Showing papers by "Louis J. Farrugia published in 2007"

Synthesis, characterisation and anti-protozoal activity of carbamate-derived polyazamacrocycles

Abstract: A short, highly efficient approach for the synthesis of a novel class of polyazamacrocycles containing N-functionalised carbamate side-chains has been developed. The key steps involved a phase-transfer mediated macrocyclisation to form the ring system as well as a tin-catalysed reaction with isocyanates to introduce the carbamate side-chains. X-Ray crystallography confirmed successful formation of the 1,4,7,10-tetraazacyclododecane ring and N-functionalisation of all the amine centres. Preliminary testing of the biological activity of the compounds revealed significant anti-parasitic activity against bloodstream form African trypanosomes.

Sodium tungstate dihydrate: a redetermination

Abstract: There have been two previous structure determinations of the title compound, Na2WO4·2H2O: in 1969 [Mitra & Verma (1969). Indian J. Chem. 7, 598–602] and in 1974 [Okada et al. (1974a). Bull. Tokyo Inst. Technol. 120, 7–11]. However, both structures are incorrect according to their entries in the Inorganic Crystal Structure Database [(2007), URL: http://www.fiz-karlsruhe.de/ecid/Internet/en/DB/icsd/index.html]. Despite the high absorption coefficient, the H-atom positions could be observed and refined in the present study. Owing to the accurate analytical absorption correction, all non-H atoms could be refined satisfactorily with anisotropic displacement parameters. There are hydrogen-bonding inter­actions between all H atoms and the O atoms of the tungstate dianion.

5-Bromo­anthranil

Abstract: Crystals of the title compound, C7H4BrNO, are twinned by a twofold rotation about [001]. The crystal structure is stabilized by π-stacking of the virtually planar fused ring system along the crystallographic a axis, and through weak inter­molecular C—H⋯O, C—H⋯N and C—H⋯Br inter­actions.