Protonierung und Solvatation schwacher organischer Basen. IV. H-NMR-spektroskopische Bestimmung der Basizität aliphatischer Ketone

Protonation and Solvation of Weak Organic Bases. IV. ¹H-N.M.R. Spectroscopic Determination of the Basicity of Aliphatic Ketones From protonation ratios for a series of methyl and ethyl alkyl ketones 1—13 with gradually branched alkyl groups in the H₂O–H₂SO₄ system, determined by ¹H-n.m.r. spectroscopy, basicity and solvation parameters are systematically estimated by application of extrapolation procedures based on the Hammett acidity function H₀ or the excess acidity X.     

Protonierung und Solvation schwacher organischer Basen. VII. 1H-NMR-spektroskopische Bestimmung der Basizität von cyclischen Ketonen

Protonation and Solvation of Weak Organic Bases. VII. ¹H-N.M.R. Spectroscopic Determination of the Basicity of Cyclic Ketones From protonation ratios for cycloalkanones of ring size C₄-C₇ in the acid system H₂O H₂SO₄ HSO₃F, determined by ¹H-n.m.r. spectroscopy, basicity and solvation parameters are estimated by application of extrapolation procedures based on the Hammett acidity function H₀ or the excess acidity X. The frequency shifts of the n̈_OH stretching vibrations of phenol in hydrogen bonded complexes with cycloalkanones have been measured. The Δν_OH values are related to the basicity parameter (H₀)_1/2.     

Protonierung und Solvatation schwacher organischer Basen. III. UV- und 1H-NMR-spektroskopische Untersuchungen zur Basizität von 1,3-Diketonen

Protonation and Solvation of Weak Organic Bases. III. U.V. and ¹H-N.M.R. Spectroscopic Investigations of the Basicity of 1,3-Diketones By ¹H-n.m.r. spectroscopy it is possible to determine separately the basicity parameters (H₀)_1/2 or pK and the solvation paramters m, ϕ or m^* for the keto and the enol form of acetylacetone. By u.v. spectroscopy only brutto parameters of the equilibrium mixture for acetyl- and benzoylacetone as for dibenzoylmethane are available.     

Protonierung und Solvatation schwacher organischer Basen. I. Zur Basizität von ω-Chloracetophenonen

Protonation and Solvation of Weak Organic Bases. I. Basicity of ω-Chloroacetophenones The protonation equilibria of ω-chloroacetophenone and some p-substituted derivates have been studied in the acid system H₂O/H²SO⁴/SO₃ by u.v. and ¹H-n.m.r. spectroscopy. From the determined H₀ values for half-protonation _pK_BH+ values were calculated by means of the solvation parameters m of YATES and McCLELLAND . The (H₀)_1/2 and the _pK_BH+ values were successfully correlated with σ_p and σ_p⁺ substituent constants.     

Darstellung und 1H-NMR-spektroskopische Untersuchungen von β-substituierten Äthylen-diphenylphosphinoxiden

Preparation and ¹H-N.M.R. Spectroscopic Investigation of β-Substituted Ethylene Diphenylphosphine Oxides The diphenyl ester 1d of diphenylphosphinyl-methanephosphonic acid in benzene reacts regiospecifically with aldehydes, in presence of strong bases, to β-substituted ethylene diphenylphosphine oxides 4 . The yields are satisfactory on a preparative scale. The ABX type H-n.m.r. spectra of compounds 4 were analysed. The isolated pure products 4 exhibit trans configuration, characterized by the specific signal sequence of the ethylene proton H_B which in some cases could be separated by use of shift reagents. The cis or trans configuration of compounds 4 can be referred partially to steric hindrance in the transition state of the second reaction step.     

Zur copolymerisation von α-methylstyrol und butadien. V. Bestimmung der chemischen heterogenität durch gelchromatographie

The distribution function of the compositional heterogeneity of copolymers from α-methyl styrene and butadiene has been determined from gel permeation chromatography by detection of refractive index and ultraviolet absorption.     

Inline‐Bestimmung der CO2‐Beladung von wässrigem Diglykolamin in Abhängigkeit von Viskosität und Temperatur

The solvents CO₂ loading is an important factor when evaluating the efficiency of an absorption/desorption process. There is almost no possibility to measure the CO₂ loading inline. Therefore experiments were made to determine a correlation between the CO₂ loading and the solvents viscosity as well as the solvents temperature. The correlation was verified using control tests and values from the literature. An overall maximum relative error under 10 % could be observed. Simultaneously investigations were made to understand if the solvents electrical conductivity and pH value are suitable for a similar correlation.     

Darstellung und 1H-NMR-spektroskopische Untersuchung von β-substituierten Äthylen-phenylphosphinsäure-äthylestern

Preparation and ¹H N.M.R. Spectroscopic Investigation of β-Substituted Ethyl Esters of Ethylene-phenylphosphinic Acid The ethyl ester 3 of diphenylphosphorylmethyl-phenyl-phosphinic acid in benzene reacts regiospecifically and stereoselectively with aldehydes, in presence of sodium hydride, to 2-substituted ethyl esters of trans-ethylene-1-phenylphosphinic acid 8 (E-isomers) in satisfactory yields. The ABX type H-n.m.r. spectra of isolated pure products 8 were analysed. The trans configuration of these compounds is characterized by the specific signal sequence of ethylene proton H_B.