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2016 Volume 31 Issue 6
2016, 31(6): 1-6
doi: 10.3866/PKU.DXHX201508003
Abstract:
Employing ortho or papa-substituted benzoic acids as starting materials, meta-substituted aromatic compounds, which are much more difficult to be prepared by the traditional methods, can be generated via an ortho C―H functionalization directed by carboxyl and subsequent ipso decarboxylation. In these reactions, carboxyl acts as the function of traceless-directing group. This paper reviews the recent progress in the transition-metal-catalyzed decarboxylative coupling reactions of aromatic acids to construct C―C and C―heteroatom bonds with carboxyl as the traceless-directing group.
Employing ortho or papa-substituted benzoic acids as starting materials, meta-substituted aromatic compounds, which are much more difficult to be prepared by the traditional methods, can be generated via an ortho C―H functionalization directed by carboxyl and subsequent ipso decarboxylation. In these reactions, carboxyl acts as the function of traceless-directing group. This paper reviews the recent progress in the transition-metal-catalyzed decarboxylative coupling reactions of aromatic acids to construct C―C and C―heteroatom bonds with carboxyl as the traceless-directing group.
2016, 31(6): 7-9
doi: 10.3866/PKU.DXHX201605004
Abstract:
Physical Chemistry Teaching in "Excellent Students Training Program in Basic Scientific Disciplines"
2016, 31(6): 10-15
doi: 10.3866/PKU.DXHX201509015
Abstract:
The "Taishan School of Shandong University" is built to cultivate top talents with creativity to lead effectively in the basic science fields and to become the first-class scientific professionals. The key in physical chemistry teaching is to select great textbook and give diversified teaching about important contents. Besides the basic knowledge and the learning method of physical chemistry, the enhancement of innovation ability is also very important, which benefits the cultivation of good physical chemistry quality and strong adaptive capacity of students. Meanwhile, we should pay attention to the combination of the theory and experiments, leading students the more profound understanding of the theory, experiments, innovation, creation and re-theorizing.
The "Taishan School of Shandong University" is built to cultivate top talents with creativity to lead effectively in the basic science fields and to become the first-class scientific professionals. The key in physical chemistry teaching is to select great textbook and give diversified teaching about important contents. Besides the basic knowledge and the learning method of physical chemistry, the enhancement of innovation ability is also very important, which benefits the cultivation of good physical chemistry quality and strong adaptive capacity of students. Meanwhile, we should pay attention to the combination of the theory and experiments, leading students the more profound understanding of the theory, experiments, innovation, creation and re-theorizing.
2016, 31(6): 16-20
doi: 10.3866/PKU.DXHX201506015
Abstract:
In this paper, we summarized the problems of traditional evaluation in the course of fundamentals of modern chemistry (inorganic chemistry), and explored the new evaluation method based on "formative evaluation (50%) + summative evaluation (50%)". Formative evaluation includes five contents: homework (10%), micro interview (10%), micro paper (10%), micro in-class exercises (10%), micro presentation (10%).The new evaluation has promoted the synergetic development of the students, teachers and the chemistry course.
In this paper, we summarized the problems of traditional evaluation in the course of fundamentals of modern chemistry (inorganic chemistry), and explored the new evaluation method based on "formative evaluation (50%) + summative evaluation (50%)". Formative evaluation includes five contents: homework (10%), micro interview (10%), micro paper (10%), micro in-class exercises (10%), micro presentation (10%).The new evaluation has promoted the synergetic development of the students, teachers and the chemistry course.
2016, 31(6): 21-25
doi: 10.3866/PKU.DXHX201509023
Abstract:
A teaching reform of college chemistry by combination of aeronautics and astronautics has been well performed in our university. This reform has stimulated students' interest in studying college chemistry with their professional pride. Above all, most students have solidly mastered the basic concepts and theories of this course.
A teaching reform of college chemistry by combination of aeronautics and astronautics has been well performed in our university. This reform has stimulated students' interest in studying college chemistry with their professional pride. Above all, most students have solidly mastered the basic concepts and theories of this course.
2016, 31(6): 26-28
doi: 10.3866/PKU.DXHX201510003
Abstract:
It is known that polymers affect our life in all aspects, and the necessity of setting up the course of polymer chemistry in colleges especially in normal universities has been addressed in this paper. To solve the problems confronted in the teaching in normal universities, a newly designed teaching strategy has been explored. In this way, the students have been divided into different groups. According to the characteristics of students, the learning content has been adjusted to be suited for students at different levels. At the same time, a multi-feedback and assessment system was also established.
It is known that polymers affect our life in all aspects, and the necessity of setting up the course of polymer chemistry in colleges especially in normal universities has been addressed in this paper. To solve the problems confronted in the teaching in normal universities, a newly designed teaching strategy has been explored. In this way, the students have been divided into different groups. According to the characteristics of students, the learning content has been adjusted to be suited for students at different levels. At the same time, a multi-feedback and assessment system was also established.
2016, 31(6): 29-32
doi: 10.3866/PKU.DXHX201601040
Abstract:
This paper discusses the differences in choice of teaching materials and main contents, teaching mode, teaching practices and the teaching program between undergraduates and graduate students in teaching the organic spectroscopic analysis course. The article comes up with a viewpoint that undergraduate teaching should emphasize the basics with moderate difficulty, while postgraduate teaching should emphasize on the principles, the practice, the development of discipline and the ability to analyze complicated spectra.
This paper discusses the differences in choice of teaching materials and main contents, teaching mode, teaching practices and the teaching program between undergraduates and graduate students in teaching the organic spectroscopic analysis course. The article comes up with a viewpoint that undergraduate teaching should emphasize the basics with moderate difficulty, while postgraduate teaching should emphasize on the principles, the practice, the development of discipline and the ability to analyze complicated spectra.
2016, 31(6): 33-39
doi: 10.3866/PKU.DXHX201507005
Abstract:
In order to meet the demands of the pesticide chemistry education in the fast developing era, the teaching reform and practice have been made on the pesticide chemistry course by the "three-in-one" model which integrates classroom teaching, student experiments and production practice. It was showed that this model could improve students' innovation ability and comprehensive quality
In order to meet the demands of the pesticide chemistry education in the fast developing era, the teaching reform and practice have been made on the pesticide chemistry course by the "three-in-one" model which integrates classroom teaching, student experiments and production practice. It was showed that this model could improve students' innovation ability and comprehensive quality
2016, 31(6): 40-43
doi: 10.3866/PKU.DXHX201506019
Abstract:
In the inorganic chemistry laboratory teaching, we use a series of ways to improve the teaching effects. Questions and scenario design are used when introducing some key knowledge points. Students are guided and encouraged to set up and carry out chemical experiments by themselves. By these approaches and the experimental results in the laboratory class, students can have a deep understanding of the related knowledge learned in the course.
In the inorganic chemistry laboratory teaching, we use a series of ways to improve the teaching effects. Questions and scenario design are used when introducing some key knowledge points. Students are guided and encouraged to set up and carry out chemical experiments by themselves. By these approaches and the experimental results in the laboratory class, students can have a deep understanding of the related knowledge learned in the course.
2016, 31(6): 44-48
doi: 10.3866/PKU.DXHX201506004
Abstract:
The discussion-based teaching method is applied to the physical chemistry course for insightful understanding of the work-heat transfer in thermodynamic reversible process. By means of the discussionbased teaching, students can have a good command of essential characteristics of thermodynamic reversible process, which lays a solid foundation for subsequent leaning contents.
The discussion-based teaching method is applied to the physical chemistry course for insightful understanding of the work-heat transfer in thermodynamic reversible process. By means of the discussionbased teaching, students can have a good command of essential characteristics of thermodynamic reversible process, which lays a solid foundation for subsequent leaning contents.
2016, 31(6): 49-52
doi: 10.3866/PKU.DXHX201507001
Abstract:
In Zhejiang University, a series of practice and exploration on laboratory management and teaching assistant have been carried out to improve the general chemistry laboratory teaching. This article analyzed and proposed effective methods in optimizing resources, saving chemicals, maintaining instruments, and establishing the safety system.
In Zhejiang University, a series of practice and exploration on laboratory management and teaching assistant have been carried out to improve the general chemistry laboratory teaching. This article analyzed and proposed effective methods in optimizing resources, saving chemicals, maintaining instruments, and establishing the safety system.
2016, 31(6): 53-57
doi: 10.3866/PKU.DXHX201507004
Abstract:
The preparation of bismuth vanadate yellow pigment by the liquid-phase precipitation method using Bi(NO3)3 and NH4VO3 as raw materials is recommended as an inorganic chemistry experiment. Students are required to obtain small and uniform BiVO4 yellow pigment particles with good dispersity by controlling the initial concentration of reactants, the pH of solution, the reaction temperature and duration. The experimental procedures involve solution preparation, heating, stirring, simple reflux, temperature and pH control, ion test, the suction filtration, washing and drying. Bismuth vanadate not only is a kind of green environmental protection yellow pigment, but also has the photocatalytic performance to degrade pollutants. Therefore, the experiment not only is beneficial to the improvement of students' preparation ability in inorganic chemistry experiment, but also imparts the environmental education in the experimental teaching.
The preparation of bismuth vanadate yellow pigment by the liquid-phase precipitation method using Bi(NO3)3 and NH4VO3 as raw materials is recommended as an inorganic chemistry experiment. Students are required to obtain small and uniform BiVO4 yellow pigment particles with good dispersity by controlling the initial concentration of reactants, the pH of solution, the reaction temperature and duration. The experimental procedures involve solution preparation, heating, stirring, simple reflux, temperature and pH control, ion test, the suction filtration, washing and drying. Bismuth vanadate not only is a kind of green environmental protection yellow pigment, but also has the photocatalytic performance to degrade pollutants. Therefore, the experiment not only is beneficial to the improvement of students' preparation ability in inorganic chemistry experiment, but also imparts the environmental education in the experimental teaching.
2016, 31(6): 58-61
doi: 10.3866/PKU.DXHX201506014
Abstract:
Experimental improvements on determination of dissociation constant of acetic acid have been made by using thermostat, improving solution preparation, and changing the way of using electrode. These improvements greatly expand the lifetime of electrodes and reduce the amount of reagents, reducing the experimental cost. The experimental procedure is much simpler and results are more accurate. These improvements enhance the students' understanding about the principle and the method.
Experimental improvements on determination of dissociation constant of acetic acid have been made by using thermostat, improving solution preparation, and changing the way of using electrode. These improvements greatly expand the lifetime of electrodes and reduce the amount of reagents, reducing the experimental cost. The experimental procedure is much simpler and results are more accurate. These improvements enhance the students' understanding about the principle and the method.
2016, 31(6): 62-66
doi: 10.3866/PKU.DXHX201506012
Abstract:
The four basic manners through which the catalyst accelerates the organic chemical reaction have been summarized, including setting up electron flow channel, changing electron flow property, improving electron flow ability and stabilizing electronic flow. The aim of the paper is to reveal the essence of catalytic action of catalyst in organic chemical reactions and help students better understand organic chemical reactions.
The four basic manners through which the catalyst accelerates the organic chemical reaction have been summarized, including setting up electron flow channel, changing electron flow property, improving electron flow ability and stabilizing electronic flow. The aim of the paper is to reveal the essence of catalytic action of catalyst in organic chemical reactions and help students better understand organic chemical reactions.
2016, 31(6): 67-71
doi: 10.3866/PKU.DXHX201508001
Abstract:
The shortcomings of the graphic statements on electrode polarization curves and electrolysis curves in current physical chemistry textbook were discussed. The electrolysis curves were recorded using Pt as the electrode, and 1.0 mol·L-1 KOH and 0.50 mol·L-1H2SO4 as electrolytes. The key experimental phenomena in both low-voltage and high-voltage regions were discussed, which would be helpful for the profound understanding of the electrolysis process. On this basis, the electrolysis and polarization curves in the forms helpful for the physical chemistry teaching were suggested.
The shortcomings of the graphic statements on electrode polarization curves and electrolysis curves in current physical chemistry textbook were discussed. The electrolysis curves were recorded using Pt as the electrode, and 1.0 mol·L-1 KOH and 0.50 mol·L-1H2SO4 as electrolytes. The key experimental phenomena in both low-voltage and high-voltage regions were discussed, which would be helpful for the profound understanding of the electrolysis process. On this basis, the electrolysis and polarization curves in the forms helpful for the physical chemistry teaching were suggested.
2016, 31(6): 72-79
doi: 10.3866/PKU.DXHX201510022
Abstract:
In this article, the relationship equation between the photoelectron lifetime of the conduction band of photocatalyst and the dielectric constant of photocatalyst is derived. According to the photocatalytic mechanism and the derived equation, the relationship between the photocatalytic and the dielectric constant of the photocatalyst is elucidated as follows: the larger dielectric constant of the photocatalyst, the longer the photoelectron lifetime. Consequently, the transition of the photoelectrons from conduction band to the valence band to combine with the holes becomes harder through the stimulated emission and spontaneous emission, facilitating effective production of hydroxyl free radicals via the sufficient oxidation of hydroxyl ion and water by the holes occurring on the surface of photocatalyst.
In this article, the relationship equation between the photoelectron lifetime of the conduction band of photocatalyst and the dielectric constant of photocatalyst is derived. According to the photocatalytic mechanism and the derived equation, the relationship between the photocatalytic and the dielectric constant of the photocatalyst is elucidated as follows: the larger dielectric constant of the photocatalyst, the longer the photoelectron lifetime. Consequently, the transition of the photoelectrons from conduction band to the valence band to combine with the holes becomes harder through the stimulated emission and spontaneous emission, facilitating effective production of hydroxyl free radicals via the sufficient oxidation of hydroxyl ion and water by the holes occurring on the surface of photocatalyst.
2016, 31(6): 80-83
doi: 10.3866/PKU.DXHX201506008
Abstract:
In teaching chemical kinetics, especially for the transition- state theory and steady- state approximation method, the use of Materials Studio and Matlab software can help visualize the learning of the abstract chemical theory. This facilitates the cultivation of imaginary thinking of the students, enhances the teaching effects, and motivates students' interest in learning physical chemistry.
In teaching chemical kinetics, especially for the transition- state theory and steady- state approximation method, the use of Materials Studio and Matlab software can help visualize the learning of the abstract chemical theory. This facilitates the cultivation of imaginary thinking of the students, enhances the teaching effects, and motivates students' interest in learning physical chemistry.
2016, 31(6): 84-89
doi: 10.3866/PKU.DXHX201507008
Abstract:
On the basis of spatial-temporal characteristic of ideal reactors, the inherent relations among the batch reactor, the plug flow reactor (PFR), and the continuous stirred tank reactor (CSTR) were discussed. Both the F and E functions of the recycle PFR reactor were derived. The role of CSTR in series or the recycle PFR as a bridge or a link among the ideal reactors was addressed. Based on the discussion, the relations among the ideal reactors were briefly summarized.
On the basis of spatial-temporal characteristic of ideal reactors, the inherent relations among the batch reactor, the plug flow reactor (PFR), and the continuous stirred tank reactor (CSTR) were discussed. Both the F and E functions of the recycle PFR reactor were derived. The role of CSTR in series or the recycle PFR as a bridge or a link among the ideal reactors was addressed. Based on the discussion, the relations among the ideal reactors were briefly summarized.
2016, 31(6): 90-97
doi: 10.3866/PKU.DXHX201504001
Abstract:
The molecular structure information of functional group and chemical bond has been provided in IR spectra. In general, a chemical bond may present multiple IR peaks, and one peak may be a superimposed absorption from more than one chemical bonds. It is important to be able to interpret the characteristic peaks from the major functional groups in the compounds.
The molecular structure information of functional group and chemical bond has been provided in IR spectra. In general, a chemical bond may present multiple IR peaks, and one peak may be a superimposed absorption from more than one chemical bonds. It is important to be able to interpret the characteristic peaks from the major functional groups in the compounds.
2016, 31(6): 98-102
doi: 10.3866/PKU.DXHX201504029
Abstract:
The absolute value of titration break in precipitation titration is deduced with the Ringbom titration curve equation, and the conditions for accurate precipitation titration are thus deduced with the absolute value of the titration break.
The absolute value of titration break in precipitation titration is deduced with the Ringbom titration curve equation, and the conditions for accurate precipitation titration are thus deduced with the absolute value of the titration break.
2016, 31(6): 103-110
doi: 10.3866/PKU.DXHX201604027
Abstract:
The design of experimental test for the 29th Chinese Chemical Olympiad (Finals) was introduced and analyzed. Experimental test, design ideas, the development of experimental selection and evaluation rules were provided.
The design of experimental test for the 29th Chinese Chemical Olympiad (Finals) was introduced and analyzed. Experimental test, design ideas, the development of experimental selection and evaluation rules were provided.
