TY  - GEN
A1  - Banerjee, Shiladitya
A1  - Stüker, Tony
A1  - Saalfrank, Peter
T1  - Vibrationally resolved optical spectra of modified diamondoids obtained from time-dependent correlation function methods
N2  - Optical properties of modified diamondoids have been studied theoretically using vibrationally resolved electronic absorption, emission and resonance Raman spectra. A time-dependent correlation function approach has been used for electronic two-state models, comprising a ground state (g) and a bright, excited state (e), the latter determined from linear-response, time-dependent density functional theory (TD-DFT). The harmonic and Condon approximations were adopted. In most cases origin shifts, frequency alteration and Duschinsky rotation in excited states were considered. For other cases where no excited state geometry optimization and normal mode analysis were possible or desired, a short-time approximation was used. The optical properties and spectra have been computed for (i) a set of recently synthesized sp2/sp3 hybrid species with C[double bond, length as m-dash]C double-bond connected saturated diamondoid subunits, (ii) functionalized (mostly by thiol or thione groups) diamondoids and (iii) urotropine and other C-substituted diamondoids. The ultimate goal is to tailor optical and electronic features of diamondoids by electronic blending, functionalization and substitution, based on a molecular-level understanding of the ongoing photophysics.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 211 
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-86826
ER  - 
TY  - GEN
A1  - Schulze, Michael
A1  - Utecht, Manuel Martin
A1  - Moldt, Thomas
A1  - Przyrembel, Daniel
A1  - Gahl, Cornelius
A1  - Weinelt, Martin
A1  - Saalfrank, Peter
A1  - Tegeder, Petra
T1  - Nonlinear optical response of photochromic azobenzene-functionalized self-assembled monolayers
N2  - The combination of photochromic and nonlinear optical (NLO) properties of azobenzene-functionalized self-assembled monolayers (SAMs) constitutes an intriguing step towards novel photonic and optoelectronic devices. By utilizing the second-order NLO process of second harmonic generation (SHG), supported by density-functional theory and correlated wave function method calculations, we demonstrate that the photochromic interface provides the necessary prerequisites en route towards possible future technical applications: we find a high NLO contrast on the order of 16% between the switching states. These are furthermore accessible reversibly and with high efficiencies in terms of cross sections on the order of 10−18 cm2 for both photoisomerization reactions, i.e., drivable by means of low-power LED light sources. Finally, both photostationary states (PSSs) are thermally stable at ambient conditions.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 196 
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-81198
ER  - 
TY  - GEN
A1  - Matis, Jochen René
A1  - Schönborn, Jan Boyke
A1  - Saalfrank, Peter
T1  - A multi-reference study of the byproduct formation for a ring-closed dithienylethene photoswitch
N2  - Photodriven molecular switches are sometimes hindered in their performance by forming byproducts which act as dead ends in sequences of switching cycles, leading to rapid fatigue effects. Understanding the reaction pathways to unwanted byproducts is a prerequisite for preventing them. This article presents a study of the photochemical reaction pathways for byproduct formation in the photochromic switch 1,2-bis-(3-thienyl)-ethene. Specifically, using single- and multi-reference methods the post-deexcitation reaction towards the byproduct in the electronic ground state S0 when starting from the S1–S0 conical intersection (CoIn), is considered in detail. We find an unusual low-energy pathway, which offers the possibility for the formation of a dyotropic byproduct. Several high-energy pathways can be excluded with high probability.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 215 
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-89594
SP  - 14088
EP  - 14095
ER  -