Synthesis and crystal structures of nickel(ii) and palladium(ii) complexes with o-carboranyl amidine ligands.

A number of new nido-carboranyl amidines 10-R(CH)NHC(Et)[double bond, length as m-dash]HN-7,8-CBH (n = 2, R = OH, OMe, and NMe; n = 3, R = OH) were synthesized by the nucleophilic addition of amino alcohols and N,N-dimethylethylenediamine to the highly activated -C[triple bond, length as m-dash]N- triple bond of the 10-propionitrilium derivative of nido-carborane. A similar reaction of 10-EtC[triple bond, length as m-dash]N-7,8-CBH with ethylenediamine unexpectedly resulted in the cleavage of the C[triple bond, length as m-dash]N bond to form the ammonium derivative 10-HN-7,8-CBH. The complexation of the synthesized carboranyl amidines 10-MeO(CH)NHC(Et)[double bond, length as m-dash]HN-7,8-CBH and 10-MeN(CH)NHC(Et)[double bond, length as m-dash]HN-7,8-CBH with nickel and palladium phosphine complexes [(PhP)MCl] (M = Ni, Pd) was studied.