CHEM 2 Organic Chemistry Notes PDF

Summary

These notes cover the history of organic chemistry, from alchemy to modern concepts. They detail atomic structure, chemical bonding, and the different classes of organic compounds. The document also includes practice questions.

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CHEM 2 I-DVM Bicol University Guinobatan History of ORGANIC CHEMISTRY Hannah Angelie H. Olivarez TABLE OF CONTENTS 01 02 03 Pre-1600’s 1300’s-1500’s 1600’s-1700’s 04 05...

CHEM 2 I-DVM Bicol University Guinobatan History of ORGANIC CHEMISTRY Hannah Angelie H. Olivarez TABLE OF CONTENTS 01 02 03 Pre-1600’s 1300’s-1500’s 1600’s-1700’s 04 05 06 1800’s 1900’s 20th century 01 Pre-1600’s Time of Christ ALCHEMY The practice of alchemy led to a) processes for production of pure compounds b) invention of tools and laboratory apparatus beakers, flasks, funnels, crucibles, mortars and pestles; distillation still 02 1300’s-1500’s 1300’s-1500’s Actual fractionation of alcoholic distillates production of whisky and brandy. “Essence” of natural materials used by doctors for medical purposes leading to the isolation of relatively pure organic compounds; e.g. acetic acid from vinegar, formic acid from ants. 03 1600’s-1700’s Birth of chemistry as a science in Europe Torbern Bergman (1770) Distinguished between organic and inorganic compounds Torbern Bergman Definition Organic compounds Inorganic compounds Substances derived from substances derived from the animal and vegetable world; did the atmosphere and mineral not seem to obey the Law of Definite kingdom Proportions; could not be prepared not manipulated in the laboratory Hilaire Rouelle (1780) Isolated urea from human urine Antoine Lavoisier (1789) Table of elements (33 substances) Foundation of modern chemistry; said that organic compounds were composed of C, H, and sometimes N and P. Jons Jakob Berzelius (1789) Proponent of Vis vitalis theory (vitalistic theory): A vital force present in living organisms was responsible for the production of organic compounds; organic chemistry was defined as the chemistry of compounds from living organisms 04 1800’s Michel Chevreul (1816) Prepared soap by the reaction of alkali with animal fat; the soap could be acidified and separated into several pure organic compounds, the fatty acids. Friedrich Wöhler (1828) “I must tell you that I can make urea without requiring kidneys or even an animal, whether a human being or a dog. Ammonium cyanate is urea.” -first multi-step transformation; considered the father of organic chemistry William Brande (1848) “No definite line can be drawn between organic and inorganic chemistry... Any distinctions must for the present be merely considered matters of practical convenience calculated to further the progress of students.” Adolph Wilhelm Hermann Kolbe (1840’s) Acetic Acid Synthesis 19th Century 05 Birth of Organic Chemistry Edward Frankland (1852) Advanced the concept of valence (from Latin, meaning “power”) Stanislao Cannizzaro (1858) used Avogadro’s hypothesis to determine accurate molecular weights. A. Kekule & A. Cooper (1850-1860) use of structural formulas to propose tetravalency of carbon (w/ 4 affinity units) Emil Erlenmeyer (1850-1860) proposed multiple bonding, e.g. acetylene Kekule’s Dream Carbon chains can double back and form rings of atoms. J. van’t Hoff and J. LeBel: 3-D view of molecules 20th Century 06 (1916) Modern concepts of chemical bonding IONIC BONDING (W. Kossel, Ger.) COVALENT BONDING (G. N. Lewis, USA) QUANTUM MECHANICAL MODEL OF THE ATOM (Dirac & Heisenberg) Organic Chemistry Organic chemistry is the study of the chemistry of carbon compounds. Carbon is singled out because it has a chemical diversity unrivaled by any other chemical element. Its diversity is based on the following: 1. Carbon atoms bond reasonably strongly with other carbon atoms. 2. Carbon atoms bond reasonably strongly with atoms of other elements. 3. Carbon atoms make a large number of covalent bonds (four). Most organic chemicals are covalent compounds, which is why we introduce organic chemistry here. By convention, compounds containing carbonate ions and bicarbonate ions, as well as carbon dioxide and carbon monoxide, are not considered part of organic chemistry, even though they contain carbon. THANKS! Do you have any questions? [email protected] +639154045310 FB:Hannah Olivarez CREDITS: This presentation template was created by Slidesgo, including icons by Flaticon and infographics & images by Freepik 01 The practice of _______ led to processes for production of pure compounds. 02 An organic compound isolated from ants. 03 Substances derived from the animal and vegetable world. 04 Inorganic substances derived from the _____________ and mineral kingdom. 05 Urea was first isolated from what source? 06 He is known as the father of Organic Chemistry. 07 Michel Chevreul prepared soap from alkali and what? 08 “Valence” in Latin means _____. 09 Carbon chains can double back and form rings of atoms known as _______. 10 He dreamt of a snake eating its own tail. I-DVM Bicol University Guinobatan CHEM 2 Organic Chemistry Structure and Bonding Hannah Angelie H. Olivarez, RCh Table of contents 01 02 03 Atomic Structure Development of Describing Chemical The Nucleus, Orbitals, bonds: Valence Bond Chemical Bonding Electron Configurations Theory Theory and Molecular Bond Theory 04 05 Hybridization Drawing Chemical of N, O, P, S Structures What is organic chemistry, and why should you study it? Why should we study organic chemistry? Every living organism is made of organic chemicals. The proteins that make up your hair, skin, and muscles; the DNA that controls your genetic heritage; the foods that nourish you; and the medicines that heal you are all organic chemicals. Organic Chemistry mid-1700s mid-1800s Present the chemistry of there was no fundamental the study of carbon substances found in living difference between compounds organisms organic and inorganic compounds Why is carbon special? Because of its electronic structure and its consequent position in the periodic table. As a group 4A element, carbon can share four valence electrons and form four strong covalent bonds. carbon atoms can bond to one another, forming long chains and rings Carbon, alone of all elements, is able to form an immense diversity of compounds Carbon Not all carbon compounds are derived from living organisms, however. Modern chemists have developed a remarkably sophisticated ability to design and synthesize new organic compounds in the laboratory—medicines, dyes, polymers, and a host of other substances. 01 Atomic Structure The Nucleus Orbital Electronic Configuration The Nucleus The nucleus The nucleus consists of subatomic particles called neutrons, which are electrically neutral, and protons, which are positively charged. Because an atom is neutral overall, the number of positive protons in the nucleus and the number of negative electrons surrounding the nucleus are the same. The nucleus nevertheless contains essentially all the mass of the atom. Mass of Subatomic particles Relative Charge Relative Mass Proton 1 1.007 Neutron 0 1.009 Electron -1 5.486 x 10-4 Approximate size Atomic symbol Isotopes Atoms with the same atomic number but different mass numbers. Isotopes of Carbon Atomic Weight The weighted-average of an element’s naturally occurring isotopes Orbitals How are the electrons distributed in an atom? Quantum Mechanical Model The behavior of a specific electron in an atom can be described by a mathematical expression called a wave equation—the same type of expression used to describe the motion of waves in a fluid. The solution to a wave equation is called a wave function, or orbital, and is denoted by the lowercase Greek letter psi (ψ). Quantum Mechanical Model When the square of the wave function, ψ2, is plotted in three-dimensional space, an orbital describes the volume of space around a nucleus that an electron is most likely to occupy. For practical purposes we can set the limits by saying that an orbital represents the space where an electron spends 90% to 95% of its time. What do orbitals look like? There are four different kinds of orbitals, denoted s, p, d, and f, each with a different shape. Electron Shells The orbitals in an atom are organized into different layers around the nucleus called electron shells, which are centered around the nucleus and have successively larger size and energy. Different shells contain different numbers and kinds of orbitals, and each orbital within a shell can be occupied by two electrons. Subshell Number of orbitals per Level Max no. of Electrons s 1 2 p 3 6 d 5 10 f 7 14 Electron Levels p orbital d orbital f orbital Electronic Configuration The lowest-energy arrangement, or ground-state electron configuration, of an atom is a list of the orbitals occupied by its electrons. We can predict this arrangement by following three rules. Rules for Electronic Configuration Rule 1 Rule 2 Rule 3 Aufbau principle Pauli exclusion principle Hund’s rule The lowest-energy Only two electrons can If two or more empty orbitals of orbitals fill up first occupy an orbital, and equal energy are available, one they must have opposite electron occupies each with spins spins parallel until all orbitals are half-full Give it some thought… What is the ground-state electron configuration of each of the following elements: a. Oxygen b. Nitrogen c. Sulfur To be continued… Thanks! Do you have any questions? CREDITS: This presentation template was created by Slidesgo, and includes icons by Flaticon, and infographics & images by Freepik Please keep this slide for attribution Bicol University Guinobatan Organic Chemistry Classes of Organic Compounds Hannah Angelie H. Olivarez, RCh Table of contents Structure 01 Introduction 02 Determination Classical Methods Molecular 03 Spectroscopy 04 Functional Groups Definition Modern tools 05 Classes of Organic compounds Organic Compounds! Organic compounds typically consist of groups of carbon atoms covalently bonded to hydrogen, usually oxygen, and often other elements as well. 01 Introduction Organic Analysis Our understanding of organic molecules, their structure and the way they react, has been enhanced by organic analysis. History of Organic Analysis 1772-1777 1830 1831 1911 Lavoisier Jean Dumas Justus von Fritz Pregl Combustion Method for Liebig MIcroanalysis Experiments; analyzing organic Organic analysis using Identification of Nitrogen method microbalance elements (empirical formula) 02 Structure Determination Classical Methods Physical state, color, Physical observation clarity, density, odor Physical data MP, BP, solubility behavior, flammability Conversion to compound of known derivatization structure 03 Molecular Spectroscopy Molecular Spectroscopy Modern tools for structural determination: mass spectroscopy (ms) infrared spectroscopy (IR) nuclear magnetic resonance spectroscopy (NMR) ultraviolet spectroscopy (UV Mass Spectroscopy 04 Functional Groups Functional Groups 01 03 structural features the most polar or the common to a given most easily polarizable class of compounds portion(s) of the molecule; may include 02 heteroatoms (i.e., atoms other than an atom or a group of C or H) atoms that is responsible for the 04 characteristic chemical behavior of Compounds may range compounds from: Monofunctional difunctional polyfunctional 05 Classes of Organic Compounds Classes of Organic Compounds Functional Groups Functional Groups Functional Groups Functional Groups Functional Groups Functional Groups Functional Groups Functional Groups Functional Groups Examples 1. Alkyl halide 2. Amine (10) 3. Ketone 4. Aromatic hydrocarbon 5. Alkene 6. Carboxylic acid 7. Alcohol (20) 8. Amine (30) 9. Alkyne 10. Alkane Give it some thought… Principles of chemistry Molecules Atom Mercury is the closest planet Venus has a beautiful name to the Sun and the smallest and is the second planet from one in the Solar System—it’s a the Sun. It’s hot and has a bit larger than the Moon poisonous atmosphere Structure of matter Mars Venus Neptune Mars is actually a Venus also has extremely Neptune is the farthest extremely cold place high temperatures planet from the Sun Mercury Saturn Jupiter Mercury is the closest Saturn is a gas giant with Jupiter is the biggest planet to the Sun several rings planet of them all Awesome words “This is a quote, words full of wisdom that someone important said and can make the reader get inspired.” —Someone Famous A picture is worth a thousand words 500,000 Big numbers catch your audience’s attention 75% 100,000 Mars is actually a extremely Venus has extremely high cold place temperatures 50,000 25% Saturn is a gas giant and has Jupiter is the biggest planet several rings in the Solar System Chemistry in percentages Mars Saturn Neptune 25% 50% 95% Mars is actually an Saturn is a gas giant Neptune is an ice giant extremely cold place with several rings and a very big planet Desktop software You can replace the image on the screen with your own work. Just right-click on it and select “Replace image” Thanks! Do you have any questions? Please keep this slide for attribution CREDITS: This presentation template was created by Slidesgo, including icons by Flaticon, infographics & images by Freepik Bicol University Guinobatan CHEM 13 Organic Chemistry Isomerism Hannah Angelie H. Olivarez, RCh Learning Outcomes Introduction One of the interesting aspects of organic chemistry is that it is three-dimensional. A molecule can have a shape in space that may contribute to its properties. Molecules can differ in the way the atoms are arranged – the same combination of atoms can be assembled in more than one way. These compounds are known as isomers. Isomers Isomers are molecules with the same molecular formulas, but different arrangements of atoms. There are several different types of isomers which will be described and a flowchart (see figure on the right) can help you determine which type of isomers are present. Conformational isomers Conformational isomers of pentane. Structural isomers Structural isomers Stereo isomers Geometric (cis/trans) isomers Geometric (cis/trans) isomers Propene does not have a geometric isomer. Geometric Isomers Optical Isomers Enantiomers Two models that are mirror images and superimposable. Since they are superimposable, they are the same molecule and are not isomers. Enantiomers Your hands and some molecules are mirror images but are not superimposable. These pairs of molecules are called enantiomers. Chirality A chiral carbon has four unique groups attached to it. Diastereomers Diastereomers Thank you!

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