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Pyrene Schiff base: photophysics, aggregation induced emission, and antimicrobial properties.
- Source :
-
The journal of physical chemistry. B [J Phys Chem B] 2014 Nov 26; Vol. 118 (47), pp. 13573-81. Date of Electronic Publication: 2014 Nov 17. - Publication Year :
- 2014
-
Abstract
- Pyrene containing Schiff base molecule, namely 4-[(pyren-1-ylmethylene)amino]phenol (KB-1), was successfully synthesized and well characterized by using (1)H, (13)C NMR, FT-IR, and EI-MS spectrometry. UV-visible absorption, steady-state fluorescence, time-resolved fluorescence, and transient absorption spectroscopic techniques have been employed to elucidate the photophysical processes of KB-1. It has been demonstrated that the absorption characteristics of KB-1 have been bathochromatically tuned to the visible region by extending the π-conjugation. The extended π-conjugation is evidently confirmed by DFT calculations and reveals that π→π* transition is the major factor responsible for electronic absorption of KB-1. The photophysical property of KB-1 was carefully examined in different organic solvents at different concentrations and the results show that the fluorescence of this molecule is completely quenched due to photoinduced electron transfer. Intriguingly, the fluorescence intensity of KB-1 increases enormously by the gradual addition of water up to 90% with concomitant increase in fluorescence lifetime. This clearly signifies that this molecule has aggregation-induced emission (AIE) property. The mechanism of AIE of this molecule is suppression of photoinduced electron transfer (PET) due to hydrogen bonding interaction of imine donor with water. A direct evidence of PET process has been presented by using nanosecond transient absorption measurements. Further, KB-1 was successfully used for antimicrobial and bioimaging studies. The antimicrobial studies were carried out through disc diffusion method. KB-1 is used against both Gram-positive (Rhodococcus rhodochrous and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacterial species and also fungal species (Candida albicans). The result shows KB-1 can act as an excellent antimicrobial agent and as a photolabeling agent. S. aureus, P. aeruginosa, and C. albicans were found to be the most susceptible microorganisms at 1 mM concentration among the bacteria used in the present investigation.
- Subjects :
- Anti-Infective Agents chemistry
Anti-Infective Agents radiation effects
Electrons
Escherichia coli drug effects
Fluorescence
Hydrogen Bonding
Imines chemistry
Models, Chemical
Molecular Structure
Phenols radiation effects
Photochemical Processes
Pseudomonas aeruginosa drug effects
Pyrenes radiation effects
Rhodococcus drug effects
Schiff Bases radiation effects
Solvents chemistry
Spectrum Analysis
Staphylococcus aureus drug effects
Water chemistry
Phenols chemistry
Pyrenes chemistry
Schiff Bases chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1520-5207
- Volume :
- 118
- Issue :
- 47
- Database :
- MEDLINE
- Journal :
- The journal of physical chemistry. B
- Publication Type :
- Academic Journal
- Accession number :
- 25360825
- Full Text :
- https://doi.org/10.1021/jp509697n