Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2 A, D-12489 Berlin, Germany.
J Phys Chem A. 2012 Jul 26;116(29):7636-44. doi: 10.1021/jp303864m. Epub 2012 Jul 18.
The N-H stretching vibrations of adenine, one of the building blocks of DNA, are studied by combining infrared absorption and nonlinear two-dimensional infrared spectroscopy with ab initio calculations. We determine diagonal and off-diagonal anharmonicities of N-H stretching vibrations in chemically modified adenosine monomer dissolved in chloroform. For the single-quantum excitation manifold, the normal mode picture with symmetric and asymmetric NH(2) stretching vibrations is fully appropriate. For the two-quantum excitation manifold, however, the interplay between intermode coupling and frequency shifts due to a large diagonal anharmonicity leads to a situation where strong mixing does not occur. We compare our findings with previously reported values obtained on overtone spectroscopy of coupled hydrogen stretching oscillators.
通过将红外吸收和非线性二维红外光谱与从头计算相结合，研究了 DNA 组成部分之一腺嘌呤的 N-H 伸缩振动。我们确定了溶解在氯仿中的化学修饰的腺苷单体内 N-H 伸缩振动的对角和非对角非谐性。对于单量子激发谱，具有对称和不对称 NH（2）伸缩振动的正则模式图像是完全合适的。然而，对于双量子激发谱，由于大的对角非谐性导致的模式间耦合和频率位移的相互作用导致强混合不会发生。我们将我们的发现与以前在耦合氢伸缩振荡器的倍频光谱学中报道的值进行了比较。
