Cobalt(II) Complexes of Creatinine
TL;DR: In this paper, the electronic spectra and magnetic moments suggest a d7 configuration for cobalt: a tetrahedral geometry (4.4 B.M.) for halide and thiocyanate complexes, and an octahedral geometry for the carboxylate complexes.
Abstract: Cobalt(II) complexes of creatinine [Co(creat)2X2] (X = Cl, Br, I or NCS) and [Co(creat)2X2(H2O)2] (X = HCO2, HOCH2CO2 or CNCH2CO2) have been prepared. Their i.r. spectra show an increase in ν(NH) of the cyclic secondary amine group, compared to free ligand (3300 cm−1), indicating that cyclic nitrogen is involved in coordination. The thiocyanate group coordinates through nitrogen and carboxylates coordinate as univalent unidentate ligands. The electronic spectra and magnetic moments suggest a d7 configuration for cobalt: a tetrahedral geometry (4.4 B.M.) for halide and thiocyanate complexes, and an octahedral geometry (5.0 B.M.) for the carboxylate complexes. On heating, the ligand moiety is lost and the respective cobalt halide or cobalt carboxylate is formed, which is converted finally into Co3O4. There is a correlation between the high intensity electronic transitions and the polarographic half-wave potentials.
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01 Apr 2010
TL;DR: In this article, the optimized structure of creatinine was obtained using DFT/B3LYP method with 6-311+G(d,p) and LANL2DZ basis sets.
Abstract: Article history: Creatinine (2-amino-1-methyl-5H-imidazol-4-one) is an amino acid that occurs in vertebrate tissues and in urine. The mid and far infrared spectra of creatinine were recorded in the solid phase. The optimized structure of creatinine was obtained using DFT/B3LYP method with 6-311+G(d,p) and LANL2DZ basis sets. The harmonic frequencies of creatinine were calculated using DFT/B3LYP/6-311+G(d,p) method. The complete assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. The creatinine-metal {cadmium (Cd(II)), zinc (Zn(II)) and mercury (Hg(II))} halogen (chloride (Cl - ) and bromide (Br - )) complexes were synthesized. DFT calculations, DFT-B3LYP/LANL2DZ were performed for the determination of geometrical structure and vibrational assignment for metal- complexes.
19 citations
Cites background from "Cobalt(II) Complexes of Creatinine"
...The X-ray crystal structure and the coordination chemistry with transition metal ions of creatinine have been widely studied [12-29]....
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TL;DR: In this article, the complex formation between creatinine and Cu(II) was studied by means of electronic, IR and EPR spectroscopy, and spectral data showed the formation of a four-membered chelate with distorted rhombic structure.
19 citations
TL;DR: In this paper, X-ray crystallography established two unprecedented coordination modes for creatine in complexes 6 and 7, where the creatinine is bound to iridium in a monodentate fashion through the exocyclic nitrogen, whereas the iridium serves as a bidentate η 2 -(N,O)-ligand in 7.
18 citations
TL;DR: In this paper, two creatinine complexes were obtained in the form of suitable crystals for X-ray crystallography, one in triclinic space group P 1 (#2) with a = 9.940(2) A, b = 15.732(6), A, c = 9,339(3) A, α = 96.30 (3)°, γ = 75.83(3)-°, V = 1369(2), Z = 1, R = 0.039.
16 citations
TL;DR: In this article, three Ni(II)-creatinine complexes are synthesized in organic media and it is proved that the complexes are formed only in nonaqueous media and their dissolution in water is connected with immediate dissociation.
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