Ground- and excited-state spectroscopic studies on [1-(4-methoxyphenyl)-3-(amino)-2,4-(dicyano)-9,10-tetrahydrophenanthrene]. 1996

I A Al-Ansari
Department of Chemistry, Faculty of Science, University of Qatar, P.O. Box 2713, Doha, Qatar.

The effects of polar and nonpolar solvents on both the ground and the excited-state properties of [1-(4-methoxyphenyl)-3-(amino)-2,4-(dicyano)-9,10-tetrahydrophenanthrene] is examined. Light absorption results in a population of a locally excited (LE) first singlet state (S1,nπ(*)) which shows sensitivity to the polarity of the surrounding solvent and hydrogen-bonding ability to the quencher 4-methylpyridine. Relaxation of this state leads to an intramolecular charge-transfer state (ICT) which leads to a large Stokes shift in polar solvents and an excited-state dipole moment of μe= 10D. The quenching of the fluorescence state by 4-methylpyridine studied inn-hexane and acetonitrile at room temperature is found to be efficient and a positive deviation from linearity was observed in the Stern-Volmer plots even at concentrations of 4-methylpyridine below 0.4M. This is explained as a result of the occurrence of both a dynamic and a static quenching mechanism. The static quenching constants (K sv) along with those obtained by visible spectroscopy (K GS) indicate that the ground-state complex is weak and relatively solvent dependent.

UI MeSH Term Description Entries

Related Publications

I A Al-Ansari
May 2013, The journal of physical chemistry. A,
I A Al-Ansari
November 2012, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy,
I A Al-Ansari
April 2012, Acta crystallographica. Section E, Structure reports online,
I A Al-Ansari
April 2012, Acta crystallographica. Section E, Structure reports online,
I A Al-Ansari
March 2020, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy,
I A Al-Ansari
February 2012, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy,
I A Al-Ansari
July 2006, Acta crystallographica. Section C, Crystal structure communications,
I A Al-Ansari
June 1972, Journal of medicinal chemistry,
Copied contents to your clipboard!