Hydrothermal Synthesis And Research Of Gallium Phosphates (Gallium Phosphite) With Open-framework

Inorganic microporous materials have popular application in catalysis, adsorption, ion-exchange, separation and host-guest assemblies due to their uniquepore architectures. And the rational design and synthesis of new microporouscompounds, as well as the development of new synthetic ways are becoming thetopics of microporous chemistry. In the last decade, the synthesis of new materials that might combine the nanoporosity of zeolites with the magnetic and opticalproperties, electronic conductivity and ferrodlectricity of transition metal phosphates such as TiPOs, VPOs, FePOs, ZnPOs and CoPOs have been reported in the literature. Many of these materials exhibit unique structures and may have potential applications in catalysis and magnetic field. In addition to phosphates, open framework metal arsenates, phosphite, selenite, germinates, sulfates and carbonate have also been reported in the literature. The successful syntheses of these new compounds with open-framework open a new field for the microporous compounds. For the structural feature of the pyramidal [HPO32-] hydrogen phosphite group, representing a member of the phosphorus oxoanions, can make at most three links to adjacent cations via P-O-M (M = metal) bonds and provide more variety and novelty of the new materials. Since the syntheses of vanadium phophites in the presence of piperazinium cation as structural director by Zubieta et al., the great interest in the synthesis of new transition metal phosphites has been aroused. Up to date, transition metal phosphites have been extensively studied, the compounds of V(III), Fe(III), Co(II), Mn(II), Zn(II) and Cr(III) with their various properties have been reported. Little Organically-templated main block metal Be(II), Ga(III), In(III) phophites were also prepared.。In this paper, we described the synthesis, crystal structure and some properties of a series of gallophosphites(gallophosphates) and heterometal-substituted gallophosphites(gallophosphates) and summarized the rules of synthesis and compared the difference of structures and synthesis. Influences of other experimental factors,such as reaction temperatures,reaction times,pH values and molar ratios of the starting materials etc on the composition,the structures,purity and crystallinity of the final products'were studied. This paper describes two novel [H3N(CH2)2NH3]1/2·[Ga5(PO4)4(OH)4] and Ga3(PO4)3F2·0.75C4N4H8·0.75C4N4H4·0.5H3O open-framework gallophosphate synthesized with ethylenediamine (en) as template and obtained in presence of fluorine in the reaction medium. F is used in two kind of different purpose, used as mineraliser in synthesis of compound 1 while template in compound 2. The interesting feature of compound 1 is the presence of the new SBU Ga4P4O20(OH)4. The network has a Ga/P ratio of 5/4. The framework topologies of compound 2 is built up from a common hexameric unit.In contrast with extensively study of transition metal phosphites, only a few main group metal phosphites have been reported because of rigorous synthesis condition. We lead hydrothermal combinatorial approach into system to find out the precise synthesis condition of gallophosphite.Combinatorial method demonstrates great potential for the discovery of new open-framework materials, as well as in helping to understand the synthetic factors on the influence of the crystallization of such materials. The investigations to the crystallization process and rational synthesis give some new insight into the formation mechanism of microporous aluminophosphates. Combinatorial approach is a useful technique in the study of inorganic microporous compounds. This method should be applicable to other organically templated microporous materials and extend to other fields of chemistry. The gallophosphates Ga2(PO4)3·2NH4·H3Oand gallophsphite Ga2(OH)(H2O)-(HPO3)3·0.5[C2H10N2] have been prepared by hydro(solvo)thermal synthesis. By changing the experimental factors,such as menstruum,reaction times,PH values and molar ratios, we obtain heterometal-substituted FeGa2(PO4)3·2H2O·H3O gallophosphates and [GaZn(HPO3)3(H2O)2] ·0.5 [C2H10N2] Gallophosphite.