A plot of dicyclopentadiene at different concentrations shows it to be very linear. The process of producing highpurity cyclopentadiene cpd has been investigated, including a gas phase thermal cracking process of dicyclopentadiene dcpd in the presence of h2 on a continuous. We started with dicyclopentadiene which had to be cracked into cyclopentadiene. Liquidphase cracking of dicyclopentadiene by reactive. At its simplest, this dimerisation can be described as a. To crack the dicyclopentadiene, we used fractional distillation, which involves boiling the mixture to remove a certain compound by recondensing it. Cracking apparatus the dielsalder reaction of cyclopentadiene with maleic anhydride the dielsalder reaction that you will be performing between cyclopentadiene and maleic anhydride occurs rapidly at room temperature. Experiment 2 organic chemistry ii pahlavancherif diels. However, it can stay unchanged for a long time in soil and in. The 250 ml three neck round bottom flask contains approximately 100 ml of the commercially available dicyclopentadiene. The integrator is calibrated to report ppm based on the concentration of the analytical standard, a 10.
The dicyclopentadiene will be cracked for you by your t. The rate of monomer formation cracking becomes reasonable at temperatures above 150 c and approaching the boiling point of the dimer. But i was wondering why we added ligroin to the maleic anhydride and ethyl acetate. Dielsalder and melting point chem217labsfall07 openstax cnx. Also, when cooling a piece of equipment that contains the hot bottoms from the distillation or cracking of dicyclopentadiene, care should be taken to exclude air. Dicyclopentadiene dcpd, a dimer of cyclopentadiene, is a white crystalline chemical compound with camphorlike odor. A process for depolymerizing dicyclopentadiene which is free from materials boiling in the neighborhood of cyclopentadiene, with a relatively large yield of substantially pure cyclopentadiene, comprising heating a body of said dicyclopentadlene under temperature conditions between 160 and 2000 c. Gas phase cracking of dicyclopentadiene to produce. Its a colorless, waxy, flammable solid or liquid, with a camphorlike odor.
Process for the vaporphase thermal cracking of dicyclopentadiene and a process for the manufacture of high purity dicyclopentadiene. This information was last updated on march 23, 2005. Cyclopentadiene has a much lower boiling point than the original substance, so we were able to. It will dissolve in water and evaporates quickly from water and soil surfaces. We have tried to make it as accurate and useful as possible, but can take no responsibility for its use, misuse, or accuracy. View lab report lab report 1 from che 211l at quinnipiac university. In this event a periodic increase in the variac setting may be required. Preparation of cyclopentadiene from dicyclopentadiene. Procedure the apparatus for the cracking of dicyclopentadiene to cyclopentadiene will be set up in the hood and will be used to prepare all of the cyclopentadiene needed for the dielsalder reaction and for the preparation of ferrocene. In order to be of any use, the dimer must be cracked and distilled.
Diels alder reaction lab report conclusion essay example. In other words, in the cracking of dicyclopentadiene, why is it necessary to distill the product very slowly. This was attained through a threestep reaction involving the cracking of dicyclopentadiene, reaction of cyclopentadiene with maleic anhydride, and the final hydrolysis reaction. The dielsalder is unlike other organic reactions in that it doesnt involve any nucleophiles, leaving groups, or radicals, so there is no real mechanism to learn.
Cracking the dicyclopentadiene is a retrodielsalder reaction and a schematic of this reaction is shown on page 253 of your lab text and below. Us3719718a process for the production of cyclopentadiene. This colorless liquid has a strong and unpleasant odor. Undergoes a spontaneous dimerization at room temperature to give dicyclopentadiene c10h12, cas no. Dicyclopentadiene, abbreviated dcpd, is a chemical compound with formula c 10 h 12. It plays a role in how your page is seen by search engine crawlers, and how it appears in serps. I recently did a distillation of dicyclopentadiene bp 166 c to get cyclopentadiene bp 40 c. A reactive distillation process was developed for cracking dicyclopentadiene dcpd to produce cyclopentadiene cpd. Preparation of cyclopentadiene from its dimer journal of. The monomer must be used immediately or the cracking and distillation procedure will have to be repeated.
If the polymerization takes place inside a container, the container may violently rupture. The purpose of this lab is to introduce the concept of the melting point of an. Dcpd is a cyclic hydrocarbon that appears as colorless crystals, soluble in ethanol, diethyl ether, and acetic acid. To aid in product isolation, the entire reaction will. High purity dcpd in the range of 9899% is produced by thermal cracking of the lower purity dcpd. Synthesis of cyclopentadiene derivatives by retrodiels. Dicyclopentadiene c10h12 cid 6492 structure, chemical names, physical and. Cyclopentadiene and its dimer, dicyclopentadiene is an irritant, flammable, has an unpleasant odor and is harmful if inhaled avoid breathing its vapors. An unsaturated tricyclic hydrocarbon 3a,4,7,7atetrahydro4,7methano1hindene produced in the cracking of naphtha. It is produced in bulk quantities through steam cracking of c5 petroleum products such. The purpose of this experiment was to demonstrate the formation of sixmembered rings by cycloaddition, also known as a dielsalder reaction.
The vapors are irritating to the eyes and respiratory system. The setup as instructed by my supervisor consisted of a simple watercooled liebig condenser. You have selected the maximum number of product attributes 3 to compare. A dielsalder reaction of cyclopentadiene with maleic anhydride experiment was conducted in lab. This experiment will involve the synthesis of an airstable compound. Place 2 g of maleic anhydride in a 50ml erlenmeyer flask and dissolve it in 8 ml of ethyl acetate by warming on a hot plate. Characterization of the proteins from vigna unguiculata seeds. Prior to running the dielsalder reaction in lab, the cyclopentadiene was cracked.
If your institution is not listed, please contact your librarian. The report must include a cost analysis of all materials needed to do the synthesis. If you were to attempt to distill the monomer from the dimer at say 60 c it would probably take a very long time due to the slow rate of monomer formation at that. However, this dielsalder reaction is reversible by cracking dicyclopentadiene using slow distillation and keeping the cyclopentadiene cold. The reaction kinetics of cyclopentadiene dimerization. Both contain two cyclopentadienyl rings that sandwich a central metal site to give an overall neutral complex co a.
The reaction is strongly exothermic hazardous chemicals desk reference, p. A dielsalder reaction of cyclopentadiene with maleic. Chemistry stack exchange is a question and answer site for scientists, academics, teachers, and students in the field of chemistry. Dicyclopentadiene is coproduced in large quantities in the steam cracking of naphtha and gas oils to ethylene. The dicyclopentadiene dimer c10h12 is broken down cracked to the monomer. Fractional distillation process was set up by clamping the flask. Experiment 14 the dielsalder cycloaddition reaction pg. In the analogous reactions of 8a, 8c, and 8i, however, we isolated a mixture of isomeric cp derivatives 12 and 14. The ta will crack the dicyclopentadiene using the apparatus shown in figure 1.
As dicyclopentadiene enters the air, it breaks down quickly into simpler, lesstoxic chemicals. A meta description is an html tag in the html code of your website, which allows you to customize a section of text that describes the page itself. The first reaction was cyclopentadiene with maleic anhydride to from the product of cisnorbornene5,6endodicarboxylic anhydride. Cyclopentadiene acts as the diene for the reaction. The dimer endodcpd can be formed easily at room temperature although full conversion takes several days. Jul 19, 2011 this week youll be creating a product via the dielsalder reaction. Diels alder reactions of cyclopentadiene brainmass. Non confidential 2012 chemical data reporting information on chemical. This dimer can be restored by heating to give the monomer the compound is mainly used for the production of cyclopentene and its. View lab report experiment 48 lab report from che 211l at quinnipiac university. A process of preparing cyclopentadiene from dicyclopentadiene, which comprises continuously passing dicyclopentadiene in vapor phase into a cracking zone at a pressure not above 500 mm.
Procedure for preparing cyclopentadiene from its dimer. The reaction of tetrazine with 8b, 8d, 8e, 8j, 8k, and 8l resulted in the formation of desired and nonisomerized cp derivatives as sole products. The mass of cyclopentadiene that was collected was 0. During this time the rate of cracking may decrease. Draw the reaction mechanism for the thermal cracking of dicyclopentadiene. Two classic metallocene complexes are ferrocene and cobaltocene. The experimental procedure of obtaining cyclopentadiene followed the work from magnusson and eastwood and coworkers. The major use is in resins, particularly, unsaturated polyester resins. Cracking of dicyclopentadiene performed by your instructor, see figure l 2. Subject to polymerization if subjected to heat for prolonged periods or if contaminated. The apparatus for the cracking of dicyclopentadiene to cyclopentadiene will be set up in the hood and will be used to prepare all of the cyclopentadiene needed for the dielsalder reaction and for the preparation of ferrocene.
Check that all joints are well sealed and that the apparatus is stable and tight. You are instructed to use 140 mg of cyclopentadiene d 0. Dcpd products originate from high temperature cracking of petroleum fractions and are best characterized as highly reactive intermediates used for a. Thus, commercial dicyclopentadiene is thermally decomposed cracking process to obtain cyclopentadiene by fractional distillation scheme 1. Cdc niosh pocket guide to chemical hazards cyclopentadiene. The dicyclopentadiene dimer c 10 h 12 is broken down cracked to the monomer c 5 h 6 cp. Insert a syringe needle into the septum of the receiving. Dielsalder reaction and the dielsalder reaction that you plan to do in this lab. This new compound must be separated before the desired compound can be used. A dielsalder reaction was used to produce the products of this experiment.
At room temperature, this cyclic diene dimerizes over the course of hours to give dicyclopentadiene via a dielsalder reaction. Before the beginning of lab the cyclopentadiene was prepared by a lab technician by. Cyclopentadiene dimer, 4,7 methano 3a,4,7,7a tetrahydroindene, dicyclopentadiene. I know ligroin can be used as a solvent and it is also nonpolar, though ethyl acetate is also a solvent and nonpolar in this experiment.
Cyclopentadiene is an organic compound with the formula c 5 h 6. Cyclopentadiene dimer chemical reference number cas. Dicyclopentadiene dcpd 3a,4,7,7atetrahydo4,7methano1hindene c10h12 general dicyclopentadiene or dcpd is the dimer of cyclopentadiene cpd formed by a dielsalder addition reaction. The dicyclopentadiene dimer is cracked to the monomeric cyclopentadiene by. Before that could be produced, dicyclopentadiene had to be cracked to get cyclopentadiene for the starting material. Nov 20, 20 after learning about the reaction, i was able to complete a dielsalder reaction in organic lab. The reaction product has been claimed to be solely endodcpd. Dispense and use these chemicals in the hood to minimize inhalation hazards. Dielsalder reaction of cyclopentadiene with maleic anhydride.
In the autoclave reactor, reaction temperature, reaction time, diluent, and. This is achieved by using the fractional distillation set up shown in the photo. Cyclopentadiene cpd and dicyclopentadiene dcpd are two important products obtained from oil cracking, which are interconvertable through a dielsalder reaction. Commercial dicyclopentadiene must be thermally degraded to the monomer, which is used in the preparation of ferrocene. In preparing this report you are free to use references and consult with others. Dicyclopentadiene wisconsin department of health services. Cyclopentadiene is made by thermal cracking of its dimer, and on standing it slowly reverts to this species. This lab was a great way to get tangible reinforcement from what was. Dicyclopentadiene appears as a liquid with an acrid odor.
This week youll be creating a product via the dielsalder reaction. At room temperature, it is a clear light yellow color liquid with an acrid odor. The process for the production of cyclopentadiene by the substantially quantitative splitting or monomerizing of a dicyclopentadiene concentrate containing thermally stable dimers of isoprene and codimers of cyclopentadiene, isoprene and piperylene and having been obtained by the heat treatment of a c5 fraction of a pyrolysis petrol and its subsequent enrichment by fractional distillation. The first step in the synthesis of cpru pph 3 2 cl is to crack the dicyclopentadiene dimer. May react exothermically with reducing agents to release hydrogen gas.
Dicyclopentadiene may react vigorously with oxidizing agents. When pure cyclopentadiene is stored it also undergoes a dielsalder cycloaddition reaction and forms dicyclopentadiene. Abstract the objective of this experiment was to crack dicyclopentadiene to create two molecules of cyclopentadiene, and then perform a dielsalder reaction by reacting the diene with maleic anhydride, the dienophile, to create cisnorbornene5,6endodicarboxylic anhydride. Contacting the hot bottoms with air could lead to rapid peroxide formation with a resulting disruptive polymerization. Now writing the report i went hunting for some procedure references.
Cyclopentadiene, which will be used in this experiment cannot be purchased commercially, and must be prepare in the lab by thermally cracking dicyclopentadiene. Type part of your institution name for a list of matches. In a cycloaddition reaction, a 1,3diene reacts with an alkene, or dienophile, to produce a sixmembered ring. Cracking of dicyclopentadiene before the beginning of lab the cyclopentadiene was prepared by a lab technician by cracking it. When pure cyclopentadiene is stored it also undergoes a dielsalder cycloaddition reaction and forms. To crack the dicyclopentadiene, we used fractional distillation, which. C and then collected by fractional distillation process within an icecooled receiver. The reaction kinetics of cyclopentadiene dimerization using. It is produced in bulk quantities through steam cracking of c5 petroleum products such as gas oils, naphtha, and crude oil. Dielsalder reactions chemical and biomolecular engineering. Process for converting dicyclopentadiene to cyclopentadiene. Cracking of dicyclopentadiene chemistry stack exchange.
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