Lehnig Rudolf, Slipchenko Mikhail, Kuma Susumu, Momose Takamasa, Sartakov Boris, Vilesov Andrey
Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA.
J Chem Phys. 2004 Nov 15;121(19):9396-405. doi: 10.1063/1.1804945.
The laser-induced fluorescence (LIF) excitation spectra of free base phthalocyanine (Pc), Mg-Pc, and Zn-Pc molecules in superfluid helium droplets at T=0.38 K have been studied. The spectra reveal the rich vibronic structure of the S(1)<--S(0) electronic transitions. The band origins of the transitions consist of zero phonon lines accompanied by phonon wings, which originate from simultaneous electronic excitation of the molecule and excitation of the collective modes of the helium surrounding it. The phonon wings have discrete structures suggesting localization of some helium atoms in the neighborhood of the molecules. Zero phonon lines of Mg-Pc and Zn-Pc molecules are split into three components, which are separated by 0.2-0.4 cm(-1). Possible mechanism of splitting involves static or dynamic Jahn-Teller interaction of metal-phthalocyanine molecules in the twofold degenerate S(1)((1)E(u)) state with the helium shell.
研究了在T = 0.38 K的超流氦滴中，游离碱酞菁（Pc）、Mg-Pc和Zn-Pc分子的激光诱导荧光（LIF）激发光谱。这些光谱揭示了S(1)<--S(0)电子跃迁丰富的振转结构。跃迁的带起源由零声子线以及声子翼组成，声子翼源于分子的同时电子激发和其周围氦的集体模式激发。声子翼具有离散结构，表明分子附近一些氦原子的局域化。Mg-Pc和Zn-Pc分子的零声子线分裂为三个分量，它们相隔0.2 - 0.4 cm(-1)。分裂的可能机制涉及处于双重简并S(1)((1)E(u))态的金属 - 酞菁分子与氦壳的静态或动态 Jahn - Teller 相互作用。
