A SPECTROSCOPIC THERMODYNAMIC STUDY OF THE RHODAMINE-B LACTONE REVERSIBLE ZWITTERION EQUILIBRIUM
A SPECTROSCOPIC THERMODYNAMIC STUDY OF THE RHODAMINE-B LACTONE REVERSIBLE ZWITTERION EQUILIBRIUM
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DOI：
10.1016/0584-8539(88)80227-7
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发表时间：
1988-01-01
影响因子：
4.4
通讯作者：
SEYBOLD, PG
中科院分区：
文献类型：
--
作者：
HINCKLEY, DA;SEYBOLD, PG
已经检查了罗丹明B（RB）在水和18种醇溶剂中的可见吸收光谱的温度依赖性，并用于估计热力学参数（Δ G °，Δ H °，$. degree.）对于RB内酯. dblarw. zwittera（L.dblarw. Z）在这些溶剂中的平衡。从L.dblarw.在强氢键溶剂三氟乙醇中的Z平衡具有ε的本征RB两性摩尔吸光系数。= 1.30 ×105 dm3/mol. cm估计。热力学结果表明，RB L. dblarw. Z平衡强烈地受溶剂的自缔合的影响。脂肪醇中的平衡位置可以从溶剂分子的简单特征来预测。讨论了从吸收光谱计算荧光态自然辐射寿命的结果的后果。
Temperature dependence of the visible absorption spectra of rhodamine B (RB) in water and 18 alcohol solvents have been examined and utilized to estimate thermodynamic parameters (.DELTA.G.degree., .DELTA.H.degree., $.degree.) for the RB lactone .dblarw. zwitterion (L .dblarw. Z) equilibria in these solvents. From the L .dblarw. Z equilibrium in the strong hydrogen-bonding solvent trifluoroethanol an intrinsic RB zwitterion molar absorptivity of .epsilon. = 1.30 .times. 105 dm3/mol .cntdot. cm is estimated. The thermodynamic results suggest that the position of the RB L .dblarw. Z equilibrium is strongly influenced by self-association of the solvent. The position of the equilibrium in aliphatic alcohols can be predicted from simple features of the solvent molecules. Consequences of the results regarding calculation of the natural radiative lifetime of the fluorescent state from the absorption spectrum are discussed.