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  • 1
    Digitale Medien
    Digitale Medien
    Determination of equilibrium constants for electron donor/acceptor complexes by resonance Raman spectroscopy (1977)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 81 (1977), S. 1489-1492 
    Details
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/j100530a012
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  • 2
    Digitale Medien
    Digitale Medien
    Synchrotron infrared photoacoustic spectroscopy (2001)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 72 (2001), S. 4331-4336 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: The use of synchrotron radiation (SR) as a far- and mid-infrared source in the measurement of photoacoustic Fourier transform infrared spectra of solids is demonstrated for the first time in this work. Initial experiments were performed at beamline U10A at the National Synchrotron Light Source, Brookhaven National Laboratory. For synchrotron photoacoustic spectroscopy to be feasible, it must yield results superior to those obtained with a conventional thermal (Globar®) source; accordingly, SR and Globar® photoacoustic spectra recorded under similar conditions were compared in detail. The intensities of SR far-infrared photoacoustic spectra were found to be consistently greater than the corresponding Globar® spectra. At shorter wavelengths, SR always underfills the effective aperture (or, alternately, sample size); SR is a superior source in a spectral region that is a function of this aperture. The high wave number limit of this region exhibits a power-law dependence on aperture size. This investigation also showed that the entire mid-infrared photoacoustic spectrum is more intense using SR and apertures smaller than approximately 0.5 mm. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1416107
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  • 3
    Digitale Medien
    Digitale Medien
    The Raman-active O–H and O–D stretching vibrations and Raman spectra of gaseous formic acid-d1 and -OD (1986)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 85 (1986), S. 4779-4789 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: In keeping with current theoretical activity concerning the OH and OD stretching bands of the carboxylic acids, we report the Raman spectra of gaseous formic acid-OD and formic acid-d1 for the first time. We emphasize the OH and OD stretching bands, which can be studied cleanly in these isotopomers but not in normal or perdeuterated formic acid. The spectra of the dimers and monomers below 2000 cm−1 are assigned, and current knowledge of the vibrations of the molecules is summarized. The Raman spectra allow the estimation of the energies of the Bu combination levels that may be in Fermi resonance with the infrared active Bu, OH or OD stretching fundamental, as well as those of the Ag overtone and combination levels that may interact with the Raman-active stretching fundamental. We conclude that the sharp features on the Raman OH and OD stretching bands are due to overtone and combination transitions, that the stretching modes cause the underlying broad scattering, namely three broad bands, centered at 2430, 2270, and 2080 cm−1 for (HCOOD)2 and at 3240, 3074, and 2880 cm−1 for (DCOOH)2. We further conclude that the higher and lower frequency broad bands are due to sum and difference transitions with the hydrogen bond modes, which lie between 60 and 240 cm−1. The infrared OD and OH stretching bands of (HCOOD)2 and (DCOOH)2 are consistent with this interpretation. The Raman OD stretching band of HCOOD ⋅ HCOOH coincides with that of (HCOOD)2 apart from the overtone and combination transitions. The centers of Raman intensity, corrected for instrument, wave number, and temperature dependencies, of the OD stretching bands of (HCOOD)2 and HCOOH ⋅ HCOOD are 2300 ±5 and 2305 ±10 cm−1, respectively, and that of the OH stretching band of (DCOOH)2 is 3035±10 cm−1. This data and the near coincidence of the infrared and Raman bands of (HCOOD)2 show that the vibrational coupling of the two OD bonds in the dimer is not unusually large. Comparison of the infrared and Raman OH stretching bands indicates a larger coupling between OH oscillators. These results agree with earlier result for acetic acid.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.451737
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  • 4
    Digitale Medien
    Digitale Medien
    Water-Soluble imide-amide copolymers. I. Preparation and characterization of poly [acrylamide-co-sodium N-(4-sulfophenyl) maleimide]Presented at the 72nd Canadian Chemical Conference, Victoria, British Columbia, June 4-8, 1989.Dedicated to the memory of Dr. W. M. Leung (1990)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 28 (1990), S. 2949-2968 
    Details
    ISSN: 0887-624X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Sodium N-(4-sulfophenyl) maleimide (SPMI) and its saturated succinimide counterpart were first prepared according to established methods. Hydrolysis experiments on these monomers monitored by 1H-NMR showed that although SPMI monomer was about 15% hydrolyzed in D2O at 23°C in 24 h. Sodium N-(4-sulfophenyl) succinimide, which is similar in structure to the imide units in the copolymers, was only 1% hydrolyzed after 18 days at 23°C and 29% hydrolyzed after 18 days at 60°C. This indicated that the saturated imide rings in the copolymer might be sufficiently stable to hydrolysis for the copolymers to be useful. However, hydrolysis at high pH demonstrated that the imide rings would be rapidly saponified under alkaline conditions, destroying the structural rigidity that the intact rings might have provided in the copolymer chains. Sodium N-(4-sulfophenyl) maleimide (SPMI) was copolymerized with acrylamide in water at 30°C without cleavage of the imide ring. Water-soluble poly [acrylamide-co-sodium-N-(4-sulfophenyl) maleimide] (PAMSM) samples containing from 7.4 to 64 mol % imide were prepared. Photoacoustic FTIR and 13C-NMR spectra were used to confirm the structure of the copolymers obtained. Elemental analysis was used to determine the imide content of the copolymers, and from this composition data reactivity ratios were calculated for the two component monomers.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pola.1990.080281106
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  • 5
    Digitale Medien
    Digitale Medien
    Water-Soluble imide-amide copolymers. II. Preparation and characterization of poly (acrylamide-co-p-maleimidobenzoic acid)Presented at the 72nd Canadian Chemical Conference, Victoria, British Columbia, June 4-8, 1989.Dedicated to the memory of W. M. Leung (1990)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 28 (1990), S. 2969-2982 
    Details
    ISSN: 0887-624X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The comonomer required, p-maleimidobenzoic acid (MBA) was first prepared in good yield by refinements of published methods. p-Carboxysuccinanilic acid (CSA), and p-succinimidobenzoic acid (SBA), were also prepared to provide models useful for IR and NMR for spectroscopic assignments of the new copolymers. Polymerization of MBA with acrylamide in glacial acetic acid at 60°C gave copolymers with estimated viscosity average molecular weights of 60,000 to 90,000. Yields and viscosity average molecular weights decreased as the MBA to acrylamide monomer feed ratio was increased. The rate of incorporation of MBA into the copolymer rose from 7 to 23% when the mole ratio in the feed was raised from 5 to 20%. Decreasing the initiator concentration increased molecular weights by less than predicted and reduced the yield of copolymer for any given feed ratio of MBA to acrylamide. In all cases about 30-40% of the MBA units in the purified copolymers were hydrolyzed. A change to dimethyl sulfoxide solvent gave good, and poor yields of copolymer at 5 and 10 mol % MBA, respectively, and no copolymer at 20 mol % MBA. Viscosity average molecular weights of the copolymer products prepared in DMSO were somewhat lower than obtained for the copolymers prepared in acetic acid. Polymerization in a DMSO-water mixture gave a negligible yield of polymeric product. Instead, only hydrolysates of MBA precipitated when the coloured polymerization solutions were added to methanol.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pola.1990.080281107
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  • 6
    Digitale Medien
    Digitale Medien
    Water-Soluble imide-amide copolymers. III. Preparation and characterization of poly (acrylamide-co-N,N-diallylaniline) and poly (acrylamide-co-sodium N,N-diallylsulfanilate)Presented at the 72nd Canadian Chemical Conference, Victoria, British Columbia, June 4-8, 1989.Dedicated to the memory of W. M. Leung (1990)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 28 (1990), S. 2983-2996 
    Details
    ISSN: 0887-624X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: N,N-diallylaniline monomer was prepared in good yields, for use in preparation of homopolymer and for copolymerization with acrylamide. Functionalized N,N-diallylaniline monomer, as sodium N,N-diallylsulfanilate, was also prepared in good yields for copolymerization with acrylamide. Both monomers were fully characterized by elemental analysis, IR, and NMR. Poly (N,N-diallylaniline) was obtained by polymerization of a strongly acidic aqueous solution of N,N-diallylaniline initiated with hydrogen peroxide. Spectroscopic data from this homopolymer was used to facilitate spectral assignments of the new copolymers. Copolymers of acrylamide with N,N-diallylamine were prepared at monomer feed ratios of 10, 20, and 30 mol % amine and gave 3.5, 7.4, and 8.9 mol % incorporation, respectively. Similar diallyl monomer incorporation rates were obtained for the copolymerization of sodium N,N-diallylsulfanilate with acrylamide. With 10, 30, and 50 mol % of the sodium salt relative to acrylamide, 3.9, 8.4, and 19.2 mol % incorporation of the diallyl monomer was obtained.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pola.1990.080281108
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