Ferromagnetic interaction in mu1,3-cyanamido-derived copper(II) cryptates.
The reaction of dinuclear copper(II) cryptates with calcium cyanamide, CaNCN, and sodium dicyanamide, Na[N(CN)(2)] results in dinuclear compounds of formulae [Cu(2)(HNCN)(R3Bm)](ClO(4))(3) (1), [Cu(2)(dca)(R3Bm)](ClO(4))(3)4H(2)O (2), and [Cu(2)(NCNCONH(2))(R3Bm)](CF(3)SO(3))(3) (3), in which R3Bm=N[(CH(2))(2)NHCH(2)(C(6)H(4)-m)CH(2)NH(CH(2))(2)](3)N and dca=dicyanamido ligand (NCNCN(-)). The X-ray diffraction analysis reveals for both 1 and 3 a dinuclear entity in which the copper atoms are bridged by means of the -NCN- unit. The molar magnetic susceptibility measurements of 1-3 in the 2-300 K range indicate ferromagnetic coupling. The calculated J values, by using theoretical methods based on density functional theory (DFT) are in excellent agreement with the experimental data. Catalytic hydration of a nitrile to an amide functional group is assumed responsible for the formation of 3 from a mu(1,3)-dicyanamido ligand.
Escuer
Albert
A
Departament de Química Inorgànica, Universitat de Barcelona, c. Martí i Franquès 1-11, 08028 Barcelona, Spain.
Mc Kee
Vickie
V
Nelson
Jane
J
Ruiz
Eliseo
E
Sanz
Núria
N
Vicente
Ramon
R
D002412:Cations; D003300:Copper; D003484:Cyanamide; D005290:Ferric Compounds; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation
D002412:Cations; D005290:Ferric Compounds; C001215:ferrite; D003484:Cyanamide; D003300:Copper