Ni(II) and Pb(II) dithiocarbamate complexes as precursors for the synthesis of HDA-capped NiS and PbS nanoparticles
- Authors: Chintso, Thobani
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11349 , http://hdl.handle.net/10353/d1020201
- Description: Ni(II) and Pb(II) dithiocarbamate complexes were synthesized and characterized by elemental analysis, UV-Vis, FTIR and TGA and some of the Ni(II) complexes and one Pb(II) were further analyzed by 1H-NMR and 13C-NMR spectroscopy. Generally all the dithiocarbamate ligands are soluble in water while the complexes were soluble mostly in solvents such as chloroform, toluene, DMSO and DCM. Based on the elemental analysis, the dithiocarbamate complexes are formulated as four coordinate (tetrahedral or square planar) compounds. However, the FTIR showed that each of the dithiocarbamate ligands acted as bidentate ligand through two sulfur atoms. The TGA of the most complexes showed one major decomposition step to give respective metal sulfide above 200 oC. In this research project, dithiocarbamate complexes were used as single source precursor for the synthesis of metal sulfide nanoparticles. We studied the optical and structural properties of metal sulfide nanoparticles using UV-Vis, photoluminescence (PL), powder X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The absorption spectra of the metal sulfide nanoparticles are blue shifted in respect to bulk material and they also showed broad emission. The XRD of the NiS nanoparticles were indexed to the cubic and rhombohedral phase, with crystallite sizes of 15 - 18 nm. The XRD of PbS nanoparticles were indexed to the face centered cubic and cubic rock salts, with the crystallite sizes 12 - 18 nm. The TEM images of the metal sulfide nanoparticles showed particles with spherical and rectangular shapes with crystallite sizes 4 - 35 nm.
- Full Text:
- Date Issued: 2015
- Authors: Chintso, Thobani
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11349 , http://hdl.handle.net/10353/d1020201
- Description: Ni(II) and Pb(II) dithiocarbamate complexes were synthesized and characterized by elemental analysis, UV-Vis, FTIR and TGA and some of the Ni(II) complexes and one Pb(II) were further analyzed by 1H-NMR and 13C-NMR spectroscopy. Generally all the dithiocarbamate ligands are soluble in water while the complexes were soluble mostly in solvents such as chloroform, toluene, DMSO and DCM. Based on the elemental analysis, the dithiocarbamate complexes are formulated as four coordinate (tetrahedral or square planar) compounds. However, the FTIR showed that each of the dithiocarbamate ligands acted as bidentate ligand through two sulfur atoms. The TGA of the most complexes showed one major decomposition step to give respective metal sulfide above 200 oC. In this research project, dithiocarbamate complexes were used as single source precursor for the synthesis of metal sulfide nanoparticles. We studied the optical and structural properties of metal sulfide nanoparticles using UV-Vis, photoluminescence (PL), powder X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The absorption spectra of the metal sulfide nanoparticles are blue shifted in respect to bulk material and they also showed broad emission. The XRD of the NiS nanoparticles were indexed to the cubic and rhombohedral phase, with crystallite sizes of 15 - 18 nm. The XRD of PbS nanoparticles were indexed to the face centered cubic and cubic rock salts, with the crystallite sizes 12 - 18 nm. The TEM images of the metal sulfide nanoparticles showed particles with spherical and rectangular shapes with crystallite sizes 4 - 35 nm.
- Full Text:
- Date Issued: 2015
Synthesis and characterization of Ru(II) phenyl-3-indenylidene olefin metathesis type complexes
- Authors: Yalezo, Ntsikelelo
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11351 , http://hdl.handle.net/10353/d1021128
- Description: In this study, a series of Ru(II) phenyl-3-indenylidene complexes with general formula of [RuCl2(NHC)(Ind)(L)] (where L= triphenylphosphine, pyridine and NHC = five different types of N-heterocyclic carbene ligands), have been synthesized and characterized using FT-IR, UV-Vis, elementally analysis and melting/decomposition point. The N,N’-diarylimidazolinium chlorides have been used as N-heterocyclic carbene precursors and were synthesized from their corresponding N,N’-diarylformamidines and further characterized using 1H-NMR, 13C-NMR, FTIR and melting point determination. The infrared spectra of the N,N’-diarylimidazolinium chlorides show a quaternary nature (R2N=C+) with broad vibration band in region 3300-3400 cm-1. The disappearance of this vibration band in the infrared spectra of the ruthenium(II) complexes was used to confirm the coordination of the ligand to the ruthenium ions. The percentage analysis of carbon, hydrogen and nitrogen obtained corresponded with the calculated percentages of these atoms in the complexes with the slight difference of less than 1%. The electronic spectra of the complexes show three distinct absorption bands. The two bands are due to intraligand charge transfers transition assigned to π→π*, n→π* and third band is due to d-d transition, signifying the presence of the metal ion. The synthesized Ru(II) complexes did not show any of melting, however a change in colour was observed signifying the decomposition of the complexes.
- Full Text:
- Date Issued: 2015
- Authors: Yalezo, Ntsikelelo
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11351 , http://hdl.handle.net/10353/d1021128
- Description: In this study, a series of Ru(II) phenyl-3-indenylidene complexes with general formula of [RuCl2(NHC)(Ind)(L)] (where L= triphenylphosphine, pyridine and NHC = five different types of N-heterocyclic carbene ligands), have been synthesized and characterized using FT-IR, UV-Vis, elementally analysis and melting/decomposition point. The N,N’-diarylimidazolinium chlorides have been used as N-heterocyclic carbene precursors and were synthesized from their corresponding N,N’-diarylformamidines and further characterized using 1H-NMR, 13C-NMR, FTIR and melting point determination. The infrared spectra of the N,N’-diarylimidazolinium chlorides show a quaternary nature (R2N=C+) with broad vibration band in region 3300-3400 cm-1. The disappearance of this vibration band in the infrared spectra of the ruthenium(II) complexes was used to confirm the coordination of the ligand to the ruthenium ions. The percentage analysis of carbon, hydrogen and nitrogen obtained corresponded with the calculated percentages of these atoms in the complexes with the slight difference of less than 1%. The electronic spectra of the complexes show three distinct absorption bands. The two bands are due to intraligand charge transfers transition assigned to π→π*, n→π* and third band is due to d-d transition, signifying the presence of the metal ion. The synthesized Ru(II) complexes did not show any of melting, however a change in colour was observed signifying the decomposition of the complexes.
- Full Text:
- Date Issued: 2015
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