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M Devereux

Publications and source records attributed to M Devereux.

6 recordsLinked to original sources

Rendering of quantum topological atoms and bonds.

In this article, we describe and apply an algorithm that visualizes atoms and bonds in molecules and van der Waals complexes, based on the topology of the electron density. The theory of quantum chemical topology defines both atoms and bonds via a single consistent procedure, and enables the association of an atomic shape with an atomic property (charge, dipole moment, volume, ...). Special attention is paid to the bridging of gaps arising in interatomic surfaces, in the presence of ring critical points or high ellipticity. This algorithm, in conjunction with the graphical user interface of the computer program MORPHY enables robust and efficient rendering of complicated interatomic surfaces, as found in larger systems.

Adamantane↗

The quantum topological electrostatic potential as a probe for functional group transferability.

The electrostatic potential can be used as an appropriate and convenient indicator of how transferable an atom or functional group is between two molecules. Quantum-chemical topology (QCT) is used to define the electron density of a molecular fragment and the electrostatic potential it generates. The potential generated on a grid by the terminal aldehyde group of the biomolecule retinal is compared with the corresponding aldehyde group in smaller molecules derived from retinal. The terminal amino group in the free amino acid lysine was treated in a similar fashion. Each molecule is geometry-optimized by an ab initio calculation at B3LYP/6-311G+(2d,p)//HF/6-31G(d) level. The amino group in lysine is very little influenced by any part of the molecule further than two C atoms away. However, the aldehyde group in retinal is influenced by molecular fragments six C atoms away. This dramatic disparity is ascribed to the difference in saturation in the carbon chains; retinal contains a conjugated hydrocarbon chain but lysine an aliphatic one.

Aldehydes↗

Synthesis and antimicrobial activity of copper(II) and manganese(II) alpha,omega-dicarboxylate complexes.

Copper(II) alpha,omega-dicarboxylate complexes of general formulae, [Cu(O2C(CH2)nCO2)].xH2O, [Cu(O2C(CH2)nCO2) (phen)2].xH2O and [Cu(O2C(CH2),CO2)(bipy)y].xH2O (n = 1-8; y = 1, 2; phen = 1,10-phenanthroline; bipy = 2,2'-bipyridine) were synthesised. These copper complexes, some related manganese(II) complexes and the metal-free ligands were screened in vitro for their ability to inhibit the growth of Candida albicans. Metal-free 1,10-phenanthroline and all of the copper(II) and manganese(II) phenanthroline complexes were potent growth inhibitors, with only one bipyridine complex, [Cu(O2C(CH2)CO2)(bipy)2].2H2O, having moderate activity. The remaining substances were effectively inactive. Complexes which were active against C. albicans also proved effective against C. glabratta, C. tropicalis and C. kreusi with the manganese complexes retaining superior activity. For the phenanthroline complexes the active drug species is thought to be the dication [M(phen)2(H2O)n]2+ (M = Cu, Mn). Escherichia coli and Staphylococcus aureus were resistant to all of the metal complexes and also to metal-free 1,10-phenanthroline. Only the copper phenanthroline complexes showed intermediate activity against Pseudomonas aeruginosa.

Anti-Bacterial Agents↗