Ab initio molecular orbital study of energies and conformers of 3,4-dihydro-1,2-dithiin, 3,6-dihydro-1,2-dithiin, 4H-1,3-dithiin, and 2,3-dihydro-1,4-dithiin

✍ Scribed by Freeman, Fillmore; Lee, Choonsun; Po, Henry N.; Hehre, Warren J.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 228 KB
• Volume: 19
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/(sici)1096-987x(19980715)19:9<1064::aid-jcc7>3.0.co;2-o

✦ Synopsis

Optimized geometries and energies for 3,4-dihydro-1,2-dithiin Ž .

Ž . Ž . Ž . 1 , 3,6-dihydro-1,2-dithiin 2 , 4H-1,3-dithiin 3 , and 2,3-dihydro-1,4-dithiin 4 were calculated using ab initio 6-31G U and MP2r6-31G U rr6-31G U methods. At the MP2r6-31G U rr6-31G U 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 kcalrmol, respectively. The half-chair conformers of 1, 2, 3, and 4 are 2.9, 7.1, 2.0, and 5.6 kcalrmol, 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 Ž .

Ž . Ž . Ž .