A very rapid electronic relaxation process in a highly conjugated Zn(ii)porphyrin–[26]hexaphyrin–Zn(ii)porphyrin hybrid tape

2016 ◽  
Vol 18 (4) ◽  
pp. 3244-3249 ◽  
Author(s):  
Sangsu Lee ◽  
Hirotaka Mori ◽  
Taegon Lee ◽  
Manho Lim ◽  
Atsuhiro Osuka ◽  
...  
Keyword(s):  
Relaxation Process ◽  
Vibrational Relaxation ◽  
Energy Relaxation ◽  
Relaxation Processes ◽  
Electronic Relaxation ◽  
Vibronic State ◽  
Molecular Systems

We demonstrate that the electronic deactivation overtakes the vibrational relaxation processes in the energy relaxation processes from the initially excited vibronic state manifolds in highly conjugated molecular systems.

scholarly journals Фемтосекундная абсорбционная спектроскопия восстановленной и окисленной форм цитохром c оксидазы: возбужденные состояния и релаксационные процессы в гемовых центрах a и a-=SUB=-3-=/SUB=-

2019 ◽  
Vol 127 (10) ◽  
pp. 697
Author(s):  
И.В. Шелаев ◽  
Ф.Е. Гостев ◽  
Т.В. Выгодина ◽  
С.В. Лепешкевич ◽  
Б.М. Джагаров
Keyword(s):  
Cytochrome C ◽  
Excitation Energy ◽  
Cytochrome C Oxidase ◽  
Ground State ◽  
Vibrational Relaxation ◽  
Vibrational Energy ◽  
Relaxation Processes ◽  
Electronic Relaxation ◽  
Electronic Excitation Energy ◽  
Reduced Forms

AbstractExcited electronic states and intraheme relaxation processes in the oxidized and reduced forms of mitochondrial cytochrome c oxidase extracted from a beef heart have been investigated by femtosecond absorption spectroscopy. The spectral and kinetic characteristics of short-lived intermediates have been measured from 80 fs to 20 ps after the photoexcitation. It is found that nonradiative electronic relaxation of the excitation energy in heme a , both in the oxidized (Fe(III) a ) and reduced (Fe(II) a ) forms, occurs successively as three processes, after the end of which heme a is in the ground state with a large store of vibrational energy. The subsequent vibrational relaxation (heme cooling) lasts for several picoseconds. It is found for reduced heme a _3 (Fe(II) a _3) that the electronic relaxation occurs as a result of two successive stages, which changes to vibrational relaxation in the ground state. The mechanism and dynamics of electronic excitation energy conversion in cytochrome c oxidase are analyzed.

Femtosecond UV Studies of the Electronic Relaxation Processes in Cytochromec

2011 ◽  
Vol 115 (46) ◽  
pp. 13723-13730 ◽  
Author(s):  
Olivier Bräm ◽  
Cristina Consani ◽  
Andrea Cannizzo ◽  
Majed Chergui
Keyword(s):  
Relaxation Processes ◽  
Electronic Relaxation

scholarly journals The Dynamic Properties of 5Cb Filled with Aerosil Particles Investigated by Pcs

1999 ◽  
Vol 559 ◽  
Author(s):  
F.M. Aliev ◽  
M. Kreuzer ◽  
Yu.P. Panarin
Keyword(s):  
Liquid Crystal ◽  
Temperature Dependence ◽  
Relaxation Process ◽  
Nematic Liquid Crystal ◽  
Broad Spectrum ◽  
Dynamic Properties ◽  
Relaxation Times ◽  
Correlation Spectroscopy ◽  
Relaxation Processes ◽  
Optoelectronic Application

ABSTRACTNematic liquid crystal filled with Aerosil particles, a prospective composite material for optoelectronic application, has been investigated by static light scattering and Photon Correlation Spectroscopy (PCS). The Aerosil particles in filled nematic liquid crystals (FN) form a network structure with LC domains about 2500 Å in size with a random distribution of the director orientation of each domain.We found that the properties of 5CB are considerably affected by the network. The N-I phase transition in filled 5CB was found to be smeared out and depressed. PCS experiments show that two new relaxation processes appear in filled 5CB in addition to the director fluctuation process in bulk. The slow relaxation process, with a broad spectrum of relaxation times, is somewhat similar to the slow decay, which is observed in confined nematic liquid crystal.The middle frequency process was assigned to the director fluctuations in the surface layer formed at the particle-LC interface. The decay function describing this relaxation process is a stretched exponential (β ≍ 0.7). The temperature dependence of the relaxation times of the middle frequency obeys the Vogel-Rilcher law. Such a temperature dependence, accompanied by a broad spectrum of relaxation times suggests that the dynamics of the director fluctuations near the Aerosil particle-LC interface is glass-like.

Structural Relaxation Process in CuHfTi Amorphous Alloys

2009 ◽  
Vol 283-286 ◽  
pp. 533-538 ◽  
Author(s):  
Kazumasa Yamada ◽  
N. Shinagawa ◽  
M. Sogame ◽  
I.A. Figueroa ◽  
Hywel A. Davies ◽  
...  
Keyword(s):  
Activation Energy ◽  
Relaxation Process ◽  
Structural Relaxation ◽  
Amorphous Alloys ◽  
Melt Spinning ◽  
Amorphous Materials ◽  
Ternary Alloys ◽  
Relaxation Processes ◽  
Scanning Calorimetry ◽  
Structure Relaxation

The aim of this research is to clarify a quantitative evaluation in the structural relaxation processes focusing on the activation energy in Cu based amorphous alloys. The activation energy for structural relaxation process in a metal type amorphous CuHfTi ternary alloys, with cross sections of typically 0.03 mm x 2.0 mm, prepared by chill-block melt spinning has been investigated by Differential Scanning Calorimetry (DSC) with a cyclically heating technique. Activation energies for structural relaxation with a spatial quantity in amorphous materials have been discussed by use of a relaxed ratio function that depends on annealing temperature and time. In the present work, the distributions for the Activation Energy Spectrum (AES) were observed almost 152 kJmol-1 (1.58 eV). Another result has been also established that the “reversible” AES model energy distribution though the cyclically structure relaxation occurs even in amorphous Cu60Hf20Ti20 alloy.

Sign in / Sign up

Export Citation Format

Share Document