摘要:

AbstractInfrared spectra (4000‐150 cm−1) and Raman spectra (4000‐50 cm−1) of 3(5)‐methylpyrazole (MPZ) and coordination compounds of formula M2+(MPZ)n(anion)2−have been investigated.Assignments are proposed for the free‐ligand normal modes of vibration and for the metal‐ligand vibrations. The shift in some of the ligand vibrations upon coordination to metal salts is discussed, and interpreted on the basis of differences in binding properties of the several metal ions and anions.The N‐H vibrations of MPZ especially appear to be strongly dependent upon the hydrogen‐bonding properties of the anions present in the coordination compounds. The strongest hydrogen bond is found with Cl−anions, followed by Br−, I−, NO3−, BF4−, whereas the ClO4−anions appear to be scarcely hydrogen bonded with the MPZ ligands in the coordination compounds.The metal‐ligand vibrations in the complexes appear to be dependent on the metal ion, and follow the usual Irvin

ISSN:0165-0513    

DOI:10.1002/recl.19710900202

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe reduction of alkyl‐substituted benzoic acids with lithium in liquid ammonia has been investigated. Without added proton donor the aromatic acid yields a dianion which can either be protonated with ammonium chloride or alkylated to give the corresponding 1,4‐dihydrobenzoic acid and 1‐alkyl 2,5‐cyclohexadiene‐1‐carboxylic acid, respectively.In the presence of ethanol, 3‐ and 4‐alkylbenzoic acids yield either 1,4‐dihydro or 4,5‐dihydro products depending on the working up procedure Benzoic acid behaves similarly. Water is shown to be a useful proton donor in the reduction of 3‐ and 4‐alkylbenzoic acids to 1,4‐dihydro products. 2‐Alkylbenzoic acids yield 1,4‐dihydro products, irrespective of the experimental procedure.Experiments with 4‐deuterobenzoic acid show the first proton addition to be irreversible in ammonia as well as in ammonia‐ethanol.Some thirty new alkyl‐ and dialkyl‐cyclohe

ISSN:0165-0513    

DOI:10.1002/recl.19710900203

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

Abstract1,1′‐Dimethyl‐2,2′‐bis(trimethylammonio)bicyclopropyl dihydroxide (XIb) was synthesized from 2,3‐dimethylbutadiene and methyl diazoacetateviaseveral difunctional 1,1′‐dimethylbicyclopropyl derivatives. Hofmann degradation of XIb yielded ∼7% of a xylene mixture [o: (m+p) = 10 : 1], together with 2,2′‐bis(dimethylamino)‐1,1′‐dimethylbicyclopropyl (X), 3‐[2‐(dimethylamino)‐1‐methylcyclopropyl]‐3‐methylcyclopropene (XII) and 1‐(3‐butynyl)‐2‐(dimethylamino)‐1‐methylcyclopropane (XIII). The possible intermediacy of 1,

ISSN:0165-0513    

DOI:10.1002/recl.19710900204

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe Raman spectra of solid powders of phosphorus pentabromide, phosphorus heptabromide and caesium tribromide are reported. The spectra are explained in terms of site symmetry splitting and factor group splitting.

ISSN:0165-0513    

DOI:10.1002/recl.19710900205

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe iron(II)‐ iron(III) electron‐exchange rate has been measured at 0° in aqueous perchloric acid‐sodium perchlorate and perchloric acid‐lithium perchlorate mixtures of varying acid concentration, at three values of the ionic strength.The medium effects upon the rate of this reaction are interpreted as a result of a) the displacement of hydrolysis equilibria with the hydrogen ion concentration, and participation of the hydrolyzed ions in the exchange reaction, and b) the variation of the activity coefficients of the reacting species with the hydrogen ion conce

ISSN:0165-0513    

DOI:10.1002/recl.19710900206

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractA method is proposed for calculating retention indices of apolar solutes on apolar stationary phases from the vapour pressures of the solutes and the molar volumes of the solutes and the solvent. Retention indices calculated by this method, as well as values calculated otherwise, are compared with experimental data.The temperature dependence of the retention indices is discussed from a thermodynamic standpoint.The corresponding standard partial molar entropies, enthalpies and free enthalpies of vaporization from solution appear to depend on molecular size and shape. The latter phenomenon is contributed to more or less shielded solute‐solvent interactions and to less or more restricted molecular translation and rotatio

ISSN:0165-0513    

DOI:10.1002/recl.19710900207

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractAn investigation is reported on the temperature dependence of the splitting of the C‐band (1A1g→1T1u) in the electronic absorption spectrum of TeCl62−. The splitting appears to be linearly dependent on the square root of temperature.This behaviour proves the correctness of our previous assumption1about the dynamic character of the spli

ISSN:0165-0513    

DOI:10.1002/recl.19710900208

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe reaction of neat toluene with a number of different sulfonation reagents at 25° has been studied. With sulfur trioxide vapour as reagent, the reaction leads to monosulfonation only. Theo/(o + m + p)ratio varies with the degree of toluene conversion, the limiting values at zero and high conversion being 0.34 ± 0.03 and 0.11 ± 0.01, respectively. The former value is ascribed to the sulfonation of toluene with sulfur trioxide, the latter to sulfonation in the acid phase with toluenepyrosulfonic acid as the sulfonating entity.The heterogeneous reaction of toluene with a deficient amount of a matured mixture of methanesulfonic acid and sulfur trioxide ‐ i.e. with a methanepyrosulfonic acid reagent — leads to monosulfonation only. Theo/(o + m + p)ratio varies from 0.15 ± 0.01 at zero toluene and zero time conversion to 0.11 ± 0.01 at high toluene conversion. The former value is ascribed to sulfonation in the acid phase of dissolved toluene by methanepyrosylfonic acid, the latter to that by both toluene‐ and methane‐pyrosulfonic acids.Heterogeneous sulfonation with a deficient amount of fuming sulfuric acid takes place mainly ( ∼97 %) in the acid phase. Sulfonation in the toluene phase leads to monosulfonic acids only with 41 ± 2 % ofortho‐substitution. Sulfonation in the sulfuric acid phase yields monosulfonic acids and, at the higher sulfuric acid concentrations, also toluene‐2,4‐disulfonic acid. The degree ofortho‐substitution for sulfonation in the acid phase at 25° changes from 48.5 to 40 % on varying the acid concentration fr

ISSN:0165-0513    

DOI:10.1002/recl.19710900209

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractBy treatment with potassium amide in liquid ammonia, 2‐chloropyrazine is converted into a mixture of 2‐cyanoimidazole, imidazole and 2‐aminopyrazine. The mechanism of the formation of the two ring‐contracted products is di

ISSN:0165-0513    

DOI:10.1002/recl.19710900210

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe solubilities of cerium(III) oxalate, both inactive and labelled with144Ce, in water at 25°, have been determined by chemisorption on cation exchange paper followed by X‐ray fluorescence analysis of the paper and proved to be identical within experimental error.The specific count rates of labelled cerium(III) oxalate in a saturated solution and in a standard solution in hydrochloric acid proved to be identical within experimental error.These results, which are in contrast with those ofSpitsynet al., demonstrate once more, the validity of the radiometric method for the determination of solubility.The solubility of anhydrous cerium(III) oxalate in water at 25° is 3.11 ± 0.16 mg

ISSN:0165-0513    

DOI:10.1002/recl.19710900211

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY