4.0 Discussion : 4.1 Hypothesis The hypothesis of the reaction, there was similarity by comparing the compound in case nitrogen was neutral and protonated. Table (1) illustrated that there was clearly different in the energy between two cases of that compound by 119 kJ/mole with basis set 6-311+G(d,p) and 128 kJ/mole with basis set 6-31 G(d) and similarly in level of theory(B3LYP). Therefore, the protonated nitrogen of the HALS molecule had higher energy than the neutral nitrogen through the potential energy of the reaction. Accordingly, the hypothesis that was reported becomes incorrect against to the calculation result found it from Gaussian program. 4.2 The aim of calculation the activation energy The objective of this report is to calculate the activation energy for the molecule of HALS reaction using GAUSSIAN 09 via the WebMO interface. There have been assumed that the transition state can be obtained through the reaction as in (Scheme3). By using the program and format (opt=(TS,calcfc,noeigen) freq=noraman) , the structure was optimized and formed as a ring shape in order to be able to transfer Hydrogen from Carbon to nitrogen in the molecule. It also was attempted re-drawing some of the N-O and O-C bond lengths/angles to try and get that final H down closer to the N. Consequently, the result of transferring hydrogen directly to nitrogen was slightly very weak resulting from the frequency output (the first one is negative) given a quite low number by -252 (cm-1). Beside that, it was animated the molecule from the program and did not look like a H- transfer is going to N (Figure 3 (A)). That is because the strongly effect of methyl group located surrounding into two sides of nitrogen led not to... ... middle of paper ... ... The aim of this report was to compute the activation energy of the HALS molecule. Based on that , the transition state was not determine correctly while followed steps by using different format on it. Moreover, the energy of protonated nitrogen in the molecule was higher than where it was neutral. There also were different value in enthalpy of reaction with changing (R=H) level of theory and basis set. It can be suggested that changing the mechanism of HALS molecule can contribute stabilization obtaining transition state. 6.0 Acknowledgment I would like to thank my supervisor, Dr. Stephen Blanksby for the available advice and support he has given me in the writing of this report. I would also like to thank my demonstrator David Marshall for his encouraged and guidance in carrying out the transition state of my report.
Discussion and Conclusions: Interpreting these results have concluded that relative reactivity of these three anilines in order of most reactive to least reactive go; Aniline > Anisole > Acetanilide. Aniline, has an NH2 , the most active substituent , and adds to any ortho/para position available on the ring. This data is confirmed with the product obtained, (2,4,6 tribromoaniline, mp of 108-110 C). As for anisole, it has a strongly activating group attached, OMe an alkoxy group, and it added in two of the three available spots, both ortho. The results conclude: (2,4-Dibromoanisol mp 55-58 C ). Acetanilide has a strong activating group attached, acylamino group, but this group is large and the ortho positions are somewhat hindered so the majority of the product obtained added at the para position, results conclude: (p-bromoacetanilide mp 160-165 C). Since all the substituents attached to the aromatic rings were activators the only products able to be obtained were ortho/para products.
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.
Abstract: This week we experimentally determined the rate constant k for the reaction 2HCl (aq) +Na2S2O3 (aq) → S (s) + SO2 (aq) + H2O (l) + 2NaCl (aq). In order to do this the average reaction time was recorded in seconds during two trials. The data from the experiment shows this reaction is in the first order overall: rate=.47s-1 [HCl]0 [Na2S2O3]1. These findings seem to be consistent with the expected results
Experimental and Computation Vibration-Rotation Spectroscopy for Carbon Monoxide Through the Use of High-Resolution Infrared (IR) Spectra
In this experiment, four elimination reactions were compared and contrasted under acidic (H2SO4) and basic (KOC(CO3)3) conditions. The acid-catalyzed dehydration was done on 2-butanol and 1-butanol; a 2ᵒ and 1ᵒ alcohol, respectively. The base-induced dehydrobromination was performed on 2-bromobutane and 1-bromobutane; isomeric halides. The stereochemistry and regiochemistry of the four reactions were analyzed by gas chromatography (GC) to determine product distribution (assuming that the amount of each product in the gas mixture is proportional to the area under its complementary GC peak. The three butene products have been verified that they elute in the following order: 1-butene, trans-2-butene, and cis-2-butene.
Chemical kinetics is the study of rates of chemical processes with respect to reaction rates, result of differing variables, re-arrangement of atoms, formation and intermediates etc (Theodore L. Brown,2010)(Chung Chieh,2016). The study of chemical kinetics is one that is a major importance in chemical research. It is powerful research tool in determining the reaction mechanism of several different reactions in chemistry(The University of Sydney,2002).
This chemistry book report is focus on a book called “Napoleon's buttons: How 17 molecules changed history” by Penny Le Couteur and Jay Burreson. The publisher of this book is Tarcher Putnam, the book was published in Canada on 2003 with 17 chapters (hey the number match the title of the book!) and a total of 378 pages. The genre of this book is nonfiction. “Napoleon's Buttons” contain a fascinating story of seventeen groups of molecules that have greatly changed the course of history and continuing affect the world we live in today. It also reveal the astonishing chemical connection among some unrelated events, for example: Chemistry caused New Amsterdamers to be renamed New Yorkers and one little accident of detonating cotton apron in a minor housekeeping mishap lead to the development of modern explosives and the founding of the movie industry.
If under normal conditions, when the nucleophilic nitrogen attacks, it will attack the cyclohexanone. If under rigorous conditions, the nitrogen will attack 2-furaldehyde. This is due to the carbon on cyclohexanone being secondary (i.e. more stable) than the primary carbon of 2-furaldehyde. The trend observed is thermodynamic control seem to effect primary carbons, whereas, kinetic control seem to effect secondary carbons. Under thermodynamic control the intermediate seems the most unstable. The kinetic controlled intermediate seems the least unstable of the two.
Hydrogen is a tasteless, odorless, colorless gas. Hydrogen is found in group 1 and period 1 on the periodic table. Hydrogen is classified as a nonmetal on the periodic table. The symbol for hydrogen is represented by an H, its atomic number is 1, and its atomic weight is 1.0079. The hydrogen atom consists of one proton, which has a positive charge, and one electron, which has a negative charge. The term hydrogen comes from two Greek words meaning water-former. Henry Cavendish, an English scientist, discovered it in 1766. Named by Lavoisier, hydrogen is the most abundant of all elements in the universe. The sun and many other stars consist of mostly hydrogen. It is the third most abundant element on earth. It is estimated that hydrogen makes up more than 90% of all the atoms or three quarters of the mass of the universe. Hydrogen plays an important part in powering the universe though both the proton-proton reaction and carbon-nitrogen cycle. Hydrogen occurs in almost all organic compounds. Many of the compounds found in plant and animal tissues are organic. Production of hydrogen in the U.S. alone now amounts to about 3 billion cubic feet per year. Some of the methods that hydrogen is prepared by are steam on heated carbon, decomposition of certain hydrocarbons with heat, action of sodium or potassium hydroxide on aluminum, or displacement from acids by certain metals. Hydrogen may be condensed to a liquid that boils at -257.87°C and freezes at -259.14°C. Hydrogen ...
The computer model that was developed by three intellectual chemists is not only about chemistry. Without help from quantum physics and advanced computer technology, the computer would not have been created. These studies allowed the chemists to simulate small and large molecules. With this research information, it is arguable that the computer has become more important in the research of chemistry.
From the figure1, there is an activation energy which is a minimum kinetic energy that necessary for particles to be participating of the reaction. According to (Ltd., 2014)Occurrence of chemical reaction requires collision of particles which ha...
7- When describing the properties of JNJ 40279486, the authors highlight the selectivity of the compound over the hERG channel. Explain wh...
Chemical kinetics is a branch of chemistry which refers to chemical reactions with respect to reaction rates, effect of various variables, re-arrangement of atoms, formation of intermediates and much more (Chung Chieh, 2016).The importance of chemical kinetics is that it provides evidence for the mechanisms of chemical processes and provides a very detailed description of what happens to each molecule —which bonds are broken and formed, and how the three-dimensional shapes of the chemicals changes during the course of a chemical reaction (Keith J. Laidler, 2016).
I would like to express my gratitude to my supervisor Neha Hamilton for the useful comments, remarks and engagement through the learning process of this report. I would like to thank my loved ones, who have supported me throughout entire process, both by keeping me harmonious and helping me putting pieces together. I will be grateful forever for your love.
Sigfusson, Thorsteinn I. "Pathways to Hydrogen as an Energy Carrier." Philosophical Transactions: Mathematical, Physical and Engineering Sciences 365.1853 (2007): 1025-42. Web.