Assessment of metal ion substitution as a technique for the assignment of metal-ligand stretching modes in the far-infrared spectra of transition metal complexes

1993 ◽  
Vol 4 (3) ◽  
pp. 309-319 ◽  
Author(s):  
David A. Thornton
1967 ◽  
Vol 20 (4) ◽  
pp. 675 ◽  
Author(s):  
RW Hay ◽  
LJ Porter

A variety of transition metal complexes of a-amino acid esters have been synthesized, and characterized by analysis, conductivity measurements, and infrared spectra. The complexes can be broadly divided into two groups: (a) complexes in which only a metal-nitrogen bond occurs with the α-amino group of the ester, and (b) complexes in which chelate ring formation occurs via secondary donor groups on the ligand. These latter complexes are found with methyl L-histidinate, methyl γ-glutamate, and methyl L-cysteinate. With the exception of a methyl tryptophanate complex, the infrared spectra show that there is no interaction between the carbonyl group of the ester and the metal ion. The visible spectra of aqueous solutions of the esters and copper(II) at a ligand/metal ratio of 5 : 1 have maxima in the 600-650 mμ range at pH 7 consistent with copper-nitrogen bonding only.


1973 ◽  
Vol 51 (10) ◽  
pp. 1567-1581 ◽  
Author(s):  
A. B. P. Lever ◽  
Elvio Mantovani

The far infrared spectra of 35 complexes of the formula M(diamine)2X2 are reported where M = Co(II) and Ni(II), X = Cl−, Br−, I−, NO3−, SCN−, ClO4−, and AgI2− and the diamine is ethylenediamine or its N,N-symmetric or antisymmetrically substituted dimethyl or diethyl derivative. Isotopic substitution studies with 62Ni and with 2H are carried out with eleven characteristic complexes and assignments for the metal–nitrogen modes in both octahedral and square planar complexes so deduced. In most cases the appropriate number of metal–ligand modes, based on symmetry considerations, are observed. The variations in observed M—N frequencies are discussed in terms of the electronic and geometric factors previously utilized for the corresponding copper(II) complexes. In complexes containing the asymmetric ligands, stretching vibrations arising from the two types of metal–nitrogen bond can be separately identified. Isotopic studies of pairs of complexes containing the same ligand and metal ion but with the latter in alternate spin states are reported here for the first time. All of the cobalt(II) complexes and several of the nickel(II) complexes are reported here for the first time.


1973 ◽  
Vol 27 (3) ◽  
pp. 213-217 ◽  
Author(s):  
Y. Saito ◽  
C. W. Schläpfer ◽  
M. Cordes ◽  
K. Nakamoto

The far infrared spectra of Ni (pyridine)4X2 and Ni(γ-picoline)4X2 (X = CI, Br and I) have been measured. The Ni-X and Ni-N stretching bands have been assigned based on isotopic shifts due to the 58Ni-62Ni, pyridine-pyridine-d5, and Cl-37Cl substitutions.


Sign in / Sign up

Export Citation Format

Share Document