摘要:

The parachors of a group of organotins were measured and compared with calculated values using both atomic constants and bond constants to obtain corresponding values for tin. The variation was found to be lower for the first method. The parachors were found to be about 8 times the molar refractions and could be approximately predicted from calculated molar refractions.The refrachors of the organotins were calculated and a suitable series of additive constants devised to approximate the found values. Excellent correlation was obtained between the order of refrachors corrected for molecular weight and the order of dispersions as expressed by the Nu (ν) values. An initial indication of alternation in methylene group increments for both molar refraction and Nu values was found. For a constant dispersion ratio (Qvalue) the refractive indices for the F and C lines of hydrogen were calculated.

ISSN:0008-4042    

DOI:10.1139/v66-202

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The rate constants for the ion–molecule reactions forming the protonated molecule in CH3CN, H2, CH4, and CH3OCH3, the equivalent reactions in the deuteriated species, and the reactions forming COD+in CO–CD4mixtures have been measured at thermal energies and at 10.5 V/cm repeller field strength. For H2, HD, D2and the reactions in CO–CD4mixtures the rate constant for the thermal reaction is approximately 0.3–0.5 that of the 10.5 V/cm rate constant. For all other cases the ratio of rate constants is approximately unity as predicted by the ion-induced dipole model. The absolute values of the rate constants in most cases are considerably lower than predicted by theory.

ISSN:0008-4042    

DOI:10.1139/v66-203

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

A new method is described for the analysis of water in nonpolar organic liquids. It is based on an isotope dilution procedure and involves the exchange of the water present in the sample with D2O. The change in isotopic composition of the D2O is determined by infrared difference spectroscopy. The method appears to be accurate to ± 0.8%.The principal advantage of this method is that the difficult problem of calibration with organic–water standards is avoided. It is restricted, however, to solvents which have a low solubility in water and do not have exchangeable hydrogens.A series of solubility measurements were carried out for H2O in C6H6from 10 to 60 °C. The data were fitted to the usual interpolation equation In (f/x) = −A/T + BlnT + C, and the thermodynamic functions of solution, ΔG, ΔH, ΔCP, and ΔS, were computed for the transfer of 1 mole of water from the benzene phase to the vapor phase.

ISSN:0008-4042    

DOI:10.1139/v66-204

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The reactions of samarium isopropoxide with ethyl acetoacetate have been carried out in benzene medium in different stoichiometric ratios and the compounds of the type Sm(OPri)2(Etacac), Sm(OPri)(Etacac)2, and Sm(Etacac)3have been isolated in quantitative yields. However, the reaction of samarium isopropoxide with excess of the acetoacetic ester lead to the formation of Sm(Etacac)3.Etacac, which on heating under reduced pressure at 110 °C forloses its addition molecule of ester. The reactions are exothermic and the amount of heat liberated also increases with the increase in the concentration of the ester.The interchange reactions of the products Sm(OPri)2(Etacac) and Sm(OPri)(Etacac)2witht-butyl alcohol have also been carried out; they are endothermic reactions. The compounds Sm(OBut)2(Etacac) and Sm(OBut)(Etacac)2have been obtained in quantitative yields from the reaction mixture. All the products are stable up to 200 °C at 0.5 mm, but at higher temperature they decompose to deep-red solids. Molecular weight determinations show that they are dimeric in nature.

ISSN:0008-4042    

DOI:10.1139/v66-205

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The endothermal decomposition of 18 β-quinol clathrates has been studied by thermo-analysis, calorimetry, and X-ray diffraction, and the decomposition process shown to beFor those symmetrical guest molecules (M) which do not distort the β-quinol cavities from their normal dimensions, both temperatures and enthalpies of clathrate decomposition increase with increasing volume of the guest molecule. For those unsymmetrical guest species which require distortion of the cavities along their c-axis, temperatures and enthalpies of decomposition tend to decrease as the initial distortion required to accommodate the guest increases. Thermal stability of β-quinol clathrates is thus strongly influenced both by the size and shape of the guest molecule.The mechanism of thermal decomposition is suggested to involve a combination of the loss of stabilizing guest–wall interactions, together with increased thermal motion of the interpenetrating networks of hydrogen-bonded quinol molecules.

ISSN:0008-4042    

DOI:10.1139/v66-206

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Several ortho-substituted radicals of the benzhydryl type and a variety of diaryl ketyls have been studied through the nuclear hyperfine structure of their electron spin resonance spectra. A strong similarity is found between the spectra of a given ketyl and its hydrocarbon analogue. This suggests that when ketones are reduced, a very tight ion pair is formed between the ketyl anion and its cation. Although the coupling constants of the protons vary with different reducing agents, larger variations are observed when bulky groups are substituted into ortho positions. These larger changes are attributed to a forced internal rotation of the phenyl rings. The distortion results from the steric repulsion between the ortho groups. The effect of 'buttressing' of ortho methyl groups is also studied. Deuterium and13C substitutions have been effected in some of the compounds.

ISSN:0008-4042    

DOI:10.1139/v66-207

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

This paper presents a model in which internal rotations of diphenylmethyl radical types effectively average out differences between the ortho and the meta substituent pairs in each ring. The process involves a very low energy of activation even though π-electron bonds are broken. The model is supported by valence bond (VB) and Huckel molecular orbital (HMO) calculations, and comparison is made with experimentally determined quantities wherever this is possible. Certain cases in which transannular pseudosymmetry has not been found are also discussed in relation to the above model.

ISSN:0008-4042    

DOI:10.1139/v66-208

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The infrared intensity of the C≡N group in β-cyanopyridine complexes with some first-row transition metal ions (Zn(II), Cu(II), Ni(II), Co(II), Fe(II), and Mn(II)) in aqueous solution has been measured. The coordination between the nitrogen atom on the pyridine ring and these metal ions exerts a marked change in the magnitude of the band intensity of the functional group. This can be interpreted in terms of a simple molecular orbital model and the relative magnitudes of σ-bonding and π-bonding involved in the complexes. A "coordination constant" is introduced for this system, and a linear correlation between these constants and the C≡N band intensities of the metal complexes is obtained from both the experimental data and theoretical considerations.

ISSN:0008-4042    

DOI:10.1139/v66-209

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The result given by Maxwell and by Boltzmann for the collision rate in a dilute classical gas has been widely accepted. Investigation of a stochastic model for the collisions indicates that the collision rate averaged over a macroscopic period of time is about 3% lower than the original result.

ISSN:0008-4042    

DOI:10.1139/v66-210

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The photolysis of CHCl3, in the vapor phase, was carried out using the 1 849 Å line of Hg as the exciting radiation. The photosensitized reaction was also studied using benzene as a photosensitizer. In the latter case, the exciting wavelength was the 2 537 Å line of mercury, which CHCl3does not absorb.The study was primarily concerned with establishing the initial steps of the direct photolysis and photosensitized reactions. Experimental observations rule out a molecular detachment of HCl in both the direct photolysis and photosensitized reactions at the wavelength used. The initial step of the photolysis appears to be a carbon–chlorine bond cleavage, but in the photosensitized reaction a carbon–hydrogen bond break is indicated as the primary step. It is concluded that in neither case does dissociation take place from the ground electronic state.

ISSN:0008-4042    

DOI:10.1139/v66-211

出版商:NRC Research Press    

年代:1966

数据来源: NRC