Structural, theoretical and optical investigations of two lateral twisting trinuclear Co(II) and Ni(II) salamo type complexes

Two trinuclear Co(II) and Ni(II) complexes, [{Co3(L)2(mu-OAc)2 }2] middot3CH2Cl2 ( 1 ) and [Ni3(L)2(mu- OAc)2(EtOH)2] middot2EtOH ( 2 ) have been successfully obtained by a new nonsymmetrical salamo type ligand H2L with Co(OAc)2middot4H2O and Ni(OAc)2middot6H2O, respectively. Single crystal X-ray diffraction analysis revealed that complex 1 is an unsymmetric trinuclear structure, two tetradentate N2O2-donor ligand (L) 2-units are coordinated to three Co(II) atoms where two terminal Co(II) atoms are penta-coordinated lateral twisting trigonal bipyramidal geometries but central Co(II) atom is hexa-coordinated lateral twisting octahedral configuration. Complex 2 is a centrosymmetrical trinuclear structure, all of the three Ni(II) atoms are hexa-coordinated lateral twisting octahedral configurations. In addition, complexes 1 and 2 have been characterized by physicochemical and spectroscopic methods. Molecular electrostatic potential analysis revealed that the phenolic oxygen atoms in the ligand H2L have nucleophilic reactions with Co(II) and Ni(II) atoms to form chemical bonds. Hirshfeld surfaces analyses showed that H middotmiddotmiddotH/H middotmiddotmiddotH interactions are the predominant, indicating the presence of great amount hydrogen bonds in complexes 1 and 2 . IRI analyses indicated the presence of weak hydrogen bonding interactions that made complexes 1 and 2 more stable.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Two trinuclear Co(II) and Ni(II) complexes, [{Co3(L)2(mu-OAc)2 }2]·3CH2Cl2 (1) and [Ni3(L)2(mu-OAc)2(EtOH)2]·2EtOH (2), have been successfully synthesized using a new nonsymmetrical Salamo-type ligand H2L with Co(OAc)2·4H2O and Ni(OAc)2·6H2O. X-ray crystallography analysis revealed that complex 1 is an unsymmetric trinuclear structure with penta-coordinated and hexa-coordinated Co(II) atoms, while complex 2 is a centrosymmetrical trinuclear structure with hexa-coordinated Ni(II) atoms. Physicochemical and spectroscopic characterization confirmed the formation of chemical bonds between the phenolic oxygen atoms in the ligand H2L and the Co(II) and Ni(II) atoms.