Group 3 tetrahydroborates. Part 2. The molecular structures of dimethylaluminium tetrahydroborate and dimethylgallium tetrahydroborate in the gas phase as determined by electron diffraction
- 1 January 1979
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in J. Chem. Soc., Dalton Trans.
- No. 11,p. 1793-1800
- https://doi.org/10.1039/dt9790001793
Abstract
The molecular geometries of Al(BH4)Me2 and Ga(BH4)Me2 in the gas phase have been studied by electron diffraction. Both species appear to be monomeric molecules with skeletons having C2v, symmetry and containing bidentate tetrahydroborate groups. Salient parameters for Al(BH4)Me2 are: ra(Al–C) 192.9(0.4), ra(Al–B) 212.8(0.8), ra(Al–Hb) 177.0(3.2),ra(B–Hb) 123.0(1.7), ra(B–Ht) 120.7(1.7) pm; C–Al–C 118.4(0.7), Hb–Al–Hb 70.6(4.8)°(t = terminal, b = bridging). The corresponding parameters for Ga(BH4)Me2 are: ra(Ga–C) 194.4(0.4), ra(Ga–B) 216.3(0.8), ra(Ga–Hb) 179.1 (3.0), ra(B–Hb) 121.7(1.9), ra(B–Ht) 119.2(1.9) pm; C–Ga–C 118.8(1.2), Hb–Ga–Hb 68.4(4.6)°. Exchange of methyl for tetrahydroborate groups in molecules of the type M(BH4)3–n(CH3)n(M = Al or Ga, n= 2 or 3; M = Al, n= 0) evokes but small changes in the dimensions of the (CH3)2M and M(BH4) groups although there are signs suggestive of modest variations of the bonding within these two groups.Keywords
This publication has 0 references indexed in Scilit: