Molecular interactions in the spectra of diaza-aromatics

1974 ◽  
Vol 27 (8) ◽  
pp. 1613 ◽  
Author(s):  
JR Honner ◽  
PR Nott ◽  
BK Selinger
Keyword(s):  
Hydrogen Bonding ◽  
Absorption Spectra ◽  
Molecular Interactions ◽  
Electronic Absorption ◽  
Low Temperatures ◽  
Electronic Absorption Spectra ◽  
Polar Solvents ◽  
Hydrogen Bonding Interactions ◽  
Low Concentrations

A reported variation of the electronic absorption spectra of diaza-aromatics in non-polar solvents with temperature appears to be explicable in terms of three effects. Hydrogen bonding interactions occur in all but exhaustively dried non-polar solvents. Microcrystals form readily at low temperatures at even quite low concentrations (c. 10-5M). The solutions are sensitive to exposure to light. The diaza-aromatics undergo photochemical change forming, in some cases, photoadducts with the solvent.

ELECTRONIC ABSORPTION SPECTRA AND INTERMOLECULAR HYDROGEN BONDING IN MESOGEN–NONMESOGEN SYSTEMS

2020 ◽  
Vol 61 (10) ◽  
pp. 1530-1540
Author(s):  
N. I. Giricheva ◽  
K. E. Bubnova ◽  
E. M. Chernova ◽  
M. S. Fedorov ◽  
S. A. Syrbu ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Intermolecular Hydrogen Bonding

THE ELECTRONIC ABSORPTION SPECTRA OF DIXANTHOGENS

1961 ◽  
Vol 39 (12) ◽  
pp. 2590-2592 ◽  
Author(s):  
M. L. Shankaranarayana ◽  
C. C. Patel
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
High Intensity ◽  
Electronic Absorption Spectra ◽  
Blue Shift ◽  
Polar Solvents ◽  
Low Intensity

The electronic absorption spectra of diethyl, diisopropyl, di-n-butyl, and diisoamyl dixanthogens have been studied in polar and non-polar solvents. The compounds exhibit a low-intensity band around 365 mµ and two high-intensity bands around 285 and 242 mµ. The 365 mµ band is assigned, as a result of the solvent studies, to n → π* transition and the 285 mµ band to π → π* transition. The band around 242 mµ may be due to the n → σ* transition, since in polar solvents it shows mainly a blue shift.

Excited State Polarizability of Some Polycyclic Polyenes

2017 ◽  
Vol 68 (2) ◽  
pp. 307-310 ◽  
Author(s):  
Ana Maria Ciubara ◽  
Andreea Celia Benchea ◽  
Carmen Beatrice Zelinschi ◽  
Dana Ortansa Dorohoi
Keyword(s):  
Excited State ◽  
Absorption Spectra ◽  
Excited States ◽  
Electronic Absorption ◽  
Ground State ◽  
Electronic Absorption Spectra ◽  
Photon Absorption ◽  
Absorption Process ◽  
Polar Solvents ◽  
Molecular Parameters

The electronic absorption spectra of five polycyclic polyenes were recorded in non-polar solvents in order to determine their polarizability in excited states from the strength of the dispersive interactions in their diluted solutions. The bathochromic shifts of p-p* vibronic bands prove the increase of the molecular polarizabilty in the photon absorption process. Some molecular parameters of the analyzed polyenes in their ground state were computed by using the programs from Spartan�14.

Electronic absorption spectra of substituted phthalocyanines in solution and as films

2003 ◽  
Vol 07 (08) ◽  
pp. 551-557 ◽  
Author(s):  
Hiroshi Ogata ◽  
Ryuji Higashi ◽  
Nagao Kobayashi
Keyword(s):  
Absorption Band ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Film Formation ◽  
Polar Solvents

The electronic absorption spectra of several phthalocyanines substituted at the so-called α-, β- and α and β-positions of the macrocycle have been recorded in solution and as films (α = 1,4,8,11,15,18,22, and 25 positions or 1,8 (or 11),15 (or 18), and 22 (or 25) positions, and β = 2,3,9,10,16,17,23, and 24 positions or 2,9 (or 10),16 (or 17), and 23 (or 24) positions). Phthalocyanines substituted with bulky groups at the α-positions prevent cofacial aggregation so that their Q-absorption band remains at a similar wavelength both in solution and films, although the film spectra are generally broader. Phthalocyanines substituted at the β-positions are apt to aggregate cofacially in polar solvents but in films they may show broad Q-bands which spread out to both shorter and longer wavelengths of the solution Q-band, depending on the bulkiness of the substituents. The film spectra of hexadeca-substituted phthalocyanines exhibit Q-bands at a similar wavelength as in solution, with insignificant broadening of the Q-band on film formation. However, the Soret bands for most of the substituted phthalocyanines are shifted and broadened to longer wavelength in the films.

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