1. The major goal of this paper is to examine the electronic effects of how substituent groups impact the hydroboration of the substituted styrene molecules. The scientists focused mainly on understanding the positioning in which the boron-hydrogen moiety was added to the carbon-carbon double bond. 2. The purpose of the experiments reported in Table 1 was to determine the reproducibility of the α and β alcohol distribution as a result of the hydroboration of styrene. This was achieved through manipulating the variations of the hydride/styrene ratios. The results indicated a 19:81 α to β ratio that showed consistency with the reported 20:80 ratio. The results in Table 1 deduced that there was no significant change through the distribution of …show more content…
The presence of ethylbenzene complicated the analysis of results because the increased appearance of ethylbenzenes as a product of o- and p-trifluromethylstyrene and m-nitrostyrene was inversely related with a decrease in the yield of α alcohol. The author concluded that the product of ethylbenzene was due to competing reactions taking place. 4. The α hydrogen in p-nitrotoluene would be more acidic than the α hydrogen in m-nitrotoluene because the conjugate base of p-nitrotoluene has more resonance allowing for a greater delocalization of the charge and more stability. The more stable a molecule is the faster it will react when compared to a less stable molecule and thus the α hydrogen in p-nitrotoluene is more likely to donate its …show more content…
With increased amounts of boron distribution in the α position would come from a greater desire for the transition state III. The p-CF isomer has the highest α-boron distribution due to the highly electronegative CF substituent. The tri-fluoro group connected to the carbon would stabilize the partial negative of the α carbon in transition state III through induction. Fluorine is more electronegative than chlorine, so fluorine would have a greater inductive force. The p-CH3O isomer would favor transition state II. This is because the partial positive of α carbon in transition state II could be stabilized through resonance. The styrene molecule H would favor transition state II because the molecule is stabilized through hyperconjugation and resonance. Transition state III is not preferred because the partial positive would have less hyperconjugation and the boron would cause steric strain. The p-Cl isomer would have a higher α boron distribution. The chlorine acts as an electron withdrawing substituent. This would stabilize the partial negative on the α carbon in transition state
The percent yield of products that was calculated for this reaction was about 81.2%, fairly less pure than the previous product but still decently pure. A carbon NMR and H NMR were produced and used to identify the inequivalent carbons and hydrogens of the product. There were 9 constitutionally inequivalent carbons and potentially 4,5, or 6 constitutionally inequivalent hydrogens. On the H NMR there are 5 peaks, but at a closer inspection of the product, it seems there is only 4 constitutionally inequivalent hydrogens because of the symmetry held by the product and of this H’s. However, expansion of the peaks around the aromatic region on the NMR show 3 peaks, which was suppose to be only 2 peaks. In between the peaks is a peak from the solvent, xylene, that was used, which may account to for this discrepancy in the NMR. Furthermore, the product may have not been fully dissolved or was contaminated, leading to distortion (a splitting) of the peaks. The 2 peaks further down the spectrum were distinguished from two H’s, HF and HE, based off of shielding affects. The HF was closer to the O, so it experienced more of an up field shift than HE. On the C NMR, there are 9 constitutionally inequivalent carbons. A CNMR Peak Position for Typical Functional Group table was consulted to assign the carbons to their corresponding peaks. The carbonyl carbon, C1, is the farthest up field, while the carbons on the benzene ring are in the 120-140 ppm region. The sp3 hybridized carbon, C2 and C3, are the lowest on the spectrum. This reaction verifies the statement, ”Measurements have shown that while naphthalene and benzene both are considered especially stable due to their aromaticity, benzene is significantly more stable than naphthalene.” As seen in the reaction, the benzene ring is left untouched and only the naphthalene is involved in the reaction with maleic
The objective of this experiment was to conduct the Friedel-Crafts Alkylation of p-xylene. This reaction substituted an alkyl group instead of a hydrogen atom on the aromatic ring. The compound used was p-xylene, the reactant was n-propyl chloride, and the Lewis acid catalyst was aluminum chloride. The products consisted of the group of n-propyl that combined with p-xylene to form 1,4 Dimethyl-2-propylbenzene, and the group of isopropyl that combined with p-xylene to form 2-isopropyl-1,4-dimethylbenzene
The purpose of this lab was to determine what vegetation was present above and below the water’s surface and to observe the water visibility depth. We took sampling data from the two different lakes at Noxubee Refuge. The two lakes were Bluff Lake and Loakfoma Lake. The Bluff lake consists of 800 acres of the Noxubee Refuge, and Loakfoma Lake consists of 400 acres (About the Refuge). Many different wildlife species are present at these two lakes. The wildlife includes migratory waterfowl, shoreline birds, and alligators. We observed all three of these wildlife species while collecting data. Along with the wildlife, there are many different plant species to observe. The plant species consist of upland species and bottomland species.
Considering a duty cycle equal to 0.8, a static gain equal to q = 10 is obtained for n = 1, q = 15 for n = 2 and q = 20
Discussion The reaction of (-)-α-phellandrene, 1, and maleic anhydride, 2, gave a Diels-Alder adduct, 4,7-ethanoisobenzofuran-1,3-dione, 3a,4,7,7a-tetrahydro-5-methyl-8-(1-methylethyl), 3, this reaction gave white crystals in a yield of 2.64 g (37.56%). Both hydrogen and carbon NMR as well as NOESY, COSY and HSQC spectrum were used to prove that 3 had formed. These spectroscopic techniques also aided in the identification of whether the process was attack via the top of bottom face, as well as if this reaction was via the endo or exo process. These possible attacks give rise to four possible products, however, in reality due to steric interactions and electronics only one product is formed.
Ensure gloves are worn at all times when handling strong acids and bases within the experiment of the preparation of benzocaine. 4-aminobenzoic acid (3.0g, 0.022 moles) was suspended into a dry round-bottomed flask (100cm3) followed by methylated sprits (20 cm3). Taking extra care the concentrated sulphuric acid of (3.0 cm3, 0.031 moles) was added. Immediately after the condenser was fitted on, and the components in the flask were swirled gently to mix components. It should be ensured that the reactants of the concentrated sulphuric acid and the 4-aminobenzoic acid were not clustered in the ground glass joint between the condenser itself and the flask. In order to heat the mixture to a boiling point, a heating mantle was used and then further left for gently refluxing for a constituent time of forty minutes. After the duration of the consistent forty minutes the rou...
The spots moved 3.8cm, 2.3cm, 2.1cm, 1.8cm, and 2.5 cm, for the methyl benzoate, crude product, mother liquor, recrystallized product, and isomeric mixture, respectively. The Rf values were determined to be.475,.2875,.2625,.225, and.3125, for the methyl benzoate, crude product, mother liquor, recrystallized product, and isomeric mixture, respectively. Electron releasing groups (ERG) activate electrophilic substitution, and make the ortho and para positions negative, and are called ortho para directors. In these reactions, the ortho and para products will be created in a much greater abundance. Electron Withdrawing groups (EWG) make the ortho and para positions positive.
As a final point, the unknown secondary alcohol α-methyl-2-naphthalenemethanol had the R-configuration since it reacted the fastest with S-HBTM and much slower with R-HBTM. TLC was a qualitative method and ImageJ served as a quantitative method for determining which reaction was the faster esterification. Finally, 1H NMR assisted in identifying the unknown from a finite list of possible alcohols by labeling the hydrogens to the corresponding peaks.
With regard to temperature, the reaction moving to the right is exothermic i.e. it gives off energy (in the form of heat). Therefore reference to Le Chatlier's Principle shows that the reaction to the right is favoured by low temperatures.
The chemical history of trinitrotoluene, other wise known as TNT, Trotyl, 2,4,6-Trinitrotoluene, 2-Methyl-1,3,5-trinitrobenzene, and C7H5N3O6, was first made in 1863 by Joseph Wilbrand, a German chemist born in Gießen, or Giessen, on August 22, 1839 and died on June 22, 1906 (he was 66 and two months from turning 67). at the age of around 25. He had created TNT, or trinitrotoluene by putting toluene, which is C7H8, through the process of nitration. 130 mg/L TNT is soluble in water at 20˚C. The steam pressure of it, at 20˚C, is 150 Pa to 600 Pa (about 0.001 atm. to about 0.006 atm.). When the TNT explodes, it travels 6700 to 7000 (usually meters per second, at a density of 1.6 grams per centimeter cubed. In a Lead (Symbol: Pb) block test, TNT’s result is 300 milliliters /10 grams. The sensitivity to impact is 15 newton meters, the same as about 11 pound
I predict that the order of the reaction with respect to I- ions will be 1 and the order of the reaction with repect to S2O82-ions will also be 1 giving a overall order for the reaction of 2. This is information obtained from data books and backed up by information from the internet. (see references)
In the petroleum refining process, nitrobenzene is mostly used as solvent in the production of acetate and ethers
Staudt, Maureen, and Michael Stranz, eds. General Chemistry for Engineering and Science II. Mason,Ohio: Cengage Learning, 2012. Print.
...n initiated with Sn(Oct)2 were studied by conducting various reactions incorporating various ratio and amount of reagents, co-initiator and trapping agents. Furthermore, reaction kinetics were monitored and intermediate /trapped compounds were isolated and identified. The results indicated that propagation did not proceed as cationic polymerization. Reaction was co-initiated by alcohol or alkoxide compound and Sn was attached to the propagating group.
Chemical Engineering Journal. 39. 604-610. Wang, X.Q., Wang, Q.H., Liu, Y.Y. & Ma, H. Z. 2009. The 'Standard' of the 'Standard'.