He Xuemei, Xu Fengmin, Yu Pengyun, Wu Yanzhou, Wang Fuyi, Zhao Yao, Wang Jianping
Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
Phys Chem Chem Phys. 2018 Apr 18;20(15):9984-9996. doi: 10.1039/c7cp08606g.
The vibrational and anisotropic relaxation dynamics and structural dynamics of a potential anticancer prodrug, trans,trans,trans-[Pt(N3)2(OH)2(py)2], were investigated using time-resolved infrared pump-probe spectroscopy and ultrafast two-dimensional infrared (2D IR) spectroscopy. Herein, two representative bio-friendly solvents, H2O and DMSO, were used, in which the local structural and dynamical variations were monitored using the antisymmetric linear combination of the two N3 stretching vibrational modes as an infrared probe. It was found that the vibrational relaxation process of the N3 antisymmetric stretching (as) mode in H2O is two to three times faster than that in DMSO. The anisotropic relaxation process of the anticancer prodrug was observed to be hindered in DMSO; this indicated a tighter solvent environment around the sample molecule in this solvent. The vibrational frequency time correlation of the N3 antisymmetric stretching mode in H2O decays with a time constant of 1.94 ps, in agreement with the hydrogen bond formation and breaking times of water. In DMSO, the frequency time correlation of the N3 as mode decays on a much longer time scale; this further indicates its sensitivity to the out-layer DMSO structural dynamics, which are relatively static in the experimental time window.
利用时间分辨红外泵浦-探测光谱和超快二维红外（2D IR）光谱，研究了一种潜在的抗癌前药反式、反式、反式-[Pt(N₃)₂(OH)₂(py)₂]的振动和各向异性弛豫动力学以及结构动力学。在此，使用了两种具有代表性的生物友好型溶剂，即水和二甲基亚砜（DMSO），其中利用两个N₃伸缩振动模式的反对称线性组合作为红外探针来监测局部结构和动力学变化。研究发现，水中N₃反对称伸缩（as）模式的振动弛豫过程比在二甲基亚砜中快两到三倍。观察到抗癌前药在二甲基亚砜中的各向异性弛豫过程受到阻碍；这表明在该溶剂中样品分子周围的溶剂环境更紧密。水中N₃反对称伸缩模式的振动频率时间相关性以1.94皮秒的时间常数衰减，这与水的氢键形成和断裂时间一致。在二甲基亚砜中，N₃ as模式的频率时间相关性在长得多的时间尺度上衰减；这进一步表明其对外层二甲基亚砜结构动力学的敏感性，而在实验时间窗口内，外层二甲基亚砜结构动力学相对静止。
