Synthesis and Structures of Lead(II) Complexes with Substituted Derivatives of the -Decaborate Anion with a Pendant N Group.

In this work, we studied lead(II) and cobalt(II) complexation of derivatives [2-BHO(CH)O(CH)N] and [2-BHO(CH)N] of the -decaborate anion containing pendant azido groups in the presence of 1,10-phenanthroline and 2,2'-bipyridyl. Mononuclear [PbL{An}] and binuclear [PbL(NO){An}] lead complexes (where {An} is the N-substituted boron cluster) were isolated and studied by IR spectroscopy and elemental analysis. The mononuclear lead(II) complex [Pb(phen)[BHO(CH)O(CH)N] and the binuclear lead(II) complex [Pb(phen)(NO)[BHO(CH))N] were determined by single-crystal X-ray diffraction. In complex [Pb(phen)(NO)[BHO(CH))N], the boron cluster is coordinated by the metal atom only via the 3c2e MHB bonds. In complex [Pb(phen)[BHO(CH)O(CH)N], the coordination environment of the metal includes BH groups of the boron cluster and the oxygen atom of the exo-polyhedral substituent. When the reaction was performed in a CHCN/water mixture, the binuclear lead(II) complex [(Pb(bipy)NO)(Pb(bipy)NO)(BHO(CH)O(CH)N)]·CHCN·HO was isolated, where the boron cluster acts as a bridging ligand between lead atoms coordinated by the boron cage via the O atoms of the substituent and/or the BH groups. In the course of cobalt(II) complexation, the starting compound (PhP)[BHO(CH)N] was isolated and its structure was also determined by X-ray diffraction. Although a number of lead(II) complexes with coordinated N are known from the literature, no complexes with the boron cluster coordinated by the pendant N group involved in the metal coordination have been isolated.