铁钾盐加合物催化合成丙酸丁酯

本文以铁钾盐加合物为催化剂，合成了丙酸丁酯。最佳反应条件，以0．4mol丙酸为基准。n(丙酸)／n(丁醇)=1：1．03。催化剂用量为1％(丙酸与丁醇总质量的质量百分数)，反应时间7h，酯化率达84．70％。     

11-苄硫醇十一酸-N-羟基琥珀酰亚胺酯的制备

硫醇类化合物通过Au-S可以共价结合于金表面,形成高度有序的自组装膜,因而硫醇及其衍生物的合成引起了人们的广泛兴趣,而本文主要是通过活化酯法合成含不同链长的巯基生物素衍生物的中间体——11-苄硫醇十一酸-N-羟基琥珀酰亚胺酯,并用1HNMR对产物的分子结构进行了表征。     

硅钨酸催化合成乙酰水杨酸

以水杨酸和乙酸酐为原料,硅钨酸为催化剂合成了乙酰水杨酸。考察了催化剂用量、反应物物料配比、反应时间、温度等因素对反应的影响。结果表明:硅钨酸具有催化活性高、稳定,对环境友好的特点。最佳工艺条件为:n(水杨酸):n(乙酸酐):n(硅钨酸)=1．0,2．5:0．002 4,76-80℃反应15 min,乙酰水杨酸收率达92．6％。     

酯化反应的探讨

酯化反应是重要的有机化学反应,有机酸酯是重要的化工原料,本文从酯化反应历程、催化剂、反应机理等几个方面探讨,认为无机盐是一种良好的酯化反应催化剂,符合绿色化学的要求.     

磷钨钼杂多酸催化氧化环己醇清洁合成己二酸

以自制H3PW6Mo6O40·nH2O为催化剂,在无有机溶剂、相转移催化剂的情况下,用过氧化氢氧化环己醇合成己二酸。探讨了催化剂用量、过氧化氢用量、反应时间、反应温度对反应的影响。在优化条件下,即n(环己醇)∶n(磷钼钨杂多酸)∶n(过氧化氢)=100∶0.15∶500,在120℃反应8h,己二酸的分离收率达82%。     

微波促进NdH_3P_2W_(18)O_(62)·nH_2O/硅藻土催化绿色合成己二酸

在微波辐射作用下,用自制的NdH_3P_2W_(18)O_(62)·nH_2O/硅藻土为催化剂,在无有机溶剂及相转移催化剂的条件下,催化30%H_2O_2氧化环己酮制备己二酸。通过正交实验和单因次实验探讨了各因素对反应的影响,确定了优化工艺条件为:w(催化剂)=12.7%(按环己酮质量计),n(30%H_2O_2)∶n(环己酮)=4,100℃,400 W,4.0h。在此条件下,己二酸收率达77.7%。催化剂重复使用3次,收率仍可达到68.1%。     

N-羟基琥珀酰亚胺生物素酯的合成与应用

利用两种方法合成了N-羟基琥珀酰亚胺生物素酯，并用核磁共振谱进行了结构表征，N-羟基琥珀酰亚胺生物素酯的应用前景非常广泛。     

通过绿色化学实验培养学生创新能力

我们以绿色化学思想为指导,在实验教学活动中开展微型化实验、串联实验、利用CAI模拟实验等绿色化学实验研究和应用,从而培养了学生的创新能力。     

Preparation,Characterization of Dawson-type Heteropoly Acid Cerium (III) Salt and Its Catalytic Performance on the Synthesis of n-Butyl Acetate

A novel cerium (III) salt of Dawson type tungstophosphoric acid (Ce₂P₂W₁₈O₆₂·16H₂O) was prepared by doping cerous nitrate in H₆P₂W₁₈O₆₂·13H₂O powder and characterized by thermogravimetry and differential thermal analyses (TG/DTA), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), pyridine infrared spectroscopy (Py-IR) and scanning electron microscopy (SEM). Its catalytic activity was evaluated by the probe reaction of synthesis of n-butyl acetate with acetic acid and n-butanol. The effects of various parameters such as molar ratio of n-butanol to acetic acid, reaction temperature, reaction time, and catalyst amount have been studied by single factor experiment. The results show that Ce₂P₂W₁₈O₆₂·16H₂O behaved as an excellent heterogeneous catalyst in the synthesis of n-butyl acetate. The optimum synthetic conditions were determined as follows:molar ratio of n-butanol to acetic acid at 2.0:1.0, mass of the catalyst being 1.44% of the total reaction mixture, reaction temperature of 120 ℃ and reaction time of 150 min. Under above conditions, the conversion of acetic acid was above 97.8％. The selectivity of n-butyl acetate based on acetic acid was, in all cases, nearly 100%. The catalysts could be recycled and still exhibited high catalytic activity with 90.4% conversion after five cycles of reaction. It was found by means of TG-DTA and Py-IR that the catalyst deactivation was due to the adsorption of a complex of by-product on the active sites on catalysts surface or the catalyst loss in its separation from the products. Compared with using sulfuric acid as catalyst, the present procedure with Ce₂P₂W₁₈O₆₂·16H₂O is a green productive technology due to simple process, higher yield, catalyst recycling and no corrosion for the production facilities.     

H6P2W18O62·nH2O/MWCNTs催化剂的制备、表征及其对乙酸正丁酯合成的催化性能

以多壁碳纳米管(MWCNTs)为载体,采用浸渍法制备了H6P2W18O62·nH2O/MWCNTs催化剂,对其进行了FT-IR、EDX、XRD、SEM表征,并以乙酸和正丁醇合成乙酸正丁酯为探针反应,考察了催化剂的酸催化性能,以及反应条件和催化剂重复使用次数对酯化率的影响。结果表明,H6P2W18O62·nH2O/MWCNTs催化活性高于单一组分的H6P2W18O62·13H2O和MWCNTs。该酯化反应的最佳条件为磷钨酸负载量50%,催化剂用量(按反应体系总质量计)0.6%,醇/酸摩尔比2,反应温度120℃,反应时间2.0h。此时,酯化率可达97.1%。催化重复使用5次后,酯化率仍可达60.9%。