Li Xiaobo, Patterson Howard H
Department of Chemistry, University of Maine, Orono, ME 04469, USA.
Department of Chemistry, University of Rhode Island, Kingston, RI 02881, USA.
Materials (Basel). 2013 Jun 25;6(7):2595-2611. doi: 10.3390/ma6072595.
Dicyanoaurate, dicyanoargentate, and dicyanocuprate ions in solution and doped in different alkali halide hosts exhibit interesting photophysical and photochemical behavior, such as multiple emission bands, exciplex tuning, optical memory, and thermochromism. This is attributed to the formation of different sizes of nanoclusters in solution and in doped hosts. A series of spectroscopic methods (luminescence, UV-reflectance, IR, and Raman) as well as theoretical calculations have confirmed the existence of excimers and exciplexes. This leads to the tunability of these nano systems over a wide wavelength interval. The population of these nanoclusters varies with temperature and external laser irradiation, which explains the thermochromism and optical memory. DFT calculations indicate an MLCT transition for each nanocluster and the emission energy decreases with increasing cluster size. This is in agreement with the relatively long life-time for the emission peaks and the multiple emission peaks dependence upon cluster concentration.
溶液中以及掺杂在不同碱金属卤化物主体中的二氰合金酸盐、二氰银酸盐和二氰铜酸盐离子表现出有趣的光物理和光化学行为，如多重发射带、激基复合物调谐、光学记忆和热致变色。这归因于在溶液和掺杂主体中形成了不同尺寸的纳米团簇。一系列光谱方法（发光、紫外反射、红外和拉曼）以及理论计算证实了准分子和激基复合物的存在。这导致了这些纳米系统在很宽的波长区间内具有可调谐性。这些纳米团簇的数量随温度和外部激光照射而变化，这解释了热致变色和光学记忆现象。密度泛函理论计算表明每个纳米团簇都有一个金属-配体电荷转移跃迁，并且发射能量随团簇尺寸的增加而降低。这与发射峰相对较长的寿命以及多重发射峰对团簇浓度的依赖性相一致。
