Hd. Hornung et al., PREPARATION AND PROPERTIES OF BINUCLEAR A NTIMONY(V) COMPLEXES WITH BRIDGING BENZYLMETHOXOPHOSPHONATO LIGANDS, Zeitschrift fur Naturforschung. B, A journal of chemical sciences, 51(7), 1996, pp. 975-980
The binuclear antimony(V) complexes Cl3Sb(O)[R(3)(R(1)O)PO2](OR(2))SbC
l3 with R(1) = R(2) CH3 and R(3) = p-ClC6H4CH2 (1), p-O2NC6H4CH2 (2) a
re prepared by reaction of the corresponding benzylmethoxophosphonic a
cids with antimony(v) chloride; water and methanol. 2 crystallizes in
the orthorhombic space group Pnma with a = 1297.3, b = 1324.8, c = 126
9.7 pm and Z = 4. The molecules of 1 and 2 are formed from two octahed
ra sharing one edge with antimony central atoms. Oxygen atoms are the
links between the antimony atoms which are bridged by the bidentate ph
osphonato ligand. In solution the bridging phosphonato groups are inve
rted rapidly and the R(2) groups undergo a slow intermolecular exchang
e. Two isomers can be detected by NMR spectroscopy.