Vibrational analysis of spectra of quinonoid molecular ions. Part 3.—Vibrational spectra and assignment of 7,7,8,8-tetracyanoquinodimethane radical anion

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 mol1 are observed in the 1700900 cm1 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 LeeYangParr 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 cm1 are dominated by the contribution from one molecular symmetry coordinate, in which the CC 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, electronvibration interaction, naphthalene, radical anion.

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Vibrational spectra of molecular ions isolated in solid neon. XV. Infrared spectroscopic evidence for NeHF+ and HFFH+

The Journal of Chemical Physics ◽

10.1063/1.478402 ◽

1999 ◽

Vol 110 (11) ◽

pp. 5037-5046 ◽

Cited By ~ 9

Author(s):

Catherine L. Lugez ◽

Marilyn E. Jacox ◽

Russell D. Johnson

Keyword(s):

Vibrational Spectra ◽

Molecular Ions ◽

Spectroscopic Evidence ◽

Infrared Spectroscopic

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ChemInform Abstract: VIBRATIONAL ANALYSIS OF THIOCYANOGEN AND THE TRANSIENT THIOCYANOGEN RADICAL ANION (SCN)2-

Chemischer Informationsdienst ◽

10.1002/chin.198007047 ◽

1980 ◽

Vol 11 (7) ◽

Author(s):

N. H. JENSEN ◽

R. WILBRANDT ◽

P. PAGSBERG ◽

R. E. HESTER ◽

E. ERNSTBRUNNER

Keyword(s):

Radical Anion ◽

Vibrational Analysis

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Gelification Effects on the Structure and Birefringence of Charge Transfer Complex Terthiophene Bisililated – TCNQ Hybrid Materials

Materials Science Forum ◽

10.4028/www.scientific.net/msf.517.257 ◽

2006 ◽

Vol 517 ◽

pp. 257-261

Author(s):

N. Kancono ◽

H.B. Senin

Keyword(s):

Charge Transfer ◽

Detection Limit ◽

Hybrid Materials ◽

Vibrational Spectra ◽

Lamellar Structure ◽

Radical Anion ◽

Charge Transfer Complex ◽

Visible Spectrum ◽

Charge Transfer Complexes

Charge transfer complexes (CTC) can be readily introduced into materials by cohydrolysis-copolymerisation of bis-silylated ter-thiophenes as precursors with TMOS and TEOS in the presence of TCNQ. CTC formation is shown in the visible spectrum of the xerogel by the band at 850 nm characteristic of the TCNQ·- radical anion. Vibrational spectra have shown that strong vibration of C≡N bond at 2184, 2120 and 1595 cm-1 as peaks characteristics of CTC. The CTC bands are weak and the complex is easily destroyed by washing with acetone, which removes the TCNQ. The gelification effect of the charge transfer complexes on the hybrid materials of 2,5’’- bis(trime thoxysilyl)terthiophene/TCNQ/ TMOS showed that the peak with distance of more than 11.68 Å, formed by precursors and matrices, as a lamellar structure. The birefringence of xerogel BTS3T in presence of alkoxysilane showed that the value is near the detection limit of 0.1 – 0.4 x 10-3, which is weaker than BTS3T / THF with the birefringence value of 4.5 x 10-3.

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The crystal structure and vibrational spectra of cis-dichlorobis(cyclopropylamine)-platinum(II), PtCl2(C3H5NH2)2

Canadian Journal of Chemistry ◽

10.1139/v81-395 ◽

1981 ◽

Vol 59 (18) ◽

pp. 2737-2745 ◽

Cited By ~ 11

Author(s):

Helen Elaine Howard-Lock ◽

Colin James Lyne Lock ◽

Graham Turner ◽

Maruta Zvagulis

Keyword(s):

Crystal Structure ◽

Least Squares ◽

Vibrational Spectra ◽

Vibrational Analysis ◽

Full Matrix ◽

Space Group ◽

Bond Lengths ◽

Deuterated Analogue

Crystals of cis-dichlorobis(cyclopropylamine)platinum(II), PtCl2(C3H5NH2)2, are monoclinic, a = 12.770(5), b = 5.838(2), c = 15.113(6) Å, β = 104.46(3)°, Z = 4, space group P21/c. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares to R = 0.057, Rw = 0.055 for 1577 reflections with I > 3σ(I). Bond lengths and angles are normal. A vibrational analysis of the compound and its d2-deuterated analogue was performed.

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