Dian Brian C, Clarkson Jasper R, Zwier Timothy S
Department of Chemistry, Purdue University, West Lafayette, IN 47907-2084, USA.
Science. 2004 Feb 20;303(5661):1169-73. doi: 10.1126/science.1093731.
Stimulated emission pumping (SEP)-hole filling spectroscopy and SEP-induced population transfer spectroscopy have been used to place narrow bounds on the energy thresholds for isomerization between individual reactant-product isomer pairs involving the seven conformational minima of tryptamine. The thresholds for isomerizing conformer A to all six other conformations divided into three groups at 750 wavenumbers (cm-1)(A-->B, F), 1000 cm-1 [A-->C(2)], and 1280 to 1320 cm-1 [A-->D, E, and C(1)]. The appearance of the first band and the absence of the band below it were used to place upper and lower bounds to the barrier heights for each process. The thresholds for A-->B and B-->A isomerizations were also combined to determine the relative energies of these two lowest energy minima. The combined data from all X-->Y isomerizations identify important isomerization pathways on the potential energy surface linking the minima.
受激发射泵浦（SEP）-空穴填充光谱法和SEP诱导的布居转移光谱法已被用于对涉及色胺七个构象极小值的各个反应物-产物异构体对之间异构化的能量阈值进行精确界定。构象异构体A异构化为其他六个构象的阈值分为三组，分别在750波数（厘米⁻¹）（A→B、F）、1000厘米⁻¹ [A→C(2)] 和1280至1320厘米⁻¹ [A→D、E和C(1)]。利用第一条谱带的出现及其下方谱带的缺失来确定每个过程势垒高度的上限和下限。A→B和B→A异构化的阈值也被结合起来以确定这两个最低能量极小值的相对能量。来自所有X→Y异构化的综合数据确定了势能面上连接这些极小值的重要异构化途径。
