采用离子热方法合成夹心型钨磷酸盐

Ionothermally synthesized sandwich-type phosphotungstate

采用离子热方法在离子液体[Emim]Br(1-乙基-3-甲基咪唑溴盐)中合成了夹心型的钨磷酸盐H3(Emim)7[Ni4(Mim)2(PW9O34)2]·4H2O(1)(Mim为乙基咪唑).通过X射线衍射、元素分析、红外光谱、热重、XRD、电化学和光催化等对该化合物的结构和性质进行了测试和表征.X射线单晶衍射分析表明:化合物1属单斜晶系,C2/c空间群,晶胞参数:a=35.584(7),b=14.513(3),c=24.423(5),α=90.000°,β=101.38(3)°,γ=90.000°,V=12365(4)3,Z=4.在化合物1的晶体结构中,阴离子框架为2个乙基咪唑分子修饰的有机无机杂化夹心型阴离子[Ni4(Mim)2(PW9O34)2]10-,而且多酸阴离子的表面氧原子与游离的抗衡阳离子1-乙基-3-甲基咪唑之间存在着广泛的C-H···O氢键作用,进而构筑成为一个三维的超分子框架.

A new sandwich-type phosphotungstate compound, H3（Emim）7[Ni4（Mim）2（PW9O34）2]·4H2O, was successfully synthesized. We used the ionothermal method with 1-ethyl-3-methyl imidazolium bromide （[Emim]Br） ionic liquids （ILs） to synthesize the compound. We characterized the material using X-ray diffraction, elemental analysis, infrared spectroscopy, thermogravimetric analyses, electrochemistry and photocatalysis. The crystal state of the sandwich-type phosphotungstate was： Monoclinic; space group C2/c; a = 35.584（7） ; b = 14.513（3） ; c = 24.423（5） ; α = 90.000°; β= 101.38（3）°; γ= 90.000°; V = 12365（4） 3; and Z = 4. The polyoxoanion of the sandwich-type phosphotungstate is two methylimidazole molecules and a modified sandwich-type hybrid tungstophosphate [Ni4（Mim）2（PW9O34）2]10-. In the packing arrangement, the adjacent hybrid polyoxoanions of the compound are connected through C-H-O hydrogen bonds between the dissociative [Emim]＋ cations and the surface oxygen atoms of the polyoxoanions. This structure forms a three-dimensional open-framework.