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Paramagnetic Cobalt(III) Complexes with Organic Ligands. X. The Preparation and Properties of Radical Diamminebis(5-nitrosalicylideneaminato)cobalt(III) Complex and Biradical Diamminebis(5-nitrosalicylideneaminato)cobalt(II) Complex

1987; Oxford University Press; Volume: 60; Issue: 4 Linguagem: Inglês

10.1246/bcsj.60.1299

1348-0634

Yoshihisa Yamamoto, Hidetaka Konno,

Metal-Catalyzed Oxygenation Mechanisms

Abstract From the reaction mixture of diamminebis(salicylideneaminato)cobalt(III) complex, (Remark: Graphics omitted.) (1) and 60% nitric acid, radical diamminebis(5-nitrosalicylideneaminato)cobalt(III) complex, (Remark: Graphics omitted.) (2), and biradical diamminebis(5-nitrosalicylideneaminato)cobalt(II) complex,(Remark: Graphics omitted.) (3), have been isolated and characterized by analytical, magnetic, spectroscopic, and XPS methods. The effective magnetic moments of 2 and 3 were 1.7 and 5.5 BM, respectively. In the IR spectrum of 2, a band due to the rocking deformation vibration of NH3 was observed at ca. 840 cm−1. The absorption spectra of 2 and 3 showed a strong absorption peak at ca. 690 nm. In the XPS, Co 2p spectra for 3 showed strong satellites, indicating the oxidation number of the cobalt to be +2, whereas no satellites were observed for the other complexes. In comparison with diamagnetic cobalt(III) complex, (Remark: Graphics omitted.) (4), C 1s spectra for 2 and 3 showed much larger shoulders on the higher binding energy side due to the electron-poor carbons. It suggests the presence of an unpaired spin on ligands in accordance with paramagnetism of the complexes.