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The high resolution photoelectron spectra for the following iodine-containing molecules have been measured: iodomethane, 1-iodoethane, 1-iodopropane, 1-iodobutane, 1-iodopentane, 1-iodohexane, 2-methyl-1-iodopropane, 3-methyl-1-iodobutane, 2-iodopropane, iodocyclopentane, iodocyclohexane, 2-methyl-2-iodopropane, trifluoroiodomethane, 2,2,2-trifluoro-1-iodoethane, pentafluoroiodoethane, 3,3,3,2,2,1,1-heptafluoro-1-iodopropane, iodobenzene, pentafluoroiodobenzene, vinyl iodide, allyl iodide. The spectra are discussed in terms of extended Hückel (EH) molecular orbital calculations and of the qualitative changes upon variation of the alkyl group.

The carbonylation of iodobenzene has been studied kinetically in the presence of catalytic amount of palladium chloride. ln the reaetion of iodobenzene and carbon monoxide under pressure in a methanol solution, the addition of a suMcient amount of pyridine makes the catalyst soluble to form a homogeneous solution, and facilitates the methyl benzoate formation under mild conditions.Based on the assumption thatthe reaction involves methoxy and carbomethoxy-palladium cQmplexes, following rate equation has been derived(CH80)PdC1(py)2+CO rl; (CH300C)PdCl(py)2(cH, OOc)PdCl (py)d phl 13 L. PhCO2CHs + PdCII(py)2kik2HPee(PdC12)o((Phl)e (Ester))(1 kd(PdC12)gt) (k-I kiHPco k2((Phl)g (Ester))) kd(PdC12)cWhere kd-is rate constant of deactivation. This equation is in reasonabl. e, qgreement with the experimental results. The rate constants and the overall activation energyt have been determined to be kiH=8.16 10m2 a/tmpti, minFi, (H; Henry constant of CO), k.. i=O.185 min-i, k2=7.64 mol-i, 1, min-i, kd=31.7mol-i, 1, min-i at 1000C and E. =20.9kcal, mol-i, respectively.

Reactions of thiophene, t-butylbenzene, phenyltrimethylsilane and iodobenzene with (NH3)3Cr(CO)3 in refluxing dioxane have produced the corresponding arenetricarbonylchromium complexes in yields as good as or better than similar reactions using Cr(CO)6. This synthetic technique also has a major advantage over Cr(CO)6 in such reactions in that (NH3)3Cr(CO)3 does not sublime under these conditions. Iodobenzenetricarbonylchromium reacts with magnesium in ethyl ether to form the corresponding Grignard reagent in low yield. The formation and properties of a series of complexes derived from (NH3)3Cr(CO)3 and triptycene, dibenzobarrelene and biphenylene have also been studied.

A molecular beam photodissociation study has been made of a number of simple aryl iodides and bromides. The angular distribution of photofragments is characterized by an anisotropy parameter β which was measured for each molecule. The values of β depend on the lifetime of the excited state compared to the rotational correlation times of the molecule as well as on the orientation of the transition dipole with respect to the C–X bond. Knowing these orientations we can extract excited state liftimes as follows: methyl iodide, 0.07 picoseconds (psec); iodobenzene, 0.5 psec; α‐iodonaphthalene, 0.9 psec; and 4‐iodobiphenyl, 0.6 psec. It is concluded that methyl iodide directly dissociates but that the aryl compounds predissociate. The analogous aryl bromides have small anisotropy parameters and it is estimated that they live in the excited state perhaps two orders of magnitude longer than the aryl iodides. The data suggest a mechanism for predissociation in which S2 undergoes intersystem crossing to a triplet s...

A kinetic treatment describing the time dependence of the exchanged fraction (F) is presented for the photochemically-induced isotopic exchange process: AX+BX∗→hvAX∗+BX when complicated by a net change in the concentration of AX due to the side reaction: AX→hvBX. The kinetic equations are numerically integrated and applied to the specific case in which AX ≡ iodobenzene and BX∗ is radioactive iodine (I131I). The treatment accounts quantitatively for the experimental F vs. time plots. It also leads to the evaluation of the relative rate constants of the phenyl radical (Ph·) scavenging processes: Ph· + I2→PhI+I. and Ph·+S→scavenging products where S is benzene, toluene or molecular oxygen.

Used as a gas chromatographic detector, the plasma chromatograph produces low resolution positive and negative mobility spectra to identify chromatographed components. The negative plasma chromatographic mobility spectra obtained for chlorobenzene, bromobenzene, and iodobenzene give only Cl−, Br−, and I− ionic species. Application of a deconvolution technique to the halide ion peaks gives resolution of the same number of components as isotopes present: two for the Cl− and Br−; one for the I−. The areas of the Cl− and Br− deconvoluted components were approximately equal to the isotope abundances of these elements. Enhanced resolution by this technique increases qualitative data obtainable with the plasma chromatograph.

Aroyl peroxides andt-butylperoxy isopropyl carbonate decarboxylate aliphatic carboxylic acids in the presence of iodine to form iodides in high yields. The aroyl peroxides also abstract carboxylic acid hydrogen from aromatic and perfluorocarbon acids. A proposed scheme is presented for the reaction of aroyl peroxides with carboxylic acids illustrating homolytic decarboxylation as taking place in an equilibrium between a pair of acyloxy radicals. These radicals are derived from the peroxide and acid and maintained in association by hydrogen bonding and iodine complexation.

Recent interpretations of Evans' experiments on the oxygen-induced singlet-triplet transitions in aromatic molecules are briefly discussed. In addition to the oxygen-induced singlet-triplet absorption for naphthalene there is a second absorption band which is possibly due to a simultaneous transition, i.e. a transition of the aromatic molecule from the ground state to the lowest triplet excited state and the 3Σ− → 1Δ transition of the oxygen molecule. Singlet-triplet transitions can also be stimulated by solvents containing heavy atoms. The results are shown for naphthalene, pyrene and fluoranthene with the solvents ethyl iodide, bromoform and iodobenzene. A qualitative discussion is given.

SummaryIncorporation of labeled iodobenzene and p-chlorophenylcysteine into the conjugated proteins and “soluble RNA fractions” of rat liver and intestine has been demonstrated. The possibilities for production of hydrocarbon-protein conjugates by either direct reaction with the protein or initial reaction to form an amino acid analogue are recognized.

The decomposition of 2-thenoyl peroxide in iodobenzene was carried out at 80C. In the presence of copper(II)chloride, iodopheny12-thenoates were produced. The isomer distribution and the partial rate factors suggested that the 2-thenoyloxylation reaction would proceed through the addition of a 2-thenoyloxy radical to an aromatic nucleus to give a cyclohexadienyl radical, fo11owed by rapid oxidation by copper(II)chloride. On the other hand, in the absence of copper(II)chloride the substitution of iodine by 2-thenoyloxy group took place to give phenyl 2-thenoate, which was not detected in the presence of copper(II)chloride. This substitution reaction is best explained on the assumption that the 2-thenoylexy group in the cyclohexadienyl radicals rearranges through an intramolecular migration of the carbonyl group to the carbon bearing an unpaired electron, and that phenyl 2-thenoate arises from a rearranged cyclohexadienyl radical with elimination of the iodine atom.

The relationship between thermal electron attachment and electron beam studies for chlorobenzene, 0‐dichlorobenzene, 0‐chlorotoluene, 3′‐ and 4′‐chloroacetophenone, 1‐chloronaphthalene, bromobenzene, 0‐bromotoluene, 1‐bromonaphthalene, and iodobenzene is shown. The empirical negative‐ion potential‐energy function used to describe electron attachment to aliphatic halides is used for convenience in showing this relationship. Use of the two‐dimensional potential‐energy function permits a more quantitative representation of the mechanisms previously proposed. In some cases, the mechanisms have been altered from the earlier qualitative interpretation. In general the two types of measurement appear to be essentially in complete agreement. The agreement between the results further supports the empirical potential‐energy function for the negative ion. Also, thermal electron attachment to additional aromatic halogen derivatives was investigated by the pulse sampling technique as a function of temperature to further support the mechanism. In particular, the thermal electron attachment of 3′‐ and 4′‐chloroacetophenone shows a unique temperature dependence involving three different phenomena over the temperature range 30°–240°C, which adds further support to the proposed mechanisms. In all the other cases investigated (chlorobenzene, 0‐chlorotoluene, 0‐bromotoluene), the electron attachment shows only one temperature region, again in complete agreement with the proposed mechanisms.

The vacuum ultra-violet spectra of various mono-substituted benzenes were measured in the wavelength region of 1550 A to 2200 A in the vapour phase by a recording vacuum ultra-violet spectrophotometer. The compounds studied here are phenols (phenol, anisole, phenetole and thiophenol), halogenobenzenes (fluorobenzene, chlorobenzene, bromobenzene and iodobenzene), and toluene. It was found that four π→π* transition bands appear in the wavelength region of 1550 A to 3000 A for phenol, anisole, phenetole, fluorobenzene, chlorobenzene and bromobenzene. On the other hand, six π→π* transition bands were found in the same wavelength region for thiophenol and iodobenzene. The absorption spectra of the former group are similar to that of benzene itself. On the other hand, the absorption spectra of the latter group are very different from that of benzene and rather similar to those of the anilines studied in a previous paper. From this point of view, the former group may be regarded as the molecules with weak substi...

Theoretical analyses of the PMR spectra of chloro-, bromo-, and iodobenzene, with the aid of deuterium decoupled spectra of the para deutero derivatives of the chloro- and bromo- compounds, have provided a complete set of spectral parameters for these compounds. Some surprisingly simple correlations have been observed between the shifts and the couplings, and between each of these and other molecular parameters. In general these results do not appear to be explicable in terms of the existing theories of these parameters.

The effects of temperature and electron scavengers on the hydrogen yield in the radiolysis of methylcyclohexane have been investigated by conventional kinetic techniques. The I value for hydrogen formation from pure methylcyclohexane varied from 4.9 to 4.4 in the range from room temperature to liquid nitrogen temperature. In the iodobenzene-methylcyclohexane system, the decrease in hydrogen yield was equal to the yield of benzene produced within experimental error. It is concluded that the benzene is formed through H atom abstraction from the solvent molecules by phenyl radicals which are formed by dissociative electron attachment to iodobenzene and that the benzene yield indicates the scavenged electron yield. Furthermore, a kinetic treatment for electron scavenging in the glassy state was presented. In the N2O-methylcyclohexane system, it was found that the ratio of the nitrogen yield, G(N2), to the decrease in hydrogen yield, ΔG(H2), is 2 in the temperature range from room temperature to −140°C, 1 at −...

132TeCl4 was contacted with aliphatic-aromatic mixtures until establishment of the radioactive equilibrium 132Te→132I, the mole fraction of both organic components being varied from zero to one. The distribution of 132I among the various products was then determined by gas-chromatographic analysis. The specific activity of the aliphatic 132I-labelled products increases with the concentration of the aromatic component (benzene). The results obtained are interpreted in the terms of intermolecular energy transfer.

The infrared and Raman spectra of penta-deutero-bromobenzene and penta-deutero-iodobenzene are reported and assigned. By means of the Redlich—Teller product rule the assignments are shown to be consistent with those of the corresponding non-deuterated compounds.

The strength of the liquid bridge between a sphere and a plate of dissimilar materials was studied. An equation was derived using the surface energy approach. For small amounts of liquid, the force of adhesion f was f=2πRy(cosθ1 + cosθ2 where R is the sphere radius, y is the surface tension, and θ2 , θ2 the contact angles. In the derivationn, major simplications about the meniscus shape were possible. The equation was experimentally tested with water, ethyl alcohol, aniline and iodobenzene using factorial combinations with different solids. Force of adhesion measurements were carried out using a tensile testing machine at controlled loading rates. Excellent agreement was obtained in the experimental and predicted adhesion values. The McFarlane-Tabor equation was identified as correct only for small amounts of liquids and similarly wet solids.

The angular dependence of X-ray scattering intensities of solutions of diiodobenzenes was compared with that of iodobenzene solutions containing the same concentration of iodine atoms. The data yielded interiodine distances of 3.6, 5.9, and 6.9 A for the ortho, meta, and para isomers, respectively, in good agreement with the known values of 3.52, 5.92, and 6.84 A. The same method was applied to a study of inter-iodine separations in ICH2CH2(OCH2CH2)nI (n = 1, 2, 3) using CH3CH2OCH2CH2I as the monoiodo analog. Experimental limitations preclude detailed interpretation of the data in terms of a probability distribution of the end-to-end distances of these model compounds. The intramolecular inter-iodine distances were characterized by the first minimum and the first maximum of the scattering function i(s) = ΔĪcorr/f, where ΔĪ is the difference in the scattering intensity from solutions of the diiodo and monoiodo compounds corrected for polarization, fI is the form factor of iodine and s = 4π sin Θ/λ, 2Θ is the scattering angle and λ the wavelength of the X-rays. The molecular chains of all three oligomers were significantly more expanded in m-xylene than in ethanol, the difference increasing with increasing chain length. A conformational analysis was carried out for ICH2CH2OCH2CH2I choosing the energies for conformational transition so as to yield a conformational distribution with the observed average square dipole moment and scattering function in non-polar media. The contraction of the molecule in ethanol is much larger than can be accounted for by the reduction in the COULOMBic energy of dipole interaction in a medium of higher dielectric constant. Die Winkelabhangigkeit der Intensitat der Rontgenstreuung von Losungen von Dijodbenzolen wurde mit der von Jodbenzol mit gleicher Jodkonzentration verglichen. Die aus den Resultaten berechneten intramolekularen Jodabstande betrugen 3,6, 5,9 und 6,9 A fur die ortho-, meta- und para-Isomeren; diese Werte stimmen mit den bekannten Grosen 3,52, 5,92 und 6,84 A gut uberein. Dieselbe Methode wurde zur Untersuchung der Jod-Jod-Abstande in JCH2CH2(OCH2CH2)nJ benutzt, wobei CH3CH2OCH2CH2J als das Monojod-Analoge benutzt wurde. Experimentelle Schwierigkeiten erlauben es nicht, die Resultate in Form einer Wahrscheinlichkeitsverteilung des Endenabstandes der Modellmolekule auszudrucken. Die zwischenmolekularen Abstande wurden durch das erste Minimum und das erste Maximum der Streufunktion i(s) = ΔĪcorr/f charakterisiert. Hier gibt ΔĪ den Unterschied zwischen der Streuintensitat der Losungen der Dijod- und der Monojodver-bindung an, fI ist der Formfaktor des Jods und s = 4π sin Θ/λ. 2Θ ist der Streuwinkel und λ die Wellenlange der Rontgenstrahlen. Die Molekulketten der drei Oligomeren sind in m-Xylen merklich ausgedehnter als in Athylalkohol, wobei der Unterschied mit der Kettenlange anwachst. Eine Konformations-Analyse wurde fur JCH2CH2OCH2CH2J durchgefuhrt, wobei die Energien der Konformations-Ubergange so gewahlt wurden, das eine Konformations-Verteilung erhalten wurde, die mit dem Dipolmoment und der Streukurve in nichtpolaren Losungsmitteln ubereinstimmt. Die Verkurzung des Endenabstandes in Athylalkohol ist viel zu gros, um durch die Verringerung der COULOMBschen Energie der Dipol-Wechselwirkungen erklart werden zu konnen.

High-resolution Raman spectra have been measured of chloro-, bromo-, and iodobenzene for line shifts up to 1600 cm−1 and several new lines were resolved. The line-shape parameters and depolarization ratios of most of these lines are reported here for the first time. The 1595 cm−1 benzene E2g doublet was resolved into the A1 and B1 monohalogen substituted lines. In going from bromoto iodobenzene a reversal in the A1-B1 line intensities was observed.

Arylation of propylene, ethylene, styrene, and methyl acrylate with iodobenzene was found to be catalyzed by metallic palladium in methanol to give methylstyrene, styrene, t-stilbene, and methyl cinnamate, respectively. Their yields and selectivities increased significantly by the addition of excess potassium acetate as an acceptor of hydriodic acid formed. The course of catalytic reaction is discussed in terms of the oxidative addition of iodobenzene to a palladium complex of low oxidation state.

The reaction of diphenylmercury with chromium hexacarbonyl in a boiling diglyme/octane mixture results in the formation of bis(phenyltricarbonylchromium)mercury in 70% yield. This compound reacts with mercuric chloride, iodine, hydrochloric acid and LiAlH4 producing (phenyltricarbonylchromium)mercury chloride, iodobenzene chromium tricarbonyl and benzene chromium tricarbonyl, respectively, all in high yield.

The order of reactivity of halobenzenes towards oxidative addition to Pd(PPh3)4 has been found to be PhI $PhBr $PhCI. Iodobenzene will react with Pd(PPh3)4 in benzene at room temperature, and bromobenzene will react at 80° Chlorobenzene, however, is unreactive even at 135°. Aryl chlorides substituted with electron-donating groups similarly are unreactive, but aryl chlorides substituted with electron-withdrawing groups are reactive. This increased reactivity, and order of reactivity 4-NO2C6H4Cl4-CN-C6H4Cl4-PhCOC6H4ClPhCl suggests that the mechanism of the oxidative addition is similar to that of a bimolecular nucleophilic aromatic displacement reaction in which breaking of the bond to the leaving group is involvevd in the rate determining step.

The Friedel–Crafts acetylation and benzoylation of iodobenzene and the isomeric iodotoluenes have been investigated in a range of solvents and at a range of temperatures. Under specific conditions good yields of p-iodoacetophenone or p-iodobenzophenone may be obtained. The reactivities of the iodotoluenes follow the sequence p- 2-iodo-4-methyl- > 2-iodo-6-methyl. In acylations p-iodotoluene gives very-low yields of 3-iodo-6-methylacetophenone only, or a mixture of 3-iodo-6-methyl- and 2-iodo-5-methyl-benzophenones; rearranged ketones, those formally derived from o-iodotoluene, are also formed. In addition all the iodo-substrates give by-products in major amounts: di-iodobenzenes, or di- and tri-iodotoluenes; aceto- or benzophenone, or the isomeric methylaceto- or methylbenzo-phenones. Acylations of o- and p-iodotoluenes also give isomeric chloromethylaceto-(or chloromethylbenzo-)phenones. Benzoylations carried out in ethylene chloride solution give low yields of 2-chloroethyl benzoate.

Organo transition metal σ-complexes undergo carbon monoxide insertion reactions under comparatively mild conditions. Carbonylation of phenyl derivatives of transition metals known to form metal carbonyls yields benzophenone. Pentacyano benzylcobaltate is inactive towards carbon monoxide but the coordinatively unsaturated tricyano benzylnickelate absorbs carbon monoxide at 0°C in aqueous solution to give dibenzyl ketone. A variety of organolithium compounds are found to react with carbon monoxide at -70°C to give symmetrical ketones.Amines undergo carbonylation reaction with carbon monoxide in the presence of metal carbonyls or carbonyl selenide to produce 1, 3-dialkyl ureas. Especially, carbonyl selenide is an excellent carbonylating agent to amines and may be used as a catalyst.The halides which contain unsaturated bond at the β, γ-position of the halides are found to be reactive towards metal carbonyls (iron or nickel) and to give unstable σ-complexes as intermediates, whose decomposition yields dimers, ketones or β-epoxy ketones. The reaction of benzyl halides or iodobenzene with metal carbonyls (nickel or iron) in the presence of certain olefins gives benzylation or phenylation products of the olefins.Organolithium compounds add to metal carbonyls reductively to form lithium acyl- or aroylmetal carbonylates, which are found to be useful reagents, for organic synthesis. The synthesis of aldehydes, 1, 4-diketones and unsymmetrical ketones have been achieved by using these acyl- or aroylmetal carbonylate reagents.

The organic yields of radio-iodine produced by neutron irradiation of mixtures containing iodobenzene and iodine have been investigated; they were unaffected by a slow radiolytic exchange reaction and there was little evidence that they are influenced by thermal exchange occurring in the hot zone. The results can be explained by assuming that in such systems, phenyl radicals react to form iodonium radicals by addition to iodobenzene molecules. In the presence of benzene organic yields are reduced, possibly by reaction between phenyl radicals and benzene to form diphenyl compounds. This explanation is consistent with the absence of any self-scavenging effect in solutions of iodine in benzene.

1. Structural analysis by the oxidation method was carried out on chloromethylation products from ethyl phenylacetate, benzyl chloride, ethylbenzene, cumene, tert-butylbenzene, and all four monohalobenzenes. In all cases, apart from that of tert-butylbenzene, it was found that mixtures of ortho and para isomers were formed. The relative amounts of the isomers were determined and were found to depend greatly on the character of the substituent. 2. In the chloromethylation of toluene, ethylbenzene, cumene, and tert-butylbenzene, the content of para isomer in the mixture progressively increases; this is to be explained by the effect of the size of the substituent (steric factor). In the chloromethylation of halobenzenes, the amount of para isomer progressively diminishes as we pass from fluorobenzene to iodobenzene, this being determined by the ionizing effects of the halogen atoms. 3. On the basis of our results and data in the literature on reaction rates, it is concluded that chloromethylation is an electrophilic-substitution reaction.

A method for the iodination of water-insoluble aromatic compounds in a homogeneous system is reported; an acetic acid solution of peroxyacetic acid is introduced into a solution of iodine and excess aromatic compound. The yields of iodobenzene and iodotoluenes were 60·5 and 84·6%, respectively. Iodic acid is formed simultaneously, and is the main product in the absence of aromatic compounds. A kinetic study comparing the rate equation and rate constants for the iodination of benzene with those for the reaction of iodine with peroxyacetic under similar conditions has been made. The acidity of the solution has no appreciable effect on the rate and the data suggest a mech- anism which involves a rate-determining formation of iodine acetate or hypoiodous acid followed by a rapid condensation with benzene to form iodobenzene.

Gamma radiolysis of iodobenzene yields diphenyliodonium tri-iodide, biphenyl, and 4-iodobiphenyl. 2-lodobn-phenyl behaves similarly. Diphenylene was not detected in irradiated 2-iodo- or 2-bromo-biphenyl. (auth)

Phenyl radicals have been prepared and trapped in a variety of solid matrices by the reaction of either sodium or potassium atoms with iodobenzene on the surface of the matrix material which was frozen at 77°K. A rotating cryostat was used to accumulate many layers of the products. The same e. s. r. spectrum was obtained in every case when water, benzene, deuterobenzene and perfluorocyclohexane were used as matrices. This spectrum has been attributed to the phenyl radical. When camphane, hexamethylethane and cyclohexane were used as matrices, different spectra were obtained in each case, and these have been attributed to the radicals formed by the abstraction of a hydrogen atom from a molecule of the matrix. This demonstrates the exceptional reactivity of the phenyl radical. When iodobenzene and xenon were used as matrices the spectra obtained may have been those of the phenyl radical, but modified by the surrounding matrix. The spectrum of the phenyl radical consists of nine hyperfine lines which can be attributed to a major hyperfine coupling of 18·1 Oe to the two ortho protons and a smaller coupling of 6·4 Oe to the two meta protons. It indicates that the unpaired electron remains in an sp 2 orbital on the carbon atom at which bond scission has occurred, to give a σ type radical. Such a structure contrasts with those of many aromatic radicals, such as benzyl, where the unpaired electron is delocalized over the π electron system, and is in accord with the high reactivity of the phenyl radical. This reactivity, however, is even higher than that of alkyl radicals, where the unpaired electrons are localized in π orbitals, and is attributed to the projection of the sp 2 orbital radially outwards from the ring of carbon atoms.

The reaction of iodobenzene with t-butyl hypochlorite proceeds by a free radical chain mechanism, forming as the sole product iodobenzene t-butoxy chloride (IBBC). The photoinduced or thermally induced reactions of IBBC with hydrocarbon substrates yield chlorinated hydrocarbons by a radical chain halogenation sequence involving t-butoxyiodonyl benzene as the principal chain-carrying species. The photolysis or thermolysis of IBBC in the absence of molecular oxygen yields products resulting from a variety of free radical chain reactions, while thermolysis in the presence of oxygen yields only iodobenzene and t-butyl hypochlorite.

Iodobenzene dichloride or diacetate initiates the polymerization of 2,6-dimethylphenolate anion to poly [oxy(2,5-dimethyl)-l, 4-phenylene]. Electron spin resonance spectroscopy was used to identify the polymeric radical that is the growing chain. Infrared and NMR spectroscopy identified the final polymer. The mechanism proposed is probably applicable also to other phenol oxidation processes yielding substituted poly(oxyphenylenes). The anomalous chemistry of those compounds of xenon, iodine, and tellurium in which the number of bonding electrons exceeds that given by Lewis valence theory has been considered in general terms by Musher [1] who coined the term “hypervalent” to describe these substances. The oxidizing properties of these compounds is in a general way similar to that of peroxides and other strong oxidizing agents, but has not been characterized in any exact fashion. We have observed [2] that the iodobenzene esters have polymeric analogs of the formula, [-I(R)OOCXCOO-], and these compo...

The hyperfine quadrupole coupling structure in the microwave rotational spectrum of iodobenzene has been resolved and the quadrupole coupling constants have been evaluated; the rotational constants have also been improved.

The reaction of benzyl chloride with mononuclear iron pentacarbonyl quantitatively gave hydrocarbon polymer, (CH 2 C 6 H 4 ) n , n ∼ 62, and the reaction of benzyl chloride or iodobenzene with polynuclear iron carbonyls gave the corresponding symmetrical ketones. The formation of benzyl(or phenyl-)iron carbonyl (σ-complex) is considered to precede ketone formation. The reaction of benzyl chloride with polynuclear iron carbonyls in the presence of acrylonitrile (or ethyl acrylate) produce 4-phenylbutyronitrite (yield 15.0%) (or ethyl 4-phenylbutyrate, 22.2%), 4-cyano-6-phenylhexanenitrile (yield 3.3%) (or diethyl 2-β-phenethylglutarate, 4.4%) and 4-phenylcrotononitrile (1.0%). The mechanisms of these reactions are discussed.

When p-nitrobenzenediazonium tetrafluoroborate is decomposed in the presence of dimethyl sulfoxide/benzene or dimethyl sulfoxide/nitrobenzene systems under nitrogen, the respective biphenyl derivatives are obtained in good yield. With benzenediazonium tetrafluoroborate in the same systems the yields are low. The influence of oxygen, iodine, iodobenzene and N, N-diphenylhydroxylamine on the products of the reactions were determined. The by-products, isomer distribution with nitrobenzene as a substrate, and the partial and total rate factors were also determined. From the above data it can be shown that the reaction with p-nitrobenzenediazonium salt is a homolytic process and that with the unsubstituted benzenediazonium salt is essentially a heterolytic reaction. The problem of the mechanism of the radical forming steps (electron transfer or adduct formation) and the mechanistic relationship to other modes of arylation (aroylperoxide, classical two-phase Gomberg-Bachmann reaction, catalysis by transition metal ions, nitrite ions, etc. electron transfer properties of DMSO) are discussed.

As a sequel to previous studies on the ultraviolet absorption spectra of halogen-substituted benzenes the spectra of iodobenzene in various solvents, and the spectra of a series of substituted iodobenzenes in cyclohexane solution, are reported. It is shown that these spectra can be rationalized qualitatively in terms of simple resonance theory, if the apparent mesomeric effect of the iodine atom is assumed to be greater for iodine than for the other halogen atoms.

Mossbauer resonance experiments have been carried out at 4.2°K to investigate the iodine bonding in iodobenzene, iodobenzene dichloride, iodosobenzene, iodoxybenzene, and an iodosodilactone. The quadrupole splitting, asymmetry parameter, and isomer shift data have been analyzed to demonstrate the existence of pure p bonding in all of the compounds except PhIO2, where a small amount of s hybridization in the iodine p orbitals was found. A localized hybridization model cannot provide an adequate description of the iodine bonding in PhICl2, PhIO, and the iodosodilactone, whereas a delocalized molecular orbital approach is in good agreement with the experimental results. The C–I–O bond angle in PhIO is shown to be near 90°, rather than linear, and the iodosodilactone has an approximately planar configuration with a linear IO2 group. PhIO2 has iodine orbital populations significantly different from the other compounds, which can be associated with an O–I–O bond angle of about 95° in this molecule.

Quadrupole interaction frequencies due to Br79 and I127 are reported in a number of crystalline solids. Br79 interaction frequencies in bromobenzene derivatives and I127 frequencies in iodobenzene derivatives are correlated with Hammett's σ. The splitting between interaction frequencies found in s‐tribromophenol and related di‐ and tribromobenzene derivatives is explained tentatively on the basis of hindered rotation. Coupling constants and asymmetry parameters for I127 in iodobenzene derivatives are reported and discussed in terms of the single bond, double bond, and ionic character of the carbon‐iodine bond. Owing to the large asymmetry (∼45%) of the I127 quadrupole coupling in HIO3, |Δm| = 2 transition could be observed as well as the two |Δm| = 1 transitions. Eight interaction frequencies were found in InI3, two of which (at 26.93 Mc/sec and 36.33 Mc/sec) are attributed to (±7/2 ↔±5/2) and (±9/2 ↔±7/2) transitions of In115. From these two frequencies a coupling constant and asymmetry parameter of 219....

Luminescence‐intensity measurements, as affected by quencher concentration, solvent and scintillator, yield information on quenching constants, on specific rates of quenching, on mechanism of quenching, on contrast between quenching of solvent and quenching of scintillator, and on contrast between quenching in benzene as solvent and quenching in cyclohexane as solvent. For a number of aromatic bromides (and for iodobenzene), excitation transfer appears to be involved in the quenching process; in those cases the specific rates are higher than may be expected for simple diffusion‐controlled reactions. Typical specific rates (kq) are ≃ or >2.5×1010 M—1 sec—1 in benzene. The donor states from which excitation is transferred are not identified. In cyclohexane, calculated kq values are very much higher with an implication that the mechanism of the quenching process is quite different in such cases. Some of the results can be explained in terms of the theory of solvent domains; the data for cyclohexane suggest t...

The effect of chloromethanes (CH2Cl2, CHCl3 and CCl4) on hydrogen formation from γ-irradiated methylcyclohexane (MCH) and 3-methylpentane (3MP) at −196°C was investigated. It was found that the decrease in hydrogen yield by the presence of CH2Cl2 was almost the same as that caused by an electron scavenger such as N2O, n-butyl chloride, SF6 or iodobenzene, but the hydrogen yield was much lower in the presence of CHCl3 or CCl4 than other electron scavengers. Although the yield of CCl3. radicals formed from dissociative electron attachment to CCl4 in CCl4-MCH systems was ∼1.4G, the decrease in hydrogen yield was ∼3G. A similar result was obtained for CHCl3-MCH systems. Thus we have ascribed the effect of CH2Cl2 on hydrogen formation to electron scavenging and that of CHCl2 or CCl4 to excitation transfer as well as electron scavenging. ESR studies on radical formation from these systems also support the above interpretation.