Hexane

About: Hexane is a research topic. Over the lifetime, 3759 publications have been published within this topic receiving 57996 citations. The topic is also known as: CH3-[CH2]4-CH3 & hexyl hydride.

Synthesis of lovastatin with immobilized Candida rugosa lipase in organic solvents: Effects of reaction conditions on initial rates.

Abstract: Lipase from Candida rugosa immobilized on a nylon support has been used to synthesize lovastatin, a drug which lowers serum cholesterol levels, by the regioselective acylation of a diol lactone precursor with 2-methylbutyric acid in mixtures of organic solvents. Analogs of lovastatin having a different side chain were also obtained through this method by reacting the diol substrate with different carboxylic acids. The selection of reaction conditions that maximize the initial reaction rate is investigated. Since the diol substrate has very low solubility in non-polar solvents, reaction solvents consisting of mixtures of hexane with a different, more polar cosolvent are considered. For each of the cosolvent mixtures studied, the reaction rate is maximum for an intermediate percentage of cosolvent in hexane. With total concentrations of the diol lactone in the range 6.25-12.5 mM, maximum initial rates correspond approximately to those cosolvent concentrations that permit a complete solubilization of the substrate. At higher cosolvent concentrations, lower rates are obtained. When considering the same dissolved substrate concentration, the reaction rate was found to increase with increasing values of logP(mix) and decreasing values of the dielectric constant, when varying the composition of a binary solvent mixture. However, when comparing different cosolvents, no general trend with respect to these properties was observed. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56:671-680, 1997.

Influence of sulfation and structure of zirconia on catalytic isomerization of n‐hexane

Abstract: Two series of sulfated zirconia have been prepared by immersing amorphous or crystalline zirconia in an H2SO4 solution (0.25–2.5 M). They were compared with a commercial sulfated zirconium hydroxide. Activation temperature was varied between 300 and 725°C. Sulfate density varied so that the mean surface area of an individual sulfate ranged from 0.14 to 0.54 nm2. Three limiting sulfate states are evidenced and characterized by TPR‐MS. Catalysts are tested for isomerization of n‐hexane at 150°C and 3 MPa. Factors influencing the activity are discussed. The data show that a highly active and selective catalyst for producing hexane isomers requires tetragonal zirconia with a sulfate occupancy of about 0.40 nm2. Preparation parameters must therefore be adapted to match these constraints.

Solubilities of n-Alkanes (C6 to C8) in Water from 30 °C to 180 °C

Abstract: A solid-phase extraction method has been developed for measuring low solubilities of hydrocarbon in water. The solubilities of hexane, heptane, and octane in water were determined at temperatures ranging from (30 to 180) °C. The solubilities of alkanes in water at 30 °C decrease with increasing carbon number. At 30 °C, the mole fraction solubility is (2.06 ± 0.01) × 10-6 for hexane and (0.120 ± 0.002) × 10-6 for octane. The temperature effect on solubility in water is much more important for octane than for hexane. Increasing the temperature from (30 to 180) °C increases the solubilities by a factor of 23 for hexane and 110 for octane.