THE POLYMERIZATION OF STYRENE BY ANHYDROUS PERCHLORIC ACID AND THE SPECTRA OF BENZYLIC CARBONIUM IONS

1966 ◽  
Vol 44 (14) ◽  
pp. 1671-1676 ◽  
Author(s):  
S. Bywater ◽  
D. J. Worsfold
Keyword(s):  
Sulfuric Acid ◽  
Perchloric Acid ◽  
Spectroscopic Investigation ◽  
Chloride Solution ◽  
Methylene Chloride ◽  
Spectroscopic Studies ◽  
Polymerization Reaction ◽  
Methylene Chloride Solution ◽  
Carbonium Ions ◽  
End Groups

A spectroscopic investigation of the reaction of anhydrous perchloric acid with styrene in methylene chloride solution has been carried out, together with a study of the spectra of styrene and its derivatives dissolved in sulfuric acid. From the results it was decided that the absorbing species formed at the end of the reaction in methylene chloride are derivatives formed from the cyclized end groups of the polymer chain, and not the polystyrylcarbouium ion. It is not thought possible to determine from spectroscopic studies whether the polymerization reaction goes via a true ionic intermediate or a perchlorate ester.

The addition of 2,4-dinitrobenzenesulphenyl chloride to 1,3-disubstituted allenes: a reexamination

1979 ◽  
Vol 57 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Dennis G. Garratt ◽  
Pierre Beaulieu
Keyword(s):  
Double Bond ◽  
Chloride Solution ◽  
Methylene Chloride ◽  
Effective Mechanism ◽  
Substituent Group ◽  
Methylene Chloride Solution ◽  
Inductive Effects ◽  
Allene System

The reaction of 2,4-dinitrobenzenesulphenyl chloride with eight alkyl 1,3-disubstituted allenes in methylene chloride solution has been investigated. In contrast to earlier reports, attack by sulphur is found to occur exclusively at the central allenic carbon. The direction of approach of sulphenyl chloride leads preferentially to the formation of the E isomers in accord with the concept of steric approach control. The ratio of E to Z alkene is found to increase as the bulk of the substituent group cis to the arylthio group increases. We observe, however, very little regioselectivity with respect to which of the mutually perpendicular π bonds of the allene system is attacked, suggesting the presence of an effective mechanism for transmission of inductive effects to the more distant double bond.

The reactions of [Pd2Cl2(μ-PP)2] (PP = dppm, dmpm) with Et2NC≡CNEt2 in methylene chloride solution: X-ray crystal structures of [Pd2Cl2(μ-CH2)(μ-dppm)2] and hexakis(diethylamino)benzene, C6(NEt2)6

1996 ◽  
Vol 74 (11) ◽  
pp. 2331-2339 ◽  
Author(s):  
Sean R. Klopfenstein ◽  
Constanze Kluwe ◽  
Kristin Kirschbaum ◽  
Julian A. Davies
Keyword(s):  
Key Words ◽  
Crystal Structures ◽  
Chloride Solution ◽  
Methylene Chloride ◽  
X Ray ◽  
Methylene Chloride Solution ◽  
Methylene Group

The binuciear palladium(I) complex, [Pd2Cl2(μ-dppm)2] (dppm = bis(diphenylphosphino)methane), has been shown to react with bis(diethylamino)acetylene, Et2NC≡CNEt2, in methylene chloride solution to yield two isolable products, the known methylene-bridged complex, [Pd2Cl2(μ-CH2)(μ-dppm)2], and hexakis(diethylamino)benzene, C6(NEt2)6, both of which have been characterized crystallographically. The source of the bridging methylene group in [Pd2Cl2(μ-CH2)(μ-dppm)2] has been shown to be the methylene chloride solvent. A mechanism that accounts for the formation of the two isolable products is proposed. The complex, [Pd2Cl2(μdmpm)2] (dmpm = bis(dimethylphosphino)methane), was similarly found to react with Et2NC≡NEt2 in methylene chloride solution to yield [Pd2Cl2(μ-CH2)(μ-dmpm)2], which was identified spectroscopically. Key words: acetylene, palladium, cyclooligomerization, aminoacetylene, hexakis(diethylamino)benzene.

Nuclear magnetic resonance studies of ketone.BF3 complexes. I. Exchange reactions in methylene chloride solution

1968 ◽  
Vol 46 (12) ◽  
pp. 2147-2157 ◽  
Author(s):  
R. J. Gillespie ◽  
J. S. Hartman
Keyword(s):  
Chloride Solution ◽  
Methylene Chloride ◽  
Chemical Exchange ◽  
Exchange Process ◽  
Exchange Reactions ◽  
Methylene Chloride Solution ◽  
Donor Acceptor ◽  
Group 3 ◽  
Proton Resonances ◽  
Increasing Temperature

1H and 19F n.m.r. studies of BF3 adducts of some simple methyl ketones in methylene chloride solution have led to the following conclusions. (1) Only 1:1 adducts are formed which are not appreciably dissociated. (2) The down-field shifts of the proton resonances caused by complexation with BF3 are essentially independent of the ketone and depend only on the distance of the proton from the carbonyl group. (3) BF3 exchange is rapid on the n.m.r. time scale at room temperature, but the exchange process can be slowed sufficiently by lowering the temperature that separate signals due to free and complexed species can be observed. (4) Collapse of the 10B−11B isotope shift with increasing temperature showed that a second chemical exchange process, which exchanges fluorine among boron atoms, occurs in addition to the process of rapid breaking and re-forming of donor–acceptor bonds. A possible mechanism for this fluorine scrambling reaction is discussed.

The reaction of some propargyl alcohols with benzeneselenenyl chloride

1981 ◽  
Vol 59 (6) ◽  
pp. 927-934 ◽  
Author(s):  
Dennis G. Garratt ◽  
Pierre L. Beaulieu ◽  
Veronique M. Morisset
Keyword(s):  
Chloride Solution ◽  
Methylene Chloride ◽  
Kinetic Control ◽  
Methylene Chloride Solution ◽  
Propargyl Alcohols

The reaction of benzeneselenenyl chloride with twenty-two propargyl alcohols in methylene chloride solution is reported. Products of both Markownikoff and anti-Markownikoff regiochemistry are formed in an anti stereospecific manner. The regioselectivity or specificity is found to be very dependent upon the nature of the substituents geminal to the alcoholic moiety. In general the presence of bulky substituents geminal to the alcoholic moiety tend to favour formation of the anti-Markownikoff adduct under conditions of kinetic control. The Markownikoff adducts are found to be favoured thermodynamically.

Fluxional Behavior of a Cadmium Zwitterion Complex:  Proton Transport and Tautomerism in Methylene Chloride Solution

2003 ◽  
Vol 42 (15) ◽  
pp. 4513-4515 ◽  
Author(s):  
Oren P. Anderson ◽  
Agnete la Cour ◽  
Andrew Berg ◽  
Andrew D. Garrett ◽  
Mark Wicholas
Keyword(s):  
Proton Transport ◽  
Chloride Solution ◽  
Methylene Chloride ◽  
Methylene Chloride Solution

Synthesen und Kristallstrukturen von Tris(di-n-propylamino)-p-brombenzylphosphonium-bromiden: [(C3H7)2N]3PCH2C6H4Br+Br- und [(C3H7)2N]3PCH2C6H4Br+Br3-/Syntheses and Crystal Structures of Tris(di-n-propylamino)-p-bromobenzyl-phosphonium Bromides: [(C3H7)2N]3PCH2C6H4Br+Br- and [(C3H7)2N]3PCH2C6H4Br+Br3-

1999 ◽  
Vol 54 (1) ◽  
pp. 113-116 ◽  
Author(s):  
J. Nolte ◽  
P. Neubauer ◽  
H. Vogt ◽  
M. Meisel
Keyword(s):  
Crystal Structures ◽  
Chloride Solution ◽  
Methylene Chloride ◽  
Monoclinic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
Methylene Chloride Solution

Tris(di-n-propylamino)-p-bromobenzylphosphonium bromide [(C3H7)2N]3PCH2C6H4Br+- Br- (1) has been prepared by the reaction of tris(di-n-propylamino)phosphine with p-bromobenzylbromide in methylene chloride. The colorless crystals are monoclinic, space group P21, Z = 2, a = 930.2(3), b = 1501.2(3), c = 1093.5(2) pm, β = 105,97(4)°. The lattice contains Br- anions and [(C3H7)2N]3PCH2C6H4Br+ cations. [(C3H7)2N]3PCH2C6H4Br+Br- (2) has been obtained by treating 1 with equimolar quantities of elemental bromine in methylene chloride solution. The yellow-red crystals of 2 are triclinic, space group P1̄, Z = 2, a = 1069.5(3), b = 1267.7(7), c = 1273.7(3) pm, α= 87.27(3), β = 82,67, γ = 67.15°, and consist of [(C3H7)2N]3PCH2C6H4Br+ cations and linear Br3- anions. The three N atoms in the cations of 2 are planar.

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