Hydroximato complexes of boron—the X-ray crystal structures of dicyclohexylammonium bis(benzohydroximato)borate chloroform solvate and tetra-n-propylammonium bis(benzohydroximato)borate
摘要:
Four new alkylammonium bis(benzohydroximato)borates have been prepared and characterized by elemental analysis, IR and H-1 NMR spectra. The crystal and molecular structures of dicycohexylammonium bis(benzohydroximato)borate chloroform solvate (1.CHCl3) and tetra-n-propylammonium bis(benzohydroximato)borate (3) have been determined by X-ray diffraction methods. In both examples the bis(hydroximato)borate anions show the expected spirochelate structure with slightly distorted tetrahedral BO4 coordination. The C-N as well as the C-O bonds within the chelate rings have considerable double bond character. Bond lengths and angles of the BONCO heterocyle are in good agreement with those observed in N-methylacetohydroxamatoboron complexes (Can. J. Chem. 55 (1977) 1, Can. J. Chem. 56 (1978) 1676). In the crystal structure of 1.CHCl3 the bis(benzoydroximato)borate anions are linked to the dicyclohexylammonium cations by strong N-H...O and N-H..N hydrogen bonds. (C) 2002 Elsevier Science Ltd. All rights reserved.