Condensation reactions of the mononuclear nickel(II) complexes [RN(PPh2)2]NiCl2 with 1,2-ethanedithiol or 1,3-propanedithiol

A series of the mononuclear nickel(II) complexes 5–16 with N-substituted bis(diphenylphosphanyl)amine RN(PPh2)2 has been prepared and structurally characterized. Treatment of NiCl2·6H2O with RN(PPh2)2 [R = CH2Ph, 1; CH(CH3)2, 2; CH2CH2CH2CH3, 3; CH2CH(CH3)2, 4] in CH2Cl2/MeOH afforded the mononuclear nickel(II) dichloride complexes [RN(PPh2)2]NiCl2 [R = CH2Ph, 5; CH(CH3)2, 6; CH2CH2CH2CH3, 7; CH2CH(CH3)2, 8] in 66–71% yields. Further treatment of [RN(PPh2)2]NiCl2 with 1,2-ethanedithiol or 1,3-propanedithiol in the presence of triethylamine in CH2Cl2 produced the mononuclear nickel(II) dithiolate complexes [RN(PPh2)2]Ni(SCH2CH2S) [R = CH2Ph, 9; CH(CH3)2, 10; CH2CH2CH2CH3, 11; CH2CH(CH3)2, 12] and [RN(PPh2)2]Ni(SCH2CH2CH2S) [R = CH2Ph, 13; CH(CH3)2, 14; CH2CH2CH2CH3, 15; CH2CH(CH3)2, 16] in 41–74% yields, respectively. All the complexes 5–16 have been characterized by 1H NMR, 31P{1H} NMR, 13C{1H} NMR and high resolution MS spectroscopy, and for 3, 4, 6, 9–12 by X-ray crystallography.