TITLE:
Synthesis, structural and spectroscopic characterization of the bis(nitrito-N) octaethylporphyrin cobalt(III) complex
AUTHORS:
Bader Belhaj Ali, Mohamed Salah Belkhiria, Michel Giorgi, Habib Nasri
KEYWORDS:
Cobalt(III) Porphyrin; X-Rays Diffraction; UV-Visible; 1H NMR
JOURNAL NAME:
Open Journal of Inorganic Chemistry,
Vol.1 No.3,
October
24,
2011
ABSTRACT: The bis(nitrito-N) cobalt(III) octaethylporphyrin derivative with the formula [K(18-C-6)(NO2)0.5(H2O)0.5]2 [CoIII(OEP)(NO2)2] (1) (OEP = octaethylporphyrin and 18-C-6 is the crown ether18-crown-6) has been synthesized and characterized by UV-vis, IR and proton NMR spectroscopy which indicate, inter alia, that the cobalt ion presents the oxidation state III. The synthesis utilizes 18-crown-6 to solubilize potassium nitrite in the synthetic procedure. This compound crystallizes in the triclinic system, with the centric space group P-1 and the following unit cell parameters: 11.6724(2) Å, b = 12.5715(2) Å, c = 13.4722(3) Å, α = 101.1290(6)°, β = 106.6498(6)°, γ= 109.1507(6)°, Z = 1 and V = 1696.74(5) Å3. The crystal structure has been solved and refined to R = 0.0499 and R(w) = 0.1319. The X-rays molecular structure of 1 shows that there is a relatively close interaction of both two NO2- axial ligands of the ion complex [CoIII(OEP)(NO2)2]- with the potassium atoms of the two counterions [K(18-C-6) (NO2)0.5(H2O)0.5]0.5+. The title compound exhibits one-dimension polymer-like structure where “monomers” are linked together through strong O(H2O)—H…O(nitrito-O) hydrogen bonds.