The nature of the absorption bands of the iodide ion in the electronic spectra of ammonium and phosphonium salts

1978 ◽  
Vol 13 (4) ◽  
pp. 409-410
Author(s):  
I. E. Boldeskul ◽  
A. N. Velichko
1997 ◽  
Vol 52 (5) ◽  
pp. 457-461 ◽  
Author(s):  
Sn. Bakalova ◽  
A. Georgieva ◽  
P. Nikolov ◽  
E. Stanoeva

Abstract The absorption and luminescence characteristics of a group of newly synthesized methyl esters of 2-alkyl (p-substituted-aryl) -aminomethylene-3,4-dihydro-1(2 H)-naphthalenone-4-carboxylic acids have been investigated. The studied compounds may exist in three tautomeric forms. On the basis of comparison of their electronic spectra to those of similar substances, the observed substituent effect on the position of the UV-VIS absorption bands, the IR spectra and the results of PPP-SCF-CI quantum-chemical calculations it is concluded that the keto tautomer predominates in solution.


1967 ◽  
Vol 20 (11) ◽  
pp. 2315 ◽  
Author(s):  
EJ Wells ◽  
AD Jordan ◽  
DS Alderdice ◽  
IG Ross

The spectrum of OsO4 has been measured in the vapour and in solution. Detailed structure reported in the main absorption bands by Langseth and Qviller was not reproduced. The irregularity of the main intervals between peaks, and their sensitivity to temperature, bespeak a perturbed spectrum which is too diffuse to analyse convincingly. Three fragmentary systems of quite different appearance were observed in all samples and could well be weak forbidden transitions. The spectrum of RuO, vapour is no better resolved. Reproducible features of both spectra are tabulated.


2005 ◽  
Vol 44 (18) ◽  
pp. 6211-6218 ◽  
Author(s):  
Koichiro Mizuoka ◽  
Satoru Tsushima ◽  
Miki Hasegawa ◽  
Toshihiko Hoshi ◽  
Yasuhisa Ikeda

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 6037
Author(s):  
Reem M. Alghanmi ◽  
Maram T. Basha ◽  
Saied M. Soliman ◽  
Razan K. Alsaeedi

UV–Vis spectroscopy was used to investigate two new charge transfer (CT) complexes formed between the K+-channel-blocker amifampridine (AMFP) drug and the two π-acceptors 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and tetracyanoethylene (TCNE) in different solvents. The molecular composition of the new CT complexes was estimated using the continuous variations method and found to be 1:1 for both complexes. The formed CT complexes’ electronic spectra data were further employed for calculating the formation constants (KCT), molar extinction coefficients (εCT), and physical parameters at various temperatures, and the results demonstrated the high stability of both complexes. In addition, sensitive spectrophotometric methods for quantifying AMFP in its pure form were proposed and statistically validated. Furthermore, DFT calculations were used to predict the molecular structures of AMFP–DDQ and AMFP–TCNE complexes in CHCl3. TD-DFT calculations were also used to predict the electronic spectra of both complexes. A CT-based transition band (exp. 399 and 417 nm) for the AMFP–TCNE complex was calculated at 411.5 nm (f = 0.105, HOMO-1 → LUMO). The two absorption bands at 459 nm (calc. 426.9 nm, f = 0.054) and 584 nm (calc. 628.1 nm, f = 0.111) of the AMFP–DDQ complex were theoretically assigned to HOMO-1 → LUMO and HOMO → LUMO excitations, respectively.


1973 ◽  
Vol 51 (1) ◽  
pp. 92-98 ◽  
Author(s):  
A. D. Allen ◽  
J. R. Stevens

The complexes [Os(NH3)5X]X2, cis-[Os(NH3)4X2]X, and trans-[Os(NH3)4X2]X (X = Cl, Br, I) have been prepared and their infrared spectra measured between 4000–150 cm−1 Assignments have been made for the observed absorption bands. The electronic spectra of the complexes were measured and compared with those of the analogous ruthenium(III) species.


1969 ◽  
Vol 24 (12) ◽  
pp. 1514-1517 ◽  
Author(s):  
A. Syamal

Copper (II), nickel (II), and palladium (II) complexes of amidinourea are reinvestigated in order to verify their structure. Electronic spectra and magnetic susceptibility measurements have been obtained on the solid complexes. Electronic spectral results indicate the donor strength of amidinourea is comparable to strong field ligands like biuret, biguanide, and I-amidino-O-alkylurea. Infra-red spectral results suggest that the carbonyl group of amidinourea is not involved in coordination and the donor atoms in amidinourea are amide nitrogens. The effect of solvents on the absorption bands is also discussed. The solution absorption spectra of bis (amidinourea) copper (II) chloride in different solvents indicate the following order of decreasing tetragonality:DMSO > methanol > ethyleneglycol > water.


2020 ◽  
Vol 22 (36) ◽  
pp. 20295-20302
Author(s):  
Wyatt Zagorec-Marks ◽  
James E. T. Smith ◽  
Madison M. Foreman ◽  
Sandeep Sharma ◽  
J. Mathias Weber

We present electronic spectra containing the Qx and Qy absorption bands of singly and doubly deprotonated protoporphyrin IX, prepared as mass selected ions in vacuo at cryogenic temperatures, revealing vibronic structure of both bands.


2016 ◽  
Vol 469 (1) ◽  
pp. 209-214 ◽  
Author(s):  
S. I. Stepanov ◽  
A. V. Boyarintsev ◽  
S. A. Polyakov ◽  
A. S. Wolf ◽  
A. M. Chekmarev ◽  
...  

1983 ◽  
Vol 38 (3) ◽  
pp. 368-377 ◽  
Author(s):  
Günter Wermuth

Abstract The positions of 1La and 1Lb type absorption bands as well as the fluorescence polarization and natural lifetime show that p-donor substituted benzonitriles emit from a 1Lb-state. On the other hand, the nature of the lowest excited state of p-substituted ethylbenzoates depends upon the kind of the donor. In case of a dialkylamino group as donor substituent the emission occurs from the 1La-state, in case of weeker donors, like methoxy, from the 1Lb-state. In the intermediate case of p-aminoethylbenzoate the excited state depends upon the polarity of the solvent.The 1Lb← 1A transition occurs at higher wave numbers for the donor substituent ethylbenzoates than for the correspondingly substituted benzonitriles, although the ester group represents the stronger acceptor substituent than the nitrile group in spectroscopic respect. This effect is interpreted using perturbation theory according to Petruska.


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