Dehydration of layered metal phosphonates M(O3PCH3)· H2O (M = Mg, Zn, Co) occurs topochemically to give anhydrous salts M(O3PCH3) with similar unit cell dimensions in the space group Pmn21 Mg(O3PCH3) absorbs water rapidly from air, forming Mg(O3PCH3)·H2O; Co(O3PCH3) does so less readily, and Zn(O3PCH3) is unreactive even with liquid water. Anhydrous Co and Zn salts M(O3PCH3) react with ammonia and primary amines to form intercalation compounds M(O3PCH3)(RNH2), R = H to n-C8H17. The intercalation reaction is shape-selective, as amines with branching at the α-carbon cannot access the metal coordination site. The packing of alkyl chains is different for primary amine intercalation compounds containing Co and Zn. In all Co(O3PCH3)(n-CnH2n+1NH2) compounds, the chains pack as double layers. In the Zn(O3PCH3)(n-C.,H2n+1NH2) series, compounds with even n also adopt double-layer structures, while odd n compounds form more efficiently packed interdigitated monolayers in the interlamellar region.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Inorganic Chemistry