Boron cluster anions B10H102- and B10H11- in complexation reactions of copper(I). Positional isomers of the complex [Cu2(9Nphen)4B10H10]

The complexation reactions of Cu-I with the B10H10 (2-) anion and its protonated form, the B10H11 (-) anion, were studied in the presence of phenanthridine (9Nphen). Depending on the reaction conditions, positional isomers of the monomeric copper(i) complex [Cu-2(9Nphen)(4)B10H10] were selectively isolated. The closo-decaborate anion in the complexes is coordinated to the Cu(i) atoms through the apical edges 1-2, 7(8)-10 or 1-2, 1-4 via the formation of multicenter CuHB bonds. The crystal structures and IR spectra of the complexes were studied. The compound [Cu-2(9Nphen)(4)B10H10] is the first monomeric complex isolated in the form of the 1-2, 7(8)-10 isomer. It extends the series of positional isomers, which we have described earlier.