M. Massacesi

ESR studies on some five coordinate copper (II) complexes in solutions

ESR and optical absorption studies have been made on four 5‐coordinate copper complexes, namely, Cu (trien) Br2, Cu (trien) (ClO4)2, [Cu (trien) NCS]Bφ4, and Cu (Me6trien) Br2 (where trien and Me6trien stand for triethylylenetetramine and N,N,N′N″,N‴,N‴‐hexamethlytrien, respectively) in solutions to study metal ligand bond nature and different contributions to line widths. The 4s character in the ground state is estimated and is found to influence spin‐Hamiltonian constants, bond parameters, and hyperfine linewidth. The hyperfine linewidth at room temperature is explained using the theory of Wilson and Kivelson.

3,5-diphenylisoxazole as ligand. Complexes of cobalt(II), nickel(II) and copper(II)

Abstract Some complexes of cobalt(II), nickel(II) and copper(II) chloride, bromide, iodide, thiocyanate and perchlorate with 3,5-diphenylisoxazole (3,5-diPhisox) have been prepared and characterized. On the basis of vibrational and electronic spectroscopy, magnetism and conductivity measurements, the structures of these complexes were identified. The ligand behaves both as monodentate N-bonded, and as a bridging N- and O-bonded ligand. All the compounds here reported have an octahedral stereochemistry with the exception of [Co(3,5-diPhisox)2X2] (X = Cl, Br, I, NCS), which are tetrahedral, while the complex [Cu(3,5-diPhisox)4] (ClO4)4·4H4O is square planar.

Group IIB metal chloride complexes with some 2-(methylpyridyl or -quinolyl)benz-X-azoles

Abstract The complexes formed by Zn(II), Cd(II) and Hg(II) chlorides with benzimidazole, benzoxazole and benzothiazole linked to 4-methylpyridine and 4-methylquinoline have been prepared and characterized by chemical analysis, infrared spectra and conductivity data. The coordination behaviour of these ligands toward the metal salts and the stereochemistry of the obtained complexes have been investigated.

Electron spin resonance and electronic spectral investigation on square planar copper(II) complexes ofN-ethyl- andN-propylimidazole

SummaryElectron spin resonance studies have been carried out onN-ethylimidazole andN-propylimidazole 4 : 1 complexes of CuX2 salts (X = ClO4−, NO3−, , Br− or Cl−) in their polycrystalline and undiluted form at 295 K and 77 K. Cupric ion hyperfine structural resolution is observed for all the complexes at 295 K and the spectra are characteristic of a CuN4 chromophore with axial symmetry. In complexes involving ClO , Br− and Cl− the anions are nonbonding, whereas those with the NO3− anion are weakly bonding. The electronic and e.s.r. spectral data have been correlated. The resolution of Cu2+ ion hyperfine structure in these complexes is attributed to a decrease in the dipolar interaction and has been observed for the first time since the first resolution reported in 1954 for CuN4 coordination with square planar symmetry for α,β,ν,σ-tetraphenylporphyrincopper (CuTPP).

Complexes of copper(II), nickel(II) and cobalt(II) with 2-fluoro,5-nitroaniline and 4-fluoro,2-nitroaniline

Abstract Preparation of new complexes of 2 - fluoro,5 - nitroaniline (2-F,5-NA) and 4 - fluoro,2 - nitroaniline (4-F,2-NA) of the type ML n X 2 · m H 2 O (where M = Cu(II), Ni(II), Co(II); L = 2-F,5-NA; 4-F,2-NA; n = 2,4,6; X = Cl − , Br − , SCN − , ClO 4 − ; m = 0–2) are described and their i.r., electronic spectra, and magnetic moments are reported. The ligands act always as monodentate O-bonded. The compounds are generally high spin, non electrolytes, and present square planar, tetrahedral and hexacoordinate structures.

Cobalt(II) and copper(II) complexes of 3-amino-5-methylisoxazole

SummaryCobalt(II) and copper(II) halide, nitrate, thiocyanate and perchlorate complexes of 3-amino-5-methylisoxazole (3-AMI) have been prepared and characterized by means of magnetic, spectroscopic and molar conductivity measurements. In Cu(3-AMI)2X2 compounds (X = Cl, Br, N02) the 3-AMI ligand is bridging and bidentate [N (ring), O(bonded)]. In the other derivatives it is monodentate [N(ring) bonded]. All cobalt(II) complexes have an octahedral stereochemistry, if the Co(3-AMI)2X2 derivatives (X = Cl, Br), which are tetrahedral, are excluded. Copper(II) complexes have generally a distorted square pyramidal stereochemistry in the solid state and in solution.

Complexes of cobalt(II), nickel(II) and copper(II) with 4-amino-3,5-dimethylisoxazole

SummaryComplexes of the type M(4-ADI)nX2 · mH2O (where 4-ADI = 4-amino-3,5-dimethylisoxazole; n = 1–4; X = Cl, Br, I, SCN, ClO4; m = 1–4) have been studied by i.r. and electronic spectroscopy, magnetic and conductivity measurements. The ligand behaves as a monodentate -NH2 bonded species in monomeric complexes, but as a bridging ligand-NH2 and -N(ring) bonded species in polymeric complexes. All the compounds have an octahedral stereochemistry, except Co(4-ADI)2X2 (X = Cl, Br, I) complexes, which are tetrahedral.

Chromium (III) halide complexes with isoxazole and substituted isoxazoles as ligands

Abstract Complexes of chromium (III) with isoxazole, 3,5-dimethylisoxazole, 3-methyl, 5-phenylisoxazole and 3,5-diphenylisoxazole have been prepared and characterized by magnetic and spectroscopic techniques. lie stereochemistries of the complexes are discussed with emphasis on their i.r. spectra. The complexes Cr L 3 X 3 involve unidentate ligands, are neutral, monomeric and hexacoordinate. The complex [Cr 2 (3-Me,5-Phisox) 3 Br 6 ]·6H 2 O is a polymeric structure with terminal halides and bridging N- and O-bonded ligands. The ligand field parameters for the complexes have been calculated and compared with similar complexes containing CrO 3 X 3 and CrN 3 X 3 chromophores.

Spectroscopic and biological characterization of the palladium(II) and platinum(II) complexes with benzoxazole and 2-methylbenzoxazole

Abstract Complexes of the type ML 2 X 2 (where M = Pd(II), Pt(II); L = benzoxazole (BO), 2-methylbenzoxazole (MeBO); X = Cl, Br, I, NO 3 , SCN) have been prepared and characterized by spectroscopic methods and conductivity measurements. The two ligands act as monodentate; the benzoxazole behaves as N-bonded, the 2-methylbenzoxazole as O-bonded. The compounds are non electrolytes and generally trans -square planar with exception of cis -square planar Pt(BO) 2 X 2 (X = Cl, Br), Pt(MeBO) 2 Cl 2 and Pd(MeBO) 2 X 2 (X = Cl, Br, NO 3 ). The biological activity of some compounds was also investigated.

Synthesis, spectroscopic, and biological characterization of the palladium(II) oxalato complexes with heterocyclic ligands

Abstract Palladium(II) oxalato complexes with heterocyclic ligands have been prepared and characterized by spectroscopic and biological studies. The compounds are of the general formula Pd(ox)(L) n where ox = oxalato For n = 1, the ligand is isoxazole, 3,5-dimethylisoxazole, 2-methyl-benzoxazole, 2,5-dimethylbenzoxazole, and ethylenediamine, for n = 2, the ligand is N methylimidazole, N -ethylimidazole, N -propylimidazole, 3-amino, 5-methylisoxazole, and 5-amino 3,4 dimethylisoxazole. The Pd(ox)(L) 2 soluble in water are monomeric square-planar; the Pd(ox)(L) that are little soluble in water are dimeric square-planar with the ligand bridging bidentate except to the chelate ethylenediamine. All the compounds exhibit a certain inhibitorial effect with the exception of the Pd(ox)(en) derivative.