Isotopic Studies of the Metal–Ligand Bond. Part III. The Far Infrared Spectra of Some Tetragonal Diamine Complexes of Cobalt(II) and Nickel(II): Studies of the Metal–Nitrogen Bond, as a Function of Metal Ion and of Spin State

Abstract

The far infrared spectra of 35 complexes of the formula M(diamine),X, are reported where M = Co(I1) and Ni(II), X = C1-, Br-, I-, NO3-, SCN-, C104-, and AgIZ-and the diamine is ethylenediamine or its N,N-symmetric or antisymmetrically substituted dimethyl or diethyl derivative. Isotopic substitution studies with 62Ni and with 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(I1) 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(I1) complexes and several of the nickel(I1) con~plexes are reported here for the first time.Les spectres dand l'infrarouge lointain de 35 complexes de formule M (diamine),X, ont etC rapportds, avec M = Co(I1) et Ni(II), X = C1-, Br-, I -, NO3-, SCN-, ClO4-, et Ag1,-et la diamine est 1'6th~-lenediamine ou ses derives N,N-dimethyles ou N,N-diethylis, symetriquement ou antisymetriquenlent substitues. Les etudes de substitution isotopique avec 62Ni et ,H ont etC effectuees sur onze complexes caracteristiques et les attributions sur les modes concernant la liaison metal-azote, a la fois pour les complexes octaedral et carre-plan, ont pu Ctre deduites. Dans la plupart des cas, le nombre approprie de modes relatifs au nlCta1-ligand bask sur des considerations de symetrie, a pu 6tre observe. Les variations dans les frequences M-N observees ont Cte discutees par rapport aux facteurs electroniques et gComCtriques precedemment utilises pour les complexes de cuivre(I1) correspondants. Dans les complexes comprenant des ligands asymktriques, les vibrations d'elongation qui sont dues aux deux types de liaison metal-azote ont pu 6tre separement identifiees. Les etudes isotopiques portant sur les paires de complexes contenant le mCme ligand et le mCme ion metal, ce dernier se trouvant dans des Ctats de spin alternes, ont etk rapportees ici pour la premiere fois. TOLE les complexes de cobalt(I1) et plusieurs complexes de nickel(I1) ont Bte decrits ici pour la premiere fois.[

A silicon-containing polyazomethine and derived metal complexes: synthesis, characterization, and evaluation of the properties

“…[34] The far infrared region includes vibrations arising from coordination of the metal to the ligand. In far-IR ( Figures 13S-15S), it can be seen the appearance of the absorption bands characteristic for the new created metal-ligand bonds at 370 and 397 cm −1 (Cu-N), 384 and 417 cm −1 (Co-N) and 384 and 424 cm −1 (Zn-N) [31,[34][35][36] (Figure 12Sd). These observations support the hypothesis that metal ions are complexed through both nitrogen atom types from azomethine group and oxadiazole ring.…”

Silica Grafted Imprinted Mesoporous Polymer for the Development of SPE Coupled FAAS Method of Nickel Determination, Removal, and Spent Polymer for Reduction of Permanganate: Multivariate Optimization

“…Moreover, the bands appeared in the similar areas in both imprinted and non‐imprinted sorbent ascribing to the fact that the polymeric structure is same in both the cases and that the incorporation of Ni(II) brings no change to the polymer backbone. The successful incorporation of Ni(II) can also be seen in the FIR spectra of APS@Ni‐IIP, which shows a defined band at 550 cm −1 corresponding to the Ni−N bond [15] and a peak at 639 cm −1 corelating to the Ni−O bond, [16,17] these peaks are completely absent in the spectra of leached polymer, evidencing the complete elution of Ni(II).…”

Metallopolymers based on a polyazomethine ligand containing rigid oxadiazole and flexible tetramethyldisiloxane units

“…In the far‐IR region, the characteristic vibrations for the newly created MN coordination bonds can be seen at 424 and 370 cm −1 (CuN), 413 cm −1 (CoN), and 384 and 417 cm −1 (ZnN) (Figure 6S, Supporting Information). In addition, those assigned to MCl (330 and 243 cm −1 for PAZ2–Cu, 326 and 303 cm −1 for PAZ2–Co, and 332 cm −1 for PAZ2–Zn; Figure 8S, Supporting Information) were observed.…”