Fakhri O Yousef, Raed Ghanem, Omar K Almashaqbeh, Ihsan A Shehadi
{"title":"Investigation of H-Bonding and pH on the Fluorescence Spectral Behavior of Valsartan.","authors":"Fakhri O Yousef, Raed Ghanem, Omar K Almashaqbeh, Ihsan A Shehadi","doi":"10.1007/s10895-024-04002-2","DOIUrl":null,"url":null,"abstract":"<p><p>The photophysical properties of valsartan (VAL), a potent phenyl tetrazole derivative sartan, were investigated. Valsartan has absorption bands at 230 nm and 255 nm and a fluorescence band at about [Formula: see text] = 346 nm in butanol which is red shifted depending on the H-bonding capability of the solvent. The role of H-bonding in the excited state was approved through the linear correlation of the emission energy of VAL with Camlet-Taft acidity and basicity parameters, α and β, of polar protic solvents. The position and intensity of fluorescence emission bands of VAL are found to be pH dependent, shifting from 425 nm at pH 2 to 375 nm at pH 4 with enhancement of intermolecular H-bonding and fluorescence intensity depletion beyond pH 5 with formation of tetrazole anion. The results were supported by time-resolved fluorescence measurements which indicated the presence of different species with different lifetimes in the excited state depending on solution pH value. Computational results based on time dependent density functional methods (TDDFT) show that the tetrazole moiety is involved in the [Formula: see text] absorption transitions, while natural bond analysis (NBO) shows that VAL adopts a dimer conformation in water because of effective intermolecular H-bonding.</p>","PeriodicalId":15800,"journal":{"name":"Journal of Fluorescence","volume":null,"pages":null},"PeriodicalIF":2.6000,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Fluorescence","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1007/s10895-024-04002-2","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMICAL RESEARCH METHODS","Score":null,"Total":0}
引用次数: 0
Abstract
The photophysical properties of valsartan (VAL), a potent phenyl tetrazole derivative sartan, were investigated. Valsartan has absorption bands at 230 nm and 255 nm and a fluorescence band at about [Formula: see text] = 346 nm in butanol which is red shifted depending on the H-bonding capability of the solvent. The role of H-bonding in the excited state was approved through the linear correlation of the emission energy of VAL with Camlet-Taft acidity and basicity parameters, α and β, of polar protic solvents. The position and intensity of fluorescence emission bands of VAL are found to be pH dependent, shifting from 425 nm at pH 2 to 375 nm at pH 4 with enhancement of intermolecular H-bonding and fluorescence intensity depletion beyond pH 5 with formation of tetrazole anion. The results were supported by time-resolved fluorescence measurements which indicated the presence of different species with different lifetimes in the excited state depending on solution pH value. Computational results based on time dependent density functional methods (TDDFT) show that the tetrazole moiety is involved in the [Formula: see text] absorption transitions, while natural bond analysis (NBO) shows that VAL adopts a dimer conformation in water because of effective intermolecular H-bonding.
期刊介绍:
Journal of Fluorescence is an international forum for the publication of peer-reviewed original articles that advance the practice of this established spectroscopic technique. Topics covered include advances in theory/and or data analysis, studies of the photophysics of aromatic molecules, solvent, and environmental effects, development of stationary or time-resolved measurements, advances in fluorescence microscopy, imaging, photobleaching/recovery measurements, and/or phosphorescence for studies of cell biology, chemical biology and the advanced uses of fluorescence in flow cytometry/analysis, immunology, high throughput screening/drug discovery, DNA sequencing/arrays, genomics and proteomics. Typical applications might include studies of macromolecular dynamics and conformation, intracellular chemistry, and gene expression. The journal also publishes papers that describe the synthesis and characterization of new fluorophores, particularly those displaying unique sensitivities and/or optical properties. In addition to original articles, the Journal also publishes reviews, rapid communications, short communications, letters to the editor, topical news articles, and technical and design notes.