ic034458o_si_001.cif (97.47 kB)
Structural Motifs in (t-butoxy)Zirconium Phosphinates, Arsinates, and Phosphates†
dataset
posted on 2003-08-19, 00:00 authored by K. C. Kumara Swamy, Michael Veith, Volker Huch, Sanjay MathurReaction of zirconium tetrakis(tert-butoxide) (1) with dicylohexylphosphinic acid in toluene leads to the dinuclear
compound [Zr(μ,μ‘-O2P(cycl-C6H11)2)(O-t-Bu)3]2 (2) in which the zirconium is pentacoordinated. An analogous reaction
using diphenylphosphinic acid in tetrahydrofuran also leads to a dinuclear complex [Zr(μ,μ‘-O2PPh2)(THF)((O-t-Bu)3]2·C6H5CH3 (3·C6H5CH3), in which zirconium is hexacoordinated. A novel exchange of tert-butoxy and phenoxy
groups occurs when 1 is treated with diphenyl phosphate [(PhO)2PO2H] leading to the isolation of the exchange
product [Zr{μ,μ‘-O2P(O-t-Bu)(OPh)}(μ-OPh)(O-t-Bu)2]2 (4). In contrast to the above, trinuclear zirconium compounds
Zr3(μ,μ‘-O2AsMe2)2(μ2,μ‘-O2AsMe2)(O-t-Bu)7(μ-O-t-Bu)2 (5) and Zr3(μ,μ‘-O2P(O-t-Bu)2)5(O-t-Bu)7·1/2C6H5CH3 (6·1/2C6H5CH3) have been isolated from the reaction of 1 with cacodylic acid and di-tert-butyl phosphate, respectively.
The X-ray structures of 2, 3, 5, and 6 have been determined; although the X-ray structural analysis of 4 could not
be satisfactorily finished, it reveals the disposition of the substituents. The solution state NMR data suggest that
these compounds undergo structural changes in solution. Possible relationships among the various structures are
discussed.