The synthesis and structural characterization of the mu-sulfur dioxide complex Re2(mu-SO2)(mu-Cl)Cl4(mu-dppm)2

Triphenylphosphinecyanoborane (1), diphenyl(2-methoxyphenyl)phosphinecyanoborane (2), diphenyl(p-tolyl) phosphinecyanoborane (3), methyldiphenylphosphinecyanoborane (4) were synthesized either by Lewis-base exchange reaction or by the reaction of the sodium cyanoborohydride with the corresponding phosphine hydrochloride in 54–88% yields. All the products were characterized by spectroscopic techniques and elemental analyses. These compounds were evaluated for their antitumor activity.