摘要:

Thermal explosions of methyl isocyanide have been studied in spherical reaction vessels with volumes in the range 300–5000 ml. The normal inverse dependence of the explosion limit on the square of the radius appears to hold over limited ranges, e.g. from 300–1000 ml and from 2000–3000 ml, but the explosion limits at 1000 ml and 2000 ml are characterized by markedly different values of the critical parameter δc. Temperature measurements were made at and near the vessel walls, but they do not reveal any abnormalities which could be used to explain these results.An appendix reports measurements of the thermal conductivities of methyl cyanide and methyl isocyanide from 200–350 °C.

ISSN:0008-4042    

DOI:10.1139/v77-538

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Dimolar tosylation of 1,5-anhydro-D-glucitol (1) in pyridine yielded the 2,6-di-O-tosylate (6) (35%) as the major product, along with the tetra-O-tosylate (2) (1%), the 3,4,6-tri-O- (3) (1%), 2,4,6-tri-O- (4) (8%), and 2,3,6-tri-O-tosylate (5) (6%), and the 3,6-di-O- (7) (4%) and 4,6-di-O-tosylate (8) (6%). The order of the relative reactivity of the hydroxyl groups in1towards tosyl chloride was predicted as 6-OH > 2-OH > 4-OH > 3-OH.

ISSN:0008-4042    

DOI:10.1139/v77-539

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Volumetric specific heats (25 °C) and densities (24 °C) were measured with a flow microcalorimeter and flow densimeter for 12 polyols in water (0.05 to 2 m), and for NaCl andn-Bu4NBr in 1 maqueous alditol solutions. The infinite dilution propertiesof the polyols show specificities in polyol−water interactions which are discussed in terms of the compatibility of the polyol stereochemistry and the existing water environment. The derived heat; capacities and volumes of transfer of hydrophobic and hydrophilic probes to aqueous solutions of homologous polyols suggest that structural interactions are reduced in these systems as compared to pure water.

ISSN:0008-4042    

DOI:10.1139/v77-540

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The ir spectrum of the isotopically isolated NH3D+ion was used to deduce the possible site symmetries of the NH4+ion in ammonium benzoate, NH4PhCOO, and ammonium hydrogen bisbenzoate, NH4H(PhCOO)2. The NH4+ion in both crystals is strongly hydrogen-bonded, one of the two isotopically isolated ND frequencies in ammonium benzoate being the lowest such frequency reported to date. The site symmetryC2of NH4+in NH4H(PhCOO)2has been confirmed by determining the crystal structure of this compound. Thebond in the dibenzoate ion,is short, 2.46(1) Å, and probably symmetric.

ISSN:0008-4042    

DOI:10.1139/v77-541

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The mass and ir spectra of the complexes formed between S4N4and MCl2(M = Ni, Co, Pd) in methanol solution have been investigated. The mass spectral data indicate that the stoichiometry of the complexes is M(S2N2H)2and the principal fragmentation is the stepwise loss of SN units, as is the case for S4N4itself. The ir spectra of the complexes show the presence of N—H groups and suggestcis-planar configurations for the S2N2H chelating ligands.

ISSN:0008-4042    

DOI:10.1139/v77-542

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Intermolecular fluorine exchange in the systems SiF4–SiF5−, MeSiF3–MeSiF4−, PhSiF3–PhSiF4−, SiF5−–SiF62−, SiF4–SiF62−, and MeSiF3–SiF62−has been studied by fluorine and proton nmr spectroscopy. Exchange is postulated to involve fluorine-bridged intermediates; alternative pathways of exchange, such as fluoride dissociation or impurity (HF and H2O) catalyzed exchange, have been eliminated. Addition of NH3to SiF5−–SiF62−slows down exchange whereas addition of Et2NH to MeSiF3promotes exchange.

ISSN:0008-4042    

DOI:10.1139/v77-543

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The temperature dependence of the limiting equivalent conductances of the ions 2-methoxyethylammonium, bis-2-methoxyethylammonium, 3-methoxypropylammonium, piperidinium, quinuclidinium, cyclohexylammonium, and diethylammonium have been determined over the range 5–45 °C. The probable effect of these ions on the adjacent water structure has been explored in terms of an approach used by Kay and co-workers and the behaviour in water has been compared with that of other alkylammonium ions.

ISSN:0008-4042    

DOI:10.1139/v77-544

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

This paper reports the radiochemical study of the kinetics of ion-exchange of Rb+and Cs+with H+on zirconium antimonate. The slow step which determines the rate of exchange of these ions is diffusion through the particle. Values for the diffusion coefficients, energy of activation, and entropy of activation have been calculated. The data obtained have been compared with those reported for other organic and inorganic exchangers.

ISSN:0008-4042    

DOI:10.1139/v77-545

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The Raman spectrum of crystalline CH4in phase II has been obtained. Thev1,v2, andv3bands have been observed as well as two weak bands in the lattice vibration region. The spectrum is found to be consistent with the structure originally proposed by James and Keenan. There is excellent agreement between a theoretical model proposed by Yamamoto and co-workers and the spectra presented here.

ISSN:0008-4042    

DOI:10.1139/v77-546

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Apparent molal volumes of potassium salts ofpara-substituted (—F, —Cl, —I, —CH3) and unsubstituted benzoic acids in water –tert-butyl alcohol mixtures (0–40% by weight) are reported. Large volume changes are observed in media rich in water. Substituents size effects on both the location and the amplitude of the volume maxima are discussed in terms of the structure of the mixed solvents.

ISSN:0008-4042    

DOI:10.1139/v77-547

出版商:NRC Research Press    

年代:1977

数据来源: NRC