Light-induced excited state X-ray crystallography of multinuclear copper complexes

多核Cu（I）配合物如[CuI（py）]4在紫外光照射下显示出发光。在光激发态下，金属团簇核的畸变是可以预期的。为了通过单晶X射线衍射分析直接观察光激发态的分子畸变，我们开发了衍射仪，建立了激发态结构精细计算，并对目标化合物进行了调查。在“低温真空X射线照相机”上安装了光照明装置，用于在低温下获得低噪声衍射图像。多重曝光成像板（IP）方法是本项目开发并安装在该相机中的一种新的检测技术，通过该方法，在光照射和非照射条件下测量的衍射图案都记录在同一IP上。X射线照相机已经安装在使用高亮度X射线辐射源的Spring-8光束线上。光照射晶体中的分子畸变可以通过差分傅立叶合成来检测，该差分傅立叶合成使用X射线衍射强度在光打开和关闭条件之间的变化，然后使用最小二乘精化来定性计算晶体中的激发态布居和几何变化。本文报道了在蓝光激光照射下，α-双铂（Ⅱ）配合物（Bu_4N）_2H_2[Pt_2（pop）_4]单晶的结构分析。1.4%人口的光激发分子在蓝色激光照射下显示出0.23 A的Pt-Pt键收缩，这与光谱研究一致。

Multinuclear Cu(I) complexes such as [Cul(py)]4 have shown luminescent by UV light irradiation. In the photoexcited states, distortion of metal cluster core has been expected. To observe this molecular distortion in the photoexcited states directly by single crystal X-ray diffraction analyses, we have performed development of a diffractometer, establishment of excited states structure refinement calculations, and survey of target compounds. Light illuminating devices has been installed in the "low-temperature vacuum X-ray camera" which are designed for obtaining low noise diffraction images at low temperature. The multiple-exposure image plate (IP) method is a new detection technique developed in this project and installed in this camera, by which both diffraction patterns measured for light irradiated and non-irradiated conditions are recorded on the same IP. The X-ray camera has settled in a Spring-8 beamline utilizing highbrilliant X-ray radiation sources. Molecular distortion in the light irradiated crystal can be detected by a differential Fourier syntheses using X-ray diffraction intensity changes between light-on and off conditions, followed by qualitative calculation of excited state population and geometrical changes in a crystal, using least square refinements. Structure analysis of a luminescent a diplatinum(II) complex (Bu_4N)_2H_2[Pt_2(pop)_4] single crystal under blue laser irradiation has been successfully performed. Photoexcited molecule of 1.4% population shows Pt-Pt bond shrinkage of 0.23 A under blue laser irradiation which is consistent with spectroscopic investigations.