scholarly journals Electronic Spectroscopy of Anthracene Cations and Protonated Anthracene in the Search for Carriers of Diffuse Interstellar Bands

2021 ◽  
Vol 913 (2) ◽  
pp. 136
Author(s):  
Miriam Meyer ◽  
Paul Martini ◽  
Arne Schiller ◽  
Fabio Zappa ◽  
Serge A. Krasnokutski ◽  
...  
Keyword(s):  
Electronic Spectroscopy ◽  
Diffuse Interstellar Bands

scholarly journals DIVISION B COMMISSION 14 WORKING GROUP: MOLECULAR DATA

2015 ◽  
Vol 11 (T29A) ◽  
pp. 137-152
Author(s):  
Steven R. Federman ◽  
Peter F. Bernath ◽  
Holger S.P. Müller
Keyword(s):  
Physical Chemistry ◽  
Working Group ◽  
Electronic Spectroscopy ◽  
Theoretical Work ◽  
Molecular Data ◽  
Related Research ◽  
The Past ◽  
Diffuse Interstellar Bands ◽  
The Many ◽  
Current Report

The current report covers the period from the second half of 2011 to late 2014. It is divided into three areas covering rotational, vibrational, and electronic spectroscopy. A signifcant amount of experimental and theoretical work has been accomplished over the past three years, leading to the development and expansion of a number of databases whose links are provided below. Two notable publications have appeared recently: An issue of The Journal of Physical Chemistry A in 2013 honoring the many contributions of Takeshi Oka (J. Phys. Chem. A, 117, pp. 9305-10143); and IAU Symposium 297 on Diffuse Interstellar Bands (Cami & Cox 2014). A number of the relevant papers from these volumes are cited in what follows. Related research on collisions, reactions on grain surfaces, and astrochemistry are not included here.

Electronic spectroscopy of the nonlinear carbon chains C4H4+ and C8H4+

2004 ◽  
Vol 82 (6) ◽  
pp. 848-853 ◽  
Author(s):  
Mitsunori Araki ◽  
Pawel Cias ◽  
Alexey Denisov ◽  
Jan Fulara ◽  
John P Maier
Keyword(s):  
Gas Phase ◽  
Electronic Transition ◽  
Electronic Spectroscopy ◽  
Carbon Chain ◽  
Cavity Ringdown Spectroscopy ◽  
Cavity Ringdown ◽  
Carbon Chains ◽  
Diffuse Interstellar Bands ◽  
Phase Spectra ◽  
Electronic Transition Energies

The electronic spectrum of a nonlinear carbon chain radical C4H4+ was observed after mass-selective deposition in a 6 K neon matrix. The corresponding gas-phase spectra of C4H4+ and C4D4+ have been observed in the 512 to 513 nm region and at 710 nm for C8H4+. These were detected in direct absorption by cavity ringdown spectroscopy through a supersonic planar discharge. The electronic transition energies of these nonlinear carbon chain radicals correlate well with those of the polyacetylene cations HCnH+ (n = 4, 6, 8). The observed profiles are reproduced with rotational constants obtained by ab initio geometry optimizations and extrapolation between the ground and excited electronic states. Key words: nonlinear carbon chain, carbon cation, electronic transition, diffuse interstellar bands, molecular structure.

scholarly journals Laboratory Studies on the Role of PAHs as DIB Carriers

2013 ◽  
Vol 9 (S297) ◽  
pp. 265-275
Author(s):  
F. Huisken ◽  
G. Rouillé ◽  
M. Steglich ◽  
Y. Carpentier ◽  
C. Jäger ◽  
...  
Keyword(s):  
Gas Phase ◽  
Cross Sections ◽  
Molecular Beam ◽  
Electronic Spectroscopy ◽  
Laboratory Studies ◽  
Diffuse Interstellar Bands ◽  
Matrix Isolation Spectroscopy ◽  
Laboratory Results ◽  
Polycyclic Aromatic

AbstractThe electronic spectroscopy of various polycyclic aromatic hydrocarbon (PAH) molecules has been studied in the laboratory at low temperatures using both molecular beam and matrix isolation spectroscopy techniques. While molecular beam spectra can be readily compared to astronomical observations, the band positions measured in Ne and Ar matrices are extrapolated to obtain rather good estimates for the same transitions in the gas phase. Absolute absorption cross sections are determined for gas-phase and matrix spectra by comparing them with calibrated solution spectra. All laboratory results are analyzed and discussed in view of the role that PAHs can play as carriers of the diffuse interstellar bands (DIBs). Our studies suggest that regular neutral PAHs are not responsible for any of the known strong DIBs.

Coordination Compounds of Some 3d-Transition Metal Ions with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)- thiosemicarbazide

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu
Keyword(s):  
Coordination Compounds ◽  
Magnetic Moments ◽  
Thermo Gravimetric Analysis ◽  
Electronic Spectroscopy ◽  
Transition Metal Ions ◽  
Synthesis And Characterization ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
New Compounds

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.

Spectroscopy Fundamentals

2017 ◽  
Author(s):  
Kelly Chance ◽  
Randall V. Martin
Keyword(s):  
Vibrational Spectroscopy ◽  
Cross Sections ◽  
Nuclear Spin ◽  
Electronic Spectroscopy ◽  
Rotational Spectroscopy ◽  
Absorption Cross ◽  
Transfer Processes ◽  
Atmospheric Spectroscopy ◽  
Quantitative Spectroscopy ◽  
Broad Overview

This chapter provides a broad overview of the spectroscopic principles required in order to perform quantitative spectroscopy of atmospheres. It couples the details of atmospheric spectroscopy with the radiative transfer processes and also with the assessment of rotational, vibrational, and electronic spectroscopic measurements of atmospheres. The principles apply from line-resolved measurements (chiefly microwave through infrared) through ultraviolet and visible measurements employing absorption cross sections developed from individual transitions. The chapter introduces Einstein coefficients before in turn discussing rotational spectroscopy, vibrational spectroscopy, nuclear spin, and electronic spectroscopy.

Ultrafast fs coherent excitonic dynamics in CdSe quantum dots assemblies addressed and probed by 2D electronic spectroscopy

2021 ◽  
Vol 154 (1) ◽  
pp. 014301
Author(s):  
Elisabetta Collini ◽  
Hugo Gattuso ◽  
R. D. Levine ◽  
F. Remacle
Keyword(s):  
Quantum Dots ◽  
Electronic Spectroscopy ◽  
Cdse Quantum Dots

scholarly journals Excitonic structure and charge separation in the heliobacterial reaction center probed by multispectral multidimensional spectroscopy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yin Song ◽  
Riley Sechrist ◽  
Hoang H. Nguyen ◽  
William Johnson ◽  
Darius Abramavicius ◽  
...  
Keyword(s):  
Reaction Center ◽  
Charge Separation ◽  
Electronic Spectroscopy ◽  
Spectroscopic Studies ◽  
Primary Electron ◽  
Reaction Centers ◽  
Separation Mechanism ◽  
Photosynthetic Reaction Centers ◽  
Density Analysis ◽  
Function Relationship

AbstractPhotochemical reaction centers are the engines that drive photosynthesis. The reaction center from heliobacteria (HbRC) has been proposed to most closely resemble the common ancestor of photosynthetic reaction centers, motivating a detailed understanding of its structure-function relationship. The recent elucidation of the HbRC crystal structure motivates advanced spectroscopic studies of its excitonic structure and charge separation mechanism. We perform multispectral two-dimensional electronic spectroscopy of the HbRC and corresponding numerical simulations, resolving the electronic structure and testing and refining recent excitonic models. Through extensive examination of the kinetic data by lifetime density analysis and global target analysis, we reveal that charge separation proceeds via a single pathway in which the distinct A0 chlorophyll a pigment is the primary electron acceptor. In addition, we find strong delocalization of the charge separation intermediate. Our findings have general implications for the understanding of photosynthetic charge separation mechanisms, and how they might be tuned to achieve different functional goals.

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