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Using solid-state molecular organometallic (SMOM) techniques, in particular solid/gas single-crystal to single-crystal reactivity, a series of σ-alkane complexes of the general formula [Rh(Cy2PCH2CH2PCy2)(ηn:ηm-alkane)][BArF4] have been prepared (alkane = propane, 2-methylbutane, hexane, 3-methylpentane; ArF = 3,5-(CF3)2C6H3). These new complexes have been characterized using single crystal X-ray diffraction, solid-state NMR spectroscopy and DFT computational techniques and present a variety of Rh(I)···H–C binding motifs at the metal coordination site: 1,2-η2:η2 (2-methylbutane), 1,3-η2:η2 (propane), 2,4-η2:η2 (hexane), and 1,4-η1:η2 (3-methylpentane). For the linear alkanes propane and hexane, some additional Rh(I)···H–C interactions with the geminal C–H bonds are also evident. The stability of these complexes with respect to alkane loss in the solid state varies with the identity of the alkane: from propane that decomposes rapidly at 295 K to 2-methylbutane that is stable and instead undergoes an acceptorless dehydrogenation to form a bound alkene complex. In each case the alkane sits in a binding pocket defined by the {Rh(Cy2PCH2CH2PCy2)}+ fragment and the surrounding array of [BArF4]− anions. For the propane complex, a small alkane binding energy, driven in part by a lack of stabilizing short contacts with the surrounding anions, correlates with the fleeting stability of this species. 2-Methylbutane forms more short contacts within the binding pocket, and as a result the complex is considerably more stable. However, the complex of the larger 3-methylpentane ligand shows lower stability. Empirically, there therefore appears to be an optimal fit between the size and shape of the alkane and overall stability. Such observations are related to guest/host interactions in solution supramolecular chemistry and the holistic role of 1°, 2°, and 3° environments in metalloenzymes.

A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose (CMC) by impregnation method for n-hexane/3-methylpentane separation. The surface properties of ZIF-8 were tailored by introducing CMC into ZIF-8 nanoparticles. In this work, adsorption separation of n-hexane (nHEX) and 3-methylpentane (3MP) on ZIF-8-CMC were investigated by batch vapor-phase adsorption and liquid-phase breakthrough adsorption. The adsorption selectivity of nHEX/3MP reversed from preferable adsorption of nHEX to preferable adsorption of 3MP upon the increasing of CMC containing in the hybrid materials. As the temperature increases, the adsorption amounts of nHEX and 3MP decrease. With the increasing of CMC contents, the nHEX uptake decreased, the uptake capacity of 3MP increased gradually. For liquid-phase breakthrough adsorption, the dynamic adsorption capacity of nHEX also decreased with the increasing of temperature.

In this work, we present densities at high pressures of three branched hydrocarbons: 3-methylpentane, 2,4-dimethylpentane, and 2,3,4-trimethylpentane from 283.15 to 363.15 K and at pressures up to ...

Equations of state for three hexane isomers, 3-methylpentane, 2,2-dimethylbutane, and 2,3-dimethylbutane, have been developed based on experimental thermodynamic property data from the literature. These equations are explicit in the Helmholtz energy with independent variables of temperature and density. The temperature, pressure, and density validity ranges of the equations of state were determined by the available measured data for these three fluids. The uncertainties in densities, vapor pressures, saturated liquid and vapor densities, and caloric properties were estimated by comparisons with experimental data of these properties. The behavior of various thermodynamic properties was analyzed to assess the quality of the equations of state. Physically correct behavior within the region of validity and at extremely high temperatures and pressures, and temperatures far below the triple-point temperature, was obtained through fitting multiple constraints of various properties.

Although abundant literature data are available on liquid–liquid phase equilibrium for select hydrocarbon–water systems at ambient or near ambient temperatures, a deficiency exists for data at elevated temperatures. In this study, we sought to (a) evaluate existing mutual hydrocarbon–water liquid–liquid equilibrium (LLE) data, (b) develop an experimental apparatus capable of measuring accurately the hydrocarbon–water (LLE) mutual solubilities, and (c) perform measurements on the benzene–water, toluene–water, and 3-methylpentane–water systems. A continuous flow apparatus was utilized to measure the LLE mutual solubilities at temperatures ranging from ambient to 500 K, which is near the three-phase critical end point of the benzene–water and toluene–water systems. The well-documented benzene–water system was used to validate the reliability of the sampling and analytical techniques employed. Generally, the present measurements showed adequate agreement with available literature data. An error propagation an...

A new flexible ligand, 1,5-bis(8-oxaquinoline)-3-methylpentane (C5MeOQ), was synthesized and used in the preparation of the new dinuclear copper(II) complex 1: [Cu2(μ-OMe)2(μ-C5MeOQ)(NO3)2]. Single crystal X-ray analysis revealed that complex 1 contains dinuclear Cu(II) units with bridging methoxo groups. The ligand, C5MeOQ, takes on a bent conformation in order to connect to and complete the square planar coordination environment of both copper centers; and one of the two Cu(II) centers adopts a distorted square planar configuration as a result of the ligand conformation. The magnetic properties of complex 1 were investigated by variable-temperature magnetic susceptibility measurements in the 100–300 K range. Interestingly, the susceptibility data for complex 1 reveals that the compound is diamagnetic, suggesting the presence of very strong antiferromagnetic coupling interactions between the adjacent Cu(II) centers.

The influence of the loading on the self-diffusion of 3-methylpentane within silicalite-1 has been studied with Positron Emission Profiling technique. A monotonous decrease in the self-diffusivities of alkane was observed with zeolite loading, which could be approximated by a stretched exponential. As a consequence, the apparent activation energy increases with partial pressure.

Excess molar enthalpies, measured at 298.15 K in a flow microcalorimeter, are reported for diisopropyl ether + 3-methylpentane + octane and for diisopropyl ether + 3-methylpentane + decane. Smooth representations of the results are described and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. The latter are compared with diagrams obtained when the model of Liebermann and Fried is used to estimate the excess molar enthalpies of the ternary mixtures from the physical properties of the components and the excess molar enthalpies of their constituent binary mixtures.

The reactivity of 3-methylpentane (3MP) and hexane (H) on HZSM-5 at 120–160 °C changes from gas (H > 3MP) to liquid phase (3MP > H), as does product selectivity. The liquid phase reactivity ratio is similar on HZSM-5 and in trifluoromethanesulfonic acid (TFMSA), where the reaction involves initiation by oxidation to allyl cations. In both cases, olefins are intermediates, but do not appear in the products. Because hydride transfer catalysis is absent in the reaction of H and the steric requirements for hydride transfer are smaller than for cracking, the mechanism involving protonation of sigma bonds, as in liquid superacids, does not operate in zeolites. The H:3MP reactivity ratio does not measure steric constraints in cavities.

Isothermal vapor−liquid equilibrium data were measured for two binary systems, 3-methylpentane + 2-methyl-2-propanol at 331 K and 3-methylpentane + 2-butanol at 331 K. The measurements were made with a recirculation still. The results were correlated with the Soave−Redlich−Kwong equation of state and the Wilson activity coefficient model.

Isobaric vapor−liquid equilibria data were obtained for the 3-methylpentane + 2-methyl-2-propanol binary system and methyl 1,1-dimethylethyl ether + 3-methylpentane + 2-methyl-2-propanol ternary system at 101.3 kPa in a temperature range from 329 to 356 K. The data were found to be thermodynamically consistent according to the Van Ness−Byer−Gibbs method for the binary system and according to the McDermott−Ellis method for the ternary one. The binary system shows a minimum boiling azeotrope that boils at 333.4 K and contains 82.6 mol % of 3-methylpentane. The binary interaction parameters obtained from this work and literature data are used to predict the vapor−liquid equilibrium for the ternary system using the UNIQUAC, NRTL, and Wilson models. The ternary system is well predicted from binary data.

This paper reports experimental densities, viscosities, and refractive indices of the binary systems methyl tert-butyl ether (MTBE) + 2-methylpentane, + 3-methylpentane, + 2,3-dimethylpentane, and + 2,2,4-trimethylpentane over the entire range of composition, at 298.15 K and atmospheric pressure. Excess molar volumes and viscosity deviations were evaluated from the experimental data. These excess or derived properties were fitted to the Redlich−Kister equation to estimate the binary interaction parameters. The experimental values of viscosity have been compared to values predicted by means of the GC−UNIMOD model.

The neutron scattering experiments of glassy 3-methylpentane were performed with two high resolution spectrometers LAM-40 at KEK and HER at ISSP. A clear boson peak was found around 2.5 meV in the energy spectrum by LAM-40. The scattering-vector dependence of the boson peak intensity measured by HER indicated that the boson peak of 3-methylpentane can be treated as a single harmonic oscillator. The mean square atomic displacement for the oscillator was proportional to the temperature and much larger than that obtained from the scattering-vector dependence of the elastic peak intensity.

Self-diffusion coefficients and viscosities for the saturated hydrocarbons having six carbon atoms such as hexane, 2-methylpentane (2MP), 3-methylpentane (3MP), 2,2-dimethylbutane (22DMB), 2,3-dimethylbutane (23DMB), methylcyclopentane (McP) and cyclohexane (cH) were measured at various constant temperatures; obtained results were discussed in connection with their molar volumes, molecular structures and thermodynamic properties. The values of self-diffusion coefficients as the microscopic property were inversely proportional to those of viscosities as the macroscopic property. The order of their viscosities was almost same to those of their melting temperatures and enthalpies of fusion, which reflect the attractive interactions among their molecules. On the other hand, the order of the self-diffusion coefficients inversely related to the order of the melting temperatures and the enthalpies of the fusion. Namely, the compound having the larger attractive interaction mostly shows the less mobility in its liquid state, e.g., cyclohexane (cH), having the largest attractive interaction and the smallest molar volume exhibits an extremely large viscosity and small self-diffusion coefficient comparing with other hydrocarbons. However, a significant exception was 22DMB, being most close to a sphere: In spite of the smallest attractive interaction and the largest molar volume of 22DMB in the all samples, it has the thirdly larger viscosity and the thirdly smaller self-diffusion coefficient. Consequently, the dynamical properties such as self-diffusion and viscosity for the saturated hydrocarbons are determined not only by their attractive interactions but also by their molecular structures.

The mean-square diffusion distance of electrons photoliberated from traps depends on the photon energy: the limit value (solvation length) in 3-methylpentane is ≃63 A.

Enthalpies of mixing H E for the binary systems of 1,3-dioxolane with n-pentane, 3-methylpentane, or methylcyclopentane were measured by means of an isothermal flow microcalorimeter as a function of composition, under atmospheric pressure and at 298.15 K

Studies on the isotropic hyperfine splitting constants of protiated and deuterated 3-methylpentyl radicals produced by γ-ray accompanied with the radical yield determinations reveal that the radicals are distributed in clusters in the matrix. A tentative mechanism with the migration of positive hole is proposed for the formation of UV-induced new radicals following γ-irradiation in 3-methylpentane glasses at 77°K; and to account for all the experimental observation.

EPR microwave power saturation technique has been applied to the systems of radiation-induced radicals in protiated and wholely deuterated 3-methylpentane to obtain the information concerning the high local spin concentration and radiation energy deposition mechanism. Evidences of spin-spin interactions have been given from the studies of isothermal decay of these trapped radicals at 77°K. The annealing of the matrix is shown to have almost no effect on the relaxation times of radicals. The influence of nuclear magnetic moment on the spin-lattice relaxation process of radicals is revealed and discussed on the basis of experimental results from the deuteration of the compound studied.

Using the pulse radiolysis method the excimer formation of diphenyl derivatives in low temperature 3-methylpentane was investigated. For diphenyls two emission bands are found in the temperature range 140 – 230 K. The band at 320 nm is due to monomer fluorescence, whereas the second at 380 – 390 nm is as an excimer emission.

Autoxidation of 3-methylpentane in the presence of tert-butyl hydroperoxide gives, after reduction with triphenylphosphine, 3-methyl-3-pentanol and 3-methyl-2-pentanol as the major reaction products. The overall rate constant for reaction of (CH3)3COO· with this substrate at 30 °C is 0.008 ± 0.001 M−1 s−1 which consists of k/tertiary C—H = 0.007 ± 0.001 M−1 s−1 and k/secondary C—H = 0.0002 ± 0.0001 M−1 s−1. The products from cooxidation of cumene and 3-methylpentane in the presence of tert-butyl hydroperoxide are formed in yields which are consistent with these rate constants relative to a value of 0.16 M−1 s−1 for cumene. The Arrhenius equations for reaction of (CH3)3COO• with the t-C—H and s-C—H of 3-methylpentane relative to the Arrhenius equation for reaction of (CH3)3COO• with cumene (log (k10/M−1 s−1) = (8.7 ± 0.3) − (13.2 ± 0.4)/θ) are[Formula: see text]respectively, where θ = 2.303 RT kcal mol−1.

The destructive alkylation reaction of benzene with 3-methylpentane to give ethylbenzene in the presence of aluminum chloride was investigated. When 3-methylpentane-1-14C was employed, radioactive ...

Radical conversions in γ-irradiated 3-methylpentane-isobutene systems were observed by means of the electron spin resonance method after keeping the sample at −196°C for a few days, or by subjecting it to ultraviolet irradiation. One of the changes was caused by hydrogen atom abstraction from neighboring molecules by original free radicals. The other change was attributed to dissociation of the free radicals from 3-methylpentane by ultraviolet irradiation.

In order to elucidate the behavior of a positive hole in irradiated alkane glasses, the effect of solutes having ionization potential lower than that of a glass matrix molecule upon the decay of a trapped electron was examined in a 3-methylpentane glass at 77°K by means of electron spin resonance. The decay was found to be explained in terms of the superposition of two exponentially decaying processes, as in the absence of a solute. Although the fast process was not affected by a solute, the slow process was further slowed by the addition of a solute. The effect of a solute is described by the empirical relation, k⁄k0=1⁄(1+fN), where k and k0 are the rate constants of the slow decay in the presence and in the absence of a solute, respectively. N is the mole fraction of a solute. The observed values of the slowing-down efficiency, f, increase in parallel with the decreasing values of ionization potential of solutes: 2-methyltetrahydrofuran, diethylether, methylvinylether, 2-methylpentene-1 and n-butylvinyl...

1. Experiments on the aromatization of mixtures of n-hexane with 2-methylpentane, 3-methylpentane or methylcyclopentane on an aluminum-chromium catalyst at 550° with a volumetric velocity of 0.35 per hour have been carried out. 2. Under the conditions of the experiments, the methylpentanes form benzene with a yield of 23% by weight, while methylcyclopentane yields 5% of benzene based on the weight of the hydrocarbon passed through.

Excess enthalpies and excess volumes were determined over the entire composition range and at the three temperatures 283.15,298.15 and 313.15 K for mixtures of n-hexane with the three isomeric hexanes: 2- methylpentane, 3-methylpentane and 2,3-dimethylbutane. The excess enthalpies were measured with a microflow calorimeter and the excess volumes with a vibrating-tube densimeter. ��� The results are correlated with the molecular shape of the isomeric hexane.