Building open-framework metal phosphates from amine phosphates and a monomeric four-membered ring phosphate

Several amine phosphates have been synthesized and their structures elucidated by single crystal X-ray diffraction. The amine phosphates, on reaction with metal ions, give rise to a large variety of metal phosphate structures incorporating the amine molecules, thus providing a facile route to the open-framework materials. By means of such a soft chemical method, it has been possible to generate novel architectures, typical of these being a cloverite structure, a new chlorophosphate incorporating chlorine as part of the framework, and a four-membered ring monomeric phosphate. The studies indicate that amine phosphates are likely to act as intermediates in the formation of open-framework metal phosphates. The transformation of the monomeric zinc phosphate to an open-framework layered structure on heating it in water suggests the four-membered ring to be the basic building unit. (C) 2000 Academic Press.