Infrared spectral data

D. Dolphin, A. Wick, Thbulation of Infrared Spectral Data, Wley, New York, 1977. 

Bromine Trifluoride. Bromine trifluoride is a colorless Hquid. The commercial grade is usually amber to red because of slight bromine contamination. The molecule has a distorted T stmeture (26). Infrared spectral data (26—30), the uv-absorption spectmm (31), and vapor pressure data (32) may be found in the Hterature. 

B. J. ZwoHnski and co-workers. Catalog of Selected Infrared Spectral Data, Serial No. 321, Thermodynamics Research Center Data Project, Texas A M University, College Station, Tex., 1967. 

As mentioned in Section II,B, solutions of y9-hydroxypyridines in the nonpolar solvents chloroform and carbon tetrachloride show sharp infrared absorption bands near 3600 cm indicating that they exist in the hydroxy form. Infrared spectral data also led Mason to conclude that -hydroxypyridines probably exist largely as such in the solid state and exhibit O— 0 hydrogen bonding, a conclusion which is contrary to an earlier proposal favoring a zwitterion structure. 

In the isoquinoline series, infrared spectral data favor nonaromatic forms of type 50 for homophthalimide," a series of substituted homo-phthalimides, and certain iV-hydroxyhomophthalimides the predominance of this structure type gains support from the ultraviolet spectra of homophthalimide and A"-ethylhomophthalimide. ... 

Little work has been reported on pyrazine-2,3-diones, however spectral evidence has been advanced by HonzL to support the dioxo formulation 126. Dioxo structures have been assigned to quin-oxaline-2,3-dione (127) and its 1-methyl analog on the basis of ultraviolet and infrared spectral data, and according to... 

In a preliminary communication, the dihydroxy-1,2,4-triazine derivative 163 has been assigned the structure shown on the basis of infrared evidence. The pK and ultraviolet and infrared spectral data support the formulation of 6-azauracil (164) as a dioxo compound. 

Tautomerism of type 197 198 has been postulated to occur in flavin derivatives on the basis of infrared spectral data. ... 

In 1939, the ultraviolet spectrum of 4-methylquinol-2-thione was reported to differ from that of the 2-alkylthio analog, and the former compound was concluded to exist in the thione form. However, other investigators were unable to reach any conclusions from ultraviolet and infrared spectral data concerning the tautomerism of quinol-2- and -4-thione. A definitive pK and ultraviolet spectral investigation by Albert and Barlin has recently established that the thione forms of quinol-2- and -4-thione and of isoquinol-1- and -3-thione (cf. 202) greatly predominate (Table V). The infrared... 

Anhydrous quinazoline hydrochloride absorbs one molecule of water readily, and. the product is difficult to dehydrate completely even in a high vacuum at 60°. Infrared spectral data suggest that this water is covalently bound because of (o) the absence of several bands in the spectrum of the hydrate which are present in the spectrum of the anhydrous hydrochloride and (6) the presence of extra bands at 1474 and 1240 cm that have been attributed to C— H and O— H bending vibrations of the — CHOH group. 

Chemical evidence has been advanced for the formulation of p nitrosoindoles as either 115 or 116 (sec reference 119 and references therein), but ultraviolet spectral comparison with both methylated forms clearly indicated that 116 was favored. Infrared spectral data are also considered to support structure 116. °... 

K = Me) and especially infrared spectral data indicated that 3-phenylisoxazol-5-one exists in the CH form (45, R —H)." The... 

Infrared spectral data have been advanced to support the oxo formulation for 96 (R —propyl). Structure 96 (R= phenyl) has also been proposed on the basis of the fact that benzoin does not condense with urea, and this conclusion is probably correct, although the argument is not convincing. The oxo forms of benzimidazolone, 97 106,10- related pyrazinoimidazolone 98 have been shown... 

Ultraviolet - and infrared spectral data "- indicate that hydan-toin and its thio analogs (119, X, Y = O or S) exist in the diamide form shown. 

Benzothiazole-2-thiones are associated,but the predominance of the thione forms (154, R = H, Me) has been demonstrated by ultraviolet spectral comparisons wdth the methylated derivatives of both possible tautomeric forms (cf. reference 182), comparative dipole moment data, and infrared spectral data. " Ultraviolet spectroscopy has also been used to demonstrate that benzoseIenazole-2-thione exists as such. The predominance of the thione form of nonaromatic 3,4-dihydrothiazole-2-ones (155) has also been established on the basis of ultraviolet spectral evidence. ... 

The tautoraerism of certain difunctional derivatives of l-thia-3,4-diazole has received considerable attention. Pala assigned structure 156 to 2,5-dimercapto-l-thia-3,4-diazole on the basis of infrared spectral data, and Thorn" reached the same conclusion by comparing its ultraviolet spectrum (measured in ethanol) with those of the four possible methylated derivatives. However, the infrared spectrum of a chloroform solution of the parent compound showed bands at 2600-2550 cm indicating an SH group and the probable occurrence of form 157 under these conditions, and this conclusion is supported by the occurrence of SH bands in solid state spectra obtained by Swiss investigators. For a summary of earlier work on these compounds, see reference 187. 

Infrared spectral data show that thiazoloin exists in the hydrogen bonded ene-diol form 231 (cf. a-pyridoin, in Volume 1, article II, Section VI,F). 

This simple picture of bonding is convenient to use, and often completely acceptable. However, it does lack sophistication and may not be used to explain some of the subtleties of these systems. One obvious point in this regard concerns infrared spectral data. Coordination of carbon monoxide to a metal invariably leads to a lower carbonyl stretching frequency (vco). implying a lower CO bond order as predicted. However, the values for vcn may be considerably higher for metal complexes of an isocyanide than are the values for the ligand itself. The valence-bond picture cannot rationalize... 

W. Windig and D.A. Stephenson, Self-modeling mixture analysis of second-derivative near-infrared spectral data using the Simplisma approach. Anal. Chem., 64 (1992) 2735-2742. 

Smith [83] classified large sets of hydrocarbon oil infrared spectral data by computer into correlation sets for individual classes of compounds. The correlation sets were then used to determine the class to which an unknown compound belongs from its mass spectral parameters. A correlation set is constructed by use of an ion-source summation, in which a low resolution mass spectrum is expressed as a set of numbers representing the contribution to the total ionisation of each of 14 ion series. The technique is particularly valuable in the examination of results from coupled gas chromatography-mass spectrometry of complex organic mixtures. 

H NMR and infrared spectral data of ( )-B, ( )-B methyl ester, and ( )-B methyl ester 3-benzoate were identical with those of AAn and the corresponding derivatives. Mass spectra of the methyl esters of ( )-B and AAn were identical. Chromatographic mobility of ( )-B relative to gibberellic acid (GA3) (as standard) was identical with that reported for AAn. Therefore, this synthesis also proved that antheridium inducing factor, AAn, must be regarded as possessing stereostructure B rather than A as originally supposed. 

Even for potential energy the other approach [93] required one parameter additional to oiu-s, apart from Dq, the latter quantity, equilibrium binding energy, is stated to be based on thermochemical data, but the cited source [95] indicates a value of dissociation energy 29q <2.84eV to arise from spectral analysis. Such an upper limit must be understood to provide an asymptotic limit for V(i ) at large i in a formula of Morse type because an attempted evaluation of 29e from only infrared spectral data is unreliable. The stated reason for the choice... 

One such study details the effects of temperature variation on substrate and metabolite concentration predictions, and used an artificial neural network creating a nonlinear multivariate model to improve concentration predictions. Another study notes the effects of temperature on the mid-infrared spectral data as well, but also noted that the sensor was not affected by reactor operating conditions such as agitation, airflow and backpressure. ... 

Catalog of Infrared Spectral Data. Thermodynamics Res. Center, Texas A of M University, College Station, Texas (in collaboration with the Amer. Petrol. Inst.). 

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