Unique copper ion catalyzed hydrolytic cleavage of C–N(2) bond of thiosemicarbazide

For the first time, stable but coordinatively unsaturated Cu(II) complexes [Cu(2,2′-bpy)X2] · xH2O (X = ClO4, NO3, CH3COO and 2,2′-bpy = 2,2′-bipyridyl) have been found to promote the hydrolysis of C–N(2) bond of thiosemicarbazide (tsc) at 25 °C and at neutral pH yielding monomeric [Cu(2,2′-bpy)(NCS)2]. Direct reaction between [Cu(2,2′-bpy)2]Cl2 · 6H2O, KSCN and CuCl2 results in polymeric [Cu(2,2′-bpy)(NCS)2]n[1] [Inorg. Chim. Acta. 286 (1999) 108]. Similarly tsc is cleaved by Cu(I) complex [Cu(ϕ3P)2(CH3CN)2]ClO4 [ϕ3P = triphenylphosphine] which itself is converted into dimeric [Cu(ϕ3P)2(NCS)]2.

Graphical abstractAn unusual hydrolysis of C–N(2) bond of thiosemicarbazide is reported by [Cu(2,2′-bpy)X2] · xH2O and [Cu(ϕ3P)2(CH3CN)2]ClO4 complexes. Thiocyanate, the hydrolytic product coordinates to Cu ion, [Cu(2,2′-bpy)(NCS)2] and [Cu(ϕ3P)2(NCS)]2 are formed, respectively.Figure optionsDownload full-size imageDownload as PowerPoint slide