Cai Zhong-Sheng, Bao Song-Song, Ren Min, Zheng Li-Min
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (P. R. China).
Chemistry. 2014 Dec 15;20(51):17137-42. doi: 10.1002/chem.201404611. Epub 2014 Oct 27.
Two pairs of enantiomeric Co(II) compounds with formulas [Co2 (μ3 -OH)(cyamp)(Cn H2n+1 COO)] (cyampH2 =(S)- or (R)-[(1-cyclohexylethyl)amino]methylphosphonic acid; n=1 (1); n=7 (2)) were synthesized. The structures of S-1 and S-2 were determined by single-crystal structural analyses. Both crystallize in a monoclinic chiral space group P21 , and exhibit layered structures in which the Δ-type chains of corner-sharing Co3 (μ3 -OH) triangles are connected by the phosphonate groups. The interlayer spaces are filled with the organic groups of the phosphonate and carboxylate ligands. Therefore, the distances between the layers can be manipulated by the length of the alkyl chain of the carboxylate ligands, from 14.6 Å in 1 to 20.0 Å in 2. Magnetic studies were carried out for compounds S-1 and S-2. Both show metamagnetism at low temperature. The critical field decreases with increasing interlayer distance from 8.18 kOe for S-1 to 7.01 kOe for S-2 at 1.8 K. The optical properties were also studied.
合成了两对分子式为[Co2(μ3 -OH)(cyamp)(CnH2n+1COO)]的对映体钴(II)化合物（cyampH2 =(S)-或(R)-[(1-环己基乙基)氨基]甲基膦酸；n = 1(1)；n = 7(2)）。通过单晶结构分析确定了S-1和S-2的结构。二者均结晶于单斜手性空间群P21中，并呈现出层状结构，其中由角共享Co3(μ3 -OH)三角形构成的Δ型链通过膦酸酯基团相连。层间空间填充有膦酸酯和羧酸酯配体的有机基团。因此，层间距可通过羧酸酯配体烷基链的长度进行调控，从1中的14.6 Å到2中的20.0 Å。对化合物S-1和S-2进行了磁性研究。二者在低温下均表现出变磁性。在1.8 K时，临界场随层间距的增加而减小，从S-1的8.18 kOe降至S-2的7.01 kOe。还研究了其光学性质。
