Complexation of Co(II), Ni(II), Cu(II), and Zn(II) with some hydroxy aromatic and heteroaromatic carboxylic acids: Unusual coordination mode of Zn2+ in chloro-bis(1,10-phenanthroline) zinc(II) 3,5-dinitro salicylate
نویسندگان
1 Department of Chemical and Petroleum Industries Engineering Technologies, Polytechnic College of Engineering Specializations-Baghdad, Middle Technical University, Baghdad, Iraq.
2 Department of Environmental Analytical, Institute of Environmental Chemistry Vietnam - Russia Tropical Center, Hanoi, Vietnam.
3 Kosygin Russian State University (Technology. Design. Arts), Moscow, Russia.
4 Laboratory of Structural Chemistry, Federal Research Center of Problem of Chemical Physics and Medicinal Chemistry RAS, Chernogolovka, Moscow Region, Russia.
doi
10.22034/crl.2025.544285.1682چکیده
Ten complex compounds of Co(II), Ni(II), Cu(II) and Zn(II) with a number of aromatic and heteroaromatic hydroxy acids were isolated and studied by spectral and structural analysis methods. Potentiometric and spectrophotometric titration methods indicated that the processes of complexation ate accompanied by ionization of the ligands. The ML and ML2 complexes of medium and high stability are formed in neutral and slightly alkaline solutions. The organic ligands coordinate in the form of mono anions and are coordinated through an O-atom of carboxylic groups of the molecules. Crystal structures of three complexes are reported. Introduction of 1,10-phenanthroline to the reactional mixture containing ZnCl2 and 3,5-dinitrosalicylic acid leaded to formation of complex compound with unexpected five-coordinated Zn-atom. The coordination polyhedron is square pyramidal, the donating atoms are four N atoms of two phenanthroline moieties and a chloride anion. The 3,5-dinitrosalicylic acid in the form of monoanion deprotonated by the hydroxy group acts as an outer sphere anion.
