New difluoroboron complexes based on N, O-chelated Schiff base ligands: Synthesis, characterization, DFT calculations and photophysical and electrochemical properties
- Authors: Sen, Pinar , Mpeta, Lekhetho S , Mack, John , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186207 , vital:44473 , xlink:href="https://doi.org/10.1016/j.jlumin.2020.117262"
- Description: The synthesis of new Schiff bases and their dinuclear boron complexes is described, along with their characterization by 1H and 13C NMR, FT-IR, and UV–visible absorption spectroscopy, mass spectrometry, and EDX for elemental analysis. The optical and photophysical properties were examined in terms of their absorption and emission behavior, fluorescence quantum yields and fluorescence lifetimes. The flexible dinuclear boron complexes that are linked by a flexible carbon chain exhibited large Stokes shifts in the range from 92 nm to 115 nm in contrast to BODIPY dyes. Those properties make these complexes precious for applications in fluorescence materials. And also theoretical calculations were obtained by using Density Functional Theory (DFT) methods.
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- Date Issued: 2020
The effects of asymmetry in combination with reduced graphene oxide nanosheets on hydrazine electrocatalytic detection on cobalt phthalocyanines
- Authors: Mpeta, Lekhetho S , Sen, Pinar , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186023 , vital:44456 , xlink:href="https://doi.org/10.1002/elan.202060094"
- Description: New symmetric {tetrakis [4-(4-(5-chloro-1Hbenzo[d]imidazol-2-yl) phenoxy phthalocyaninato] Co (II) (CoTPc)} and low symmetry {tris tert butyl phenoxy mono [4-(4-(5-chloro-1H-benzo[d]imidazol-2-yl) phenoxy phthalocyaninato]} Co (II) (CoMPc) were successfully synthesised and combined with reduced graphene oxide nanosheets (rGONS) for electrocatalytic detection of hydrazine. Prior to electrocatalysis, the probes were characterised using cyclic voltammetry and electrochemical impedance spectroscopy. Chronoamperometry was used to determine catalytic rate constant and the limit of detection (LOD). CoMPc-rGONS gave catalytic rate constant and LOD of 1.37×106 M 1 s 1 and 0.82 μM respectively, rendering it a more suitable probe for hydrazine, due to low symmetry.
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- Date Issued: 2020