Nonlinear optical properties of metal free and nickel binuclear phthalocyanines
- Kabwe, Kapambwe P, Louzada, Marcel, Britton, Jonathan, Olomola, Temitope O, Nyokong, Tebello, Khene, Samson M
- Authors: Kabwe, Kapambwe P , Louzada, Marcel , Britton, Jonathan , Olomola, Temitope O , Nyokong, Tebello , Khene, Samson M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186846 , vital:44539 , xlink:href="https://doi.org/10.1016/j.dyepig.2019.05.003"
- Description: This work employs the open and closed Z-scan aperture technique to comparatively study the nonlinear optical (NLO) properties of nickel and metal free 4-tert-butylphenoxy phthalocyanine, biphenyl bridged bis-4-tert-butylphenoxy phthalocyanine and naphthalene bridged bis-4-tert-butylphenoxy phthalocyanine. Density functional theory (DFT) calculations of dipolar and octupolar ( J=1 and J=3) contribution were determined theoretically from hyper-Rayleigh scattering (HRS) response ( HRS) values.
- Full Text:
- Date Issued: 2019
- Authors: Kabwe, Kapambwe P , Louzada, Marcel , Britton, Jonathan , Olomola, Temitope O , Nyokong, Tebello , Khene, Samson M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186846 , vital:44539 , xlink:href="https://doi.org/10.1016/j.dyepig.2019.05.003"
- Description: This work employs the open and closed Z-scan aperture technique to comparatively study the nonlinear optical (NLO) properties of nickel and metal free 4-tert-butylphenoxy phthalocyanine, biphenyl bridged bis-4-tert-butylphenoxy phthalocyanine and naphthalene bridged bis-4-tert-butylphenoxy phthalocyanine. Density functional theory (DFT) calculations of dipolar and octupolar ( J=1 and J=3) contribution were determined theoretically from hyper-Rayleigh scattering (HRS) response ( HRS) values.
- Full Text:
- Date Issued: 2019
Application of Baylis-Hillman methodology in the direct construction of chromone derivatives
- Faridoon, H, Olomola, Temitope O, Klein, Rosalyn, Kaye, Perry T
- Authors: Faridoon, H , Olomola, Temitope O , Klein, Rosalyn , Kaye, Perry T
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442488 , vital:73992 , https://doi.org/10.1016/j.tet.2015.11.039
- Description: Pyridinium chlorochromate oxidation of Baylis-Hillman-derived tert-butyl 2H-chromene-3-carboxylates affords chromone-3-carboxylate esters, providing the first application of Baylis-Hillman methodology in a direct and convenient three-step synthesis of chromone derivatives.
- Full Text:
- Date Issued: 2016
- Authors: Faridoon, H , Olomola, Temitope O , Klein, Rosalyn , Kaye, Perry T
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442488 , vital:73992 , https://doi.org/10.1016/j.tet.2015.11.039
- Description: Pyridinium chlorochromate oxidation of Baylis-Hillman-derived tert-butyl 2H-chromene-3-carboxylates affords chromone-3-carboxylate esters, providing the first application of Baylis-Hillman methodology in a direct and convenient three-step synthesis of chromone derivatives.
- Full Text:
- Date Issued: 2016
Elucidating Latent Mechanistic Complexity in Competing Acid-Catalyzed Reactions of Salicylaldehyde-Derived Baylis–Hillman Adducts
- Olomola, Temitope O, Klein, Rosalyn, Caira, Mino, R, Kaye, Perry T
- Authors: Olomola, Temitope O , Klein, Rosalyn , Caira, Mino, R , Kaye, Perry T
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442596 , vital:74010 , https://doi.org/10.1021/acs.joc.5b02372
- Description: 1H NMR-based kinetic studies have revealed the latent mechanistic complexity of deceptively simple hydrochloric acid-catalyzed reactions of salicylaldehyde-derived Baylis–Hillman adducts. Reactions conducted at 0 °C afforded 2-(chloromethyl)cinnamic acid derivatives as the major products and the corresponding 3-(chloromethyl)coumarin derivatives as the minor products. In reactions conducted in refluxing acetic acid, however, the 3-(chloromethyl)coumarin derivatives are the sole products. Variable-temperature 1H NMR analysis permitted the determination of the rate constants and kinetic parameters involved in the pseudo-first-order formation of (Z)-2-(chloromethyl)-3-(2-hydroxyphenyl)-2-propenoic acid. The kinetic data clearly preclude the operation of classical kinetic versus thermodynamic control and indicate the operation of three independent reaction pathways. Theoretical studies of these pathways undertaken at the B3LYP/6-31G(d) level permitted rationalization of the experimental data and provided insights into the possible mechanism of the enzymic E–Z isomerization and cyclization of (E)-cinnamic acid analogues to afford coumarins.
- Full Text:
- Date Issued: 2016
- Authors: Olomola, Temitope O , Klein, Rosalyn , Caira, Mino, R , Kaye, Perry T
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442596 , vital:74010 , https://doi.org/10.1021/acs.joc.5b02372
- Description: 1H NMR-based kinetic studies have revealed the latent mechanistic complexity of deceptively simple hydrochloric acid-catalyzed reactions of salicylaldehyde-derived Baylis–Hillman adducts. Reactions conducted at 0 °C afforded 2-(chloromethyl)cinnamic acid derivatives as the major products and the corresponding 3-(chloromethyl)coumarin derivatives as the minor products. In reactions conducted in refluxing acetic acid, however, the 3-(chloromethyl)coumarin derivatives are the sole products. Variable-temperature 1H NMR analysis permitted the determination of the rate constants and kinetic parameters involved in the pseudo-first-order formation of (Z)-2-(chloromethyl)-3-(2-hydroxyphenyl)-2-propenoic acid. The kinetic data clearly preclude the operation of classical kinetic versus thermodynamic control and indicate the operation of three independent reaction pathways. Theoretical studies of these pathways undertaken at the B3LYP/6-31G(d) level permitted rationalization of the experimental data and provided insights into the possible mechanism of the enzymic E–Z isomerization and cyclization of (E)-cinnamic acid analogues to afford coumarins.
- Full Text:
- Date Issued: 2016
Towards the synthesis of coumarin derivatives as potential dual-action HIV-1 protease and reverse transcriptase inhibitors
- Olomola, Temitope O, Klein, Rosalyn, Lobb, Kevin A, Sayed, Yasien, Kaye, Perry T
- Authors: Olomola, Temitope O , Klein, Rosalyn , Lobb, Kevin A , Sayed, Yasien , Kaye, Perry T
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448963 , vital:74774 , xlink:href="https://doi.org/10.1016/j.tetlet.2010.09.121"
- Description: 3-(Chloromethyl)coumarins, obtained via acid-catalysed cyclisation of salicylaldehyde-derived Baylis– Hillman adducts, have been treated with propargylamine; reaction of the resulting 3-alkynylmethylcoumarins with azidothymidine (AZT) in the presence of a Cu(I) catalyst has afforded a series of cycloaddition products for evaluation, in their own right, as potential dual-action HIV-1 protease and non-nucleoside reverse transcriptase inhibitors, and as scaffolds for further structural elaboration.
- Full Text:
- Date Issued: 2010
- Authors: Olomola, Temitope O , Klein, Rosalyn , Lobb, Kevin A , Sayed, Yasien , Kaye, Perry T
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448963 , vital:74774 , xlink:href="https://doi.org/10.1016/j.tetlet.2010.09.121"
- Description: 3-(Chloromethyl)coumarins, obtained via acid-catalysed cyclisation of salicylaldehyde-derived Baylis– Hillman adducts, have been treated with propargylamine; reaction of the resulting 3-alkynylmethylcoumarins with azidothymidine (AZT) in the presence of a Cu(I) catalyst has afforded a series of cycloaddition products for evaluation, in their own right, as potential dual-action HIV-1 protease and non-nucleoside reverse transcriptase inhibitors, and as scaffolds for further structural elaboration.
- Full Text:
- Date Issued: 2010
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