Ring structures vanadium phosphates

Although the structural chemistry of molybdenum and vanadium phosphates is very diverse these compounds seem to be prototypes for open framework transition and main group metal phosphates. Recent results have shown that zeolite-like compounds like zinc/cobalt phosphates [731, indium phosphates [74], nickel/aluminum phosphates [75], cobalt/boron phosphates [76], manganese and cobalt phosphonates with giant 44-membered rings forming ellipsoidal cavities [77] can be synthesized. All these examples show that the diverse chemistry of octahedral-tetrahedral framework structures is a vast field where... 

All of the above compounds are oxides. The application of the fluorine route already described for AlPOs and GaPOs has shown that it is also possible to obtain open framework structures with fluoride in the VPOs. This led to the discovery by Riou and Ferey [72] of the first open-framework fluorovanado(V)phosphate, ULM-7 or (H3N(CH2-CH2)NH3)[(V 02)2(P04)F], in which the building units are V2P trimers. Vanadium exhibits both octahedral and square pyramidal coordination, and fluoride ion is shared between them. The three-dimensional network generated by comer-sharing of these trimers, exhibits 10-membered rings occupied by diprotonated amines. 

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