Molecular structure and conformational preferences of gaseous 1-iodo-1-silacyclohexane

被引：22

作者：

Belyakov, A. V. ^{[1
]}

Baskakov, A. A. ^{[1
]}

Berger, R. J. F. ^{[2
]}

Mitzel, N. W. ^{[2
]}

Oberhammer, H. ^{[3
]}

Arnason, I. ^{[4
]}

Wallevik, S. O. ^{[4
]}

机构：

[1] St Petersburg State Technol Inst, St Petersburg 190013, Russia

[2] Univ Bielefeld, Lehrstuhl Anorgan Chem & Strukturchem, Bielefeld, Germany

[3] Univ Tubingen, Inst Phys & Theoret Chem, D-72074 Tubingen, Germany

[4] Univ Iceland, Inst Sci, IS-107 Reykjavik, Iceland

来源：

JOURNAL OF MOLECULAR STRUCTURE | 2012年 / 1012卷

关键词：

Silacyclohexane; Molecular structure; Gas electron diffraction; NBO analysis; Conformational analysis; GAS ELECTRON-DIFFRACTION; LOW-TEMPERATURE NMR; DEPENDENT RAMAN-SPECTROSCOPY; SILICON-CONTAINING RINGS; NATURAL STERIC ANALYSIS; HYPERCONJUGATIVE INTERACTIONS; SUBSTITUTED CYCLOHEXANES; METHYL; ATOMS;

D O I：

10.1016/j.molstruc.2011.12.032

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The molecular structure of the axial and equatorial conformers of 1-iodo-1-silacyclohexane, CH2(CH2CH2)(2)-SiH-I, as well as thermodynamic equilibrium between these species were investigated by means of gas-phase electron diffraction (GED) and quantum chemical calculations up to MP2(full)/SDB-AUG-CC-pVTZ level of theory (MP2). According to electron diffraction data, the vapor of this compound comprises a mixture of conformers with chair conformation and Cs symmetry differing in the axial and equatorial position of the Si-I bond (axial = 73(7) mol%/equatorial = 27(7) mol%) at T = 352 K. This corresponds to a free energy difference of A = 0.59(22) kcal mol(-1). The observed gas-phase electron diffraction parameters are in good agreement with those obtained from theory. NBO analysis revealed that axial conformer of 1-iodo-1-silacyclohexane is an example for electrostatic stabilization of a conformer which is unfavorable in terms of steric and conjugation interaction. (C) 2012 Elsevier B.V. All rights reserved.

引用

页码：126 / 130

页数：5

共 40 条

[1] PROCEDURE AND COMPUTER PROGRAMS FOR STRUCTURE DETERMINATION OF GASEOUS MOLECULES FROM ELECTRON DIFFRACTION DATA [J].

ANDERSEN, B ;

SEIP, HM ;

STRAND, TG ;

STOLEVIK, R .

ACTA CHEMICA SCANDINAVICA, 1969, 23 (09) :3224-&

[2]

ANET FAL, 1974, TETRAHEDRON LETT, P3255

[3]

[Anonymous], INT TABLES CRYSTALLO

[4] Conformations of silicon-containing rings. 5. Conformational properties of 1-methyl-1-silacyclohexane: Gas electron diffraction, low-temperature NMR, and quantum chemical calculations [J].

Arnason, I ;

Kvaran, A ;

Jonsdottir, S ;

Gudnason, PI ;

Oberhammer, H .

JOURNAL OF ORGANIC CHEMISTRY, 2002, 67 (11) :3827-3831

[5]

Badenhoop JK, 1997, J CHEM PHYS, V107, P5422, DOI 10.1063/1.475149

[6] Natural bond orbital analysis of steric interactions [J].

Badenhoop, JK ;

Weinhold, F .

JOURNAL OF CHEMICAL PHYSICS, 1997, 107 (14) :5406-5421

[7]

Badenhoop JK, 1999, INT J QUANTUM CHEM, V72, P269, DOI 10.1002/(SICI)1097-461X(1999)72:4<269::AID-QUA9>3.0.CO

[8]

2-8

[9] An Improved Gas Electron Diffractometer - The Instrument, Data Collection, Reduction and Structure Refinement Procedures [J].

Berger, Raphael J. F. ;

Hoffmann, Manfred ;

Hayes, Stuart A. ;

Mitzel, Norbert W. .

ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES, 2009, 64 (11-12) :1259-1268

[10] Conformational properties of six-membered heterocycles: accurate relative energy differences with DFT, the importance of dispersion interactions and silicon substitution effects [J].

Bjornsson, Ragnar ;

Arnason, Ingvar .

PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2009, 11 (39) :8689-8697

← 1 2 3 4 →