Supramolecular structure, spectroscopic, thermal studies and antimicrobial activities of Schiff base complexes

 Metal (II) complexes of 4-(((2-hydroxynaphthalen-1-yl) methylene) amino)-1, 5-
dimethyl-2-phenyl-1, 2-dihydro-3 H-pyrazol-3-one (HL) were prepared, and their 
compositions and physicochemical properties were characterized on the basis of elemental 
analysis, with 1 HNMR, UV–Vis, IR, mass spectroscopy and thermogravimetric analysis. All 
results confirm that the novel complexes have a 1: 1 (M: HL) stoichiometric formulae M (HL) 
Cl 2 (M= Cu (II)(1), Cd (II)(5)), Cu (L)(O 2 NO)(OH 2) 2 (2), Cu (HL)(OSO 3)(OH 2) 3 2H 2 O 
(3), Co (HL) Cl 2 (OH 2) 2 3H 2 O (4), and the ligand behaves as a neutral/monobasic 
bidentate/tridentate forming a five/six-membered chelating ring towards the metal ions, 
bonding through azomethine nitrogen, exocyclic carbonyl oxygen, and/or deprotonated 
phenolic oxygen atoms.