title: Resonance Raman spectra of n-pi* singlet-triplet transition of p-benzoquinone at low concentrations.
abstract: A weak visible absorption spectrum of p-benzoquinone (p-BQ) in CS2 due to n-pi* singlet-triplet transition was measured. Using the resonance Raman (RR) effect in liquid-core optical fiber (LCOF), we have obtained the 514.5 nm excited RR spectra of p-benzoquinone near 1445 cm(-1) and have demonstrated that the new characteristic RR band is attributed to the symmetric C=O stretch (nu(C=O)) of n-pi* singlet-triplet transition of p-BQ. The effect of solution concentration on the RR band was investigated at very low concentrations. The RR peak spreads toward short wavelength side with decreasing solution concentration ranging from 10(-7) to 10(-11) mol L(-1), whereas the blue-shift isn't obvious when the concentration is, at single molecule level, lower than 10(-11) mol L(-1). Our result is useful for single molecule detection to some extent.
authors.affiliation: Key Laboratory of Coherent Light, Atomic and Molecular Spectroscopy, College of physics, Jilin University, Educational Ministry of China, Changchun 130023, PR China.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Yin
authors.forename: Zuo-Wei
authors.initials: ZW
authors.lastname: Li
mesh_terms: D016227:Benzoquinones / Q000737:chemistry*; D006860:Hydrogen Bonding; D010084:Oxidation-Reduction; D013059:Spectrum Analysis, Raman
chemical_list: D016227:Benzoquinones; C004532:quinone