Zinc Complexes of Aldehydes and Ketones, 2 Zinc-Aldehyde Complexes with Weakly Coordinating Anions

Zinc salts of low or zero water content were obtained from the hexahydrates of zinc nitrate, zinc perchlorate, and zinc tetrafluoroborate by dehydration with triethoxymethane or by solvation with acetonitrile or nitromethane. The compounds incorporated aldehydes as ligands when treated with an excess of the aromatic aldehydes benzaldehyde, mesitylaldehyde, 2chlorobenzaldehyde, and 4-fluorobenzaldehyde. Eighteen zinc-aldehyde complexes were isolated and identified by crystal structure determinations. All contain octahedral zinc to which 2, 3, 4, 5, or 6 aldehyde ligands are bound. Water, ethanol, and acetonitrile molecules act as coligands. Of the anions employed, BF4- and SbCl6- were found to be only noncoordinating and NO3- only coordinating, whereas complexes with one or two perchlorate ligands were obtained in addition to perchlorate salts.