Haldrup Kristoffer, Christensen Morten, Nielsen Martin Meedom
Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark.
Acta Crystallogr A. 2010 Mar;66(Pt 2):261-9. doi: 10.1107/S0108767309054233. Epub 2010 Feb 18.
As ultrafast time-resolved studies of liquid systems with the laser pump/X-ray scattering probe method have come of age over the past decade, several groups have developed methods for the analysis of such X-ray scattering data. The present article describes a method developed primarily with a focus on determining structural parameters in the excited states of medium-sized molecules (approximately 30 atoms) in solution. The general methodology is set in a maximum-likelihood framework and is introduced through the analysis of the photoactive platinum compound PtPOP, in particular the structure of its lowest triplet excited state ((3)A(2u)). Emphasis is put on structure determination in terms of model comparisons and on the information content of difference scattering signals as well as the related experimental variables. Several suggestions for improving the accuracy of these types of measurements are presented.
在过去十年中，随着采用激光泵浦/X射线散射探测方法对液体系统进行的超快时间分辨研究渐趋成熟，多个研究团队已开发出分析此类X射线散射数据的方法。本文介绍了一种主要为确定溶液中中等大小分子（约30个原子）激发态结构参数而开发的方法。该通用方法建立在最大似然框架内，并通过对光活性铂化合物PtPOP（特别是其最低三重激发态((3)A(2u))的结构）的分析来引入。重点在于通过模型比较进行结构测定，以及差分散射信号的信息含量和相关实验变量。文中还提出了一些提高此类测量准确性的建议。
