Ammine and monoamine complexes

Poskozim, R. Shute, R. Taylor, and J. Wysocki, J. Inorg. Nuclear Chem., 1973,35, 687. 

Treatment of sodium cobaltinitrite with methylamine yields the complexes [Co(MeNH2)g (N02)jt] (x = 4, n = 1 x = 3, n - 0). Methylamine is much more easily displaced than ammonia.  

Diamine complexes. The pK values determined for a range of cobalt(iii)-amine chelates indicated enhanced acidity for the protic chelate complexes compared with those with related unidentate ligands. Complete resolution of rac-[Co(en)3] cations has been achieved by paper electrophoresis in a background of d-tartrate and AlC. The crystal structure of (-H)D-[Co(en)3](N03)3 has been determined. The very low quantum yields for the photoreactions of [Co(en)3] have been explained as due to the lack of ligand field excitation for this ion. However, convincing evidence is presented for the reaction of [Co(en)3] and [Fe(CN)g] under photochemical conditions indicating that this is an efficient photochemical reaction of the cobalt-amine complex in a ligand field excited state (quantum yield ca. 0.2).  

A modified synthesis of trans-[CoCl2(en)2]Cl has been reported in which C0CI2 and en are cooled to 0-5 °C and H2O2 is then added. The mixture is then warmed to 60-70 °C for 15-20 min and HCl added. Other preparations of [CoX2(en)2] have also been published. The structures of [trans-CoCl2-(en)2] [TlCl4] 37 (-)5g -[Co(N02)2(en)2](-f-)589-[Co(en)(malonate)2], in 

Ulrich and B. A. Dunell, Inorg. Nuclear Chem. Letters, 1973, 9, 85. 

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