Gas-phase structures of sterically crowded disilanes studied by electron diffraction and quantum chemical methods: 1,1,2,2-tetrakis(trimethylsilyl) disilane and 1,1,2,2-tetrakis(trimethylsilyl)dimethyldisilane

TY - JOUR

T1 - Gas-phase structures of sterically crowded disilanes studied by electron diffraction and quantum chemical methods

T2 - 1,1,2,2-tetrakis(trimethylsilyl) disilane and 1,1,2,2-tetrakis(trimethylsilyl)dimethyldisilane

AU - Schwabedissen, Jan

AU - Lane, Paul D.

AU - Masters, Sarah L.

AU - Hassler, Karl

AU - Wann, Derek A.

N1 - © Royal Society of Chemistry 2014. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details. Date of Acceptance: 19/05/2014

PY - 2014/7/14

Y1 - 2014/7/14

N2 - The gas-phase structures of the disilanes 1,1,2,2-tetrakis(trimethylsilyl) disilane [(Me3Si)2HSiSiH(SiMe3)2] (1) and 1,1,2,2-tetrakis(trimethylsilyl)dimethyldisilane [(Me 3Si)2MeSiSiMe(SiMe3)2] (2) have been determined by density functional theoretical calculations and by gas electron diffraction (GED) employing the SARACEN method. For each of 1 and 2 DFT calculations revealed four C2-symmetric conformers occupying minima on the respective potential-energy surfaces; three conformers were estimated to be present in sufficient quantities to be taken into account when fitting the GED data. For (Me3Si)2RSiSiR(SiMe3)2 [R = H (1), CH3 (2)] the lowest energy conformers were found by GED to have RSiSiR dihedral angles of 87.7(17)° for 1 and -47.0(6)° for 2. For each of 1 and 2 the presence of bulky and flexible trimethylsilyl groups dictates many aspects of the geometric structures in the gas phase, with the molecules often adopting structures that reduce steric strain.

AB - The gas-phase structures of the disilanes 1,1,2,2-tetrakis(trimethylsilyl) disilane [(Me3Si)2HSiSiH(SiMe3)2] (1) and 1,1,2,2-tetrakis(trimethylsilyl)dimethyldisilane [(Me 3Si)2MeSiSiMe(SiMe3)2] (2) have been determined by density functional theoretical calculations and by gas electron diffraction (GED) employing the SARACEN method. For each of 1 and 2 DFT calculations revealed four C2-symmetric conformers occupying minima on the respective potential-energy surfaces; three conformers were estimated to be present in sufficient quantities to be taken into account when fitting the GED data. For (Me3Si)2RSiSiR(SiMe3)2 [R = H (1), CH3 (2)] the lowest energy conformers were found by GED to have RSiSiR dihedral angles of 87.7(17)° for 1 and -47.0(6)° for 2. For each of 1 and 2 the presence of bulky and flexible trimethylsilyl groups dictates many aspects of the geometric structures in the gas phase, with the molecules often adopting structures that reduce steric strain.

UR - http://www.scopus.com/inward/record.url?scp=84902277949&partnerID=8YFLogxK

U2 - 10.1039/c4dt00628c

DO - 10.1039/c4dt00628c

M3 - Article

AN - SCOPUS:84902277949

SN - 1477-9226

VL - 43

SP - 10175

EP - 10182

JO - Dalton Transactions

JF - Dalton Transactions

IS - 26

ER -