Synthesis, structure and catalytic alcohol oxidation by ruthenium(III) supported by Schiff base and triphenylphosphine ligands

Treatment of [RuCl2(PPh3)(3)] with two equiv. bi-dentate Schiff base N,O-LH-CI (N,O-LH-CI = 2[(3-chloro-phenylimino)-methyl]-phenol) or N,O-LH-NO2 (N,O-LH-NO2 = 2[(4-nitro-phenylimino)-methyl]-phenol) in the presence of triethylamine afforded cis-[RuCl(PPh3 )(kappa(2)-N,O-L-CI)(2)] (1) and trans-[RuCl(PPh3)(kappa(2)-N,O-L-NO2)(2)]center dot Et2O (2), respectively. Reactions of [RuCl2(PPh3)(3)] and equal equiv. tetra-dentate Schiff bases gave corresponding ruthenium(III) complexes [RuCl(PPh3)(salen)] (3) (H(2)salen = N,N'-disalicylidene-1,2-ethanediamine), [RuCl (PPh3)(salipn)]center dot 2CH(2)Cl(2) (4) (H(2)salipn = N,N'-disalicylidene-1,2-(1-methyl) ethanediamine), [RuCl(PPh3)(salpn)]center dot CH2Cl2 (5) (H(2)salipn = N,N'-disalicylidene-1,2-propanediamine), [RuCl(PPh3)(salphen)]center dot CH2Cl2 (6) (H(2)salphen = N,N'-disalicylidene-1,2-phenyldiamine), [RuCl(PPh3)(saltoln)]center dot CH2Cl2 (7) (H(2)saltoln = N,N'-disalicylidene-1,2-tolyldiamine) and [RuCl(PPh3)(salcyn)] (8) (H(2)salcyn = N,N'-disalicylidene-(R,R)-1,2-cyclohexanediamine). The molecular structures of complexes 1-5 and 7 have been determined by single-crystal X-ray crystallography. The catalytic oxidation properties of ruthenium(III) complexes 1-8 were tested towards alcohols in the presence of N-methylmorpholine-N-oxide. (C) 2018 Elsevier B.V. All rights reserved.