Sublevel phosphorescence spectra of pyrazine‐d4. Vibrational assignments and the mechanisms of radiative and nonradiative transitions

1982 ◽  
Vol 77 (6) ◽  
pp. 2757-2762 ◽  
Author(s):  
Fumio Kokai ◽  
Tohru Azumi
Keyword(s):  
Vibrational Assignments ◽  
Nonradiative Transitions ◽  
Phosphorescence Spectra

Vibrational assignments for the Raman and the phosphorescence spectra of 9,10-anthraquinone and 9,10-anthraquinone-d8

1979 ◽  
Vol 83 (9) ◽  
pp. 1200-1205 ◽  
Author(s):  
Kevin K. Lehmann ◽  
John. Smolarek ◽  
Omar S. Khalil ◽  
Lionel. Goodman
Keyword(s):  
Vibrational Assignments ◽  
Phosphorescence Spectra

Synthesis, Conformational Analysis, Infrared, Raman and UV-Visible Spectra of Novel Schiff Bases compiled with DFT Calculations

2020 ◽  
Vol 23 (7) ◽  
pp. 568-586
Author(s):  
Samy M. Ahmed ◽  
Ibrahim A. Shaaban ◽  
Elsayed H. El-Mossalamy ◽  
Tarek A. Mohamed
Keyword(s):  
Schiff Bases ◽  
1H Nmr ◽  
Electronic Absorption Spectra ◽  
Chemical Shifts ◽  
Basis Set ◽  
Oh Groups ◽  
Vibrational Assignments ◽  
Cartesian Coordinate ◽  
Surface Scan ◽  
Ir And Raman

Objective: Two novel Schiff bases named, 2-((2-Hydroxybenzylidene)amino)-4,5,6,7- tetrahydrobenzo[b] thiophene-3-carbonitrile (BESB1) and 2-((Furan-2-ylmethylene)amino)-4,5,6, 7-tetrahydro-benzo[b]thiophene-3-carbonitrile (BESB2) were synthesized. Methods: The structures were characterized based on CHN elemental analysis, mid-infrared (400– 4000 cm-1), Raman (100-4000 cm-1), 1H NMR, mass and UV-Vis spectroscopic measurements. In addition, quantum mechanical calculations using DFT-B3LYP method at 6-31G(d) basis set were carried out for both Schiff bases. Initially, we have carried out complete geometry optimizations followed by frequency calculations for the proposed conformational isomers; BESB1 (A–E) and BESB2 (F–J) based on the orientations of both CN and OH groups against the azomethine lonepair (NLP) in addition to the 3D assumption. Results: The computational outcomes favor conformer A for BESB1 in which the C≡N and OH moieties are cis towards the NLP while conformer G is preferred for BESB2 (the C≡N/furan-O are cis/trans towards the NLP) which was found consistent with the results of relaxed potential energy surface scan. Aided by normal coordinate analysis of the Cartesian coordinate displacements, we have suggested reliable vibrational assignments for all observed IR and Raman bands. Moreover, the electronic absorption spectra for the favored conformers were predicted in DMSO solution using TD-B3LYP/6-31G(d) calculations. Similarly, the 1H NMR chemical shifts were also estimated using GIAO approach implementing PCM including solvent effects (DMSO-d6). Conclusion: Proper interpretations of the observed electronic transition, chemical shifts, IR and Raman bands were presented in this study.

IR and Raman Vibrational Assignments for Metal-free Phthalocyanine from Density Functional B3LYP/6-31G(d) Method

2010 ◽  
Vol 22 (4) ◽  
pp. 325-332 ◽  
Author(s):  
Xian-Xi Zhang ◽  
Meng Bao ◽  
Na Pan ◽  
Yue-Xing Zhang ◽  
Jian-Zhuang Jiang
Keyword(s):  
Density Functional ◽  
Vibrational Assignments ◽  
Metal Free ◽  
Ir And Raman

Vibrational assignments and thermodynamic functions for cis- and trans-1,2-difluoro-1-chlorethylenes

1970 ◽  
Vol 74 (26) ◽  
pp. 4520-4527 ◽  
Author(s):  
Norman C. Craig ◽  
David Albert Evans ◽  
Lawrence G. Piper ◽  
Vicki L. Wheeler
Keyword(s):  
Thermodynamic Functions ◽  
Vibrational Assignments ◽  
Cis And Trans

Infrared Spectra of Some Chloro Derivatives of s-Triazine

1966 ◽  
Vol 20 (3) ◽  
pp. 159-160 ◽  
Author(s):  
T. S. Herman
Keyword(s):  
Infrared Spectra ◽  
Triazine Ring ◽  
Chlorine Atoms ◽  
Vibrational Assignments ◽  
Fundamental Frequencies ◽  
Bending Mode ◽  
Chloro Derivatives ◽  
Derivatives Of

The effects of chlorine atoms on the fundamental frequencies of the s-triazine ring are discussed and the vibrational assignments in the region 1600–700 cm−1 are extended. The variation in the position of the C3N3-ring bending mode in the region near 810 cm−1 is discussed.

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