Base metal Schiff base complexes applied as catalysts for the oxidation of n-octane

作者：Kadwa Ebrahim; Friedrich Holger B; Bala Muhammad D

来源：Inorganica Chimica Acta, 2017, 463: 112-117.

DOI：10.1016/j.ica.2017.04.032

• Paraffin functionalisation
• Schiff base
• Iron complexes
• Regioselectivity parameter

The catalytic oxidation of n-octane to value-added oxygenates has been studied with a series of salen-type complexes of iron. The four iron Schiff base complexes N,N'-bis(salicylidene)-L-iron(III) chloride [L = 1,2-phenylenediamine (5); ethylenediamine (6); propylenediamine (7) and butylenediamine (8)] were synthesised by variation of the bridging diamine backbone. All the complexes are fully characterised and the crystal structure of 7 is for the first time reported as a centrosymmetric dimer observed to crystallise in the triclinic P (1) over bar system. The application of 5-8 in this oxidation reaction represents a rare example of the systematic use of iron-salen complexes for the liquid-phase functionalisation of C-sp(3)-H bonds of straight chain alkanes. All catalysts displayed activity with H2O2 and TBHP as oxidants that resulted in a mixture of oxygenated products dominated by the ketones (2-, 3- and 4-octanones). Observed trends and variations in catalytic activities of the complexes is related to differences in chemical/structural features and changes in reaction conditions. A detailed analysis of selectivity parameters of the complexes to the variety of oxygenates is also presented and rationalised.

• 出版日期2017-7-1