## Abstract

The gas-phase structures of the disilanes 1,1,2,2-tetrakis(trimethylsilyl)disilane [(Me3Si)(2)HSiSiH(SiMe3)(2)] (1) and 1,1,2,2-tetrakis(trimethylsilyl)dimethyldisilane [(Me3Si)(2)MeSiSiMe(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 C-2-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)(2)RSiSiR(SiMe3)(2) [R = H (1), CH3 (2)] the lowest energy conformers were found by GED to have RSiSiR dihedral angles of 87.7(17)degrees for 1 and -47.0(6)degrees 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.

Original language | English |
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Pages (from-to) | 10175-10182 |

Number of pages | 8 |

Journal | Dalton Transactions |

Volume | 43 |

Issue number | 26 |

DOIs | |

Publication status | Published - 14 Jul 2014 |

## Keywords

- AB-INITIO CALCULATIONS
- MOLECULAR-ORBITAL METHODS
- VALENCE BASIS-SETS
- CONFORMATIONAL COMPOSITION
- VIBRATIONAL-SPECTRA
- DENSITY
- TETRASILANES
- HEXASILANES
- ELEMENTS