Journal of molecular catalysis a-chemical vol:134 issue:1-3 pages:209-214
The use of [5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyinato] Mn(III) and Fe(III) chloride [TDCPP(Mn)Cl and TDCPP(Fe)Cl] encapsulated in a polydimethylsiloxane (PDMS) membrane is reported for the oxidation of cyclic alcohols to ketones with t-butylhydroperoxide from an aqueous solution. Two major conclusions can be drawn from the comparison with carbon black (CB) supported complexes. Firstly, both hydrophobic carriers enhance the turnover numbers (TON) of the reaction by sorption of the reagents near the active site. Secondly, the support material requires a specific morphology to promote reaction selectivity. Indeed, the CB-supported complexes can be considered as an improved version of the homogeneous catalyst, whereas PDMS adds an extra dimension-selectivity-to the heterogeneous catalyst. (C) 1998 Elsevier Science B.V. All rights reserved.