Chemischer InformationsdienstVolume 17, Issue 11 Preparative Organic Chemistry ChemInform Abstract: Femtosecond Photofragment Spectroscopy: The Reaction ICN → CN + I. N. F. SCHERER, N. F. SCHERERSearch for more papers by this authorJ. L. KNEE, J. L. KNEESearch for more papers by this authorD. D. SMITH, D. D. SMITHSearch for more papers by this authorA. H. ZEWAIL, A. H. ZEWAILSearch for more papers by this author N. F. SCHERER, N. F. SCHERERSearch for more papers by this authorJ. L. KNEE, J. L. KNEESearch for more papers by this authorD. D. SMITH, D. D. SMITHSearch for more papers by this authorA. H. ZEWAIL, A. H. ZEWAILSearch for more papers by this author First published: March 18, 1986 https://doi.org/10.1002/chin.198611111AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume17, Issue11March 18, 1986 RelatedInformation

In this paper we study the temperature-induced homogeneous broadening of the no-phonon line in the emission spectrum of the F center in CaO. The linewidth can be fitted to n̄(n̄+1), where n̄ is the thermally averaged occupation number of phonons with a frequency of 90 cm−1. The results are characteristic of elastic scattering of pseudolocalized phonons at the defect site. These phonons also appear to dynamically couple the Jahn–Teller components of the F center in the photoexcited 3T1u state and thus give rise to a temperature dependence of the lifetime of this phosphorescent state. Finally, from experiments using laser-selective excitation it is concluded that the zero-phonon emission peaking at 571.1 nm does not originate in the F center.

In continuation of previous work, we present experimental measurements on the localization of triplet Frenkel excitons in isotopically doped phenazine and 1,4-dibromonaphthalene (2-D and 1-D effective excitation transfer topology, respectively). Dependence of steady state impurity aggregate (monomer, dimers, etc.) emission intensities on temperature, concentration of dopant, and the dimensionality is experimentally measured and theoretically modeled. Effects of phonons and excited state lifetimes are explicitly included in a numerical simulation of the data by average-lattice rate equations. The rate equations explain the major features of the experimental data quite well. For use in the rate equations, we have performed Monte Carlo experiments to determine cluster probabilities on 1-D and anisotropic 2-D lattices. Finally, the relevance of these findings to Anderson localization and percolation theory is discussed.

Measurements are presented of excitation transport in a qausi-1-D solid using time-resolved laser spectroscopy. Energy migration as a function of temperature and dopant concentration is describable in terms of step-wise incoherent transfer using a 1-D sampling function. The data indicate the effect of a superexchange interactoin between clusters.

Chemischer InformationsdienstVolume 10, Issue 48 Physical Organic Chemistry ChemInform Abstract: CHARACTERIZATION OF VIBRATIONAL OVERTONES AND “LOCAL” MODES BY EMISSION SPECTROSCOPY D. D. SMITH, D. D. SMITHSearch for more papers by this authorA. H. ZEWAIL, A. H. ZEWAILSearch for more papers by this author D. D. SMITH, D. D. SMITHSearch for more papers by this authorA. H. ZEWAIL, A. H. ZEWAILSearch for more papers by this author First published: November 27, 1979 https://doi.org/10.1002/chin.197948049AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue48November 27, 1979 RelatedInformation

We present clear evidence for the presence of Anderson's localization in molecular solids. Diagonal and off-diagonal disorder is introduced and controlled by substitutionally disordering the lattice at different temperatures. Optical and optically-detected magnetic resonance spectroscopy have been used to directly obtain the resonance interactions, the inhomogeneous site-energy fluctuations, and the threshold for Anderson's transition. The results on the two-dimensional lattice when compared with quasi-one-dimensional systems indicate that cross chain interactions and phonon-assisted processes are important in determining the nature of extended states in disordered systems.