Synthesis, optical and magnetic research of nicotinic acid ligand Zn, Cd, Mn and Co complexes

In this study, a multiple binding sites ligand, 5-(4-carboxyphenoxy)nicotinic acid ligand (H2cpna), was used to construct metal complexes with Zn2+, Cd2+, Mn2+ and Co2+ by solvothermal reaction, and four new complexes were constructed, namely, [Zn (cpna)•H2O]n (1),[Cd (cpna) (CH3CN)·2H2O]n (2), [Mn (cpna)•2H2O]n (3) and Co(cpna)•2H2O]n (4); All the complexes were characterized by single crystal X-ray diffraction, elemental analysis and infrared analysis in the solid state; Single crystal x-ray diffraction analyses reveal that complexes 1 and 2 have two-dimensional network structures, complexes 3 and 4 have three-dimensional structures. In addition, Luminescence behavior of complex 1 and 2 was investigated and magnetic properties of complex 3 and 4 were studied. The fluorescent test results show that the fluorescence intensity of complex 1 is higher than that of ligand and emission band can be considered as LLCT emission of ligand; The Magnetic results indicate weak ferromagentic interactions in complex 3 and χmT value rises slowly and then decreases sharply from 300 ​K to 2 ​K. However, magnetic results indicate antiferromagentic interactions in complex 4 and χmT value can be divided into three parts with the change of temperature from 300 ​K to 2 ​K.