含质子柠檬酸氧钒(V)配合物中间体的合成和晶体结构

Synthesis and Crystal Structure of Protonated Sodium Potassium Dimeric(citrato)dioxovanadium(V)

合成了含质子柠檬酸氧钒（V）配合物中间体NaK3[VO2（Hcit）]2·7H2O，用红外光谱和X射线衍射进行了结构表征．结果表明：晶体属单斜晶系，P21／n空间群．晶胞参数a＝1．1258（2）nm，b＝1．5774（3）nm，c＝1．6559（1）nm，β＝98．568（9）°，V＝2．908（1）nm3，Z＝4，Dc＝1．851g·cm－3，F（000）＝164。μ（CuLα）＝104．7cm-1．晶体结构中的二聚柠檬酸氧钒阴离子具有准对称中心，钒原子间的距离已超出钒-钒原子簇的单键键长．阴离子内含有准对称的V2O2四元环，环外有2个柠檬酸根配体通过连接O（1，11）桥原子和α-羧基上单齿配位的氧原子（O2，O12）形成五元环。

The titled complex NaK3 [VO2 (Hcit)]2. 7H2O (H4cit=citric acid) has been pre-pared and characterized by X-ray diffraction. It crystallizes in monoclinic space group P21/n with unit cell parameters:a = 1.125 8(2) nm, b=1. 577 4(3) nm, c=1. 655 9(1) nm, β=98. 568 (9)°and Dc = 1.851 g. cm-3, Z=4. Each dimer contains a quasi-centrosymmetric planar four-member V2O2 ring with two exocyclic citrate entities coordinated by the oxygen atoms of the hydroxy- and a-carboxylate ligand, while the other two β-carboxylate groups remain uncomplexed as its deprotonated and protonated citratovanadate(V).