| Metal phosphonates have become one of research focuses of chemists due to their potential applications in adsorption and separation,gas storage,catalysis,molecular recognition,proton conductivity,sensors and drug carriers.It is well known that properties are normally associated with the structures of metal phosphonates.Then we should give priority to the design and preparation of these materials and the relationship between structure and property during research.To solve this problem,an organic phosphonate ligand p-F-C6H5-CH2-N?CH2PO3H2?2?H4L?,synthesized and characterized by 1HNMR,has been selected to participate in the synthesis of nine new complexes with different metals or by introducing the auxiliary ligand 4,4'-bipyridine.The crystal structures of the nine new complexes have been determined by X-ray single crystal diffraction.Finally,some properties including magnetism,stability,water vapor adsorption and proton conduction of the complexes have been studied according to their structural characters.The main research contents are as follows:?1?Six new metal-phosphonates complexes,synthesized by hydrothermal method using H4L as ligand and 4,4'-bipyridine as auxiliary ligand with Fe???,Co???,Ni???and Cu???,are as follows:[Co3?HL?2?H2O?4]·2H2O?1?,[Cu?H2L?H2O]?2?,[Fe3?L?2?H2O?3OH]·2H2O?3?,[Cu2?L??4,4?-bipy?1.5?H2O?2]·3H2O?4?,[Co?H2L??4,4?-bipy?0.5]?5?,[Co?H2L??4,4?-bipy?0.5]?6?.The structures of the complexes have been fully characterized by IR,NMR,elemental analysis and X-ray diffraction.The structures of complexes 1-6 owe two-dimensional layer and the inorganic layer in complexes 1-3 is formed by metal coordination with[PO3],while the layer of complexes4-6 is formed by inorganic chain[M?PO3?2]?M is metal?connected with the auxiliary ligand 4,4'-bipyridine.The ligands of six complexes have different coordination modes.When participating in the formation of the complexes,4,4'-bipy functions as a role to inhibit the extension of inorganic chain.The magnetism of complexes 1-6 has been studied,and the complex 2 shows ferromagnetic properties and the other complexes exist antiferromagnetic interactions.The magnetic investigation for the complexes indicate that PO3orm3-O?P?units can serve as an effective pathway to transmit magnetic interactions between adjacent metal ions.The magnetic properties can switch over the distance,angle,torsion angle and bridging mode among metal ions.This work provides us with valuable information for the design and synthesis of novel metal phosphonates.?2?Two new metal phosphonates complexes,synthesized by hydrothermal method using H4L as ligand and metal Cd???,are[Cd?H2L?H2O]?7?and[Cd5?H2L?2?H3L?2]4H2O?8?,The structures of the complexes have been fully characterized by IR,NMR,elemental analysis and X-ray diffraction.The structure of complex 7 owes two-dimensional layer,while complex 8 exhibit one-dimensional chain structure.Both complexes 7 and 8 owe a three-dimensional network structure through hydrogen bonds.And chemical stability of complex 7 has been studied,which shows that complex 7 can survive in aqueous solution under different p H values and it can also maintain the original structure under extremely acidic and slight alkaline conditions.Complex 7 can play a vital role in further application with good chemical stability.?3?A new metal phosphonate complex,synthesized by hydrothermal method using H4L as ligand and metal Ni???.is[Ni3?HL?2?H2O?10]×4H2O?9?.The structure of the complexe has been fully characterized by IR,NMR,elemental analysis and X-ray diffraction.Structural analysis shows that it exhibit 1D coordination chain structure and the chains are further connected by C-H···F and O-H···O hydrogen bonds to form a supramolecular network.9 owes a unique helix water channel structure.In addition,The water stability of complex 9 has been studied,and it was found that complex 9 could exist stably in aqueous solution.In the study of the water vapor adsorption property of complex9,it was found that the adsorption capacity of complex 9 could reach 3.350 m mol/g under the condition with 90%humidity.These characters make complex 9 a potential candidate as a proton conductor,the proton conductivity of complex 9 at different temperatures and humidity showed that the its value could reach 1.43×10-3with extremely low activation energy under the condition with 297 K and 98% RH. |
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