Computational Study on the Mechanisms and Energetics of Trimethylindium Reactions with H2O and H2S.

Saved in:
Bibliographic Details
Title: Computational Study on the Mechanisms and Energetics of Trimethylindium Reactions with H2O and H2S.
Authors: P. Raghunath1, M. C. Lin1
Source: Journal of Physical Chemistry A. Jul2007, Vol. 111 Issue 28, p6481-6488. 8p.
Subjects: Physical & theoretical chemistry, Science, Chemistry, Physical sciences
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 CH4molecule 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 CH4molecule 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 R1and R2at 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. [ABSTRACT FROM AUTHOR]
Copyright of Journal of Physical Chemistry A is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
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 CH4molecule 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 CH4molecule 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 R1and R2at 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. [ABSTRACT FROM AUTHOR]
ISSN:10895639
DOI:10.1021/jp0677142