Homometallic Ni^II-Schiff base complexes with various anionic coligands have been widely studied for their structural diversity, catalytic and magnetic properties. Introduction of Mn^II as heterometal in these complexes is very much challenging to the synthetic and magneto-chemist as Mn^II possesses higher number of unpaired electrons in high spin ground state. Thus in Ni^II-Mn^II heterometallic polynuclear complexes spin-spin interaction and easy axis type magnetic anisotropy can lead to ferromagnetism, antiferromagnetism, ferrimagnetism, etc. In this dissertation we have discussed the synthetic strategies, structural features and magnetic properties of 20 homometallic Ni^II complexes and 13 heterometallic Ni^II-Mn^II complexes derived from some tridentate (NNO), tetradentate (N₂O₂) and hexadentate (N₃O₃) Schiff base ligands and various terminally coordinating or bridging anionic coligands (carboxylate, nitrate, nitrite, azide, thiocyanate, dicyanamide etc.). The profound role of anionic coligand in mediating phenoxido bridging angles and hence magnetic behavior of these complexes is also been highlighted.

具有各种阴离子配体的同金属 Ni ^II -Schiff 碱配合物因其结构多样性、催化和磁性而被广泛研究。在这些配合物中引入 Mn ^II作为异金属对合成和磁化学家来说是非常具有挑战性的，因为 Mn ^II在高自旋基态下拥有更多的不成对电子。因此在Ni ^II -Mn ^II异金属多核配合物中，自旋-自旋相互作用和易轴型磁各向异性可以导致铁磁性、反铁磁性、亚铁磁性等。本论文讨论了20种同金属Ni的合成策略、结构特征和磁性。^二络合物和 13 种异金属 Ni ^II -Mn ^II络合物，源自一些三齿 (NNO)、四齿 (N ₂ O ₂ ) 和六齿 (N ₃ O ₃ ) 席夫碱配体和各种末端配位或桥接阴离子配体（羧酸盐、硝酸盐、亚硝酸盐、叠氮化物、硫氰酸盐、双氰胺等）。还强调了阴离子配体在介导苯氧基桥接角以及这些配合物的磁性行为方面的深远作用。