Estimation of coordination bond energies of NH3, H2O and Et2NH ligands in the Ni(II) and Cu(II) complexes

Tridentate ligands 2-hydroxyphenylsalicylaldimine (SAPH 2 ), 2-hydroxyphenyl-2-hydroxy-1-naphtalaldimine (NAPH 2 ) and Ni(II) complexes with multidentate ligand Bis-N·N′-(salicylidene)-1,3-propanediamine (LH 2 ) as well as mononuclear complex of Cu(II) were prepared using the same multidentate ligand. Diethylamine (Et 2 NH), NH 3 and H 2 O monodentate ligands were bound to these complexes coordinatively. The heat absorbed at the temperatures where these ligands thermally dissociated from the complexes were measured using the TG and DSC methods. It is assumed that the states both of the complexes with and without the monodentate ligands are solid and coordination bond energy for the monodentate ligand is calculated. It is seen that these calculated coordination bond energies are comparable with hydrogen bond energies.