Boron and nitrogen cluster families analogous to carbon family: how quasi-molecule theory predicts their planarity or otherwise

Benzene ( C6 H6 ) and borazine ( B-3 N-3 H-6 ) are isoelectronic and isostructural. With the same number of electrons, their different electronic structures are often attributed to the polar nature of the B-N bond. Despite their similarity, they are also significantly different. Valence isoelectronic, Al-3 N-3 H-6 , B-3 P-3 H-6 and Al-3 P-3 H-6 show further crucial differences that question the sense of s-p hybridisation to explain their planarity or otherwise. Here also examined are compounds of the B-family involving gallium. While X-3 N-3 H-6 (X = B , Al , Ga ) tend to resemble benzene in perfect planarity, others are non-planar. Planarity is further shown to be observed for large members of the B-N series. All the above is explained by quasi-molecule theory. [GRAPHICS]