BN-NAPHTHALENE AND CARBON-CONTAINING DERIVATIVES - AN AB-INITIO STUDY

Ab initio calculations are used to examine the stability of various is omers of benzene and naphthalene after substitution of pairs of carbon atoms by the isoelectronic boron-nitrogen (BN) tandem. It is found th at stability is enhanced by keeping the B and N atoms adjacent to one another. When multiple pairs of BN are present, these pairs prefer to be consecutive with one another. The energy is also lowered by maintai ning the heteroatoms on the same ring of naphthalene. Another factor i s the preference that consecutive carbon atoms be grouped into even nu mbers. Successively higher degrees of substitution lead to a regular d rop in the molecular valency, as well as increased hardness. (C) 1997 Elsevier Science B.V.