Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Analytical Chemistry and Spectroscopy  (12)
  • Physics  (10)
  • ELISA  (5)
  • 11
    Electronic Resource
    Electronic Resource
    Effect of nonelectrostatic interactions on the macromolecular behavior of polyelectrolytes. III. Optical rotatory dispersion of PLL in water and aqueous-organic mixtures (1975)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 13 (1975), S. 2305-2318 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have investigated the optical rotatory dispersion of a stereo-irregular polyelectrolyte when neutralized with alkaline and N-tetraalkylammonium hydroxides, both in water and aqueousacetone mixtures.The variations of the optical activity properties during the neutralization can be well related to potentiometric and viscosity measurements. They are interpreted by assuming two kinds of solvation of the chiral centers located on the main chain, to which two partial optical rotary dispersions (ORD) of opposite signs are associated. The observed optical activity changes and specifically the discontinuity occurring in the neutralization range where a conformational transition between a compact structure and a more extended one is initiated, are thus accounted for in terms of the corresponding changes in the state of solvation of chains.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1975.170131012
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Effect of polyion conformation on dye binding. I. Fluorescence of acridine orange in the presence of synthetic polyacids (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 77-87 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The interaction between polyelectrolytes and Acridine Orange (AO) has been investigated in the case of poly(acrylic acid) (PAA), poly(methacrylic acid) (PMA), and a polycondensate between 1,3-benzene disulfonyl chloride and L-lysine (PLL) by visible absorption and fluorescence spectroscopy. The influence of both polymer ionization and polymer/dye ratio (P/D) on the spectral behavior of the bound dye has been studied. The stacking tendency of AO is found lower in the presence of PLL under compact conformation (in an ionization range depending on the nature of the counterion) with correlated enhancement of the green fluorescence of the monomeric species of the bound dye. The disappearance of the green fluorescence and the dimerization of bound AO are directly related to the increased flexibility of polyion chains upon ionization. Some analogy is found between the behavior of bound AO in the presence of very compact PLL chains and that reported for AO in the presence of native DNA, which might be due to specific interactions responsible for a kind of “intercalation” of the monomeric bound dye.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    High-molecular-weight hydrolyzed polyacrylamides. II. Potentiometric titrations (1979)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 193-202 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Potentiometric titrations in water of high-molecular-weight partly hydrolyzed polyacrylamides were analyzed by the Lifson - Katchalsky rodlike model. A fair concordance was found between theory and experimental curves with pK0 of acid functions of about 4.75 when 0 〈 τ 〈 0.49. Two methods were derived to calculate the parameter n of the extended Henderson-Hasselbach equation by using a series expansion of pKa vs. α, not yet reported in the literature. A new equation for n was established and comparison between two sets of values of n, obtained by using the theoretical ΔpK curves and series expansion is discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1979.170170119
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Effect of polyion conformation on dye binding. V. Induced optical activity of acridine orange bound to a synthetic nonstereoregular polyelectrolyte (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1367-1373 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is shown that the induced Cotton effects in the visible region of the absorption bands of acridine orange in the presence of a nonstereoregular α-carboxylic polysulfonamide (PLL) can be attributed to stacked bound dye molecules, irrespective of the conformation of the polymer. The existence of an ordered structure seems to be unnecessary for such an induction.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180420
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Conformational transition of poly(methacrylic acid) in methanol-water mixtures (1974)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 12 (1974), S. 2767-2778 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of ionization on the potentiometric and viscometric behavior of both poly(methacrylic acid) (PMA) and poly(acrylic acid) (PAA) was investigated in methanol-water mixtures. The potentiometric and viscosity data revealed that the conformational change which takes place for PMA in water gradually disappears with increasing content of methanol in methanol-water mixtures. For mixtures containing 40 and 50% methanol, the behavior of PMA solutions becomes similar to that of PAA, i.e., the discontinuity versus the degree of ionization is no longer detectable and the molecule unfolds regularly upon ionization. The addition of methanol leads to the breakdown of the compact structure of PMA which is stabilized, at low degree of ionization in water, by nonelectrostatic interactions between the methyl groups of PMA.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1974.170121206
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Effect of polyion conformation on dye binding. IV. Fluorescence of auramine O in relation to its binding to synthetic polyacids (1979)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 4011-4020 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of polymer conformation, polymer concentration, and added salt concentration on the quantum yield φ of Auramine O (AuO) is discussed in connection with dialysis equilibrium data. The quantum yield per bound dye molecule (φ/q) assumes different values which are related principally to solvation changes in the environment of the binding sites. Binding to globular compact a states results in high φ/q, whereas low φ/q (of the order of magnitude of φ of free AuO) are observed for the binding to expanded solvated b states. The quantum yield of bound AuO is therefore affected by the organic nature of the environment, but shows little or no relation to the amount of bound dye molecules.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1979.170171221
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Effect of nonelectrostatic interactions on the macromolecular behavior of polyelectrolyes. II. Influence of urea and dyes on the viscometric and optical behavior of PLL (1974)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 12 (1974), S. 2671-2682 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of urea and of dyes on the viscometric behavior of aqueous solutions of PLL has been investigated. The compact structure, which is characteristic of PLL in pure water, is found to disappear progressively as the amount of urea is increased. This is interpreted as due to the destruction in such media of nonelectrostatic interactions responsible for the stabilization of the compact structure of PLL in pure water. In 8M urea, the macromolecular behavior of PLL during the ionization is dependent only on the repulsive interactions between the charged groups. The extension of PLL is then practically independent of the nature of counterions, contrary to what was observed in pure water. In the presence of dye (acridine orange), the compact form of PLL is stabilized, and the dye is found to bind for the two structures of PLL. The analogy between the behavior of Bu4N+ and that of dye is in agreement with the fact the Bu4N+ leads to a stabilization of the compact structure by way of specific interactions between N-tetraalkylammonium counterions and the PLL chain through the structure of water. The hydrodynamic behavior of PLL is in good agreement with data obtained from potentiometric and optical activity measurements.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1974.170121121
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Etude par RMN de la Structure des Cyano-2 Alcoyl-2 Norbornenes-5 (1970)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 2 (1970), S. 71-78 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Interpretation of the NMR spectra of the isomeric 2-cyano-2-alkyl-5-norbornenes allowed the assignment of their respective structures. In the case of the 2-cyano-2-methyl-5-norbornene the structure assignment was confirmed by chemical synthesis (alkaline hydrolysis and iodo-lactonisation).
    Notes: L'attribution de structure des deux isomères cyano-2 alcoyl-2 norbornène-5 est possible grǎce aux données de la RMN. Une interprétation des spectres de ces dérivés bicycliques set donnée. Dans le cas des cyano-2 méthyl-2 norbornènes-5 une confirmation de structure a pu ětre donnée par voie chimique (hydrolyse basique et iodolactonisation).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270020109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Etude du couplage 2J(N15—H) en série hétérocyclique. Application à la détermination des constantes d'équilibres prototropiques rapides (1974)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 224-225 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The fast tautomeric equilibrium of (N15)-4-phenylisoxazolin-5-one (2) has been investigated by a study of 2J(N15—H3) coupling. Comparison of the observed values for 2 and for the two fixed forms (N15)-2-methyl-4-phenylisoxazolin-5-one (3) and (N15)-4-phenyl-5-methoxyisoxazol (4) indicates a considerable amount of enolic type structure for 2 in basic media.
    Notes: La comparasion des constantes de couplage 2J(N15—H3) présentées par la (N15)-4-phénylisoxazoline-5-one (2) et par deux de ses formes fixes, la (N15)-2-méthyl-4-phénylisoxazoline-5-one (3) et le (N15)-4-phényl-5-méthoxyisoxazole (4), indique une participation élevée de structure énolique (et/ou ionique) dans les milieux basiques.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270060408
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Application of low energy CID in the determination of structures of [M - halogen]+ ions obtained from diethyl halosuccinates under electron impact (1987)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 22 (1987), S. 61-63 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Low energy collision induced dissociation (CID) spectra indicate that m/z 173 ions formed by the loss of a halogen atom from diethyl chloro- and bromo-succinate under electron impact are mixtures of O-protonated diethyl maleate (〉90%) and fumarate (〈10 %). Hydrogen migration precedes the C-halogen bond cleavage in these cases. The low energy CID spectrum of the m/z 173 [M—I]+ ion obtained from diethyl iodosuccinate shows that only a small fraction of the [M—I]+ ions are the O-protonated species formed by hydrogen migration. The results of this study demonstrate the potential of low energy CID in the determination of structure (including configuration) of gas phase ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210220202
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...