title: Hydrogen bonding and solvatochromatic shift of the lowest 1(n, pi*) excitation of s-tetrazine in its hydrated clusters and dilute solutions.
abstract: Hydrogen bonding involving azine and its derivatives such as nucleic bases is very important for understanding the structure and function of biological systems. In this work, we have investigated the hydrogen bonding structures of the hydrated cluster and dilute aqueous solution of s-tetrazine using computer simulation techniques, and evaluated the absorption and fluorescence shifts of the lowest 1(n, pi*) excitation of s-tetrazine solution using our solvent shift method. For the s-tetrazine-water cluster, a linear orthodox hydrogen bond arrangement is predicted in both ground and excited states with small structural and energetic differences, and a bifurcated hydrogen bond isomerization is anticipated. Further, ab initio calculations have verified these conformations. For the s-tetrazine-water solution, a mixture of two hydrogen bonding arrangements is found to be in both ground and excited states, resulting in small magnitudes of absorption and fluorescence solvent shifts. This finalizes our series investigation of hydrogen bonding and solvent shifts of dilute azines in water.
authors.affiliation: Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, Department of Chemistry, Nanjing University, Nanjing, 210093, People's Republic of China. dqxie@nju.edu.cn
authors.forename: Daiqian
authors.initials: D
authors.lastname: Xie
authors.forename: Jun
authors.initials: J
authors.lastname: Zeng