(g)+2CH3O(a) [J. Phys. Chem. B 2006, 110, 2263].
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Affiliation(s)
- Yi-Ren Tzeng
- Center for Interdisciplinary Molecular Science, Institute of Molecular Science, National Chiao Tung University, Hsinchu 300, Taiwan.
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Raghunath P, Reddy MA, Gouri C, Bhanuprakash K, Rao VJ. Electronic Properties of Anthracene Derivatives for Blue Light Emitting Electroluminescent Layers in Organic Light Emitting Diodes: A Density Functional Theory Study. J Phys Chem A 2005; 110:1152-62. [PMID: 16420020 DOI: 10.1021/jp0555753] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular level parameters are investigated computationally to understand the factors that are responsible for the higher efficiency in derivatives of 9,10-bis(1-naphthyl)anthracene (alpha-ADN), 9,10-bis(2-naphthyl)anthracene (beta-ADN), their tetramethyl derivatives (alpha,beta-TMADN) and the t-Bu derivative (beta-TBADN) as blue light emitting electroluminescent (EL) layers in organic light emitting diodes (OLEDs). DFT studies at the B3LYP/6-31G(d,p) level have been carried out on the substituted anthracenes. The absorption spectra are simulated using time dependent DFT methods (TD-DFT) whereas the emission spectra are approximated by optimizing the excited state by HF/CI-Singles and then carrying out the vertical CI calculations by the TD-DFT method. The reorganization energy for estimating the hole and electron transport is calculated. The transfer integrals between parallely stacked molecules in the bulk state are estimated by calculating the electronic splitting. The substituted anthracenes are compared with unsubstituted anthracene and yet untested 9,10-dianthrylanthracene (TANTH). A larger and slower buildup of the electrons and holes in the EL layer, due to the higher reorganization energy and smaller electronic coupling between the adjacent molecules could lead to an increase in hole-electron recombination in the layer and thus increase the efficiency.
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Affiliation(s)
- P Raghunath
- Inorganic Chemistry Division and Organic Chemistry Division (II), Indian Institute of Chemical Technology, Hyderabad 500 007, India
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Sitha S, Srinivas K, Raghunath P, Bhanuprakash K, Jayathirtha Rao V. Linear allenic linkage for nonlinear optics: A computational study of the role of mutually orthogonal π-orbitals in controlling the charge transfer, hyperpolarizability and absorption properties in some donor–acceptor substituted allenes. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.theochem.2005.04.040] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Raghunath P, Bhanuprakash K, Srinivas R. Formation of Silicon Analogues of Thio-isocyanic Acid, HNSiS, and Its Isomers by Neutral−Neutral Reactions of the Fragments: A Computational Study. J Phys Chem A 2004. [DOI: 10.1021/jp0478211] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- P. Raghunath
- Inorganic Chemistry Division, and National Centre for Mass Spectrometry, Indian Institute of Chemical Technology (IICT), Hyderabad-500 007, India
| | - K. Bhanuprakash
- Inorganic Chemistry Division, and National Centre for Mass Spectrometry, Indian Institute of Chemical Technology (IICT), Hyderabad-500 007, India
| | - R. Srinivas
- Inorganic Chemistry Division, and National Centre for Mass Spectrometry, Indian Institute of Chemical Technology (IICT), Hyderabad-500 007, India
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Krishna GG, Reddy RS, Raghunath P, Bhanuprakash K, Kantam ML, Choudary BM. A Computational Study of Ligand Interactions with Hafnium and Zirconium Metal Complexes in the Liquid−Liquid Extraction Process. J Phys Chem B 2004. [DOI: 10.1021/jp036477p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- G. Gopi Krishna
- Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabad-500 007, India
| | - R. Sudarshan Reddy
- Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabad-500 007, India
| | - P. Raghunath
- Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabad-500 007, India
| | - K. Bhanuprakash
- Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabad-500 007, India
| | - M. Lakshmi Kantam
- Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabad-500 007, India
| | - B. M. Choudary
- Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabad-500 007, India
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Raghunath P, Sitha S, Bhanuprakash K, Choudary BM. Formation of the Silicon Analogues of Isocyanic Acid, HNSiO, and Its Isomers by Neutral−Neutral Reactions of the Fragments: A Computational Study. J Phys Chem A 2003. [DOI: 10.1021/jp035219p] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- P. Raghunath
- Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabd-500 007, India
| | - Sanyasi Sitha
- Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabd-500 007, India
| | - K. Bhanuprakash
- Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabd-500 007, India
| | - B. M. Choudary
- Inorganic Chemistry Division, Indian Institute of Chemical Technology, Hyderabd-500 007, India
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Subbannayya K, Raghunath P, Rao VA, Nayak BS. Fishmeal extract agar--a new antibiotic sensitivity test medium. Indian J Exp Biol 2002; 40:960-2. [PMID: 12597032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Fishmeal extract agar is a new antibiotic sensitivity test medium. It is simpler and cheaper than Mueller-Hinton agar and comparable in its efficacy to the latter. It can also be used for isolation of moderately fastidious and non-fastidious bacteria from clinical specimens. Fishmeal extract broth can be used as a base for biochemical tests used for the identification of bacterial isolates.
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Affiliation(s)
- K Subbannayya
- Department of Microbiology, Kasturba Medical College, Mangalore 575 001, India.
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