含氢键吡啶合钴(Ⅱ)配合物的晶体结构和磁交换作用

CRYSTAL STRUCTURE AND MAGNETIC EXCHANGE INTERACTION STUDY\= ON HYDROGEN BONDS CONTAINING PYRIDINE Co() COMPLEX

合成了含水配合物［Ｃｏ（ｐｙ）４Ｃｌ２］·Ｈ２Ｏ。分析了其单晶结构并与已知的无水配合物Ｃｏ（ｐｙ）４Ｃｌ２作了比较。发现结晶水的存在使含水配合物晶胞及分子对称性下降，由４方晶系Ｉ４１／ａｃｄ空间群变为单斜晶系Ｐ２１／ｎ空间群。并且水分子通过氢键作用把［Ｃｏ（ｐｙ）４Ｃｌ２］联接成一维长链。用Ｃｕｒｉｅ－Ｗｅｉｓｓ定律，零场分裂磁化率公式加分子场校正磁化率公式拟合变温磁化率数据，发现分子间存在弱的反铁磁性交换作用。用Ｆｉｓｈｅｒ一维线性链模型磁化率公式拟合，得出其氢键链内交换常数约为－１．

=\; Hydrous complex of H\-2O was synthesized. Its crystal and molecular structure were determined and compared with the anhydrous complex Co(py)\-4Cl\-2]. Through comparation we obtained the information that the presence of the water molecule has lowered the symmetry of the unit cell as well as the molecule. The space group of the crystal changes from tetragonal I4\-1/acd to monoclinic P2\-1/n. The water molecule was enbedded between two adjacent complex molecules and serves as a hydrogenbonded bridge CoClOClCo which connects the Co\+\{2+\} into one dimensional chain. The variabletemperature magnetic susceptibility data was fitted with CurieWeiss law and Zero Field Splitting formula. In addition, the molecular field correction was added to modify the result. It showed that there is a weak antiferromagnetic interaction between complex molecules. This magnetic exchange interaction may be propagated by the hydrogenbonded pathway or the dipoledipole interaction. We also used the Fishers one dimensional chain model formula to fit the data. The intra hdyrogenbond chain exchange constant is about -1.03K.\=\;