Stuart Aiken

A new synthetic route to donor–acceptor porphyrins

Abstract Some new donor–acceptor porphyrins have been prepared based on a metallated bis(ethynyl) porphyrin core. 4-(Dimethylamino)phenyl was used as the donor group and 4-nitrophenyl, 4-cyanophenyl and 5-nitrothiazoyl as the acceptor groups. Dipyrrylmethane was used for large scale porphyrin ring synthesis because the absence of methylene substituents reduces the difficulty of substituent scrambling that occurs during porphyrin synthesis.

Metallated porphyrins containing lead(II), copper(II) or zinc(II)

A series of ethynyl and aryl substituted porphyrins and the corresponding metallated derivatives have been synthesised and characterised.

Structures of Pb(II) porphyrins: [5,10,15,20-tetrakis-triisopropylsilylethynylporphinato]lead(II) and [5,15-bis-(3,5-bis-tert-butylphenyl)-10,20-bis-triisopropylsilylethynylporphinato]lead(II)

The crystal structures of two lead containing porphyrins are described. Structure 1 contains unprecedented stacks of three metalloporphyrins. Each structure shows disorder of the Pb atoms which are situated out of the mean plane of the porphyrin ring.

Cooperative assembly of a double-stranded hydrogen-bonded porphyrin zip

Abstract A linear zinc porphyrin dimer has been used for the first time to stabilise two identical non-covalent aggregates by a combination of N -pyridyl zinc binding and hydrogen bonding. An improved multigram synthesis of 5,15-bis-(3,5-di- tert -butylphenyl)-10,20-bis(trimethylsilylethynyl)porphyrin is described.

A combined parahydrogen and theoretical study of H2 activation by 16-electron d8 ruthenium(0) complexes and their subsequent catalytic behaviour

The photochemical reaction of Ru(CO)(3)(L)(2), where L = PPh(3), PMe(3), PCy(3) and P(p-tolyl)(3) with parahydrogen (p-H(2)) has been studied by in-situ NMR spectroscopy and shown to result in two competing processes. The first of these involves loss of CO and results in the formation of the cis-cis-trans-L isomer of Ru(CO)(2)(L)(2)(H)(2), while in the second, a single photon induces loss of both CO and L and leads to the formation of cis-cis-cis Ru(CO)(2)(L)(2)(H)(2) and Ru(CO)(2)(L)(solvent)(H)(2) where solvent = toluene, THF and pyridine (py). In the case of L = PPh(3), cis-cis-trans-L Ru(CO)(2)(L)(2)(H)(2) is shown to be an effective hydrogenation catalyst with rate limiting phosphine dissociation proceeding at a rate of 2.2 s(-1) in pyridine at 355 K. Theoretical calculations and experimental observations show that H(2) addition to the Ru(CO)(2)(L)(2) proceeds to form cis-cis-trans-L Ru(CO)(2)(L)(2)(H)(2) as the major product via addition over the pi-accepting OC-Ru-CO axis.

Co-operative stabilisation of a 15-component nanostructure

2-Amino-4-(4-tert-butylphenylamino)-6-{4-[(4-pyridyl)ethynyl]phenylamino}-1,3,5-triazine was synthesised and mixed with dibutylbarbituric acid in CDCl3 to study rosette formation. The formation of a double decker rosette aggregate was studied by complexation of the pyridyl groups to a zinc containing porphyrin dimer.