Timothy N. Danks

Alkaline anion-exchange radiation-grafted membranes for possible electrochemical application in fuel cells

Vinylbenzyl chloride was grafted onto PVDF and FEP polymer films using radiation-grafting methodology. Subsequent reaction with trimethylamine and ion-exchange with potassium hydroxide yields alkaline anion-exchange membranes that are capable of conducting hydroxide ions; such membranes may be suitable for use in low temperature direct methanol fuel cells for portable devices. The PVDF based materials underwent an undesirable degradation and were found to be less suitable for this class of membrane. FEP-based materials exhibited superior structural stability, conductivities up to 0.02 S cm−1 at room temperature, and good retention of ion-exchange capacities when treated in water at 60 °C.

Comparison of PVDF- and FEP-based radiation-grafted alkaline anion-exchange membranes for use in low temperature portable DMFCs

Vinylbenzyl chloride has been radiation grafted onto both PVDF and FEP fluoropolymer films; subsequent amination and ion-exchange to give the hydroxide ion forms yield anion-exchange membranes suitable for use in low temperature direct methanol fuel cells for portable applications.

Microwave assisted synthesis of pyrroles

Abstract The synthesis of pyrroles by reaction of hexane-2,5-dione with primary amines has been shown to occur in less than 2 minutes under microwave activation.

Stability of various metalloporphyrin catalysts during hydrogen peroxide epoxidation of alkene

Abstract The ability of certain Fe and Mn metalloporphyrins to catalyse the H 2 O 2 epoxidation of cyclooctene is analysed. The ‘efficiency’ of epoxidation is dissected into contributions due to inherent catalyst epoxidation ability, catalyst H 2 O 2 dismutation ability, and catalyst stability towards the oxidant. It is shown that catalyst stability is a major factor contributing to apparent catalyst ability. The preparation of a sol–gel encapsulated metalloporphyrin is reported and it is shown to exhibit reduced rate of epoxidation, but a much enhanced stability.

Thermal- and microwave-assisted hydrogenation of electron-deficient alkenes using a polymer-supported hydrogen donor

Abstract Under microwave conditions hydrogenation of olefinic substrates may be achieved in excellent yields using a hydrogen donor supported on an ion-exchange resin and Wilkinsons catalyst.

Evidence for parallel destructive, and competitive epoxidation and dismutation pathways in metalloporphyrin-catalysed alkene oxidation by hydrogen peroxide

Abstract A kinetic and product yield analysis of the F20TPPFeCl-catalysed H2O2 epoxidation of cyclooctene has shown that decomposition is not via either the oxoperferryl intermediate (F20TPP+ )FeIVO or the oxoferryl intermediate F20TPPFeIVO, but appears to involve direct oxidation of the porphyrin in parallel with the catalytic epoxidation cycle. This is in contrast to the reaction of F20TPPFeCl in the absence of alkene where decomposition is via F20TPPFeIVO.

Reaction of a chromium carbene complex with 1-azadienes and the synthesis of trisubstituted pyrroles

Abstract Thermolysis of chromium carbene complexes with 1-azadienes leads to formation of trisubstituted pyrroles in good yield.

Covalent coupling of an phospholipid monolayer on thesurface of ceramic materials

A new synthetic route to the covalent bonding of an organic monolayer bearing terminal phosphorylcholine (PC) groups onto the surface of silicon oxide is reported; such monolayers prohibit the deposition of enzymes and proteins and can be used to improve surface biocompatibility.

Preparation and reduction of some camphor imines

Abstract A simple procedure for the preparation and the stereoselective reduction of some camphor based imines is reported.

Microwave accelerated synthesis of cyclopentadienyl bis-phosphine ruthenium (II) thiolato complexes using focused microwave irradiation

The synthesis of cyclopentadienyl bis-phosphine ruthenium thiolato complexes of the type [RuCp(dppm)SR] from [RuCp(PPh3)2 Cl] using conventional heating and microwave irradiation using a focused monomode reactor is described and the protocols compared. A considerable decrease of the reaction time is observed under microwave conditions. Yields by both methods are comparable. Functionalities such as esters, carboxylic acids and amides on the thiolato ligands are tolerated under the reaction conditions.