Photolysis of Cobalt(III) Complexes Containing Sulfinate-S Ligands. Formation of Organic Peroxide Complexes through Desulfurization

• Published in: Bulletin of the Chemical Society of Japan 1996-10, Vol.69 (10), p.2889-2895
• Main Authors: Kojima, Masaaki, Akhter, Farooque MD, Nakajima, Kiyohiko, Yoshikawa, Yuzo
• Format: Article
• Language: English
• ISSN: 0009-2673; 1348-0634
• DOI: 10.1246/bcsj.69.2889

The photolysis of trans(t-N,S)-[Co{S(O)2CH(CH3)COO-S,O}(tren)]+ (t-N = tertiary amine nitrogen; tren = tris(2-aminoethyl)amine) with visible light yielded three complexes: pink, red-1, and red-2. The molecular structure of the pink complex tetraphenylborate was determined by the X-ray method to be trans(t-N,O(C))-[Co{OOCH(CH3)COO-O,O}(tren)][B(C6H5)4]·CH3OH·H2O (O(C) = oxygen of carboxylate group); irradiation induced desulfurization and yielded an organic peroxide complex. Crystal data: C34H48BCoN4O6, FW 678.52, triclinic, (No. 2), a = 19.583(3), b = 19.838(4), c = 9.996(1) Å, α = 103.60(1), β = 102.13(1), γ = 70.29(1)°, V = 3517(1) Å3, Z = 4, Dx = 1.29 g cm−3, μ = 0.533 mm−1 for Mo Kα radiation (λ = 0.71073 Å). The red-2 complex is thermally stable, while the red-1 one thermally reverts to the starting complex. The red-1 and red-2 complexes were assigned as linkage isomerized sulfinato-O complexes, trans(t-N,O(S))- and cis(t-N,O(S))-[Co{OS(O)CH(CH3)COO-O,O}(tren)]+ (O(S) = oxygen of sulfinate group), respectively, on the basis of the UV-vis and IR spectra and thermal stability. The irradiation of trans(t-N,S)-[Co{S(O)2CH2COO-S,O}(tren)]+ and [Co{S(O)2CH(CH3)COO-S,O}(en)2]+ also yielded both peroxide complexes and linkage isomerized sulfinato-O complexes.