Excited state conformational dynamics of semiflexibly bridged electron donor-acceptor systems: a semiempirical CI-study including solvent effects.
Semiempirical (AM1) molecular orbital theory with configuration interaction has been used to investigate the harpooning mechanism proposed from experimental studies on semiflexibly bridged electron donor-acceptor systems. Our calculations on the charge-transfer state of N-phenyl-4-(4-cyano-naphth-1-ylmethyl)-piperidine, 1, confirm the proposed harpooning mechanism including an intermediate loosely folded charge-transfer state and reproduce the thermodynamics obtained from our spectroscopic studies closely. The structural details of the extended (ECT), intermediate (ICT) and compact (CCT) charge-transfer states are discussed, as are the transition states connecting them. Solvent effects have been modeled using self-consistent reaction field (SCRF) calculations within the polarized continuum model. The effect of solvent polarity on the stabilities of the three charge-transfer states is discussed.
Computer-Chemie-Centrum der Universität Erlangen-Nürnberg, Nägelsbachstrasse 25, 91054 Erlangen, Germany. Clark@chemie.uni-erlangen.de
Timothy
T
Clark
Bernd
B
Bleisteiner
Siegfried
S
Schneider
D003198:Computer Simulation; D004583:Electrons; D036262:Empirical Research; D005740:Gases / Q000737:chemistry; D006586:Hexanes / Q000737:chemistry; D017136:Ion Transport; D008958:Models, Molecular; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry*; D010880:Piperidines / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis; D055672:Static Electricity
D005740:Gases; D006586:Hexanes; C477273:N-phenyl-4-(4-cyano-naphth-1-ylmethyl)piperidine; D009281:Naphthalenes; D010880:Piperidines; D012997:Solvents