Synthesis and structural characterization of centrosymmetric multinuclear nickel(II) complexes with neutral tetradentate N6-ligand
Document Type
Article
Publication Date
3-1-2021
Abstract
A neutral tetradentate ligand L1 L1 = 3,6-bis(pyrazol-1-yl)-pyridazine] reacts with Ni(ClO4)(2)center dot 6H(2)O and undergoes counterion exchange with PF6- to give di- and tetranuclear complexes Ni-2(L1)(2)(CH3CN)(4)](PF6)(4)center dot 4H(2)O (1) and Ni-4(L1)(4)(mu-OH)(4)](ClO4)(4)center dot 2H(2)O (2), respectively. The presence of 1,8-diazabicyclo5.4.0]undec-7-ene (DBU) as base controls the nuclearity of the complex formation. Both complexes were structurally characterized by physicochemical and spectroscopic techniques. Their crystal structures revealed that both complexes are centrosymmetric and adopt slightly distorted octahedral geometry. Complex 1 crystallizes in monoclinic space group C2/c as the Ni(II) center is octahedrally bound to L1 in a trans-isomer arrangement. Complex 2 crystallizes in tetragonal space group I4(1)/amd with four L1 and four hydroxy bridging ligands linked to Ni(II) center in cis-isomer arrangement. Cyclic voltammograms of complexes 1 and 2 were measured under Ar and CO2. Under CO2, the quasireversible peaks of both complexes become irreversible and a current enhancement occurs under reduction.
Keywords
Electrochemical reduction, Catalysts, CO2
Divisions
Science
Funders
Institute for Molecular Science International Internship Program in Asia (IMS-IIPA),RU Grant (SATU) from Universiti Malaya[ST022-2020],ASEAN-India Collaborative RD Scheme[IMRC/AISTDF/CRD/2018/000048]
Publication Title
Transition Metal Chemistry
Volume
46
Issue
3
Publisher
Springer
Publisher Location
VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS