1.1 chemistry is a central, useful, and creative science while it is facing problems随堂测验
1、what day is the international ozone protection day? a、september 11th b、september 15th c、september 16th d、july 14th
2、what's the influence of nuclear winter on climate? a、decreasing the temperature of the earth's surface. b、increasing the temperature of the earth's surface. c、no obvious influence. d、not sure yet.
1.3 requirement of sustainable development and the development of green chemistry随堂测验
1、what are the typical environmental problems in the following statements? a、global warming; nuclear winter (winter due to nuclear effect) b、depletion of ozone layer c、photochemical smog and air pollution; acid rain d、increase of heavy people
1、please choose one of the typical environmental problems involving in chemistry, state its status and the reason, and then suggest your opinion how to alleviate or solve the serious environmental problems.
2nd week. chapter 2 green chemistry
2nd week. chapter 2 homework 1
1、please state briefly the similarity and the difference between green chemistry and the traditional way of environmental pollution.
3rd week. chapter 2 green chemistry
3rd week. chapter 2 homework 2
1、please explain the concept "atom utilization".
2、please explain briefly the concept "environmental factor".
3、please explain briefly the concept "environmental quotient (eq)".
4、see the following method for the preparation of cyclohexane oxide using ch2cl2 or [bmin]bf4 (ionic liquid) as solvent. please calculate separately the atom utilization (au) and e factor of run 1 and the atom utilization (au) and e factor of run 2.
5、please give us an example to illustrate that the atomic economic reaction is a necessary condition for no pollution.
4th week. chapter 2 green chemistry
4th week. chapter 2 homework 3
1、what's the chemical essence of biodiesel? can you give us an example of effective and environmentally benign catalysts and catalytic processes for biodiesel production?
5th week. chapter 2 green chemistry
5th week. chapter 2 homework 4
1、how to make a chemical reaction greener in a reaction process?
2、please choose a used currently organic synthesis route and review it using the principles of green chemistry, then design a new greener synthesis route.
6th week. chapter 2 green chemistry
6th week. chapter 2 - unit test
1、one of the research area in green chemistry is to use renewable feedstocks for chemical production. which could be used as feedstocks for chemical production in the following resources? a、kitchen garbage b、waste cooking oil c、agricultural wastes d、microalgae
2、the reaction types involved in biomass conversion to fine chemicals and liquid fuels include: a、hydrolysis b、deoxygenation c、condensation d、hydrogenation
3、the energy is widely used in chemistry and chemical industry in the following aspects: a、accelerates the reaction rate with heat b、the need to control reactivity through cooling c、pre-heating of the reaction mixture d、separation energy requirement
4、which typical environmental problems in the following are related to chemical industry? a、depletion of ozone layer b、photochemical smog and haze c、acid rain d、global warming
5、several unconventional processing techniques that rely on alternative forms and sources of energy are of importance for process intensification. these alternative forms and sources of energy include: a、sonic b、microwaves c、solar energy d、photo and other radiation
6、in some cases, the application of atomic economical reaction in chemical synthesis is not enough for eliminating the formation of wastes. these cases include: a、the presence of parallel reaction b、low equilibrium conversion c、low product stereoselectivity d、difficulty in product separation
7、these renewable feed-stocks are most often associated with biological and plant based starting materials, including: a、agricultural wastes b、sawdust c、carbon dioxide d、coal
8、the goal of green chemistry is to treat the environmental pollutions already generated in chemical reactions.
9、the atomic economical reaction is not a requisite condition (必要条件) for eliminating the formation of wastes because the low equilibrium conversion and low product selectivity in a chemical reaction will also bring about pollutions.
10、renewable feedstocks are the substances that are easily regenerated within time frames that are accessible to the human lifetime, including carbon dioxide and methane.
11、we can control the reaction process even we cannot measure the parameters of chemical reaction.
12、the goal of green chemistry is to eliminate the potential of pollution before it occurs.
13、one of the obvious effect of catalysis to facilitate the reaction is to minimize the activation energy (energy costs), and thus reduce the reaction temperature.
14、traditional pollution treatment can provide a permanent cure.
15、chemical reaction with 100% atom utilization has two characteristics. the reactants could be fully utilized, and the resource could be most possibly used economically. the waste could be minimized.
6th week. chapter 2 homework 5
1、please state briefly the 12 principles of green chemistry.
2、how to design safer chemical?
7th week. chapter 3 designing safer chemicals
5th week. chapter 3 homework 1
1、please explain the main content of the external considerations for designing safer chemicals.
2、please explain the main content of the internal considerations for designing safer chemicals.
8th week. chapter 3 designing safer chemicals
8 th week. chapter 3 homework 2
1、how to modify the molecular properties to avoid the absorption from the gastrointestinal tract, the lung and the skin?
9th week. chapter 3 designing safer chemicals
9th week. chapter 3 homework 3
1、what are the structural characteristics of typical electrophilic substances? what are the reactions they undergo with biological nucleophiles?
1、internal considerations for designing safer chemicals mean the prevention of toxic effect. they generally include approaches using molecular manipulations to reach the following purposes. a、to avoid indirect bio-toxicity or bio-activation; b、to avoid direct toxicity; c、to facilitate the uptake of chemicals by organisms; d、to facilitate bio-detoxication.
2、properties of chemicals related to their environmental distribution or dispersion include: a、volatility or melting point; b、persistence or biodegradability; c、water solubility; d、conversion to biologically inactive substances.
3、the three fundamental requirements for chemical toxicity are: a、exposure; b、bio-accumulation; c、bio-availability; d、intrinsic toxicity.
4、we could use qsar equations to predict the aquatic toxicity of chemicals by transforming some important physicochemical properties of the chemicals into descriptors. these related physicochemical properties include: a、octanol-water partition coefficient (log p); b、water solubility; c、dissolution constant; d、relative molecular weight.
5、toxicokinetics refer to the interrelationship of the following processes: a、absorption b、distribution c、mineralization d、catalysis
6、how to change the property of a chemical in order to avoid its toxicity to human beings and environment? a、to make it not to possible to enter the body; b、to make it easily absorbed; c、to make it not possible to affect the biochemical and physiological processes hazardously; d、to make it possible to affect the biochemical and physiological processes.
7、what are wrong in the following descriptions? a、pharmacophore is a structural feature that the biological response is desired in the case of drugs; b、pharmacophore is a structural feature that the biological response is undesired in the case of drugs; c、toxicophore is a structural feature that the biological effect is undesired in the case of commercial chemicals; d、toxicophore is a structural feature that the biological effect is desired in the case of commercial chemical substances.
8、the concentration of a particular substance in its target organs is not necessarily the highest.
9、if we want to reduce the absorption of a chemical substance from the gastrointestinal tract, the lipid solubility should be designed at logp < 5.
10、electrophilic substances/metabolites react covalently with nucleophilic substituents of cellular macromolecules. the reversible covalent interaction results in a variety of toxic effects.
11、chemicals with log p≤2 exhibit low toxicity, because no sufficiently water solubility to enter the cellular membranes of aquatic organisms, then they are not bioavailable.
12、internal considerations for designing safer chemicals mean to prevent the toxic effect of chemicals.
13、the purpose of metabolism is detoxication.
14、non-polar, lipid-soluble chemicals can penetrate the cellular membranes more readily, because cellular membranes have a higher lipid content.
15、external considerations mean the increment of exposure or accessibility of chemicals.
10th week. chapter 3 homework 4
1、langmuir’s isosteric replacement
2、please list some of the typical isosteres.
11th week. chapter 4 application of designing safer chemicals
4.2 designing biodegradable chemicals随堂测验
1、which of the molecular features can generally increase resistance to aerobic biodegradation? a、halogens, especially chlorine and fluorine b、chain branching and high-substituted compounds c、nitro, nitroso, azo, arylamino groups and aliphatic ether (c-o-c) bonds d、polycyclic residues and heterocyclic residues
11th week. chapter 4 homework1
1、please discuss the feasibility of the isosteric replacement of c with si and the advantages of si substituents based on the chemical features of si and c.
2、what are the characteristics of chemical structures and physicochemical properties of degradable compounds?
3、please list the typical molecular features generally increase biodegradability.
12th week chapter 4 application of designing safer chemicals
4.4 designing aquatically safer chemicals随堂测验
1、please choose the other physicochemical properties related to the toxicity of chemicals to aquatic species except for log p. a、water solubility b、molecular size and weight c、ion pair and zwitterions d、chelation
2、the update of the chemicals with molecular weight≤1000 daltons will be negligible, because the chemical will not diffuse across the respiratory membranes (呼吸膜) of aquatic organisms.
12th week chapter 4 homework 2
1、what are the general rules for characterizing the toxicity of chemicals using octanol-water partition coefficient log p?
2、how to design the safer chemicals from the view of molecular weight and molecular size?
13th week. chapter 4 application of designing safer chemicals
13th week chpater 4- unit test
1、the following molecular features of chemicals generally do increase the resistance to aerobic(需氧) biodegradation, except: a、halogens and chain branching b、potential sites of enzymatic hydrolysis c、un-substituted linear alkyl chains d、heterocyclic residues
2、the possible effects of the solubility of chemicals on biodegradability are as follows: a、bio-activation b、rate of solubilization c、enzymatic hydrolysis d、microbial bioavailability
3、which group of metals in the following should we avoid using when we are designing metalized acid dyes (金属化酸性染料). a、al, cr, or co b、al, cr, or zn c、cr, co, or zn d、fe, cu, or zn
4、biodegradability of chemicals is usually enhanced by the following molecular features: a、un-substituted linear alkyl and phenyl rings b、heterocyclic residues c、oxygen in the form of hydroxyl or carboxylic groups d、halogens
5、for delocalized cationic dyes containing n, the toxicity comparison should be: a、primary n > secondary n > tertiary n b、primary n < secondary n < tertiary n c、the more substituents on n atom there are, the more acute the toxicity is d、the more substituents on n atom there are, the less acute the toxicity is
6、principles for designing safer dye chemicals to aquatic species include: a、the number of anions should be less than that of cations b、sulfonic group (磺酸基) is better than carboxylic group (羧酸基) c、molecular weight should be larger than 1000 daltons d、to decrease the diameter of the molecule
8、if we compare the molecule a () with another molecule b (), the molecule a shows higher toxicity than the molecule b.
9、muscarinic antagonistis is a silane analog of neopentyl carbamate , the former is more biodegradable than the latter.
10、for very insoluble chemicals, the replacement of a given functional group that increases solubility may reduce the biodegradability.
11、if o has been inserted into the structure during molecular design, the biodegradability of a chemical will be enhanced.
12、ddd is a silane analog of ddt (organochlorine pesticide ), the former is more biodegradable than the latter.
13、the eventual mineralization of organic compounds can be attributed predominantly to the biodegradation by higher organisms.
14、the majority of chemicals that are toxic to aquatic species are toxic by specific toxicity.
15、the introduction of o is particularly important for biodegradation, because the 1st step of biodegradation is some kind of oxidation reaction which is almost always the rate limiting step.
13th week chapter4 homework 3
1、please discuss the classification of organic dyes based on the group feature of dyes. what are the general principles for designing safer dye chemicals to aquatic species?
14th week chapter 5 techniques in green chemistry
14th week chapter 5 homework 1
1、why do we say a catalyst play an important role in green chemistry?
2、please illustrate the structural influence of catalysts on reaction selectivity by the alkylation of naphthalene with propylene.
3、what are new green oxidants compared with traditional inorganic oxidants? what are their features?
15th week chapter 5 techniques in green chemistry
15th week chapter 5 homework 2
1、how to change reaction solvent according to the viewpoint of green chemistry? and their characters?
2、please state the characters of scf compared with common fluid, and the advantages of scf used as a chemical medium. (characters and advantages)
16th week chapter 5 techniques in green chemistry
16th week chpater 5- unit test
1、volatile organic compounds (vocs) are frequently used as solvents in chemical reactions, which will lead to potential harmfulness to handlers and environments. from the viewpoints of green chemistry, which in the following could be used as new solvents instead of vocs for chemical synthesis? a、water b、supercritical co2 c、tetrahydrofuran(thf) d、deep eutectics
2、we can use the following substances to replace the traditional inorganic oxidants such as cro3, kmno4, and hno3 in cleaner oxidation reactions: a、h2o2 b、lattice oxygen c、n2o d、o2
3、the use of catalysts is preferred in green chemistry because of the following reasons: a、increase the selectivity of a special product b、promote the chemical processes c、reduce environmental pollutions d、activate new starting materials
4、considering the food requirement, the following biomass resources could be used as the chemical feedstocks for producing fine chemicals and liquid fuels: a、woody wastes b、microalgae c、wheat d、rice
5、catalytic distillation is a kind of technique of process intensification, which combines the catalytic reaction and product separation in a single distillation column. which equipment or techniques in the following are included in process intensification? a、membrane reactor b、static mixers c、microreactors d、vacuum distillation
6、oxidation reactions are frequently used in petrol-refinery. to minimize the pollutions induced by inorganic oxidants, some green oxidants could be used in chemical synthesis. these green oxidants include: a、hno3 b、o3 c、n2o d、lattice oxygen
7、volatile organic compounds (vocs) are frequently used as solvents in chemical reactions, thereby leading to potential harmfulness to handlers and environments. from the viewpoints of green chemistry, which in the following could be used as new solvents instead of vocs for chemical transformation? a、ionic liquids b、supercritical co2 c、dimethyl sulfoxide (dmso) d、subcritical water
8、supercritical co2 can be used as a green solvent because all of the organic, inorganic and organometallic compounds could be dissolved in it.
9、room-temperature ionic liquids (ils) are good solvents for dissolving a wide range of organic, inorganic and organometallic compounds.
10、the membrane reactor is an instance for process intensification, which combines the functions of chemical reaction and separation into a single reactor.
11、in some cases, the use of catalysts can eliminate the use of toxic reaction media in chemical synthesis.
12、catalysts can improve the reaction conditions, such as temperature, pressure and energy consuming, and eliminate the usage of toxic reaction medium.
13、ionic liquids can be used as green solvents because they exhibit high solubility to a wide of organic, inorganic and organometallic compounds, are flammable and have high vapor pressure.
14、the aqueous solubility of a chemical on biodegradability does not influence its microbial bioavailability.
16th week chapter 5 homework 3
1、what is process intensification? what ways can be used to realize the process intensification?
2、what is the reactive catalytic distillation? please discuss its characters.
the third period final exam of green chemistry
the third period final exam of green chemistry
1、for a long time, the high yield and selectivity of the target product have been gained much attentions in traditional chemical synthesis. however, a lot of wastes could be generated even in a chemical reaction with product yield as high as 100%. for instance, the wittig reaction (figure 1) is an important method for constructing c=c bond, which has been widely applied in the synthesis of complex compounds on virtue of the simple operation and high yield of 100%. as seen in figure 1, 1-(prop-1-en-2-yl) benzene (3) could be prepared by reaction of 1 and 2, accompanying with formation of 4 as a by-product. questions: (1) please calculate the atom utilization and e factor of the above wittig reaction process assuming 80% conversion of the reactants with 100% selectivity to 3. (10’) (2) please evaluate the disadvantages of the traditional wittig reaction. (4’) (3) please discuss on the advantages of using atom economy to replace yield and selectivity in evaluating the efficiency of a chemical reaction. (3’) (4) according to your understandings, please provide at least four methods to improve the atom economy of a chemical reaction in designing stage. (12’) the first question
2、pyrethrins are a class of insecticides. the pyrethrin analogs etofenprox (compound a) and mti-800 (compound b) with a central, quaternary carbon could be reasonably altered by an isosteric substitution with silicon to form silane (silafluofen, compound c). these compounds are insoluble in water and soluble in organic solvents. questions: (1) please list all the isosteres between compound a, b and c. please briefly explain why these groups are considered as isosteres? (9’) (2) please predict the insecticidal activity order of the three compounds based on their structural feature. (3’) (3) is compound b easy to biodegrade? please give 3 reasons based on the structural feature of the compound. (8’) (4) it was reported that the silane (compound c) was slightly less toxic to insects than the carbon analog mti-800 (compound b) (relative potency of 0.2-0.6) but the former was considerably less toxic to fish (0% mortality at 50 mg·l-1) than the later (lc50 = 3 mg·l-1). the degradation rate of pesticides is one of the environmentally critical parameters: the substance must last as long as required, but should last no longer. the potential route of decomposition is shown as follows: the protonation of 1 by an acid would lead to cationic intermediate 2. capture of this intermediate by a nucleophile like water would lead to cleavage of the carbon-x bond. a subtle yet influential difference in atomic size exists for silicon and carbon as shown below: pleas discuss the difference in the degradation rate of silafluofen (compound c) and its carbon analog (compound b) based on the above atomic feature. which one might be expected to have a shorter half-life of degradation? please explain why these compounds have the different toxicity to aqueous species. (8’)
3、some opportunities for pollution prevention by molecular design exist in industry. surfactants have many uses as antistatic agents, dye leveling agents, lubricants, etc., and substantial volumes of wastewater that must be treated before being release are generated in textile processing. some surfactants have been the subject of numerous pmns (pmn: premanufacturing notice) at epa (environmental protection agency). an example from epa’s pmn program is a group of alkylphosphate surfactants such as isooctadecanol phosphate that is hydrolysable. its structure is shown in the following scheme where m is the counterion. some experts have strongly recommended that phosphate inputs to surface waters be reduced significantly in the interest of environmental protection. questions: (1) please discuss the structural features of isooctadecanol phosphate and the possible consequences for environment, and suggest 2 possible reasons why the experts suggested reducing significantly the input of phosphate to water. (8’) (2) please give 4 possible approaches to reduce the potential harmfulness of the above phosphate to aqueous species by molecular modification from the viewpoints of green chemistry. (8’)
4、with the depletion of fossil energy and environmental degradation, the use of renewable resources has become a research hotspot in recent years. more and more attention has been paid to the efficient conversion and effective utilization of biomass resources. biomass raw materials have complex components and need to be processed before being used. in fact, the structural heterogeneity and the presence of networks of inter- and intra-molecular interactions in biopolymer matrices remain unsolved challenges to clean pretreatment for biocomposite processing. the traditional biomass dissolving and pretreating system includes strong alkali system and copper ammonia solution system. in 2002, rogers et al. [j. am. chem. soc. 2002, 124, 4974-4975] showed that the ionic liquid (il) 1-butyl-3-methylimidazolium chloride ([bmim]cl) is a powerful solvent for cellulose. in il, cellulose can be degraded to sugars, which can further be converted into 5-hydroxymethylfurfural (hmf), levulinic acid, formic acid, malic acid, gluconic acid, sorbitol, c12-alkane (the main component of fuel), and so on, through dehydration, hydrolysis, oxidation, hydrogenation and other reactions, as shown in figure 2. in 2007, li and zhao [adv. synth. catal., 2007, 349, 1847-1850] reported for the first time a novel method for cellulose hydrolysis in [bmim]cl catalyzed by h2so4 without pretreatment. with this method, hydrolysis proceeded at a relatively lower temperature and under atmospheric pressure with reduced acid loading and without compromising the product yield. next, schüth et al. [angew. chem. int. ed., 2008, 47, 8047-8050] used the acidic resin amberlyst 15dry catalyst to study the depolymerization of cellulose in [bmim]cl il. they found that solid acids are powerful catalysts for the hydrolysis of cellulose dissolved in an il. cellulose undergoes selective depolymerization to yield cellulose oligomers (cello-oligomers) without any substantial formation of side products. the cello-oligomers are readily separated by addition of water. interestingly, after a reaction time of 5 h, the isolated cello-oligomers consisted of approximately ten anhydroglucose units (agu). the amount of isolated cellulose decreased during the reaction from 90% at the initial time to 48% after 5 h. these results are not expected on the basis of the experience gained for conventional diluted acid hydrolysis of cellulose in aqueous slurries. the ease of cellulose processing using solid catalysts could lead to novel process options and allow the large-scale use of cellulose depolymerization as the first step in biorefineries. questions: (1) correlate the above contents to some of the 12 principles of green chemistry？(6’) (2) according to your knowledge learned in green chemistry, please try to comment on the advantages of the above-mentioned contents from the viewpoints of starting materials, solvents, catalysts, and so on. (20’)