scholarly journals Probing Intermolecular Electron Delocalization in Dimer Radical Anions by Vibrational Spectroscopy

2017 ◽  
Vol 121 (30) ◽  
pp. 7327-7335 ◽  
Author(s):  
Tomoyasu Mani ◽  
David C. Grills
Keyword(s):  
Vibrational Spectroscopy ◽  
Electron Delocalization ◽  
Radical Anions

scholarly journals Quantitative Assessment of Tetrel Bonding Utilizing Vibrational Spectroscopy

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2763 ◽  
Author(s):  
Daniel Sethio ◽  
Vytor Oliveira ◽  
Elfi Kraka
Keyword(s):  
Vibrational Spectroscopy ◽  
Quantitative Assessment ◽  
Positive Charge ◽  
Lone Pair ◽  
Electron Delocalization ◽  
Exchange Repulsion ◽  
First Time ◽  
Tetrel Bonds ◽  
Incomplete Picture ◽  
Positively Charged

A set of 35 representative neutral and charged tetrel complexes was investigated with the objective of finding the factors that influence the strength of tetrel bonding involving single bonded C, Si, and Ge donors and double bonded C or Si donors. For the first time, we introduced an intrinsic bond strength measure for tetrel bonding, derived from calculated vibrational spectroscopy data obtained at the CCSD(T)/aug-cc-pVTZ level of theory and used this measure to rationalize and order the tetrel bonds. Our study revealed that the strength of tetrel bonds is affected by several factors, such as the magnitude of the σ-hole in the tetrel atom, the negative electrostatic potential at the lone pair of the tetrel-acceptor, the positive charge at the peripheral hydrogen of the tetrel-donor, the exchange-repulsion between the lone pair orbitals of the peripheral atoms of the tetrel-donor and the heteroatom of the tetrel-acceptor, and the stabilization brought about by electron delocalization. Thus, focusing on just one or two of these factors, in particular, the σ-hole description can only lead to an incomplete picture. Tetrel bonding covers a range of −1.4 to −26 kcal/mol, which can be strengthened by substituting the peripheral ligands with electron-withdrawing substituents and by positively charged tetrel-donors or negatively charged tetrel-acceptors.

Cyclic In-Plane Electron Delocalization (σ-Bishomoaromaticity) in 4N/5e Radical Anions and 4N/6e DianionsGeneration, Structures, Properties, Ion-Pairing, and Calculations

2000 ◽  
Vol 122 (43) ◽  
pp. 10650-10660 ◽  
Author(s):  
Kai Exner ◽  
Oliver Cullmann ◽  
Markus Vögtle ◽  
Horst Prinzbach ◽  
Birgit Grossmann ◽  
...  
Keyword(s):  
Ion Pairing ◽  
Electron Delocalization ◽  
Radical Anions

VIBRATIONAL SPECTROSCOPY, RESONANCE FRACTION AND MOLECULAR MOTION

1974 ◽  
Vol 35 (C6) ◽  
pp. C6-131-C6-137 ◽  
Author(s):  
Y. HAZONY ◽  
R. H. HERBER
Keyword(s):  
Vibrational Spectroscopy ◽  
Molecular Motion

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

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