Ethyne Functionalized <i>Meso</i>-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated Species
Synthesis, structural characterization and photophysical properties for a series of new <i>trans</i>-A<sub>2</sub>B<sub>2</sub>- and A<sub>3</sub>B-type ethynyl functionalized <i>meso</i>-phenothiazinyl-phenyl porphyrin derivatives are desc...
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| Format: | Article |
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MDPI AG
2020-10-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/25/19/4546 |
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| author | Eva Molnar Emese Gál Luiza Găină Castelia Cristea Luminița Silaghi-Dumitrescu |
| author_facet | Eva Molnar Emese Gál Luiza Găină Castelia Cristea Luminița Silaghi-Dumitrescu |
| author_sort | Eva Molnar |
| collection | DOAJ |
| description | Synthesis, structural characterization and photophysical properties for a series of new <i>trans</i>-A<sub>2</sub>B<sub>2</sub>- and A<sub>3</sub>B-type ethynyl functionalized <i>meso</i>-phenothiazinyl-phenyl porphyrin derivatives are described. The new compounds displayed the characteristic porphyrin absorption spectra slightly modified by weak auxochromic effects of the substituents and fluorescence emission in the range of 651–659 nm with 11–25% quantum yields. The changes recorded in the UV-vis absorption spectra in the presence of trifluoroacetic acid (TFA) are consistent with the protonation of the two internal nitrogen atoms of the free-base porphyrin (19 nm bathochromic shift of the strong Soret band and one long wave absorption maxima situated in the range of 665–695 nm). Protonation of the phenothiazine substituents required increased amounts of TFA and produced a distinct hypsochromic shift of the long wave absorption maxima. The density functional theory (DFT) calculations of a porphyrin dication pointed out a saddle-distorted porphyrin ring as the ground-state geometry. |
| first_indexed | 2024-03-10T15:50:29Z |
| format | Article |
| id | doaj.art-2f5c2f64655e4f61ac81ffadbc5dbf86 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T15:50:29Z |
| publishDate | 2020-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-2f5c2f64655e4f61ac81ffadbc5dbf862023-11-20T16:03:32ZengMDPI AGMolecules1420-30492020-10-012519454610.3390/molecules25194546Ethyne Functionalized <i>Meso</i>-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated SpeciesEva Molnar0Emese Gál1Luiza Găină2Castelia Cristea3Luminița Silaghi-Dumitrescu4Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, 11 Arany Janos street, RO-400028 Cluj-Napoca, RomaniaFaculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, 11 Arany Janos street, RO-400028 Cluj-Napoca, RomaniaFaculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, 11 Arany Janos street, RO-400028 Cluj-Napoca, RomaniaFaculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, 11 Arany Janos street, RO-400028 Cluj-Napoca, RomaniaFaculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, 11 Arany Janos street, RO-400028 Cluj-Napoca, RomaniaSynthesis, structural characterization and photophysical properties for a series of new <i>trans</i>-A<sub>2</sub>B<sub>2</sub>- and A<sub>3</sub>B-type ethynyl functionalized <i>meso</i>-phenothiazinyl-phenyl porphyrin derivatives are described. The new compounds displayed the characteristic porphyrin absorption spectra slightly modified by weak auxochromic effects of the substituents and fluorescence emission in the range of 651–659 nm with 11–25% quantum yields. The changes recorded in the UV-vis absorption spectra in the presence of trifluoroacetic acid (TFA) are consistent with the protonation of the two internal nitrogen atoms of the free-base porphyrin (19 nm bathochromic shift of the strong Soret band and one long wave absorption maxima situated in the range of 665–695 nm). Protonation of the phenothiazine substituents required increased amounts of TFA and produced a distinct hypsochromic shift of the long wave absorption maxima. The density functional theory (DFT) calculations of a porphyrin dication pointed out a saddle-distorted porphyrin ring as the ground-state geometry.https://www.mdpi.com/1420-3049/25/19/4546phenothiazineporphyrinphotophysical properties |
| spellingShingle | Eva Molnar Emese Gál Luiza Găină Castelia Cristea Luminița Silaghi-Dumitrescu Ethyne Functionalized <i>Meso</i>-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated Species Molecules phenothiazine porphyrin photophysical properties |
| title | Ethyne Functionalized <i>Meso</i>-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated Species |
| title_full | Ethyne Functionalized <i>Meso</i>-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated Species |
| title_fullStr | Ethyne Functionalized <i>Meso</i>-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated Species |
| title_full_unstemmed | Ethyne Functionalized <i>Meso</i>-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated Species |
| title_short | Ethyne Functionalized <i>Meso</i>-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated Species |
| title_sort | ethyne functionalized i meso i phenothiazinyl phenyl porphyrins synthesis and optical properties of free base versus protonated species |
| topic | phenothiazine porphyrin photophysical properties |
| url | https://www.mdpi.com/1420-3049/25/19/4546 |
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