The Molecular Structure of 1 , 3 , 5 , 7 - Tetra ( tert - butyl ) - 2 , 4 , 6 , 8 - tetra ( chloro ) - borazocine [ 1 ]

The borazocine (ClB=NCMe3)4 crystallizes in the monoclinic system, space groupC2/c with Z = 6, i. e. there are two independent molecules in the unit cell. The first molecule has no crystallographic symmetry, while the second molecule is characterized by a twofold axis which generates the (ClB= NCMe3)4 molecule from the fragment (ClB=NCMe3)2. The molecules are tub-shaped showing alternating longer and shorter B–N bonds. Compared with the borazocine (N3B= NCM3)4 the BN bonds of (ClB=NCMe3)4 are on average shorter than those of the azide derivative. Although B–N bond lengths and N–B–N and B–N–B bond angles in both molecules of (ClB=NCMe3)4 are identical within the limits of the standard deviation, the opposite B2N2 planes differ significantly for the two independent molecules.