Synthesis, characterisation and coordination chemistry of novel N-alkyl- and N,N-dialkyl-N'-acylthioureas

Grimmbacher, Tarron

Synthesis, characterisation and coordination chemistry of novel N-alkyl- and N,N-dialkyl-N'-acylthioureas

Doctoral Thesis

1995

Publisher

University of Cape Town

Department

Department of Chemistry

Faculty

Faculty of Science

Abstract

A series of N-alkyl- and N,N-dialkyl-N'-acylthioureas are synthesised and characterised. The crystal structure of N-butyl-N'-benzoylthiourea indicates that an intramolecular hydrogen bond locks the potentially bidentate chelate moiety into a planar six-membered ring with an overall rod-like molecular structure. The rod-like structure of the N-alkyl-N'-benzoylthioureas is exploited and the synthesis and characterisation of a novel series of liquid crystals based on N-(p-alkyl(oxy))aniline-N'-(p-alkyl(oxy))benzoylthiourea is discussed. The liquid-crystalline phases are identified with the aid of Polarising Optical Microscopy and confirmed by Differential Scanning Calorimetry studies. The compounds display nematic, smectic A or a combination of these liquid crystal phases. The X-ray crystal structure of N-(p-hexyloxy)aniline-N'-(pmethyloxy) benzoylthiourea shows co-planarity of the aromatic and hydrogen-bonded six-membered rings. Intennolecular hydrogen bond interactions between adjacent molecules allow for favourable molecular interaction for the formation of liquid crystal phases.

Description

Includes bibliographical references.

Keywords

Chemistry

Reference:

Collections

PhD / Doctoral

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