Frequency-dependent absorption coefficients and refractive indices of amino acids (glycine and l-alanine) and polypeptides (polyglycine and poly-l-alanine) in the wavenumber region from 7 to 55 cm−1 were measured by terahertz time-domain spectroscopy. A vibrational band was observed at 45.5 cm−1 for polyglycine, which was assigned as an interchain mode. The reduced absorption cross sections of the amino acids and polypeptides show power-law behavior. The exponents are different between the monomers and polymers, and those of the two polypeptides suggest that the time dependences of the total dipole moments are similar in the timescale of subpico- to picoseconds.
展开▼
机译：通过测量波数在7至55 cm -1 范围内的氨基酸（甘氨酸和1-丙氨酸）和多肽（聚甘氨酸和聚-1-丙氨酸）的频率依赖性吸收系数和折射率。太赫兹时域光谱。聚甘氨酸在45.5 cm -1 处观察到一个振动带，该振动带被指定为链间模式。氨基酸和多肽吸收截面的减小显示幂律行为。单体和聚合物之间的指数不同，两种多肽的指数表明，在亚皮秒到皮秒的时间范围内，总偶极矩的时间依赖性相似。
展开▼
