D-H-MU-BENZYLALKOXOPHOSPHONATO-E-MU-ALKOX O-F-MU-OXO-BIS[TRICHLOROANTIMONY(V)] COMPOUNDS

The binuclear antimony(V) complexes Cl3Sb(O)[R(3)(R(1)O)PO2](OR(2))SbC l3 1-6 with R(1) = R(2) = CH3, C2H5 and R(3) = C6H5CH2, (CH3)(3)C6H2CH 2 in solution slowly exchanges the R(2) groups between the oxygen atom s of the Sb2O2 ring. The SbOPOSb ringsystem makes rapid pseudorotation . The isomeres are detected by nmr spectroscopy. 1 (R(1) = R(2) = CH3) crystallizes in the orthorhombic space group Pnma with a = 1247.0, b = 1324.1, c = 1207.9 pm and Z = 4. 2 (R(1) = CH3, R(2) = C2H5) and 5 ( R(1) = R(2) = CH3, R(3) = (CH3)3 . C6H2CH2) crystallizes triclinic in the space group P-1 with a = 984.1, b = 1026.7, c = 1079.9 pm, alpha = 87.93, beta = 75.70, gamma = 87.62 degrees and Z = 2 and a = 1164.6, b = 1296.9, c = 1712.9 pm, alpha = 109.9, beta = 96.3, gamma = 100.2 d egrees and Z = 4 resp., with two crystallographically independent mole cules in the asymmetric unit.