Interaction Of Olefins Research Articles

IR Spectroscopic Study of Alkane Interaction with the Brønsted Acid Sites of Hydrogen-Exchanged Zeolites

Diffuse-reflectance IR spectroscopy is used to study the interaction of C3 and C6 alkanes (propane, n-hexane, 3-methylpentane, and cyclohexane) with the Bronsted acid sites of hydrogen-exchanged mordenite, ferrierite, ZSM-5, and faujasite. It is found that a shift of the absorption band of the stretching vibrations of acidic Si(OH)Al groups toward lower frequencies (ΔνOH) due to the formation of a hydrogen bond with adsorbed alkanes increases in the following series: ΔνOH(propane) H-mordenite ≈ H-ferrierite ≫ HY. The difference between the three high-silica zeolites is not great. The results obtained are compared with the published IR data on Si(OH)Al groups of zeolites with adsorbed alkanes and other weak bases.

Protonation Reactions of [MH(Cl)(PPh3)2(norbornadiene)] (M = Ru, Os)

Protonation of [RuH(Cl)(PPh3)2(NBD)] (NBD = norbornadiene) in benzene with a limiting amount of HOTf gives [RuH(OTf)(PPh3)2(NBD)], norbornene, and [RuCl2(PPh3)2]2. In dichloromethane, [RuH(Cl)(PPh3)2(NBD)] reacts with a limiting amount of HOTf to give [RuH(OTf)(PPh3)2(NBD)], norbornene, and the trimetallic complex [Ru3Cl5(PPh3)6]OTf. In contrast, protonation of [OsH(Cl)(PPh3)2(NBD)] in benzene or dichloromethane with limiting HOTf only gives [OsH(OTf)(PPh3)2(NBD)]. In the protonation of [RuH(Cl)(PPh3)2(NBD)], the norbornene is likely produced through the intermediate [RuH(HCl)(PPh3)2(NBD)]OTf. The involvement of [RuH(HCl)(PPh3)2(NBD)]+ in the formation of norbornene is supported by theoretical calculations based on the B3LYP density functional theory. The fact that norbornene is not produced in the protonation of [OsH(Cl)(PPh3)2(NBD)] can be attributed to the stronger osmium−olefin interaction.

Interaction of Short-Chain Alkanes with the Surface and Interfaces of Multilayer Films Built from Amphiphilic Molecules: An in-Situ X-ray and Neutron Scattering Probe

Partially deuterated Cd−arachidate Langmuir−Blodgett multilayers were subjected to a gas atmosphere of n-pentane and n-hexane at room temperature. The gas−film interaction was studied by in-situ X-ray and neutron specular scattering through a gas-flow box. Both methods show an increase of the small-angle Bragg peak intensities during the gas treatment while the intensities of Kiessig oscillations decrease at the same time. The change of intensities is partially reversible after purging with air. Neutron scattering reveals that the increase of structural Bragg peaks is also accompanied by a decrease of superstructure peaks originated by the scattering length density difference between the sequentially stacked deuterated and nondeuterated chains. This indicates a gas-assisted intermixing of amphiphilic molecules in the vertical direction. The observed effect is much larger than in the case that the short-chain molecules occupy defect sites of the virgin Langmuir−Blodgett film. It can be explained by assumin...

D0 Metal Olefin Complexes. Synthesis, Structures, and Dynamic Properties of (C5R5)2Zr(OCMe2CH2CH2CHCH2)+ Complexes: Models for the Elusive (C5R5)2Zr(R)(Olefin)+ Intermediates in Metallocene-Based Olefin Polymerization Catalysis

To model the Zr−olefin interaction in the as-yet unobserved (C5R5)2Zr(R)(olefin)+ intermediates in (C5R5)2Zr(R)+-catalyzed olefin polymerization, the coordination of the tethered vinyl group in (C5R5)2Zr(OCMe2(CH2)nCHCH2)+ species has been investigated. The reaction of (C5H5)2Zr(OCMe2CH2CH2CHCH2)(Me) with B(C6F5)3 or [Ph3C][B(C6F5)4] yields the chelated olefin complex (C5H5)2Zr(OCMe2CH2CH2CHCH2)+ as the MeB(C6F5)3- (12a) or B(C6F5)4- (12b) salts. In contrast, the reaction of (C5H5)2Zr(OCMe2CH2CHCH2)(Me) with B(C6F5)3 in CD2Cl2 yields the MeB(C6F5)3- adduct (C5H5)2Zr(+)(OCMe2CH2CHCH2)(μ-Me)B(-)(C6F5)3. The reaction of (C5H5)2Zr(OCMe2CH2CH2CH2CHCH2)(Me) with B(C6F5)3 yields a 1.2/1 mixture (at −90 °C) of the chelated olefin complex (C5H5)2Zr(OCMe2CH2CH2CH2CHCH2)+ and the MeB(C6F5)3- adduct (C5H5)2Zr(+)(OCMe2CH2CH2CHCH2)(μ-Me)B(-)(C6F5)3‘. The reaction of rac-(EBI)Zr(OCMe2CH2CH2CHCH2)(Me) (EBI = ethylene-1,2-bis(1-indenyl)) with B(C6F5)3 or [Ph3C][B(C6F5)4] yields the chelated olefin complex rac-(EBI)Zr(OCMe...

Fourier Transform Infrared Spectroscopic Characterization of Olefin Complexation by Silver Salts in Solution

Complex formation between 1-hexene and silver salts in chloroform solution has been characterized using Fourier transform infrared spectroscopy. Silver tetrafluoroborate, AgBF4, and silver triflate, AgCF3SO3, form 1:2 Ag+:1-hexene complexes in solution. The olefinic CC vibrational stretching frequency at 1640 cm-1 in 1-hexene shifts to approximately 1580 cm-1 upon complexation with these silver salts. Silver trifluoroacetate, AgCF3CO2, exhibits limited complexation and silver nitrate, AgNO3, exhibits no measurable complexation. Salts with the larger BF4- and CF3SO3- anions have a much stronger tendency to form complexes than those with the smaller NO3- and CF3CO2- anions. The tendency of these salts to form complexes in solution was most strongly correlated with anion size and was not well-correlated with measures of anion-donor electron density or softness parameter. The effect of ether-containing compounds, such as triethylene glycol (TEG) and poly(ethylene glycol) (PEG), on the silver−olefin interaction in chloroform solution was also studied. The formation of a silver ion−ether oxygen−olefin complex is consistent with the data. For TEG added to a solution of AgBF4 and 1-hexene in chloroform, there are approximately 2.5 oxygens per silver ion in the complex. For PEG added to a solution of silver triflate and 1-hexene in chloroform, there are approximately 1.8 oxygens per silver ion.

Hydrodesulfurization of Catalytic Cracked Gasoline. 3. Selective Catalytic Cracked Gasoline Hydrodesulfurization on the Co−Mo/γ-Al2O3 Catalyst Modified by Coking Pretreatment

The interaction of olefins with the hydrodesulfurization (HDS) catalyst surface was studied by the time course of catalytic cracked gasoline (CCG) HDS on the Co−Mo/γ-Al2O3 catalyst. Olefin hydrogenation activity was decreased drastically in the beginning 30 h. After 75 h of time on stream, to wash the catalyst surface, toluene was flown into the reactor at room temperature and this toluene wash recovered some olefin hydrogenation activity. The oligomers of CCG olefins were found in the effluent of toluene wash. It was suggested that oligomerized and polymerized olefin (coke) selectively deactivated the olefin hydrogenation active site. The possibility of improving the HDS selectivity of Co−Mo/γ-Al2O3 by carbonaceous deposit was investigated for HDS reactions of CCG and model compounds. The catalyst with coking pretreatment after sulfiding showed the higher CCG HDS selectivity than that of the catalyst without coking pretreatment. Thiophene HDS in the presence of diisobutylene or 1-octene was also carried out, and the relative deactivation by the coking pretreatment was in the following order, isoolefin hydrogenation > thiophene HDS > n-olefin hydrogenation. The improvement of CCG HDS selectivity by the coking pretreatment was considered to be caused by the selective deactivation of isoolefin hydrogenation active site.

Dibenzotropylidene phosphanes (TROPPs): synthesis and coinage metal complexes

Dibenzocycloheptatrienyl phosphanes (dibenzotropylidene phosphanes=TROPPR) 11a–c may be easily prepared from dibenzocycloheptatrienyl chloride 8 and the secondary phosphanes R2PH [9a: R=Ph; 9b: R=4-Me-C6H4; 9c: R=cyclohexyl (Cyc)] in good yields. Alternatively, the di(tert-butyl)phosphanyl substituted TROPPBut derivative 4 was obtained along with the phosphane 5 by a mechanistically still unknown rearrangement of a strained phosphorus ylide I. The conformations of these new phosphanes were established by X-ray analyses performed for the compounds TROPPBut4 and TROPPPh11a. The R2P moiety is bonded to an axial position of the central seven-membered ring, which adopts a boat conformation. Thereby a rigid concave binding site containing a phosphane and an olefin function is formed, which should allow the synthesis of a wide range of transition metal complexes. In order to test how far the particular shape of the TROPP-type ligands enforces metal–olefin interactions, the coinage metal complexes [(TROPPPh)Cu(µ2-Cl)]2, 13, [(TROPPPh)Ag(µ2-O2SOCF3)]2, 16, [(TROPPPh)2Ag][O3SCF3], 17 and [(TROPPPh)AuCl], 19 were prepared. These were completely characterized by multinuclear NMR experiments in solution and the solid state, as well as by X-ray analyses. The structural and NMR data show that the interaction between the metal center M and the olefin moiety of the TROPP ligand is weak and decreases in the order Cu>Ag>Au. Indeed, for 19 (M=Au) no interaction could be observed. In the silver complex 17, coupling between an Ag nucleus and a proton of a bonded olefin was determined for the first time [J(109/107AgH)=0.4 Hz]. In solution the complexes derived from TROPP-type ligands seem to have an enhanced (kinetic) stability.

FT-IR Studies on Light Olefin Skeletal Isomerization Catalysis: I. The Interaction of C4 Olefins and Alcohols with Pure γ-Alumina

The skeletal isomerization ofn-butene to isobutene and the interaction of the four butene isomers and ofsec-butanol andtert-butanol with a pure γ-alumina sample were investigated. γ-Al2O3is quite active (>34% conversion) and a selective catalyst forn-butene to isobutene isomerization at 753 K (>80% selectivity). FT-IR spectroscopic experiments show that the C4 olefins are involved in two different interactions on the alumina surface at room temperature: (i) H-bonding over surface hydroxy groups and (ii) reactive adsorption giving rise to allyl species. Both species have been fully characterized spectroscopically for all four butene isomers. At higher temperatures, carboxylates appear, some of which are aromatic. Alcohol adsorption shows that 2-butoxy andtert-butoxy groups decompose to give gaseousn-butene and isobutene, respectively, near 473 K. Moreover, traces oftert-butoxy species are observed starting from 2-butoxides. H-bonded olefin species are assumed to be precursors for carbenium ions that give rise to double-bond and skeletal isomerization at high temperature. Butoxy groups are proposed to act as the unstable intermediate adsorbed forms for carbenium ions. Allyl species are identified as intermediates in double-bond isomerization at low temperature and in the formation of by-products and coking agents (aromatics and carboxylates) at high temperature.

Synthesis and structure of ruthenium(II)-diene complexes

The reaction of Ru(acac) 3 in ethanol in the presence of dienes (diene = 2,5-dimethyl-2,4-hexadiene, isoprene, 1,2,4,5-tetramethyl-1,4-cyclohexadiene) with zinc as reducing agent affords Ru(acac) 2(diene) complexes. For the acyclic diene ligands, the Ru(acac) 2 unit exhibits a preference for the trans-diene coordination. The structures for the 2,5-dimethyl-1,3-hexadiene and 1,2,4,5-tetramethyl-1,4-cyclohexadiene derivatives have been determined crystallographically. The Ru(acac) 2(hexadiene) complex crystallizes in the monoclinic space group P2 1/ n with a = 10.658(2) A ̊ , b = 12.075(3) A ̊ , c = 15.332(3) A ̊ and β = 108.07(5)° for Z = 4 . The cyclohexadiene complex crystallizes in a triclinic space group P I , with a = 8.495(4) A ̊ , b = 8.456(4) A ̊ , c = 14.364(6) A ̊ , and α = 78.88(2)°, β = 82.60(2)°, γ = 78.04(2)° for Z = 2 . The solid-state structure for the dimethylhexadiene complex revealed an η 4- trans-diene coordination, while for the cyclic diene it revealed isolated olefin interactions.

Interaction of Olefins with Carbon Monoxide on Zeolite H-ZSM-5. NMR Observation of the Friedel−Crafts Acylation of Alkenes at Ambient Temperature

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTInteraction of Olefins with Carbon Monoxide on Zeolite H-ZSM-5. NMR Observation of the Friedel−Crafts Acylation of Alkenes at Ambient TemperatureMikhail V. Luzgin, Vyacheslav N. Romannikov, Alexander G. Stepanov, and Kirill I. ZamaraevView Author Information Boreskov Institute of Catalysis Siberian Branch of the Russian Academy of Sciences Prospekt Akademika Lavrentieva 5 Novosibirsk 630090, Russia Cite this: J. Am. Chem. Soc. 1996, 118, 44, 10890–10891Publication Date (Web):November 6, 1996Publication History Received8 May 1996Published online6 November 1996Published inissue 1 January 1996https://doi.org/10.1021/ja9615381Copyright © 1996 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views608Altmetric-Citations47LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (160 KB) Get e-AlertsSUBJECTS:Hydrocarbons,Inorganic carbon compounds,Ketones,Oxides,Zeolites Get e-Alerts

Catalytic Transformations of Olefins on HZSM5 Observed by Radiolysis/EPR

A new method for elucidating elementary reaction steps in zeolite catalysis was demonstrated for reactions of isobutene and other monoolefins on HZSM5. Radiolysis was used to `spin label` reaction products, and EPR was used for product analysis. The evolution of products was revealed by quenching the reactions cryogenically in a series of equilibrium experiments. Isobutene dimerization and isomerization occur on HZSM5 even at 77 K, and cracking occurs below room temperature. The radiolysis/EPR results allow a consistent interpretation of the literature on EPR signals that arise spontaneously upon interaction of acyclic olefins with air-activated H-Mordenite and HZSM5. 55 refs., 10 figs., 2 tabs.

Interaction of Alkanes with Monolayers of Nonionic Surfactants

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInteraction of Alkanes with Monolayers of Nonionic SurfactantsR. Aveyard, B. P. Binks, P. D. I. Fletcher, and J. R. MacNabCite this: Langmuir 1995, 11, 7, 2515–2524Publication Date (Print):July 1, 1995Publication History Published online1 May 2002Published inissue 1 July 1995https://doi.org/10.1021/la00007a034RIGHTS & PERMISSIONSArticle Views293Altmetric-Citations36LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

The regularities in the interaction of alkanes with CO 2 on oxide catalysts

Catalytic oxidation of C 1-C 7 alkanes by CO 2 as a non-traditional oxidant was studied on oxide catalysts. The supported manganese oxide catalysts are the most active, selective and stable. Methane is converted mainly into synthesis gas. Ethane and propane give products of oxidative dehydrogenation. In the case of C 4-C 7 alkanes at first direct dehydrogenation takes place and after that reverse water gas shift proceeds. Reactions of carbon dioxide with hydrocarbons were up to now still insufficiently studied. This is caused by small reactivity of both CO 2 and hydrocarbons. The recent interest in carbon dioxide reactions is two-fold: 1) the necessity to fight against the so-called green-house effect and 2) the exhaustion of raw carbon material sources [ 1 ]. The CO 2 molecule can be used a non-traditional oxidant. The best reducing agent for CO 2 is hydrogen. It was shown [2] that methanol synthesis proceeds not by direct CO + H 2 interaction, but by preliminary CO transformation into CO 2 CO+H 2O= CO 2+H 2 After that the interaction of CO 2 with H 2 gives methanol CO 2+3H 2= CO 3OH+H 2O But hydrogen is expensive. Hydrocarbons in the role of CO 2 reductants are more attractive. The most intensively studied reaction of hydrocarbons with CO 2 is methane conversion into synthesis gas CH 4+CO 2= 2H 2OH+2CO The main difficulty encountered when this reaction is used for the practical process of synthesis gas production is coking of the metal catalysts [3–6]. We have studied C 1-C 7 interaction with CO 2 over oxide catalysts [7–10] and it turned out that manganese oxides containing catalysts are effective both for methane transformation into synthesis gas and for C 2-C 7 alkanes dehydrogenation and oxidative cracking. What is especially important is that these catalysts are very stable during a long period without cake accumulation. This paper provides a review of our work in this field.

Evidence for the Formation of Free 16-Electron Species Rather than Solvate Complexes in the Ultraviolet Irradiation of CpCo(CO)2 in Liquefied Noble Gas Solvents

This paper describes a study of the photochemistry of CpCo(CO){sub 2} in liquid Kr and Xe in the presence of hydrocarbons in order to estimate directly the relative strengths of the CpCo(CO)-noble gas and CpCo(CO)-alkane interactions. However, it is seen in contrast with results for Cp{sup *}Rh(CO) and other coordinatively unsaturated organometallic complexes, CpCo(CO) and Cp{sup *}Co(CO) do not bind detectably to either noble gas atom or cyclohexane. The most surprising results is the observation that the rate of reaction between the monocarbonyl and dicarbonyl cobalt complexes is essentially unaffected by changing the solvent from liquid Kr to liquid Xe, adding cyclohexane or making the cyclopentadienyl ligand substantially more hindered. 22 refs., 2 figs.

CpMO(CO) 3] 2 as a catalyst for olefin metathesis

During the interactions of olefins with [CpMO(CO) 3] 2 or [CpMO(CO) 3] 2/NO and EtAlCl 2 in chlorobenzene, a series of alkene products, alkylation products and oligomers was observed. A relationship exists between the products formed and the reaction temperature. At temperatures below 120°C dimers and oligomers formed. At higher temperatures metathesis and isomerization of olefins and alkylation of the solvent by short chain olefins occurred. Oligomerization reached a maximum yield at 120°C.

Volumetric properties of steam–carbon dioxide mixtures derived from excess molar enthalpy measurements

Flow calorimetric measurements of the excess molar enthalpy, HEm, of [0.5H2O–0.5CO2](g), which extend over the temperature range 448.2 to 698.2 K and at pressures up to 20 MPa, were recently reported. In the initial analysis of these measurements, the residual molar enthalpy of carbon dioxide was calculated from the equation of state proposed by Kubic, the residual molar enthalpy of steam was calculated from a modification of Kubic's equation proposed by Lancaster and Wormald, and simple one-fluid mixing rules were used to calculate the residual molar enthalpy of the mixture. The binary interaction constant used to secure agreement between experimental and calculated HEm values was ξ= 1.33. This value is larger than that for steam–alkane interactions, and was attributed to a weak specific interaction between steam and carbon dioxide molecules in the vapour phase. The HEm measurements have now been reanalysed using mixing rules which include terms to account for the association between the unlike molecules. This results in a value of the equilibrium constant K12(298.15 K)= 0.0954 MPa–1, and a value of ΔH12=–11.7 kJ mol–1 for the enthalpy of the specific interaction between steam and carbon dioxide. The use of the association model slightly improves the fit to the HEm measurements and gives good agreement with experimental values of volumetric properties, particularly at low temperatures.

Excess enthalpies of (carbon dioxide + pentane or hexane or heptane or cyclohexane or benzene)(g) at temperatures from 432.2 K to 573.2 K and pressures up to 2.71 MPa

A flow mixing calorimeter for the measurement of the excess molar enthalpy H E m of gaseous substances at temperatures up to 580 K and at pressures up to 15 MPa has been constructed. The apparatus has been used to measure H E m ( x = 0.5) for {0.5CO 2 + 0.5CH 3 (CH 2 ) v −2 CH 3 } where v = 5, 6, and 7, and for (0.5CO 2 + 0.5 c -C 6 H 12 ), and (0.5CO 2 + 0.5C 6 H 6 ). The measurements were in the temperature range 423.2K to 573.2K at pressures up to 2.71 MPa. The measurements at pressures up to 1 MPa were all fitted to within experimental error by the virial equation of state with second virial coefficient terms calculated from the McGlashan and Potter correlation and third virial coefficient terms from the Orbey and Vera correlation. The carbon-dioxide- n -alkane interaction energy was found to be weaker than that of alkane-alkane, but that of carbon-dioxide-benzene was found to be stronger.

Prediction of liquid-liquid equilibria and of enthalpies of mixing in alkanoic acid anhydride + n-alkane mixtures using DISQUAC

Abstract Kehiaian, H.V., Gonzalez, J.A., Garcia, I., Escarda, R., Cobos, J.C. and Casanova, C, 1991. Prediction of liquid-liquid equilibria and of enthalpies of mixing in alkanoic acid anhydride + n -alkane mixtures using DISQUAC. Fluid Phase Equilibria, 69: 91-98. The liquid-liquid equilibrium (LLE) data from the literature on acetic anhydride + heptane and our molar excess enthalpies measured previously, H E , of butyric or heptanoic anhydrides + n -alkanes (hexane through tetradecane) are examined on the basis of the DISQUAC group-contribution model. These experimental data, along with structure-property relationships derived from the properties of related classes of carbonylic compounds, were used to estimate the interaction parameters for symmetrical or asymmetrical carboxylic acid anhydride [CH 3 (CH 2 ) u -1 -CO-O-CO-(CH 2 )[ v -1 CH 3 ] + alkane [CH 3 (CH 2 ) m -2 CH 3 ] mixtures. The anhydride (CO-O-CO group)/alkane (CH 3 or CH 2 groups) interaction parameters are the same for the anhydrides of all the carboxylic acids ( u, v > 1), except for acetic acid anhydride ( u, v = 1). The model describes consistently H E , LLE and the vapor-liquid equilibrium diagram of acetic anhydride + cyclohexane.

Reactive lattice oxygen sites for C 4 hydrocarbon selective oxidation over β-VOPO 4

The role of lattice oxygen species in the catalytic oxidation of n-butane to maleic anhydride has been investigated using β-VOP0 4 labeled with 180. The catalyst was prepared by stoichiometric reaction of (VO) 2P 20 7 with 180 2 using solid state preparation techniques. The β- VOPO 7 2 18 O 1 2 was characterized using laser Raman and Fourier transform infrared spectroscopies: preferential incorporation at P-O-V sites was observed. A pulse reactor was used to react n-butane, 1-butane, 1,3-butadiene, furan, γ-butyrolactone, and maleic anhydride with the catalyst in the absence of gas-phase O 2. Incorporation of 18O into the products was monitored by mass spectrometry. Specific lattice oxygen sites could be associated with the reaction pathways for selective or nonselective oxidation. The results of this study also indicate that the initial interaction of n-butane with β-VOPO 4 is fundamentally different from the initial interaction of olefins or oxygenated species. The approach used in this research—referred to as Isotopic Reactive-Site Mapping—is a potentially powerful method for probing the reactive lattice sites of other selective oxidation catalysts.

On the reaction of trisubstituted olefins with phenylselenenyl chloride in methanol

The interaction of trisubstituted olefins with excess phenylselenenyl chloride in methanoi generates chloromethoxy dimethoxyderivatives. The mechanism of this transformation has been investigated.