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HERO ID
3453068
Reference Type
Journal Article
Title
The role of hydrogen bonding in the fluorescence quenching of 2,6-bis((E)-2-(benzoxazol-2-yl)vinyl)naphthalene (BBVN) in methanol
Author(s)
Hammam, E; Basahi, J; Ismail, I; Hassan, I; Almeelbi, T
Year
2017
Is Peer Reviewed?
1
Journal
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
ISSN:
1386-1425
EISSN:
1873-3557
Volume
173
Page Numbers
681-686
Language
English
PMID
27780128
DOI
10.1016/j.saa.2016.10.018
Web of Science Id
WOS:000390502900092
URL
https://www.scopus.com/inward/record.uri?eid=2-s2.0-84993995775&doi=10.1016%2fj.saa.2016.10.018&partnerID=40&md5=cfcedde708ced132b16c362014bbf296
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Abstract
The excited state hydrogen bonding dynamics of BBVN in hydrogen donating methanol solvent was explored at the TD-BMK/cc-pVDZ level of theory with accounting for the bulk environment effects at the polarizable continuum model (PCM). The heteroatoms of the BBVN laser dye form hydrogen bonds with four methanol molecules. In the formed BBVN-(MeOH)4 complex, the A-type hydrogen bond (N…HO), of an average strength of 25kJmol(-1), is twofold stronger than the B-type (O…HO) one. Upon photon absorption, the total HB binding energy increases from 78.5kJmol(-1) in the ground state to 82.6kJmol(-1) in the first singlet (S1) excited state. In consequence of the hydrogen bonding interaction, the absorption band maximum of the BBVN-(MeOH)4 complex, which was anticipated at 398nm (exp. 397), is redshifted by 5nm relative to that of the free dye in methanol. The spectral shift of the stretching vibrational mode for the hydrogen bonded hydroxyl groups (with a maximum shift of 285cm(-1)) from that of the free methanol indicated the elevated strengthening of hydrogen bonds in the excited state. The vibrational modes associated with hydrogen bonding provide effective accepting modes for the dissipation of the excitation energy, thus, decreasing the fluorescence quantum yield of BBVN in alcohols as compared to that in the polar aprotic solvents. Since there is no sign of photochemistry or phosphorescence, it seems reasonable in view of the outcomes of this study to assign the major decay process of the excited singlet (S1) of BBVN in alcohols to vibronically induced internal conversion (IC) facilitated by hydrogen bonding.
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IRIS
•
Naphthalene
Database searches - Jan 2017 (private)
New Jan 2017 (private)
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PubMed
Combined data set
Data set for title/abstract screening
Excluded - PECO criteria not met (TIAB)
Other
•
Naphthalene (2021 Evidence mapping publication)
Database searches - Jan 2017 (private)
New Jan 2017 (private)
Database Searches
PubMed
Combined data set
Data set for title/abstract screening
Excluded – PECO criteria not met
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