Syntheses, characterization and antifungal activity of heteroleptic nickel(II) complexes with N-alkylsulfonyldithiocarbimates and phosphines

Abstract Four nickel(II) complexes of general formula [Ni(RSO 2 N CS 2 ) (PPh 3 ) 2 ] where R = CH 3 ( 2a ), CH 3 CH 2 ( 2b ), CH 3 (CH 2 ) 3 ( 2c ) and CH 3 (CH 2 ) 7 ( 2d ) and PPh 3  = triphenylphosphine; and two nickel(II) complexes of general formula [Ni(RSO 2 N CS 2 )dppe] where R = CH 3 (CH 2 ) 3 ( 3c ) and CH 3 (CH 2 ) 7 ( 3d ) and dppe = 1,2-bis(diphenylphosphine)ethane) were prepared. These new complexes were obtained by the reaction of nickel(II) chloride hexahydrate with potassium N -alkylsulfonyldithiocarbimates and the appropriate phosphine using ethanol/water as solvent. The IR, UV–Vis and 1 H, 13 C and 31 P NMR spectra, elemental analysis of Ni and the HR-ESI-MS were consistent with the formation of square planar nickel(II) complexes with mixed ligands. The structures of the compounds 2b and 2c were determined by single crystal X-ray diffraction. The compounds are isostructural and crystallize in the space group P 1 ¯ of the triclinic system. The activities of the complexes were investigated in vitro against Botrytis cinerea , Colletotrichum acutatum and Alternaria solani , fungi species that affect various commercially important plants. All the complexes were active.