11B-chemical shifts of diboranes, polyboranes, carboranes and coupling constants 1J(11B1H), 1J(11B11B)

Abstract

Linear relationships are observed between calculated charge densities q^total_B or q^p_B at boron and δ¹¹B for a considerable number of boron compounds. The term p²_B(2s)H from the density matrix correlates linearly with ¹J(¹¹B¹H). The results obtained by CNDO/S calculations were confirmed by ab initio calculations. By correlation of J(¹¹B¹¹B) with p²_B(2s)B(2s) reasonable values for J(¹¹B¹¹B) in two centre two electron bonds can be estimated.