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Ab initio molecular orbital study of energies and conformers of 3,4‐dihydro‐1,2‐dithiin, 3,6‐dihydro‐1,2‐dithiin, 4 H ‐1,3‐dithiin, and 2,3‐dihydro‐1,4‐dithiin
Author(s) -
Freeman Fillmore,
Lee Choonsun,
Po Henry N.,
Hehre Warren J.
Publication year - 1998
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/(sici)1096-987x(19980715)19:9<1064::aid-jcc7>3.0.co;2-o
Subject(s) - conformational isomerism , ab initio , cyclohexane , chemistry , ab initio quantum chemistry methods , cyclohexene , computational chemistry , cyclohexane conformation , crystallography , molecule , organic chemistry , hydrogen bond , catalysis
Optimized geometries and energies for 3,4‐dihydro‐1,2‐dithiin ( 1 ), 3,6‐dihydro‐1,2‐dithiin ( 2 ), 4 H ‐1,3‐dithiin ( 3 ), and 2,3‐dihydro‐1,4‐dithiin ( 4 ) were calculated using ab initio 6‐31G* and MP2/6‐31G*//6‐31G* methods. At the MP2/6‐31G*//6‐31G* level, the half‐chair conformer of 4 is more stable than those of 1 , 2 , and 3 by 2.5, 3.5, and 3.6 kcal/mol, respectively. The half‐chair conformers of 1 , 2 , 3 , and 4 are 2.9, 7.1, 2.0, and 5.6 kcal/mol, respectively, more stable than their boat conformers. The calculated half‐chair structures of 1 – 4 are compared with the calculated chair conformer of cyclohexane and the half‐chair structures for cyclohexene, 3,4‐dihydro‐1,2‐dioxin ( 5 ), 3,6‐dihydro‐1,2‐dioxin ( 6 ), 4 H ‐1,3‐dioxin ( 7 ), and 2,3‐dihydro‐1,4‐dioxin ( 8 ). © 1998 John Wiley & Sons, Inc. J Comput Chem 19: 1064–1071, 1998