Synthesis of group 11 pyrazolate complexes bearing different alkyl side-chains for vapochromic chemosensors of volatile organic compounds

Vapochromic chemosensors of phosphorescent metal complexes have been developed previously for the detection of volatile organic compounds (VOCs) without studying the effect of molecular structure on their sensing capabilities. Therefore, this research aims to synthesize phosphorescent trinuclear Gro...

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Main Author: Ghazali, Nur Fatiha
Format: Thesis
Published: 2017
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spelling my-utm-ep.791692018-10-04T03:28:23Z Synthesis of group 11 pyrazolate complexes bearing different alkyl side-chains for vapochromic chemosensors of volatile organic compounds 2017 Ghazali, Nur Fatiha QD Chemistry Vapochromic chemosensors of phosphorescent metal complexes have been developed previously for the detection of volatile organic compounds (VOCs) without studying the effect of molecular structure on their sensing capabilities. Therefore, this research aims to synthesize phosphorescent trinuclear Group 11 pyrazolate complexes in a variety of molecular structures, based on amphiphilicity of different alkyl side-chains of the pyrazolate ligands and type of metal ions for development of new optical chemosensors for the VOCs detection. Trinuclear pyrazolate complexes (3d1–3d7) were synthesized by complexation of copper(I) with non-side chain, 3,5-dimethyl, 3,5-bis(trifluoromethyl), 3,5-diphenyl, 4-(3,5- dimethoxybenzyl)-3,5-dimethyl, 4-(3,4,5-trioctadecoxybenzyl)-3,5-dimethyl and 4- (3,4,5-tridecoxy triethylene glycol benzyl)-3,5-dimethyl pyrazole ligands (3c1–3c7), including 3c5 and 3c7 ligands with gold(I) and silver(I) to give 3e5, 3e7 (silver(I)) and 3f5, 3f7 (gold(I)) complexes. All the complexes showed emission bands in the range 553-644 nm when excited at 275-322 nm with large Stokes shifts (>300 nm) and luminescent lifetimes in the microscale. Moreover, they emitted from green to red when exposed to UV light at 254 nm, exhibiting phosphorescent properties from the weak metal-metal interactions. Upon exposure to alcohol derivatives, 3d5 performed the best for detection of ethanol and caused a blue-shift of the emission spectra, while amphiphilic 3d7 was found to be the best chemosensor as demonstrated by quenching of the emission intensity in the presence of hexanol. When exposed to benzene, amphiphilic 3e7 showed the best sensing capability for the detection of benzene and its derivatives, which is an important new finding emerging from this study. Therefore, phosphorescent chemosensors with high sensing capabilities could be achieved by controlling the molecular structure and fine-tuning of the amphiphilicity of the different alkyl side-chains of the pyrazolate ligands in the presence of different types of metal ions for the detection of specific VOCs. 2017 Thesis http://eprints.utm.my/id/eprint/79169/ phd doctoral Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
topic QD Chemistry
spellingShingle QD Chemistry
Ghazali, Nur Fatiha
Synthesis of group 11 pyrazolate complexes bearing different alkyl side-chains for vapochromic chemosensors of volatile organic compounds
description Vapochromic chemosensors of phosphorescent metal complexes have been developed previously for the detection of volatile organic compounds (VOCs) without studying the effect of molecular structure on their sensing capabilities. Therefore, this research aims to synthesize phosphorescent trinuclear Group 11 pyrazolate complexes in a variety of molecular structures, based on amphiphilicity of different alkyl side-chains of the pyrazolate ligands and type of metal ions for development of new optical chemosensors for the VOCs detection. Trinuclear pyrazolate complexes (3d1–3d7) were synthesized by complexation of copper(I) with non-side chain, 3,5-dimethyl, 3,5-bis(trifluoromethyl), 3,5-diphenyl, 4-(3,5- dimethoxybenzyl)-3,5-dimethyl, 4-(3,4,5-trioctadecoxybenzyl)-3,5-dimethyl and 4- (3,4,5-tridecoxy triethylene glycol benzyl)-3,5-dimethyl pyrazole ligands (3c1–3c7), including 3c5 and 3c7 ligands with gold(I) and silver(I) to give 3e5, 3e7 (silver(I)) and 3f5, 3f7 (gold(I)) complexes. All the complexes showed emission bands in the range 553-644 nm when excited at 275-322 nm with large Stokes shifts (>300 nm) and luminescent lifetimes in the microscale. Moreover, they emitted from green to red when exposed to UV light at 254 nm, exhibiting phosphorescent properties from the weak metal-metal interactions. Upon exposure to alcohol derivatives, 3d5 performed the best for detection of ethanol and caused a blue-shift of the emission spectra, while amphiphilic 3d7 was found to be the best chemosensor as demonstrated by quenching of the emission intensity in the presence of hexanol. When exposed to benzene, amphiphilic 3e7 showed the best sensing capability for the detection of benzene and its derivatives, which is an important new finding emerging from this study. Therefore, phosphorescent chemosensors with high sensing capabilities could be achieved by controlling the molecular structure and fine-tuning of the amphiphilicity of the different alkyl side-chains of the pyrazolate ligands in the presence of different types of metal ions for the detection of specific VOCs.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Ghazali, Nur Fatiha
author_facet Ghazali, Nur Fatiha
author_sort Ghazali, Nur Fatiha
title Synthesis of group 11 pyrazolate complexes bearing different alkyl side-chains for vapochromic chemosensors of volatile organic compounds
title_short Synthesis of group 11 pyrazolate complexes bearing different alkyl side-chains for vapochromic chemosensors of volatile organic compounds
title_full Synthesis of group 11 pyrazolate complexes bearing different alkyl side-chains for vapochromic chemosensors of volatile organic compounds
title_fullStr Synthesis of group 11 pyrazolate complexes bearing different alkyl side-chains for vapochromic chemosensors of volatile organic compounds
title_full_unstemmed Synthesis of group 11 pyrazolate complexes bearing different alkyl side-chains for vapochromic chemosensors of volatile organic compounds
title_sort synthesis of group 11 pyrazolate complexes bearing different alkyl side-chains for vapochromic chemosensors of volatile organic compounds
granting_institution Universiti Teknologi Malaysia, Faculty of Science
granting_department Faculty of Science
publishDate 2017
_version_ 1747818163105431552