Introduction Organometallic compounds are substances that contain carbon-metal bonds. Metals found in these compounds are typically lithium (Li), magnesium (Mg), copper (Cu), mercury (Hg), or other transition metals. Organometallic compounds are also known as Grignard reagents (1). General mechanism of organometallic compounds: R^1 CH_2-M + X-CH_2 R^2 → R^1 CH_2-CH_2 R^2 + MX Grignard reagents are among the most important in organic chemistry. The polarization of the bond between the carbon atom and the metal makes the carbon atom a Lewis base. A characteristic property is that the carbon atom is a nucleophile. However, when bonded to more electronegative atoms the carbon acts as an electrophile (1). Grignard reagents are …show more content…
This causes the stabilization of the compound. Diethyl ether or Tetrahydrofuran (THF) are the two commonly used ethereal solvents. Diethyl ether is used over tetrahydrofuran due to cost and the ability to be easily removed from the solution (1). Use caution when opening diethyl ether and tetrahydrofuran containers because they have the ability to create hydroperoxides, which are dangerous because they are explosives. Hydroperoxides can be tested for using starch/iodine test paper. If the starch/iodine test paper turns a dark shade of purple then hydroperoxides are present in the ethereal solvent (1). The magnesium used is commonly in the form of magnesium turnings to increase the surface area of the reaction. Forming the Grignard reagent is an exothermic reaction process. The temperature should be regulated as well as the rate of the reaction. The rate of the reaction should be monitored because side reactions can occur if the reaction progresses too quickly. The halide should be added in a dropwise manor over a designated time period. Adding the halide dropwise keeps the reaction rate under control because the concentration of the halide is kept at a low value …show more content…
The glassware used in this experiment (Claisen adapter, separatory funnel, condenser, stir bar, drying tube, and a 50mL round bottom flask) should be baked in an oven to ensure that they are clean and that there is no water left in them. The reaction color went from cloudy to brown after the reaction with the magnesium turnings began. Once the methyl benzoate was added the color changed from brown to an orangey-pink. After the workup steps the acidity of the aqueous layer was tested and was found to have a pH of approximately 2 due to the pH paper turning a magenta color. The recrystallization of the product was done using cyclohexane. The melting point of the product was found to be between 158ºC and 160ºC. The percent yield of the product was calculated to be 23.62%. The low yield was caused by accidently spilling some of the reaction during the washes/extractions in the separatory funnel and by the possibility of having had a side reaction occur during the preparation of the Grignard
The goal of this two week lab was to examine the stereochemistry of the oxidation-reduction interconversion of 4-tert-butylcyclohexanol and 4-tert-butylcyclohexanone. The purpose of first week was to explore the oxidation of an alcohol to a ketone and see how the reduction of the ketone will affect the stereoselectivity. The purpose of first week is to oxidize the alcohol, 4-tert-butylcyclohexanol, to ketone just so that it can be reduced back into the alcohol to see how OH will react. The purpose of second week was to reduce 4-tert-butylcyclohexanol from first week and determine the effect of the product's diastereoselectivity by performing reduction procedures using sodium borohydride The chemicals for this lab are sodium hypochlorite, 4-tert-butylcyclohexanone
Compounds are pure substances that contain atoms of two or more elements chemically combined in fixed ratios. In this lab, we observed two types of compounds, Ionic compounds and Covalent compounds. Ionic compounds are chemical compounds consisting of two or more ions that are held adjacent to each other by electrical attraction. “One of the ions, called an “anion,” has a negative charge, and the other is called a “cation,” and has a positive charge. “Cations” are usually metallic atoms and “anions” are either atoms of nonmetals or polyatomic ions. “ (1) A polyatomic ion is an ion that contains at least two atoms. A covalent compound is a compound in which the atoms that are bonded share at least one pair of valance electrons, the electrons that are located in the outermost shell of an atom, as opposed to transferring electrons from one atom to another. Covalent compounds are usually formed between nonmetal atoms.
The actual amount of crude product was determined to be 3.11 grams. The percent yield of the crude product was determined to be 67.75 %. The actual amount of pure product formed was found to be 4.38 grams. The percent yield of the pure product was determined to be 95.42%. Regarding the thin layer chromatography, the line from the solvent front is 8 centimeters.
1.In the lab experiment, the instructions told us to adulterate the concentration of hydrogen peroxide and Chlorine with some water.
Experiment to investigate factors affecting the rate of reaction between magnesium ribbon and hydrochloric acid
Input variables In this experiment there are two main factors that can affect the rate of the reaction. These key factors can change the rate of the reaction by either increasing it or decreasing it. These were considered and controlled so that they did not disrupt the success of the experiment. Temperature-
In this investigation I will be examining the rate of reaction of chloroethane, bromoethane and iodoethane, by treating them with a. solution of silver nitrate in a mixture of ethanol and water, and. timing how long it takes for a silver halide precipitate to become. visible. The sand is The faster the precipitate appears, the more reactive the... ... middle of paper ...
Click chemistry was created by taking cues from how nature naturally reacts. 1 The goal of Sharpless and colleagues was to create a number of selective blocks that could be connected in many different ways with the ability to work in many various applications. 1 For a reaction to be defined as click chemistry: “the reaction must be modular, wide in scope, give very high yields, and generate only inoffensive by products that can be easily removed” and it must have undemanding reaction conditions. 1 The high thermodynamic driving force of the click reaction is the reason click reactions are able to achieve their specified characteristics.1 High selectivity for a lone product and a rapid completion of the reaction is another feature of click reactions. 1 The formation of carbon-heteroatom bond reactions cover the majority of examples of click chemistry including cycloadditons of unstaturated species nucleophilic substitution reactions, non-aldol carbonyl chemistry , and addition carbon-carbon multiple bonds. 1
The point of neutralisation using a methyl orange indicator is determined using the following colour changes.
Chabay, Ruth; Kean, Elizabeth; Jones, Loretta; Rogers, Elizabeth; Smith, Stanley; Stovall, Iris. Fundamentals of Chemistry. University of Wisconsin-Madison, 2000. Web. March 17, 2014.
Critical Thinking Review of Organic Chemistry Organic chemistry is a creative science entailing the study of the structure, the properties, reactions and preparations of compounds containing carbon, the hydrocarbons and compounds with elements such as nitrogen, hydrogen, oxygen, halogens, sulfur, phosphorus and silicon. Organic chemistry deals with compounds produced by living organisms and also incorporate into it the human-made substances such as plastics. Studying organic chemistry enhances a better understanding of the behavior of natural and synthetic materials and aid in the discovery of new elements that will be of great help to the coming generations in supplying their needs and in dealing with their problems. Organic compounds play
In this experiment, two solutions will be mixed, and the completion of the reaction will be marked by a color change. One solution contains the iodate ion (IO3-). The other contains the hydrogen sulfite ion (HSO3-) and soluble starch.
However, in 1990s it is not used as anesthetic agent. Ethylene is eliminated from the body unchanged, primarily by the lungs, and most elimination is complete within three minutes of
Here, we can see that they contain rings with alternating single and double bonds in their chemical structure.
A coordination compound or complex is a formed when a ligand is attached to an acceptor by means of a lone pair of electrons (Rajbir Singh, 2002). Coordination compounds are formed between a metal ion and a molecule with one or more unshared electron pairs, called a ligand. According to (Geoaffrey A. L...