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Journal of the Korean Chemical Society (JKCS)

ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 53, Number 5
JKCSEZ 53(5)
October 20, 2009 

 
Title
mPW1PW91 Calculated Relative Stabilities and Structures for the Conformers of 1,3-dimethoxy-p-tert-butylthiacalix[4]crown-5-ether

1,3-디메톡시-티아캘릭스[4]크라운-5-에테르의 이형체들의 상대적인 안정성과 구조들에 대한 mPW1PW91 계산 연구
Author
Kwangho Kim, Jong In Choe*

김광호, 최종인*
Keywords
1,3-디메톡시-티아캘릭스[4]크라운-5-에테르, 이형체, mPW1PW91, 양자역학. , DFT B3LYP, mPW1PW91, Conformer, Thiacalix[4]crown-5-ether
Abstract
1,3-디메톡시-티아캘릭스[4]크라운-5-에테르 (3)의 다양한 이형체들(cone_oo, cone_oi, pc_oo, pc_io, pc_oi, pc_ii, 13a_oo, 13a_io)에 대한 구조들이 DFT B3LYP/6 - 31 + G(d,p)와 mPW1PW91/6 - 31 + G (d,p) (hybrid HF-DF) 계산 방법들에 의하여 최적화 되었다. 13a_oo (1,3-alternate 이형체에서 두 개의 메 톡시기가 모두 밖으로 향해 있는 구조)가 가장 안정하였으며, 기존에 보고된 실험 결과와 잘 일치하였다. mPW1PW91/6 - 31 + G(d,p) 계산에 의한 상대적인 안정성은 다음과 같았다: 13a_oo (가장 안정) > 13a_io∼ pc_io∼cone_oo > cone_oi∼pc_oo∼pc_oi > pc_ii.

Molecular structures of the various conformers for the 1,3-dimethoxy-p-tert-butylthiacalix[4] crown-5-ether (3) were optimized by using DFT B3LYP/6 - 31 + G(d,p) and mPW1PW91/6 - 31 + G(d,p) (hybrid HF-DF) calculation methods. We have analyzed the energy differences and structures of eight in/out orientations (cone_oo, cone_oi, pc_oo, pc_io, pc_oi, pc_ii, 13a_oo, 13a_io) of two methoxy groups in three major conformations (cone, partial-cone and 1,3-alternate). The 13a_oo (out-out orientation of the 1,3-alternate conformer) is calculated to be the most stable among eight different conformations of 3, and in accord with the experimental result. The ordering of relative stability resulted from the mPW1PW91/6 - 31 + G(d,p) calculation method is following: 13a_oo > 13a_io∼pc_io∼cone_oo > cone_oi∼pc_oo∼pc_oi > pc_ii.

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