Lewis acid-base adducts of zwitterionic alkali metal methanides and silanides with BH3

Crystal structure of di-μ-tri-hydro-(penta-fluoro-phenyl)-borato-tetra-kis-(tetra-hydro-furan)-disodium

The title compound, [Na(μ-C6F5BH3)(C4H8O)2]2, represents a dimeric structure of sodium and organoborohydride, located about a centre of inversion. The Na⋯B distances of 2.7845 (19) and 2.7494 (18) Å were apparently longer than the Li⋯B distances (2.403-2.537 Å) of the lithium organotri-hydro-borates in the previous reports. Moreover, an inter-action between the sodium atom and one fluorine atom on the 2-position of the benzene ring is observed [Na-F = 2.6373 (12) Å]. In the crystal, the dimeric mol-ecules are stacked along the b-axis via a π-π inter-action between the benzene rings.