| Abstract
| - A unified synthetic approach hasallowed us to rationalize the hydrothermal chemistry leading to theobtention of open framewok oxovanadium phosphates containing organiccations as structural directing agents. In this sense, we haveused chemical basic information and a simple model, as the partialcharge model (PCM), in order to understand the synthetic procedures.The crystal structure of the bimetallic phosphate[H3N(CH2)2NH3]2[H3N(CH2)2NH2][FeIII(H2O)2(VIVO)8(OH)4(HPO4)4(PO4)4]·4H2Ois described. A schematic view of its 3-D framework isshown.
- A general synthetic approach to rationalize the solutionpreparative chemistry of oxovanadium phosphates containingorganic species as structural directing agents is presented.Careful attention is payed to the hydrolysis andcondensation processes involving the ionic species in solution, and asimple restatement of the partial chargemodel (PCM) has been used in order to organize the experimentalresults. The structure of a new V(IV)−Fe(III)bimetallic oxovanadium phosphate,[H3N(CH2)2NH3]2[H3N(CH2)2NH2][FeIII(H2O)2(VIVO)8(OH)4(HPO4)4(PO4)4]·4H2O, has been determined by X-ray single crystaldiffraction methods. This compound crystallizes inthemonoclinic system, space group P21/nand the cell dimensions are as follows: a =14.383(3) Å, b = 10.150(2)Å, c = 18.355(4) Å, and β = 90.39(3)°(Z = 2). The existence of a complex intercrossingchannel system,including a very large channel of 18.4 Å of diameter (in which bothwater molecules and ethylenediamine speciesare located), is the more interesting feature of this structure.Thermal decomposition, including the dehydration/rehydration process, has been studied by thermal analysis and variabletemperature X-ray powder diffractiontechniques. A complementary SEM study of the differentintermediate decomposition products is presented.
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