ON NONPLANARITY AND BOND ALTERNATION OF A SIMPLE SHORT-CHAIN PHOSPHAZENE

Using a standard ab initio method at a DZ + P basis set level, the geo metry of OP(Cl-2)NP(Cl-2)NPCl3 is optimized for varying O-P(1)-N(1)-P( 2) dihedral angles without any symmetry restrictions. The phosphazene backbone prefers planar structures and its non-planarity may change th e sequence of shorter and longer P-N bonds. The sensitivity of the ele ctronic structure of phosphazenes on their geometry is extra low. (C) 1998 Elsevier Science B.V. All rights reserved.