SB-121 MOSSBAUER-SPECTRA OF ORGANOANTIMONY DERIVATIVES CONTAINING SB-SB BONDS

121-Sb Mossbauer data are reported for a number of organoantimony rings and catena-stibanes. These compounds are representative of RSb(Sb)(2) and R(2)SbSb type of coordination, and spectral parameters are compared and discussed in relation to RSbCl(2) and R(2)SbCl systems. Although the trend in isomer shift is similar, the present compounds show slightly less negative isomer shift values together with a remarkable reduction of the quadrupolar coupling constant. A rationalization of the quadrupolar interaction in the above series of compounds appears feasible by using point charge model calculations whose results, in terms of bonding, indicate a large contribution of p-electron density along Sb-Sb bonds.