29384-28-9

Upstream product

• 108-91-8 cyclohexylamine 
• 105384-19-8 C₄H₉S₂⁽¹⁺⁾ 
• 39097-02-4 phosphorous acid trimethyl ester; protonated form 

Downstream Products

• 73364-59-7 2-diphenylmethylsilylethyl S-p-methoxyphenyl phosphorothioate 
• 108-91-8 cyclohexylamine 
• 39097-02-4 phosphorous acid trimethyl ester; protonated form 

Relevant academic research and scientific papers

Experimental and Theoretical Studies of the Gas-Phase Protonation of Vinyl Ethers, Vinyl Sulfides, and Vinyl Selenides

A series of nine chalcogen-substituted ethylenes (chalcogen = O, S, Se) have been synthesized, and their gas-phase proton affinities (PA) were determined experimentally by measuring gas-phase basicities (GB) in an ion cyclotron resonance (ICR) spectrometer and theoretically by means of ab initio MO calculations at the STO-3G and 3-21G* levels.A satisfactory correlation (r = 0.978, slope = 1.41) has been obtained between the experimental and calculated 3-21G(*) values.In contrast with a number of previous reports, we consistently found that third- (SMe) and fourth-row (SeMe) substituents do not stabilize better the adjecent positive charge than does the second-row substituent OMe, even in the gas phase.In fact, comparison of experimental proton affinity value of ethylene with that of mono(methylchalco)ethylenes indicates that OMe, SMe, and SeMe groups stabilize the corresponding ethyl cations to very much the same extent.In 2-propyl cations the trend is O > S > Se, but the differences (δΔ in Table III) are quite small: 1.2 kcal mol-1 between O and S and 1.4 kcal mol-1 between S and Se.The superior ability of oxygen in carbenium ion stabilization appears the most clearly in the protonation of bis(methylchalco)ethylenes: dimethoxyethyl cation is more stable than the corresponding thio species by ca. 5.5 kcal mol-1, whereas dithio- and diselenocarbenium ions again have very similar stabilities.These conclusions are supported and extended by ab initio results on optimized geometries.

The Ionic Hydrogen Bond. 2. Multiple NH+...O and CH?+...O Bonds. Complexes of Ammonium Ions with Polyethers and Crown Ethers

Complexes of ammonium ions RNH3+ (R = CH3, c-C6H11), (CH3)3NH+, and pyridineH+ with polyethers and crown ethers are observed in the gas phase in the abscence of the solvent effects.The dissociation energies, ΔH0D, of the RNH3+ polyether complexes range from 29.4 kcal mol-1 (for RNH3+*CH3OCH2CH2OCH3) to 46 kcal mol-1 (RNH3+*18-crown-6).The large ΔH0D values for complexes of polydentate ligands indicate multiple -NH+...O-hydrogen bonding.Such mutiple bonding can contribute up to 18 kcal mol-1 to the bonding in RNH3+*CH3(OCH2CH2)3OCH3 and 21 kcal mol-1 in RNH3+*18-crown-6.Multiple interactions are also evident in the (CH3)3NH+*polyether complexes where -CH?+...O-hydrogen bonding seems to occur; and consecutive -CH?+...O-bonds contribute approximately 6, 4, and 2 kcal/mol-1 respectively for up to three such bonds.Total ΔH0D values in the (CH3)3NH+*polyether complexes thus range from 26.7 kcal mol-1 in (CH3)3NH+*CH3O(CH2)2OCH3 to 41 kcal mol-1 in (CH3)3NH+*18-crown-6.Multiple interaction effects, possibly including van der Waals dispersion forces, are observed also in pyridineH+*polyether complexes.Large negative entropies in RNH3+*acyclic polyether complexes vs.RNH3+*cyclic crown ethers make the acyclic polyethers less efficient ligands.

Properties and Reactions of Trimethyl Phosphite, Trimethyl Phosphate, Triethyl Phosphate, and Trimethyl Phosphorothionate by Ion Cyclotron Resonance Spectroscopy

The gas-phase ion-molecule reactions occurring in trimethyl phosphite, trimethyl phosphate, triethyl phosphate, and trimethyl phosphorothionate have been investigated by ion cyclotron resonance spectroscopy.Protonated parent ions, tetracoordinated phosphonium ions, and cluster ions are the reaction products observed.The proton affinities of these compounds have been determined to be 222.9, 214.2, 218.7, and 216.6 kcal/mol, respectively (relative to PA(NH3) = 207.0 kcal/mol).Homolytic bond dissociation energies of the protonated species are calculated using adiabatic ionization potentials determined by photoelectron spectroscopy.The trends in these quantities are discussed.A reasonable value for the correlated homolytic bond dissociation energy of trimethyl phosphite indicates that the first ionization potential of this molecule should be assigned to the phosphorus lone pair.The application of chemical ionization mass spectrometry to the analysis of phosphorus esters is briefly discussed.