Efficient preparation of multimetallic ONO-based Schiff base complexes of nickel(ii) and copper(ii). (27th May 2016)

• Record Type: Journal Article
• Authors: Novoa, Néstor; Roisnel, Thierry; Dorcet, Vincent; Cador, Olivier; Manzur, Carolina; Carrillo, David; Hamon, Jean-René
• Is Part Of: New journal of chemistry. Volume 40:Number 7(2016:Jul.)
• Page Start: 5920
• Page End: 5929
• Publication Date: 2016-05-27
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c6nj00932h
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Spectroscopy, structures, electrochemical behavior and magnetic properties of a series of readily prepared [(R-ONO)M(μ-4, 4′-bipy)M(R-ONO)] complexes (R = anisyl or ferrocenyl; M = Ni, Cu) have been explored. Abstract : A series of symmetrical D–π–D type complexes based on ONO tridentate Schiff base nickel(ii ) and copper(ii ) building blocks connected by a bidentate conjugated spacer [(R-ONO)M(μ-4, 4′-bipy)M(R-ONO)] (M = Ni II, R = An = anisyl (1 ), R = Fc = ferrocenyl (2 ); M = Cu II, R = An (3 ), R = Fc (4 ); 4, 4′-bipy = 4, 4′-bipyridine) have been prepared in 70–85% yield. The four new compounds were characterized by elemental analysis, FT-IR and UV-vis spectroscopy, and by 1 H-NMR spectroscopy in the case of the diamagnetic Ni II derivatives1 and2 . The molecular structures of complexes1–3 were further confirmed by single-crystal X-ray diffraction methods, along with that of the doubly phenoxide-bridged derivative [Cu2 (μ-Fc-ONO)2 ]5, formed upon dissociation of the 4, 4′-bipy spacer from4 . In1, 2 and5, the two four-coordinated nickel and copper atoms adopt a square planar geometry, whereas in3 that forms a coordination polymer through apical Cu–O interactions ( d Cu–O = 2.411(5) Å) between dimers, the Cu II metal ion is five-coordinated in a square pyramidal environment. The electrochemical behavior of compounds1–4 has also been investigated by cyclic voltammetry. Variable temperature (2–300 K) magnetic susceptibility measurements reveal a weak antiferromagnetic coupling ( J = −0.83 cm −1 ) in3, and that there is no interaction between the two Cu II spins carriers in4 .