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An improved method of preparing deuterated alkanes from the halides has been developed. Dehalogenation of ethyl iodide, 1,1-dibromoethane, and 1,1,1-trichloroethane with zinc dust in deuterium oxide – dioxane solutions, or even with deuterium oxide alone, gave excellent yields of ethane-d1, ethane-1,1-d2, and ethane-1,1,1-d3. Methane-d1, -d2, -d3, and -d4 were prepared similarly from methyl iodide, dibromomethane, chloroform, and carbon tetrachloride respectively. The isotopic purity of the products was over 90 mol.%. The reaction is also applicable to higher alkyl halides.

The application of organoaluminium compounds as components of organometallic or complex systems is connected with a knowledge of their reactions with electron donors. Reactions with nitriles, ketones, esters, ethers, alkyl chlorides, vinyl chloride, and acid chlorides as the electron donors were investigated. The first stage of the reaction of an organoaluminium compound with an electron donor involves formation of the corresponding donor-acceptor complex. A knowledge of the structure of the formed complexes is very important for an elucidation of the reaction course and mechanism. The heat of formation, composition, and molecular weight of the corresponding complexes were determined, and their i.r. and n.m.r. spectra were studied. From these investigations general conclusions were made concerning, the influence of the Lewis acidity of the organoaluminium compound on the structure of its complexes and on their reactivity; the effect of reactant mole ratio (organoaluminium compound to electron donor) on the reaction course, and the influence of the molecular structure of the complex and of dislocation of electrons on the reaction mechanism. Hallwachs and Schafarik' synthesized the first organoaluminium compound 120 years ago. By treating aluminium with ethyl iodide they prepared ethylaluminium sesqui-iodide. However, the chemistry of organoaluminium compounds received little attention until the investigations of Ziegler and his collaborators, in about 1950. The development of the direct synthesis of organoaluminium compounds from aluminium, ethylene. and hydrogen, and elaboration of normal pressure polymerization of ethylene, aroused great interest. Almost simultaneously, numerous research centres over the world undertook research and technological investigations. Organoaluminium compounds proved to be of both theoretical and technological interest because of their ability to form auto and other complexes, their high reactivity, and associated structure and valence theory problems. In spite of the two decades that have passed since Ziegler's discoveries and the intensive studies that have been conducted throughout. the interest in the chemistry of organoaluminium compounds has not declined. This is mainly due to the use of organoaluminium compounds as constituents of complex catalyst systems. 509

The aluminum chloride catalyzed reaction between β-14C-ethyl iodide and benzene in 1,2,4-trichlorobenzene as solvent was studied under different conditions of temperature and reaction time. Yields of ethylbenzene were estimated by isotopic dilution. Up to 20% rearranged product, α-14C-ethylbenzene, was found. The trend indicated that yield of ethylbenzene was lower and side chain rearrangement greater when the reaction mixture was heated at higher temperature for longer time. The rearrangement apparently occurred after the initial formation of β-14C-ethylbenzene. After a reaction time of 5 min at 154 °C, only 0.1–0.3% unreacted and unrearranged β-14C-ethyl iodide was recovered while the ethylbenzene obtained from the reaction showed about 2% rearrangement. When β-14C-ethylbenzene was heated with aluminum chloride in 1,2,4-trichlorobenzene for 2 or 24 h, rearrangement to α-14C-ethylbenzene was observed. In some experiments, a fragmentation product, toluene, was isolated. Its specific activity suggested that 1 mole of active ethylbenzene gave 2 moles of toluene only one of which was active. The mechanistic implications of these findings are discussed.

A number of very reactive radicals and atoms prepared by photolysis in rigid hydrocarbon glasses at the temperature of liquid nitrogen have been detected by their absorption spectra. Thus ethyl iodide dissociates to iodine atoms which only recombine to give I 2 when the glass is softened. Similarly CS 2 and ClO 2 give CS and CIO which can be detected spectroscopically in the frozen glass. Toluene and other benzyl derivatives yield the benzyl radical, and the spectra of a number of similar unstable aromatic radicals have been recorded for the first time. Most of these radicals have lifetimes of less than 1 ms at comparable concentrations in the gas phase or in ordinary solutions, but have been observed for many hours in the rigid glass. The method should be of general applicability for the study of the primary products of photochemical or radiation chemical processes.

1. An investigation was made of the Arbuzov rearrangement of tris-2-chloroethyl phosphite under the action of methyl iodide, ethyl iodide, and acetyl chloride. 2. Some previously undescribed 2-chloroethyl esters of phosphorous acid and methyl-, ethyl-, and acetyl-phosphonic acids were synthesized.

In a previous publication it was shown that pressure was capable of exerting a considerable influence on the rate of reactions in solution. Two reactions were studied; the first, the interaction of sodium ethoxide and ethyl iodide in alcohol solution, was a typical example of the “normal” class, in which the number of molecules reacting is approximately equal to the number of collisions with the requisite activation energy, while the second, the interaction of pyridine and ethyl iodide in acetone solution, was a typical “slow" reaction, in which the number o f molecules reacting is several powers of 10 less than the number of collisions with the requisite activation energy. The rates of both reactions were increased by pressure, but while the first was accelerated 1.6 times at 3000 kg/cm 2 , the second was accelerated 7.2 times at 3000 kg/cm 2 , and much more at higher pressures. It seemed desirable to investigate other reactions falling into these two classes, to see whether this behaviour was general. With this end in view, the hydrolysis of sodium monochloracetate by aqueous caustic soda, another typical “normal” reaction, has been studied up to 12,000 kg/cm 2 , and the work on the sodium ethoxide and ethyl iodide reaction has also been extended to this pressure.

By treatment with diethylzinc and iodoform, benzene gave 7-ethylcyclohepta-1,3,5-triene in a yield of 58%, along with a quantitative formation of ethyl iodide. Alkylbenzenes, including methyl-, ethyl-, isopropyl-, tert-butyl-, and o-dimethylbenzene, gave the corresponding alkyl-substituted 7-ethylcyclohepta-1,3,5-trienes in yields of 60, 45, 41, 35, and 52% respectively. The tropylium iodide resulting from the adduct of the iodocarbenoid of zinc to benzene (7-iodonorcaradiene) is suggested as an intermediate in the formation of the 7-ethylcycloheptatriene.

Reaction of 3, 6-dimethoxy-4-nitropyridazine 1-oxide (I) with alkyl halides were investigated, and following results were obtained. 1) Reaction with methyl iodide gave 1, 3, 4-trimethoxy-6 (1H) pyridazinone (II). 2) Reaction with ethyl iodide gave 1, 4-diethoxy-3-methoxy-6 (1H) pyridazinone (IV). 3) Reaction with ethyl chlorocarbonate gave 1-ethoxycarbonyloxy-3-methoxy-4-chloro-(VI) and 1, 4-bisethoxycarbonyloxy-3-methoxy-6 (1H) pyridazinone (VII). 4) Reaction with ethyl bromoacetate gave 1, 4-bisethoxycarbonylmethoxy-3-methoxy-6 (1H) pyridazinone (IX). Moreover the reaction of 4-nitropyridazine 1-oxide derivatives with methyl iodide was described. 1) Reaction with 3-methoxy-4-nitro-6-methylpyridazine 1-oxide (XIII) gave 3, 4-dimethoxy-6-cyanopyridazine 1-oxide (XV) and 1-methyl-3-methoxy-6-cyano-4 (1H) pyridazinone (XVI). 2) Reaction with 6-methoxy-4-nitropyridazine 1-oxide (XIV) gave 1, 4-dimethoxy-6 (1H) pyridazinone (XX).

The addition of HI to C2H4 yields C2H5I at low temperatures and C2H6+I2 at higher temperatures. From 289° to 331°C the rate law is mixed—second order with C2H6+I2 as products. The rate is independent of added I2 and has a specific rate constant k2 (units, liter/mole‐sec): logk2=8.52−(28900/4.575T). The pyrolysis of C2H5I from 330° to 392°C goes by a first‐order process to C2H4+C2H6+I2. The first‐order rate constant is given by (units, sec—1): logku=13.66−(50000/4.575T).If it is assumed that both processes have the same rate determining step, namely the reversible dissociation of C2H5I, they yield an equilibrium constant in good agreement with independently calculated values of Keq for this dissociation. Under these conditions k1, the specific rate constant for the unimolecular split of C2H5I into C2H4+HI is given by ku/2. Arguments are presented to show that this common path involves the four‐center molecular transition state rather than a radical disproportionation. The latter, however, may account for as much as 20% of the pyrolysis at 392°C.

Benzene, naphthalene, related hydrocarbons and some of their derivatives act as optical sensitizers towards the decomposition of alkyl iodides in hexane solution. Within this group, the sensitizing power of a substance towards an acceptor runs parallel with the ability of the acceptor to quench the fluorescence of the sensitizer; this is demonstrated quantitatively and in detail. The quantum yield of the naphthalene‐sensitized decomposition of ethyl iodide follows an equation of the form 1/φ=a+b(1/[EtI]), and detailed analysis of the quenching and sensitization shows that while sensitization and fluorescence are alternative processes, they are not completely reciprocal, in that more molecules may sensitize than may potentially fluoresce. All of the observed features of the sensitization are consistent with its being the result of a resonative transfer of energy at collision from the excited sensitizer to the acceptor.

A radiofrequency mass spectrometer has been used, with slight modification, to measure the kinetic energy of fragment ions from polyatomic molecules. Selected ions from CO 2 , CH 3 OH, C 2 H 5 OH, C 3 H 7 OH, i-C 3 H 7 OH, CH 3 I and C 2 H 5 I were examined for excess kinetic energy by means of retarding potential analysis before mass analysis. The excess kinetic energy for any given ion was always greater for 70 V electron impacts than for 50 V. Such ions as m/g 31 and 29 from ethanol have an excess of about 0·45 V kinetic energy for 50 and 70 V electrons; m/q 29 and 27 from isopropanol also have about 0·45 excess energy for 70 V electrons; CH + 3 ions from the alcohols and from the iodides showed excess kinetic energy while m/q 27 from ethyl iodide had 0·9 V excess energy for 70 V electrons. The results are interpreted as evidence of a significant num ber of dissociations from electronic states which are not in effective competition with one another. The existence of non ­ competing dissociation paths for a given molecular ion complex would preclude the application of the statistical theory of mass spectra to predict the breakdown scheme of that complex.

The incorporation of halogen endgroups in polymers has been established in the following cases for polymerization of styrene, methyl methacrylate and methyl acrylate: (1) chain transfer with halogenated hydrocarbons (chloroform, benzyl chloride, bromoform, ethylene dibromide, octadecyl bromide, ethyl iodide, cetyl iodide); (2) copolymerization with suitable components (vinyl bromide, tetrachloroethylene, trichloroethylene); (3) use of halogen atoms as initiators, e.g. FeCl 3 (+h v ), FeBr 3 (+h v ), HCl(+h v ) and KBr+H 2 O 2 (+h v ); (4) chemical transformation of a group already present in a polymer, e.g., conversion of hydroxyl endgroup to halogen endgroup by a usual method; addition of hydrogen bromide to double bond in polymers. The method of detection consists in converting a polymer with halogen endgroups to a quaternary pyridinium halide by refluxing with pyridine, a few drops of glycerol being added in the case of chlorine endgroup to facilitate the reaction. The converted quaternary halogen endgroup is detected independently by two tests developed in this laboratory: the dyeinteraction test with rhodamine 6GX conc. (Calco) dye and also the dye-partition test for cationic group with Bromophenol Blue or Disulfine Blue VN 150 as reagents.

This paper summarizes some of the data in the literature on the effects of phase on chemical reactions induced in organic systems by light, ionizing radiation and nuclear transformations. It also presents new data which show that: (1) the ratio of HI to I/sub 2/ produced in the radiolysis of pure isopropyl iodide with Co/sup 60/ gamma -rays is about tenfold higher in the solid phase at --190 deg than in the liquid at room temperature; (2) the yield of iodine from the radiolysis of isopropyl iodide in either the liquid or solid is dependent on the past history of irradiation of the sample in the other phase; (3) when the spectrum of ethyl iodide glass at --190 deg is examined after exposure of the solid to 2537 A. light, little or no change is observed as a result of the irradiation, but when the glass is then melted amd immediately refrozen, an absorption peak appears at 3700 A.; a similar effect is caused by the self-irradiation of tritiated ethyl iodide glass; (4) the ratio of HI to I/ sub 2/ produced by the photolysis of ethyl iodide is approximately ten-fold higher in the glass at --190 deg than inmore » the liquid at room temperature. (auth)« less

1. The velocity of decomposition of sulphur iodide in carbon tetrachloride solution has been studied at 0° and at 30°C. At 30°, the velocity of decomposition is about four times that at 0°C. 2. With sulphur iodide solutions, a complete absorption for all wavelengths below 4770 A is noticed. Data on the instability of sulphur iodide obtained by analytical methods, are confirmed by the spectroscopic investigations.

The alkaloid delsoline (C25H41O7N) was oxidized by acid permanganate mostly to dehydrooxodelsoline, and by neutral permanganate to anhydrohydroxydelsoline. Oxidation of the alkaloid with mercuric acetate produced anhydrohydroxy-N-de-ethyldelsoline which could be re-ethylated with ethyl iodide, thus showing the presence of an N-ethyl group in delsoline. Anhydrohydroxydelsoline was also obtained from O-acetyldelsoline perchlorate by oxidation to an anhydronium salt followed by hydrolysis with sodium hydroxide, and this method of preparation provides evidence of its carbinolamine structure. O-Acetyloxodelsoline, obtained from acetyldelsoline, is cleaved by lead tetra-acetate to a secodiketone that loses the elements of methanol on recrystallization. Hence the base contains two vicinal tertiary hydroxyls, one of which is β to a methoxyl group. Dehydrooxodelsoline is also cleaved by lead tetra-acetate and the product undergoes an internal aldol rearrangement. These results are interpreted in the light of a structure that is tentatively suggested for delsoline.

Treatment of 9-alkyladenines (Ia, b, c) with 30% aqueous hydrogen peroxide in acetic acid at 30° produced the corresponding 9-alkyladenine 1-oxides (II a, b, c) in 51-71% yield. The 1-N-oxides were found to undergo alkylation almost exclusively at the oxygen atoms of the N-oxide groups when treated separately with methyl iodide, ethyl iodide, and benzyl bromide in N, N-dimethylacetamide at room temperature, and the corresponding salts (III) of all the nine possible 1-alkoxy-9-alkyladenines were obtained in excellent yields. 1-Ethoxyadenosine hydriodide and 1-benzyloxyadenosine perchlorate were also prepared from adenosine 1-oxide (II d) in a similar way. The ultraviolet and nuclear magnetic resonance spectral data on the 1-alkoxyadenine derivatives obtained in the previous and present studies are collected in Tables II and III.

In [1], on the example of the telomerization of ethylene with ethyl iodide, we developed a method for determining chain transfer constants taking account of the gradual reaction of the telomers and reversibility of the chain transfer reaction. In the present investigation this procedure was used to study the influence of the telogen structure, and of temperature, in telomerization with ethylene on the chain transfer constants.

In ethanolic solution methyl iodide reduces on tin cathodes to tetramethyltin but ethyl halides do not yield the corresponding tin ethyls except in insignificant yields. Increases in alkyl halide concentrations improve the yields of tin alkyls and also increase the passivation of the surface towards the reduction. The distribution of gaseous products from ethyl iodide reduction indicates the formation of small concentrations of free ethyl radicals at less negative potentials. Electrodes directly immersed in the catholyte are inactive and require cathodic polarisation in the background medium to improve activity.

Previous work has shown that pressure has an accelerating effect on a large number of chemical reactions in the liquid phase. The rates of the reaction between pyridine and cetyl halides have been studied at different temperatures and pressures, but it was not found possible to interpret the results by means of the ordinary reaction velocity equations, and no conclusions could be drawn as to the mechanism of the pressure effect. In making a further attempt to determine this mechanism, it seemed desirable to take reactions which have already been studied at atmospheric pressure and are known to follow the simple velocity equations, and to investigate the effect of pressure on the velocity con­stants. The effect of temperature on the velocity constant of a reaction k , can be expressed by the Arrhenius expression k = A e -E/RT . A knowledge of the variation of the velocity constant with pressure at different temperatures would show whether this change is due to a change in the value of the constants A or E, or of both.

The existence of the isomer 130Im (9.2 min) has been established by the growth of the gamma‐ray spectrum of the 130I ground state following neutron irradiation of 129I, and also by the incorporation of 130I into organic combination as a result of the isomeric transition of I2(130Im) dissolved in n‐hexane. The isomer decays to the ground state by a highly converted isomeric transition with a 0.77 probability and to the 0.54‐MeV level of 130Xe by beta emission with 0.23 probability. The cross‐section ratio, σ(130Im)/σ(130I), for production of the isomers from 129I by pile neutrons is about 2.0. The fraction of the isomeric transition events which result in organic incorporation of the 130I daughter in solutions of I2(130Im) in n‐hexane, or in solutions of RI(130Im) in ethyl iodide, is about 0.40.

It is shown, that organic molecules for which a strong donor-acceptor interaction with aluminium triiodide can be expected, with formation of a molecular complex, cause a strong “exchange blocking” effect in the AlI3C2H5I liquid system. Independently of the amount of the added foreign compound, however, a significant part (about 20–30 per cent) of the radioiodine atoms primarily present in the metal iodide is transferred to the ethyl iodide in the first rapid period of the exchange. The suggest a significant role for intermediate compounds and/or solid-liquid surface exchange. Aromatic hydrocarbons and olefines which are supposed to form π-complexes with aluminium trihalides, cause no effect on the iodine exchange in the system investigated.

The radical yields of C2H5• and CCl3• observed by electron spin resonance of CCl4 + C2H5I mixtures irradiated by γ rays at 77°K are compared with yields of HCl, I2, and HI measured after thawing. The dissociative capture of thermalized electrons by CCl4 is extremely effective and accounts for most of the observed radicals. The difference between yields of HCl and CCl3• results from charge transfer from C2H5I+ to CCl3•. The formation of iodine proceeds both from neutralization processes of Cl− ions with positive ions formed from C2H5I, and from ion–molecule reactions.

Bis(diathylamino)-diorgano-biphosphine, (C2H5)2N(R)P-P(R)N(C2H5)2, werden mit Athyljodid bzw. Chlorwasserstoff in Ather umgesetzt. Die Athyljodid-Einwirkung fuhrt uber die Spaltung der PP-Bindung und Quarternisierung zu Diathylamino-organo-jod-phosphinen und Diathylamino-diathyl-organo-phosphoniumjodiden, wahrend die Umsetzung mit Chlorwasserstoff je nach den angewandten Mol-Verhaltnissen auser Cyclo-polyphosphinen Diathylamino-organo-chlor-phosphine und Organo-dichlor-phosphine liefert. Dabei wird ein unterschiedliches Verhalten des Bis(diathylamino)-diathyl-biphosphins gegenuber dem Bis(diathylamino)-dicyclohexyl- und Bis(diathylamino)-diphenyl-biphosphin festgestellt. The PP bonds in bis(diethylamino)-diorganyl-biphosphines, (C2H5)2N(R)PP(R) · N(C2H5)2, are cleaved by ethyl iodide or hydrogen chloride in ether. Ethyl iodide yields phosphine iodides and phosphonium iodides, whereas in the case of HCl, according to the experimental molar ratio biphosphine: HCl, phosphine chlorides or dichlorides are formed in addition to cyclo-polyphosphines. That biphosphine with R = ethyl exhibits a different reaction behaviour compared with those of the biphosphines having R = cyclohexyl or R = phenyl.

The organic retentions for (d,p), (n,2n), and (γ,n) activation of iodine in liquid methyl and ethyl iodide, containing added iodine, have been found to be equal to the retentions observed in radiative neutron capture. This demonstrates that the chemical effects are independent of the recoil energy of the activated nucleus, of the mode of nuclear formation, and of variation of fragmentation effects within the recoil track. In the absence of scavenger iodine, the increase in retention due to radiation damage is less than 10 percent in all cases studied.

The kinetics of the ethyl iodide–silver nitrate reaction in 0·02M-aqueous potassium nitrate solution at 5° were studied in the presence of charcoal and of silver iodide. The rates depended on the concentration of each substrate either raised to a fractional power, as in a Freundlich adsorption isotherm, or arranged in a form analogous to a Langmuir isotherm, and thus indicated a Langmuir–Hinshelwood mechanism. When the difference in surface areas was taken into account, silver iodide was found to be a more effective catalyst than charcoal by a factor of at least 40. The activation energies were 20 kcal. for the homogeneous reaction, 10.4 kcal. for the charcoal-catalysed process, and 8.5 kcal. for the reaction on the silver iodide surface.

The preparation and properties of diethyl, di-n-propyl-, di-isopropyl-, and di-t-butylaminophenylphosphines and of certain of the methyl and ethyl iodide adducts and the oxides, sulphides, and selenides are described. Diethyl and di-isopropylaminophenylphosphines have been shown to rearrange to the corresponding N-alkyldialkylaminophosphazenes, polycyclo(phenylphosphine), and alkylamines. The infrared and n.m.r. spectra of some of the compounds are reported.

1. The yield in the reaction leading to the formation of triethyl phosphorothioate depends on the nature of the metal in the metal dialklyl phosphorothioate on the nature of the halogen in the alkyl halide, and on the conditions of the experiment; a) silver and potassium diethyl phosphorothioates give the highest yields of ester; b) the highest yields of ester are obtained in alcoholic solution. 2. In the reaction of ethyl iodide and bromide with sodium, potassium, and silver diethyl phosphorothioates the same triethyl phosphorothioate is obtained in varying yield.

A simple method is described whereby millimicromole amounts of extensively purified N5-methyltetrahydrofolate-homocysteine transmethylase (vitamin B12 transmethylase) can be chemically propylated to yield an inhibited vitamin B12 enzyme which is reactivated with light. The procedure consists of a short incubation of the enzyme with propyl iodide in the presence of reduced flavin mononucleotide and dithiothreitol under hydrogen gas. Formation of a propylated (inhibited) enzyme was correlated with alterations in the visible absorption spectrum of the enzyme. When propyl-1-14C bromide was the alkylating agent a radioactive enzyme was formed which lost radioactivity upon exposure to light. The effects of several reaction parameters on the extent of propylation were examined as was the effect of propylation on four separate transmethylation reactions catalyzed by the vitamin B12 enzyme preparations. Transmethylation reactions which require catalytic amounts of S-adenosylmethionine (AMe) as a cofactor or in which AMe itself is the substrate methyl donor were inhibited by propylation; however, methyl group transfer from methyl-B12 (5,6-dimethylbenzimidazolylcobamide methyl) to homocysteine was not affected by propylation. Micromolar concentrations of both AMe and N5-methyltetrahydrofolate markedly inhibited propylation as did higher levels of methyl iodide. For the inhibition of propylation by low concentrations of N5-methyltetrahydrofolate a noninhibitory amount of AMe was essential.

The potential barrier which hinders the internal rotation in ethyl iodide molecule was studied. If the potential energy is assumed to be of the sinusoidal form \(\frac{H}{2}(1-\cos\ \text{3x})\), the barrier height is determined as H =3.22±0.5 kcal/mole from the Q b -type transition in the first excited torsional state. The torsional frequency is about 230 cm -1 . The effect of internal rotation on the quadrupole hyperfine structure of K =1 levels was analyzed.

The polymerization of ethylene sensitized by the thermal decomposition of ethyl iodide in the presence of mercury vapor has been studied at 250°, 275°, and 300 °C. C14-labelled ethyl iodide was used in a number of experiments. The increase in the rate of decomposition of ethyl iodide in the presence of ethylene and the formation of butyl iodide are accounted for by equilibrium processes of the type RI + Hg = R + HgI. The important features of the reaction were established from the identity, quantity, and activity of the various products. The predominant formation of olefins is attributed to the isomerization and decomposition of large radicals. Very little of the butane is formed by the combination of ethyl radicals. Radical disproportionation is the most important chain termination step.

The photochemical investigation of the decompositions of diethyl zinc and diethyl mercury has established that the products in each case consist principally of ethane, ethylene, and butane, with smaller amounts of hydrogen and butylene. The composition of the product varies with the alkyl, but does not change markedly with temperature from 45° to 250°. An examination of the effects of varying the concentration, intensity of radiation, packing of reaction vessel, and inert gas pressure leads to the conclusion that butane is formed by the combination of two ethyl radicals produced in the primary process, while ethane and ethylene arise from a reaction between ethyl radicals and metal alkyl molecules. The reaction between ethyl radicals and hydrogen becomes measurable at about 160°, and by analogy with the corresponding process with methyl radicals may be assigned an activation energy of 9±2 kcal. The reaction C2H5+H=2CH3 proceeds rapidly at 100°. The investigation of the photolysis of ethyl iodide in the presence of mercury vapor and the mercury photosensitized hydrogenation of ethylene supports the conclusions based on the metal alkyl studies.

The infrared absorption spectra of ethyl chloride, ethyl bromide and ethyl iodide have been determined with a prism spectrometer between 1.5μ and 15μ. Eight experimentally observed fundamental frequencies have been selected which, together with their first harmonics and simple combinations, are shown to account for the entire spectrum. A type of vibration between atom pairs believed to represent the important feature of the motion of the atoms is suggested for each of these fundamentals. The shifts in the absorption maxima produced by the substitution of the different halogens together with absorption and Raman data of related compounds are used in selecting these types of vibration. The bearing of these hypotheses on problems in chemical kinetics is discussed.

Transient absorption spectra have been detected after flash photolysis of iodine in a variety of solvents. There is some correlation between the wavelength of maximum absorption and the ionization potential of the solvent and the spectra are attributed to the charge transfer complexes between iodine atoms and the solvent which were predicted in part III. In the case of methyl iodide as chaperon a weak transient has also been observed in the vapour phase. The decay of the complex follows a second-order law and rate constants have been measured in six solvents. Values for the extinction coefficient are derived by assuming that the reaction is diffusion controlled. Equilibrium constants of complex formation have been measured in ethyl iodide and ethyl bromide.

A modification of the Simmons-Smith reaction, which involves a prior reaction of ethyl iodide with zinc copper couple followed by addition of methylene iodide and oleflns, was proposed. The improved yields of cyclopropane products were obtained with various olefin substrates. It is likely that the operating species in the present modification is ethyliodomethylzinc.

Summary A simple procedure for microdetermination of ethylene oxide content in glycols and ethylene oxide adducts has been devised. This procedure consists of treatment of the sample and its intermediate product with hydriodic acid in two stages. Under a combination of experimental conditions, ethyl iodide can be quantitatively produced for estimating of ethylene oxide content in the sample stoichiometrically. This method is especially designed for analysis of ethylene oxide adduct of polyhydroxy derivatives.

It is shown how the composite particle technique, which has proved useful for the analysis of the spectra of molecules in the isotropic liquid phase, may also be applied, with slight modifications, to spectra observed in an anisotropic environment. As an example, the analysis of the spectrum of ethyl iodide in the nematic phase is described.

Liquid methyl and ethyl iodides were irradiated at room temperature with Co/sup 60/ source at dose rates approximating 10/sup 19/ ev hr-/sup 1/ ml-/sup 1/ in air-free samples with added HI and I/sub 2/. In ethyl iodide, C/sub 4/H/sub 10/ is a small but significant product; G(C/sub 2/H/sub 4/) decreases at HI or I/ sub 2/ concentrations> 10-/sup 2/ M; G(C/sub 2/H/sub 6/) increases at HI concentrations> 10-/sup 2/ M provided I/sub 2//HI approximately 0; G(C/sub 2/H/ sub 6/) decreases at I/sub 2/ concentrations> 10-/sup 2/ M provided HI/I/sub 2/ approximately 0; and G(C/sub 4/H/sub 10/) decreases at HI or I/sub 2/ con centrations>10-/sup 2/ M. In methyl iodide, G(CH/sub 4/) increases at HI concentrations>10-/sup 2/ M and G(C/sub 2/H/sub 6/) decreases at I/sub 2/ or HI concentrations>10-/sup 2/ M. These results indicate that C/sub 2/>i and CH/sub 3/ are involved in diffusion-controlled reactions as 2C/sub 2/H/sub 5/ - C/sub 4/H/ sub 10/; C/sub 2/H/sub 5/ + I - C/sub 2/H/sub 4/ + HI; 2CH/sub 3/ i - C/sub 2/H/ sub 6/, etc. Disposition of radicals favorable to diffusion-controlled reencounters may arise from track effects in general. In particular they would be favored by the pairing of alkyl radicals followingmore » charge neutralization of the products of ion-molecule reactions, as CH/sub 3/I/sup +/ + CH/sub 3/I - C/sub 2/H/sub 6/I/sup +/ + I and C/sub 2/H/sub 5/I/sup +/ + C/sub 2/H/sub 5/I - C/sub 4/ H/sub 10/I/sup +/ + I, which were obs erved in the mass spectrometer. The reaction products are qualitatively and quantitatively consistent with electron impact cracking patterns as determined by mass spectrometry. (auth)« less

The photolysis of C2H5I and C2D5I have been investigated at 2537 and 2288 A in the presence of thermal alkyl radical scavengers such as O2 or I2. The ethane (quantum yields at 2537 A: φC2H6=0.82×10−3, φC2D6=0.29×10−3) formed in such mixtures can be entirely ascribed to abstraction of an H (or D) atom by a ``hot'' ethyl radical formed in the primary dissociation of ethyl iodide. The differences in quantum yield between C2H6 and C2D6 are in part ascribed to a difference in the partitioning of the excess energy (∼30–40 kcal) carried over from the primary process into vibrational and translational modes. When C2D5I or C2H5I is photolyzed in the presence of a cyclo‐C6H12–cyclo‐C6D12–O2 mixture (1:1:0.1), or of a cyclohexane‐1,1,2,2,3,3,‐d6–O2 mixture, the relative probability for abstraction of an H atom vs that for abstraction of a D atom (πH/πD) is equal to 1.5±0.1. The latter value shows little dependence on a change in wavelength and is also not affected when unreactive gases are added to the reaction mixt...