Molecular structures of M(Bu(t))3 (M = Al, Ga, In) using gas-phase electron diffraction and ab initio calculations: experimental and computational evidence for charge-transfer processes leading to photodissociation.

The gas-phase structures of AI(Bu')3 and Ga(Bu')3 have been investigated by electron diffraction and are shown to consist of monomeric units with very slightly pyramidal geometries. Salient structural parameters (r(hl)) include r(A1-C) = 2.008(2) A and r(Ga-C) = 2.

The molecular structure of N-fluorobis(trifluoromethanesulfonyl)imide, NF(SO(2)CF(3))(2), as studied in the gas phase by electron diffraction restrained by ab initio calculations.

The structure of N-fluorobis(trifluoromethylsulfonyl)imide, prepared by a relatively safe and easy method, has been determined by gas-phase electron diffraction (GED), employing the SARACEN method, with flexible restraints based on the MP2/6-311G* structure, and by X-ray crystallography at 150 K. The strongly electron-withdrawing CF(3) and SO(2)CF(3) groups make the C-S and N-S distances long, averaging 187.7(3) and 171.

Molecular Structure of Chlorodifluoronitrosomethane, CClF(2)NO, As Determined in the Gas Phase by Electron Diffraction and ab Initio Calculations.

The gas-phase structure of chlorodifluoronitrosomethane, CClF(2)NO, has been determined by electron diffraction and calculated ab initio. Theoretically, CClF(2)NO is predicted to consist of two conformers having C(s)() (phi = 0 degrees ) and C(1) (phi = 105 degrees ) symmetry, which are near degenerate in energy, DeltaE = 1.1 kJ mol(-1) [TZ2P/MP2 + ZPE(DZP/MP2)], and separated by a barrier of around 1 kJ mol(-1).

Synthesis of Volatile Cyclic Silylamines and the Molecular Structures of Two 1-Aza-2,5-disilacyclopentane Derivatives.

An optimized synthetic procedure for alpha,omega-bis(bromosilyl)alkanes, BrH(2)Si(CH(2))(n)()SiH(2)Br (with n = 2 and 3), is proposed. 1,2-Bis(bromosilyl)ethane reacts with ammonia to give 1,4-bis(1-aza-2,5-disilacyclopentane-1-yl)-1,4-disilabutane, traces of 1,6-diaza-2,5,7,10,11,14-hexasilabicyclo[4.4.

Molecular Structure of 3,4-Dimethylenehexa-1,5-diene ([4]Dendralene), C(8)H(10), in the Gas Phase As Determined by Electron Diffraction and ab Initio Calculations.

The molecular structure of 3,4-dimethylenehexa-1,5-diene ([4]dendralene), C(8)H(10), has been determined in the gas phase. A single conformer with C(2) symmetry, having two almost planar, anti butadiene groups orientated with a dihedral angle C(2)C(3)C(4)C(5) of 71.7(19) degrees, is detected by electron diffraction employing flexible restraints derived from ab initio computations.

Molecular Structures of Methyldifluoroarsine, CH(3)AsF(2), and Dimethylfluoroarsine, (CH(3))(2)AsF, in the Gas Phase As Determined by Electron Diffraction and ab InitioCalculations.

The structures of gaseous CH(3)AsF(2) and (CH(3))(2)AsF have been determined by electron diffraction incorporating vibrational amplitudes derived from ab initio force fields scaled by experimental frequencies and, for the difluoride, restrained by microwave constants. The following parameters (r(alpha) degrees structure, distances in pm, angles in degrees) have been determined for CH(3)AsF(2): r(As-C) = 194.6(4), r(As-F) = 173.