Ab initio study of bonding trends among cyanamidophosphates ([POn(NCN)(4-n)](3-)) and related systems

Ab initio calculations on the experimentally known anions [POn(NCN)(4-n)](3 -) are used to show that intramolecular forces are sufficient to determine their existence and structure. Structures are predicted for the analogous c yanamidosulphates and perchlorates. If one of the oxygens of the XO4q group is replaced by nitrogen or fluorine, further new anions are obtained. An e xample is NSO33-. Remarkably, the NArO3- anion is predicted to have strong inner bonding and is, together with ArO4, a candidate for an argon species.