1. Institute of Chemical Physics Research, Russian Academy of Sciences, 142432 Chernogolovka, Moscow Region, Russia, Center of Photochemistry, Russian Academy of Sciences, 7a ul. Novatorov, 117421 Moscow, Russia, Istituto FRAE-CNR, Via P. Gobetti 101, 40129 Bologna, Italy, and Dipartimento di Chimica, Università di Bologna, 40126 Bologna, Italy