The Syntheses Of Diruthenium,Heteropolymetallic Ti-Re Complexes And Their Catalytic Oxidation Of Alcohols And Sulfides

In this paper, the syntheses of diruthenium, heteropolymetallic Ti-Re complexes and their catalytic oxidation of alcohols and sulfides have been investigated. The contents include two parts as follows:(1) Three diruthenium complexes (NH4)3[Ru2(hedp)2]·2H2O (1)、 Na4[Ru2(hedp)2Cl]·16H2O (2). K3[Ru2(hedp)2(H2O)2]·6H2O (3) were used to catalyze oxidation reaction of benzyl alcohol in aqueous solution, using TBHP as oxidation reagent. While optimized conditions, the conversion rate of benzyl alcohol get to82%while using TBHP as oxidation reagent and1.0mol%catalyst1in aqueous solution. Adding proton acid or ammonia would inhibit the reaction to20%or46%while sodium carbonate promote to96%. With different alkanols as substrate,1had significant catalytic activity to rise the conversion rate up to97%from3%to7%with no catalyst. Mixture of complex1and TBHP formed a purple solution, which was charactered by UV-vis spectra.It was fond a new peak at515nm appears while peak at465nm disappeared. Presumably, reactive intermediate containing [Ru-Ru=O] group were involved.(2) Two heteropolymetallic Re-Ti complexes[(salen)Ti(ReO4)2](4) and [{(salen)Ti(ReO4)}2(μ-O)](5) were obtained by the reaction of TiⅣ complex containing salen ligand and (Me3SiO)ReO3, and characterized by IR spectra,’H-NMR spectra and X-ray diffraction. In complex5, the TiⅣ is hexa-coordinated by two O atoms and two N atoms from salen ligand, and axially coordinated with two O atoms contributed by bridged-oxo from Ti-O-Ti and O-ReO3fragments, respectively. Complex4and5both can be as catalyst for the oxidation of sulfides with ’BuOOH in dichloromethane solvent. While mixing0.1mmol methyl phenyl sulfide,0.5mmol TBHP and1.0mol%catalyst in2mL CH2C12for2hours in room temperature,78%methyl phenyl sulfide turned to sulfoxide (62%) and sulfone. Differences in catalytic effect of different sulfides might be due to steric effect and aromatic conjugation. Re peroxo species as the reactive intermediates involved in the TiⅣ/ReⅦ catalyst system(Ti-O-ReO3) similar to methyl trioxorhenium (MTO, CH3-ReO3).