Conductance and FTIR spectroscopic study of sodium tetraphenylborate in pure 1,3-dioxolane and isoamyl alcohol and their binary mixtures

Systems of 1,3-dioxolane and isoamyl alcohol complexed with sodium tetraphenylborate (NaBPh₄) are examined using electrical conductance measurements and FTIR spectroscopy at 298.15 K. The conductance data has been analysed by the Fuoss conductance–concentration equation in terms of the limiting molar conductance (Λ₀), the association constant (K _A) and the distance of closest approach of ions (R). The observed molar conductivities were explained by the formation of ion-pairs (M⁺ + X^? ? MX). Cation–anion interactions along with the hydrogen bonding interactions are investigated by evaluating the frequency shifts of the solvents in the pure state as well as their binary mixtures upon complexation with the salt.     

SO42-/SnO2-硅藻土型固体酸的制备及其对正丁酸与异戊醇的催化酯化

采用质量比为1∶3的SnCl₄·5H₂O和硅藻土制备的硅藻土Sn(OH)₄溶胶,70 ℃老化12 h,90 ℃干燥12 h、3.0 mol/L硫酸浸渍3 h、550 ℃焙烧3.5 h,制备了SO₄^2-/SnO₂硅藻土型固体酸催化剂。 利用IR、 XRD、TG测试技术表征了催化剂的理化性质。 用于催化正丁酸与异戊醇的酯化反应,当n（异戊醇）∶n（正丁酸）=1.4∶1、催化剂用量为反应物总质量的2.5%、10 mL苯、反应时间70 min时,酯收率为97.7％。 结果表明,该催化剂兼具多元氧化物型固体酸和硫酸酸化改性天然粘土固体酸催化剂的优点,催化活性高,成本低廉、制备方法简单并可适当回收循环使用。     

Enzymatic Synthesis of Fatty Acid Isoamyl Monoesters from Soybean Oil Deodorizer Distillate: A Renewable and Ecofriendly Base Stock for Lubricant Industries

In this study, soybean oil deodorizer distillate (SODD), a mixture of free fatty acids and acylglycerides, and isoamyl alcohol were evaluated as substrates in the synthesis of fatty acid isoamyl monoesters catalyzed by Eversa (a liquid formulation of Thermomyces lanuginosus lipase). SODD and the products were characterized by the chemical and physical properties of lubricant base stocks. The optimal conditions to produce isoamyl fatty acid esters were determined by response surface methodology (RSM) using rotational central composite design (RCCD, 2³ factorial + 6 axial points + 5 replications at the central point); they were 1 mol of fatty acids (based on the SODD saponifiable index) to 2.5 mol isoamyl alcohol, 45 °C, and 6 wt.% enzymes (enzyme mass/SODD mass). The effect of the water content of the reactional medium was also studied, with two conditions of molecular sieve ratio (molecular sieve mass/SODD mass) selected as 39 wt.% (almost anhydrous reaction medium) and 9 wt.%. Ester yields of around 50 wt.% and 70 wt.% were reached after 50 h reaction, respectively. The reaction products containing 43.7 wt.% and 55.2 wt.% FAIE exhibited viscosity indices of 175 and 163.8, pour points of −6 °C and −9 °C, flash points of 178 and 104 °C, and low oxidative stability, respectively. Their properties (mainly very high viscosity indices) make them suitable to be used as base stocks in lubricant formulation industries.     

微波辐射合成乙酸异戊酯的工艺研究

微波辐射下以乙酸与异戊醇为原料,硫酸为催化剂合成出乙酸异戊酯,经红外光谱等表征产物是乙酸异戊酯。考察了微波作用时间、异戊醇和乙酸的摩尔比和微波功率对反应产率的影响;还通过L9(34)正交试验,确定合成乙酸异戊酯的最佳条件是异戊醇和乙酸的摩尔比为1∶3.0、微波作用时间14 min、微波功率500 W;在最优条件下的重复实验,平均产量92.6%,实验重复性好,收率较高。     

New dammarane and ursane-type triterpenoids from the flower of Ixora coccinea Linn.

Two new esters of dammarane triterpenoids ixorene isovalerate (1), ixorene 3′,8′-dimethyloctanoate (2) and a new ursane-type triterpenoids Ixoroid acid (3) were isolated from the methanolic extract of flowers of Ixora coccinea Linn., along with the three known constituents. The structures of compounds 1 and 3 were elucidated on the basis of extensive 1D,2D NMR studies and mass spectrometry as 17β-dammara-12,20-diene-3β-isovelarate and 3β-hydroxy-18β-urs-12ene-29β-oic acid, respectively, whereas 2 was identified as 17β-dammara-12,20-diene-3β-3′,8′-dimethyloctanoate through ¹H NMR and mass spectral data. Compounds 1, 2, 4 and 5 were evaluated for their in vitro cytotoxic activity, which exhibited weak activity against the 3T3, PC3 and HeLa cell lines with the IC₅₀ value >30 μM. Antioxidant results of 1 – 5 revealed that only compound 5 showed antioxidant activity in DPPH radical scavenging inhibition with the IC₅₀ 1.31 × 10^? 6 ± 0.005 μm mL^? 1. Both activities are the first records of these isolated compounds from the flowers of Ixora coccinea Linn.     

杂多配合物催化合成羧酸异戊酯的研究

杂多配合物催化合成羧酸异戊酯的研究王玉和，周百斌，关良智，王晓光，单永奎，李萍，周宏立（哈尔滨师范大学化学系哈尔滨１５００８０）关键词杂多酸，酯化作用，异戊酯，催化羧酸异戊酯广泛用于调制各种香型的食品香料，用作溶剂、萃取剂、制革、人造丝、涂料、化妆品...     

比较学习法在化学实验教学中的应用——以环己烯制备实验和乙酸异戊酯制备实验为例

介绍了环己烯制备、乙酸异戊酯制备的实验原理和操作步骤,针对2个实验的催化剂、实验装置、终点判据以及所用干燥剂等内容进行比较和分析,阐明了物质性质与实验方法以及操作步骤的对应关系。学生根据提供的信息,结合具体实验操作,可以更好地理解化学实验内容,掌握有机化学实验的学习方法,提高创新能力和实践能力。     

研究生复试有机化学实验试题评析

介绍了研究生复试有机化学实验操作试题和评价标准,试题原型为乙酸异戊酯的制备实验。学生对混合样品进行分液、干燥、过滤、蒸馏等操作,记录实验步骤并提供纯净的产品。详细地说明了实验的操作要点,并介绍了学生测试情况。     

甲烷磺酸铜催化合成丁酸酯的性能

丁酸异戊酯;酯化反应;催化活性;甲烷磺酸铜催化合成丁酸酯的性能