Proton NMR spectroscopy and magnetic properties of a solution-stable dicopper(II) complex bearing a single mu-hydroxo bridge.
The reaction of copper(II) perchlorate with the macrocyclic ligand [22]py4pz in the presence of base leads to formation of a dinuclear complex [Cu(2)([22]py4pz)(mu-OH)](ClO(4))(3)xH(2)O, in which two copper ions are bridged by a single mu-hydroxo bridge. Each copper ion is further surrounded by four nitrogen atoms of the ligand. The mu-hydroxo bridge mediates a strong antiferromagnetic coupling (2J = -691(35) cm(-1)) between the metal centers, leading to relatively sharp and well-resolved resonances in the (1)H NMR spectrum of the complex in solution. We herein report the crystal structure, the magnetic properties, and the full assignment of the hyperfine-shifted resonances in the NMR spectrum of the complex, as well as the determination of the exchange coupling constant in solution through temperature-dependent NMR studies.
Koval
Iryna A
IA
Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
van der Schilden
Karlijn
K
Schuitema
Anna Maria
AM
Gamez
Patrick
P
Belle
Catherine
C
Pierre
Jean-Louis
JL
Lüken
Matthias
M
Krebs
Bernt
B
Roubeau
Olivier
O
Reedijk
Jan
J