Role of hydrogen bond in the synthesis and complexation of diphenylsulfilimine Ph2S → NH

Abstract

New synthesis of the mixed bis-acetylacetonate complexes of Co, Ni and Zn bearing 1 or 2 diphenylsulfilimine ligands Ph2S → NH (2) is described. Improved synthetic protocol towards anhydrous ligand 2 was developed. Earlier known Ph2S = NTs forms upon acid hydrolysis easily extractable, air-stable and non-hygroscopic tosylate salt [Ph2SNH2]+TsO‾ (1), that crystallize as dimer stabilized by hydrogen bonds in the solid state and can serve as stable and storable precursor for preparation on demand of labile ligand 2. Non-nucleophilic bases in dry ether or aromatic solvents when reacted with 1 provide 2 in high yields. Monomeric CoII (4), ZnII (5) and NiII (6) bis-acetylacetonate dihydrates when reacted with 2 form mixed complexes M(acac)2(Ph2SNH) 7, M = Zn; 8, M = Co and Ni(acac)2(Ph2SNH)29 in up to 90 % yields. Molecular structure of dimeric {CoII(acac)2(Ph2SNH)}2 complex (8) reveals strong donor Co-N interactions stabilized by intramolecular O···HN hydrogen bonds between acac-ligands and the HN group of Ph2S → NH (2).