摘要:

The microwave spectra of cyclopropyl carbinoland its deuterated (—OD) form were studied in the region of 8 to 35 gHz. Only one of the possible rotational isomers was identified. The measured rotational constants and dipole moments for C3H5CH2OH and C3H5CH2OD are, respectively,A(mHz): 12485.13, 12064.04;B(mHz): 3236.46, 3177.22;C(mHz): 2894.38, 2826.19; κ: −0.928665, −0.924001; μa(D): 1.81, 1.78; μb(D): 0.36, 0.32; μc(D): 0.31, 0.30; μtotal(D): 1.87, 1.84.Rotation is apparently hindered by hydrogen bonding between the hydroxyl hydrogen and the electrons in the strained bonds of the cyclopropyl ring.

ISSN:0008-4042    

DOI:10.1139/v70-498

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

In deaerated aqueous perchloric acid solution Tl(III) is reduced and 2-propanol oxidized to acetone in equivalent yields via a chain reaction initiated by light of 2537 Å. Initiation is attributed to a charge-transfer-to-metal excitation followed by dissociationThe formation of Tl(II) in the primary process is demonstrated by flash photolysis. An upper limit of 0.36 ± 0.07 is estimated for the primary quantum yield.

ISSN:0008-4042    

DOI:10.1139/v70-499

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Studies of aqueous solutions containing fluoride and beryllium ion in ratios between 5 and 0.5 were made by19F nuclear magnetic resonance at temperatures between the melting point of solutions and room temperature. Signals clearly identifiable as arising from BeF42−, BeF3−, BeF2, and BeF+were assigned. Chemical shifts and coupling constantsJBe–Fare reported for all species and approximate equilibrium constants are determined from intensity measurements for the reactionsand

ISSN:0008-4042    

DOI:10.1139/v70-500

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The mercury-(3P1)-photosensitized decomposition of formamide vapor has been studied briefly at 150 °C and pressures of about 1–30 Torr. Volatile products observed were CO, H2, and NH3. Three primary processes are postulatedwith estimated quantum yields of 0.53, 0.32, and 0.08, respectively. A dependence of product ratios on light intensity and formamide pressure is attributed to hydrogen-atom "cracking" reactions.

ISSN:0008-4042    

DOI:10.1139/v70-501

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

We report the synthesis of the ion V(DMSO)63+and kinetics of its reactions with SCN−, sulfosalicylic acid, and 2,2-bipyridine. The complex formation rates show some dependence on the ligand. The value of ΔS≠found for the reaction with bipyridine is quite negative. A definite mechanistic assignment cannot yet be made.

ISSN:0008-4042    

DOI:10.1139/v70-502

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The calcination of natural Ontario limestones and dolomites in a flow of 100 cm3/min of nitrogen at 745 °C required from 0.43 ± 0.03 to 0.35 ± 0.05 min/mg of 100 mesh samples, respectively. The nitrogen adsorption isotherm at 77 °K for all the calcined samples belonged to the type II isotherm of the B.D.D.T. classification. There was hardly any hysteresis between the adsorption and desorption branches which implied that most of the pores were relatively large in agreement with independent measurements of the most probable pore diameter by an Aminco mercury intrusion porosimeter (~ 0.1 μ). The B.E.T. surface areas ranged from 13.6 to 34.2 m2/g of oxide calcined at 745 °C. The surface area decreased rapidly with increasing calcination temperature. At 1090 °C the surface area was less than 1 m2/g. The surface area was also related to percentage calcination, percentage calcium oxide in the sample, and size of the sample. A sample of pure magnesium carbonate calcined at 565 °C had an inordinately large surface area of 174 m2/g; pure calcium carbonate calcined at 745 °C, 15.2 m2/g. Using a model of non-intersecting cylindrical or square capillaries for the pore configurations, one could calculate the surface area, porosity, and bulk density of the calcined samples with satisfactory agreement.

ISSN:0008-4042    

DOI:10.1139/v70-503

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Thermogravimetric analysis was done for representative calcined samples of Ontario limestones and dolomites in a 5% SO2controlled atmosphere. The SO2absorption vs. temperature curves showed three distinct regions. (i) A unimolecular chemisorption of SO2at room temperature. (ii) An intermediate temperature region between 200–450 °C where absorption of SO2was due to increased rate of SO2diffusion into the interior of CaO via grain boundaries. When the surfaces of these internal spaces were almost fully occupied the rate of SO2absorption decreased. Further absorption was due to diffusion of SO2into CaO lattice, which was a much slower process. (iii) A fast absorption region between 500–700 °C, where a disproportionation of CaSO3into CaSO4and CaS took place which effectively broke down the original CaO structure to expose fresh layers of CaO. The amount of SO2absorption after 1 h at 745 °C corresponded to approximately 80% conversion of CaO to mainly CaSO4and CaS and smaller amount CaSO3.Finally, the calculations showed that the reaction of SO2with CaO was more exothermic than the reaction of SO2with MgO, which accounted for the faster rate of the former.

ISSN:0008-4042    

DOI:10.1139/v70-504

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

From dielectric constant measurements of supercooled 1,1-dichlorocyclohexane in the anomalous dispersion region, the free energy, entropy, and enthalpy of activation for dielectric relaxation are found to be 4.05 kcal mole−1, 123 cal °K−1mole−1, and 22.3 kcal mole−1, respectively, at −125 °C. The calculated maximum free energy barrier of crystal nucleus formation based on simple nucleation theory is 3.64 kcal mole−1. In view of the qualitative agreement between the experimental free energy of activation of dielectric relaxation and the calculated free energy of activation of nucleation, it is reasonable to conclude that the processes of molecular orientation and of crystal nucleus growth are similar. A calculation of the free energy barriervs. crystal nucleus size diagram also predicts spontaneous crystallization when the radius of crystal nuclei exceeds 12.8 Å.

ISSN:0008-4042    

DOI:10.1139/v70-505

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

A method of evaluating the molar polarizations of the constituents and the dipole moment of the complex simultaneously in a quaternary molecular complex system ofin an inert solvent, S, is proposed on the basis of an empirical relationship between the specific polarization of the solution and the weight fraction of molecule A in combination with the mass action law and the mixture law of specific polarization. The validity of the method is tested by using the data obtained in Smith's papers for the systems of aniline in dioxane–benzene,n-butyl alcohol in pyridine–benzene, and pyridine inn-butyl alcohol – benzene. The agreement in dipole moment of the complex between the proposed and Smith methods for the first two systems verifies the applicability of the proposed method, which also gives consistent results for the second and third systems, while no value for the third system is given in Smith's paper.

ISSN:0008-4042    

DOI:10.1139/v70-506

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Intermolecular potential parameters for ammonia have been determined for the Stockmayer–Kihara function using experimental second virial coefficient, diffusivity and viscosity data of binary mixtures with argon, methane, nitrogen, and oxygen. The parametersU0/k = 215 °K, σ(core-to-core) = 2.70 Å anda* = 0.2 reproduce essentially all of the data nearly within experimental error and accurately reproduce pure ammonia transport properties. Upon considering both physical and chemical contributions to the second virial coefficient of ammonia, the apparent standard-state hydrogen-bond enthalpy for chemical dimerization is −3.2 kcal/mole while the vibrational entropy change is 20.2 cal/mole °K, indicating weak association.

ISSN:0008-4042    

DOI:10.1139/v70-507

出版商:NRC Research Press    

年代:1970

数据来源: NRC