Two pyrazolato-bridged, linear trinuclear Cu(II) complexes. Crystal structures and magnetic properties

Abstract

In honor of Professor Pierre Braunstein. AbstractThe single-crystal X-ray structures of two new linear trinuclear copper(II) complexes of 3,5-pyrazoledicarboxylic acid ( (2), with Me 2 en is N ,N -dimethylethylenediamine. Both complexes are trinuclear and have been obtained from a precursor ligand, through copper-induced amide hydrolysis. In 1, the central copper ion is in a distorted square-planar environment and the two outer copper ions are in a distorted square-pyramidal environment. All three copper ions in 2 are six-coordinated in an elongated octahedral environment. A weak, broad EPR signal centered around g 0/3.5, indicative for an S0/3/2 state, is observed and confirms both complexes to be trinuclear. Magnetic susceptibility measurements of 1 and 2 from 4 to 300 K indicate a weak anti-ferromagnetic exchange coupling, with J values of (/15 and (/19 cm (1 , respectively. #

Coordination Versatility of Pyrazole‐Based Ligands towards High‐Nuclearity Transition‐Metal and Rare‐Earth Clusters

“…[173] Decomposition of an amide-pyrazole derivative ligand to an L6a 3ligand during the synthesis resulted in the formation of trinuclear linear copper(II) compounds. [174] The HL6b ligand has been used in the synthesis of a linear trinuclear copper(II) compound. [174] The HL6b ligand has been used in the synthesis of a linear trinuclear copper(II) compound.…”

A new single pot synthesis of μ-bis(oxido)bis{oxidovanadium(V)} dipicolinato complex with 2-aminopyridinium as counter cation: Spectroscopic, structural, catalytic and theoretical studies

“…This ligand can be easily prepared by the condensation reaction between pyridyl bearing amines and carboxylic acid precursors promoted by coupling agents [8]. Also, the metal-induced carboxamido bond hydrolysis has been carried out in the presence of various metal ions such as Cu(II) [9], Zn(II) [10], Ni(II) [10], Co(III) [11], Cd(II) [12], La(III) [13], Ce(III) [13], Ce(IV) [14], Pd(II) [15] and Pb (II) [16] ions. However, to the best of our knowledge, any work on V (IV) ion is yet to be reported.…”

Two Pb(II) coordination polymers constructed from dicarboxamido-(2-pyridyl)-pyridine by varying ratios of mixed solvents

“…Besides, it deserves to be mentioned that Pb(II) ions can induce the cleavage of the carboxamido bond of H 2 dcapp in strong polar solvents. Metal-induced carboxamido bond hydrolysis has been already found in the presence of Cu(II) [8], Zn(II) [9], Cd(II) [10], La(II) [11] and Ce(II) [11] ions. To the best of our knowledge, the report on Pb(II) ion is rare.…”