Adipic acid(AA) has a wide range of industrial applications and is enormously demanded. However, there are many disadvantages such as high energy consumption, environmental pollution in the current industrial process. Development of environment-friendly and effective synthetic methods is in urgent need. This review mainly introduces the latest research progresses of green synthetic methods of adipic acid by direct oxidation of cyclohexane using clean oxidants such as O2 (air), H2O2 and O3.
The paper focuses on the research of the chemistry curriculums and teaching contents in the universities at home and USA based on information from the official websites of overseas colleges and doctorate students abroad. On the basis of the comparison and analysis, we can understand the different professional course systems and teaching contents in universities between China and USA. Moreover, some suggestions and thoughts for the major problems in chemistry teaching in China are put forward.
Following the top-quality courses and top-quality open courses, massive open online courses (MOOCs) will be the main form of university course construction in the next stage. MOOCs offer a feasible way to improve the teaching level and study quality. However, to construct an excellent online open course, one needs not only to have a proper understanding, but also to do more work on the course design and mechanism construction, ensuring the healthy and sustainable development of the online open courses.
It is one of essential capacities for chemists to record data scientifically, and college education is a pivotal period for students to develop the basic habit. In light of the fundamentality of significant figures, problems reflected in students' data recording and the cause are discussed. It is suggested that the key approach to solve these problems is to arouse the subjective initiative of the students to make them pay attention to the importance of significant figures. And suggestions for improvement are also proposed.
The approaches to enhance students' experimental skills and autonomous learning ability in the laboratory class of chemical engineering principles are discussed in this article, including the transformation of teaching idea, the improvement of teaching mode as well as the reform of examination form.
To ensure the teaching reform of organic chemistry course is suitable for students majored in phamaceutics, a questionnaire survey was performed to evaluate the current teaching state of organic chemistry. Results showed that the course teaching reform for guiding students to active learning should adjust all the three factors: teacher, student and course.
The relationship between Nobel Prizes in organic chemistry and organic chemistry and biological sciences has been discussed. Nobel Prizes in Chemistry have been introduced to the organic chemistry course in the teaching practices, which can highlight the importance of the course, motivate students, and improve the comprehensive quality and the innovation ability of the students.
The course of analytical chemistry laboratory is designed to better suit for the education goal of pharmaceutical sciences. The basic experiments are closely tied with comprehensive experiments that are related to the pharmaceutical sciences. As a whole package, the course is effective in helping students to develop capability in tackling practical problems.
Umpolung, or polar inversion, is a basic concept in organic chemistry which provides an efficient way to construct C―C bonds in organic synthesis. Here we summarize the types of umpolung and the related mechanisms in detail.
Green synthesis of α-biphenyldicarboxylate(α-DDB) is an exploratory experiment for secondyear undergraduates. The α-DDB is synthesized by using gallic acid as the starting material. Two safe and low toxic reagents, dimethyl carbonate(DMC) and 1,3-dibromo-5,5-dimethylhydantoin(DBDMH) were used to replace extremely toxic dimethyl sulfate(DMS) and strongly corrosive and toxic bromine, respectively. The feasibilty of green chemical synthesis of α-DDB has been explored and realized in laboratory teaching.
In this paper, the concepts and graphics of the freezing point, the triple point, standard freezing point and normal freezing point of water were discussed and analyzed.
The synthesis of a copper complex [CuIICuI(HL)(L)(H2O)2]·H2O based on the hydrothermal synthesis of 4-(1H-imidazol-4-yl)benzoic acid (H2L) with Cu(II) cation, was taken as laboratory teaching project for undergraduates, which covered the aspects of the designed synthesis, structural characterization and analysis. The aim of the laboratory teaching is to enhance the theoretical knowledge of coordination chemistry, promote the mutual integration between the theoretical knowledge and laboratory skills, and facilitate the construction of comprehensive knowledge system for undergraduates.
Two forms of the lever rule in the two-phase and three-phase regions of a multi-component system are discussed in this article. As for the two-component system, the cooling curves of solutions are explained with the lever rule in a three-phase line and the freezing point depression equation. A similar form of the lever rule is presented for three points on a line segment in a three-phase diagram region. This equation can be exploited to prepare the solution with desired concentrations of a multi-component system and to draw three-phase diagrams.
In this article, the reactions for acid-base, complexometric, redox and precipitate titrations can be generalized as M + L = N. Accordingly, their titration curve functions can be expressed as two mathematical models. MATLAB was used to analyze the titration curve models. The changing side reaction coefficients in titration process were calculated by a simple iteration method. Finally, the exact titration curves were plotted using this facile method.
Alkenes with α-H can react with bromine radical via both free radical addition and free radical substitution. In this paper, the mechanisms of the free radical addition and free radical substitution and the competition between these two reactions were discussed using propylene as an example to illustrate effects of reaction conditions on the major reaction and products.
Chinese advanced placement (AP) courses are still new to the domestic high schools and universities, but may develop to be a new route for students' evaluation and university enrollment. The Second High School Attached to Beijing Normal University was chosen to participate the pilot project, and had accomplished three rounds of AP Chemistry teaching. The curriculum objectives, contents, and methodology of AP chemistry were discussed in the paper. Some suggestions to improve the AP courses were proposed.