Intensities and Shapes of Infrared Absorption Bands of Substances in the Liquid Phase

Ramsay, D. A.

doi:10.1021/ja01121a018

Cited by 672 publications

(82 citation statements)

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“…Together they had compiled a catalog of the infrared spectra of a large number of ketosteroids and had made interesting correlations between the frequency of the carbonyl group and its position in the ketosteroid framework (2). I decided to see if intensities could add any useful infonnation and made a study of methods for measurilll g the intensities of bands with spectrometers of limited resolv ing power, such as were available at that time (3). This paper subsequently became a Citation Classic, but I do not regard it as my most significant contribution.…”

Section: Ramsaymentioning

confidence: 99%

Molecular Spectroscopy: Some Personal Reminiscences

Ramsay¹

1994

Annual Review of Physical Chemistry

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Section: Ramsaymentioning

confidence: 99%

Molecular Spectroscopy: Some Personal Reminiscences

Ramsay¹

1994

Annual Review of Physical Chemistry

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“…The use of infrared spectroscopy for qualitative and quantitative analysis in organic chemistry, and especially for polymers, is well established (Henniker, 1967) According to the nomenclature of Ramsay (1952), T O , T and a are apparent quantities due to the use of finite slit widths and a is an extinction coefficient rather than absorptivity (both terms are used interchangeably here). Because corrections were not made for reflection losses and base line procedures were used in both sample and calibration spectra, T and T O were equated with the transmittance at the peak and the transmittance at the base line, respectively.…”

Section: Infrared Spectroscopymentioning

confidence: 99%

“…While a more sophisticated unit of absorption is obtained when tilhe spectral width of the peak is taken into consideration, the interfering absorptions of neighboring peaks makes the use of this integrated absorption intensity impractical. Only for the OH stretching peak near 3450 cm -1 was this practical (and, in fact, necessary; see section IV-4d(ii)) (Ramsay, 1952): In order to improve the precision of the multicomponent analytical scheme, an over determined system of equations is used and a least squares solution determined by standard techniques (Clifford, 1973). Herschberg …”

Section: Infrared Spectroscopymentioning

confidence: 99%

Surface hydroxylation of styrene–butadiene–styrene block copolymers for biomaterials

Sefton

Merrill

1976

J. Biomed. Mater. Res.

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This work pertains to the development of high strength elastomers potentially useful as nonthrombogenic cardiovascular prostheses. Triblock copolymers of the styrene-butadiene-styrene type have been subjected to surface hydroxylation via intermediate epoxides providing reactive sites at the surface for the subsequent coupling of heparin while retaining the unique mechanical properties of the SBS copolymers.Curves of hydroxyl content versus the copolymer film thickness demonstrated the effect of swelling in the surface region on the product distribution and on the time dependence of the hydroxylation process. The results indicatedthat swelling in the surface region is modified by stress transfer to the unreacted, nonswelling core, giving rise to a lower hydroxyl content in thicker films than in thinner films due to separate effects on both the epoxidation agent and on the cleavage agents and an exponential time dependence with the appearance of a significant induction time.Detailed quantitative analysis of the infrared spectra of surface reacted samples indicated the presence of a thickness dependent diffusion lag between the cleavage agents and the peracid, confirming the observation of a decreased hydroxyl content in thicker films. Delamination of surface reacted samples occurred on swelling in chloroform. Through analysis of the weights of the resulting fractions, the depth of penetration and the shape of the reaction front was estimated as a function of time, temperature and the composition of the reaction bath.The general applicability of this surface modification scheme to biomaterial development and the use of SBS triblock copolymers as potential biomaterials was also evaluated.

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“…The intensity of the C-N band was estimated according to Rarnsay's method (8). The intensity is where ~' l '~,~ is the half-intensity width of the CEN band, log ( T o / T ) ,~~ is the observed absorbance a t band maximum, C is the total concentration of the ligand expressed in moles per liter of solution, and L is the cell length in cm.…”

Section: Infrared Absorption Spectramentioning

confidence: 99%

STUDIES OF METAL COMPLEXES OF PYRIDINE DERIVATIVES: THE EFFECTS OF COORDINATION UPON INFRARED INTENSITY OF THE FUNCTIONAL GROUP IN Β-Cyanopyridine

Brewer¹,

Wong²

1966

Can. J. Chem.

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'The infrared intensity of the C=S group in P-cyanopyridine co~nplexes with some first-row transition metal ions (Zn(II), Cu(II), Ni(II), Co(1 I), Fe(II), and Mn(I1)) in aqueous solution has been measured. The coordination between the nitrogen atom on the pyridine ring and these metal ions exerts a marked change in the magnitude of the band intensity of the functional group. This can be interpreted in terms of a simple molecular orbital model and the relative magnitudes of o-bonding arid T-bonding involved in the con~plexes. A "coordination constant" is introduced for this system, and a linear correlation between these constants and the C S V band intensities of the metal complexes is obtained from both the experimental data and theoretical considerations.The intensities of the infrared absorption band associated with the C=N functionaI group vibration in aliphatic and aromatic cyanides have been studied to a considerable extent (1-5). In particular, studies of the C=N band infrared intensities in a number of substituted benzonitriles showed that substituents on the ring exerted a pronounced effect on the magnitude of the functional group intensity; electron-reIeasing substituents enhanced the functional group intensity, whereas electron-attracting substituents loxvered the intensity.The correlation of the intensity variations in substituted benzonitriles with the socalled "substitution constants" (6) has also been studied. The results suggest that there is an essentially linear relation between the logarithm of the intensity and the substitution constant for both nleta-and para-substituted conlpounds in various solvents.In the present investigation, the intensities of the C=N band in heterocyclic cl-anides were studied. 0-Cyanopyridine was chosen as a starting point for these studies. An attempt has been made to determine the effects of coordination bet\\reen the nitrogen atoll1 on the pyridine ring and some first-row transition illeta1 ions on the C=N band intensity. A sinlple molecular orbital model is presented; this model is used to give a quantitative treatnlent of the data for the system, for \vhich purpose a "coordination constant" is introduced. EXPERIMENTAL illaterials 0-Cyanopyridine, supplied by the L. Light and Co. Ltd., was recrystallized three times from etherpetroleum ether (60-68") mixture.Pyridine, reagent grade supplied by British Drug Houses (Canada) Ltd., was dried over potash overnight and then redistilled twice.3-Pyridinol, supplied by Aldrich Chemical Co. Inc., \\.as recrystallized twice in absolute alcohol and then purified by sublimation.Most of the transition metal salts were nitrates supplied by the G. Frederick Slnith Chem. Co., and were recrystallized from water several times.Deuterium oxide was obtained from hIerck Sharp and Dohme of Canada Ltd., and had a n assay of 9'J.7y0 ' 0 2 0 .Carbonate-free potassium hydroxide solution for the p H titration was prepared by the method of Schvvarzenbacll (7).Canadian Journal of Cl~elnistry. J'oluine 44 (19fjG) 1407 Can. J. Chem. D...

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Intensities and Shapes of Infrared Absorption Bands of Substances in the Liquid Phase

Cited by 672 publications

References 1 publication

Molecular Spectroscopy: Some Personal Reminiscences

Molecular Spectroscopy: Some Personal Reminiscences

Surface hydroxylation of styrene–butadiene–styrene block copolymers for biomaterials

STUDIES OF METAL COMPLEXES OF PYRIDINE DERIVATIVES: THE EFFECTS OF COORDINATION UPON INFRARED INTENSITY OF THE FUNCTIONAL GROUP IN Β-Cyanopyridine

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