Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93053 Regensburg, Germany.
Fritz-Haber-Insitut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.
J Chem Phys. 2018 Dec 28;149(24):244306. doi: 10.1063/1.5052615.
We investigate the line shape at the electronic origin of single porphine molecules doped into superfluid helium droplets as a function of the droplet size. Helium droplets comprised of less than 10 atoms are generated from an expansion of gaseous helium, while droplets with more than 10 atoms originate from liquid helium. In contrast to our recent study on phthalocyanine, porphine is found to exhibit a solvent shift to the blue with respect to the gas-phase resonance frequency as well as a multiplet splitting. A comparison of the helium-induced features of phthalocyanine and porphine with those obtained in similar studies on tetracene and pentacene reveals that these occur chiefly as two kinds of excitations distinguished by their linewidths and their dependence on the droplet size. Moreover, at quasi-bulk conditions achieved with droplets in excess of 10 helium atoms, none of these four dopant species yields an optical spectrum that can be assigned to a plausible rotational band structure.
我们研究了掺杂在超流氦液滴中单卟啉分子的电子起源线形状，作为液滴尺寸的函数。由气态氦膨胀产生的氦液滴包含少于 10 个原子，而具有多于 10 个原子的液滴则来自液态氦。与我们最近对酞菁的研究相比，卟啉相对于气相共振频率蓝移以及多重分裂显示出溶剂位移。将酞菁和卟啉的氦致特征与在类似的研究中获得的四烯和五烯的特征进行比较表明，这些主要以两种激发态的形式出现，它们的线宽和对液滴尺寸的依赖性不同。此外，在使用超过 10 个氦原子的液滴达到准体相条件时，这四种掺杂物质都没有产生可以分配给合理的旋转带结构的光学光谱。
