Spectra and structure of phosphorus-boron compounds. IX. Vibrational analysis and molecular symmetry of solid diboron tetrachloride-bis(phosphine) and diboron tetrachloride-bis(phosphine-d3)

1975 ◽  
Vol 14 (2) ◽  
pp. 434-437 ◽  
Author(s):  
J. D. Odom ◽  
V. F. Kalasinsky ◽  
J. R. Durig
2004 ◽  
Vol 82 (6) ◽  
pp. 951-963 ◽  
Author(s):  
Hajime Torii ◽  
Yuko Ueno ◽  
Akira Sakamoto ◽  
Mitsuo Tasumi

Vibrational analysis is carried out for the radical anions of naphthalene-h8 and -d8. Their infrared (IR) spectra are observed in tetrahydrofuran by using a cell designed for IR measurements of unstable species. The vibrational force field and the IR intensities are calculated by the ab initio molecular orbital and density functional methods at various theoretical levels. As found in the cases of the radical cations of many polycyclic aromatic hydrocarbons (PAHs), a few strong IR bands with intensities of the order of 102 km mol–1 are observed in the 1700–900 cm–1 region. These observed spectral features are well reproduced by the calculations at the CASSCF (complete active space self-consistent field) and B3LYP (Becke's three-parameter hybrid method using the Lee–Yang–Parr correlation functional) levels. The calculation at the B3LYP level gives a better fit between the observed and calculated absolute IR intensities. Normal modes and the origin of the strong IR intensities characteristic of the radical anions are discussed in terms of molecular symmetry coordinates and the dipole derivatives based on these coordinates. It is found that the IR intensities of the b2u modes below 2000 cm–1 are dominated by the contribution from one molecular symmetry coordinate, in which the C—C bonds in one ring stretch while those in the other ring shrink. The mechanism that gives rise to the strong IR intensity for this vibration is discussed by examining the changes in the electronic structure induced by this vibration.Key words: vibrational spectra, electron–vibration interaction, naphthalene, radical anion.


1976 ◽  
Author(s):  
C. W. Suggs ◽  
John Wayne Mishoe

2019 ◽  
Author(s):  
Oriol Planas ◽  
Feng Wang ◽  
Markus Leutzsch ◽  
Josep Cornella

The ability of bismuth to maneuver between different oxidation states in a catalytic redox cycle, mimicking the canonical organometallic steps associated to a transition metal, is an elusive and unprecedented approach in the field of homogeneous catalysis. Herein we present a catalytic protocol based on bismuth, a benign and sustainable main-group element, capable of performing every organometallic step in the context of oxidative fluorination of boron compounds; a territory reserved to transition metals. A rational ligand design featuring hypervalent coordination together with a mechanistic understanding of the fundamental steps, permitted a catalytic fluorination protocol based on a Bi(III)/Bi(V) redox couple, which represents a unique example where a main-group element is capable of outperforming its transition metal counterparts.<br>A main text and supplementary material have been attached as pdf files containing all the methodology, techniques and characterization of the compounds reported.<br>


Author(s):  
Eduardo Farinazzo ◽  
Marcus Oliveira Filho ◽  
Emilio Janssen
Keyword(s):  

2019 ◽  
Vol 21 (7) ◽  
pp. 3606-3614 ◽  
Author(s):  
Maria Gabriella Chiariello ◽  
Umberto Raucci ◽  
Federico Coppola ◽  
Nadia Rega

We adopted excited state ab initio dynamics and a new time resolved vibrational analysis to unveil coupling between modes promoting photorelaxation.


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