THINK In Multiple Dimensions. Crafted especially for you,these support materials will help you grasp the major concepts and learn organic chemistry. Student Solutions Manual SpartanModel:An Electronic Model by Jan William Simek Kit(CD,Guide,and 3-D glasses) by Warren J.Hehre 15BN-13:978-0-13-222044-6 I58N10:0-13-222044-X al and numerous ohnctcesasotwaeuio UPAC lenging exercises that volving structure nstrate danalysis,using the molecule p are of an acid-base re supports chemistry at the molecu summary map Organic Molecular Model Kit by Steve Darling S8N-13:978-0-13-233471-6 Framework Molecular SBN.10:0-13.233471-2 Model Kit Darling Models"contain various pieces used by georae brumlik to build atoms,bonds,and molecules.This 58N-13:9780-13-330076-5 model kit allows you to build molecules and 1SBN-10:0-13-330076-5 see the three-dimensional aspects of organic chemistry that can only be imagined on a model set enables user resent all wo-dimensional drawing. Prentice Hall Molecular Model cannot be built with the most expensive Kit for Organic Chemistry sets (i.e.,cyclopropane,cubane,etc.). he Pro mo qual stics a stu plast case for easy storage
THINK Crafted especially for you, these support materials will help you grasp the major concepts and learn organic chemistry. Student Solutions Manual by Jan William Simek ISBN-13: 978-0-321-59871-4 ISBN-10: 0-321-59871-7 The Solutions Manual contains complete solutions to all the problems, with helpful hints on how to approach each kind of problem. Appendix 1 of the Solutions Manual summarizes the IUPAC system of nomenclature. Appendix 2 reviews and demonstrates how acidity varies with structure in organic molecules, and how one can predict the direction of an acid-base equilibrium . Appendix 3 provides a sample of a reaction summary map. Organic Molecular Model Kit by Steve Darling ISBN-13: 978-0-13-233471-6 ISBN-1 0: 0-13-233471-2 Darling Models'" contain various pieces used to build atoms, bonds, and molecules. This model kit allows you to build molecules and see the three-dimensional aspects of organic chemistry that can only be imagined on a two-dimensional drawing. Prentice Hall Molecular Model Kit for Organic Chemistry ISBN-13: 978-0-205-08136-3 ISBN-1 0: 0-205-08136-3 The Prentice Hall molecular model set allows you to build space-filling and ball-and-stick models of organic molecules. The components in this kit are precision-tooled from quality plastics, are virtually indestructible, and come in a sturdy plastic case for easy storage. SpartanModel: An Electronic Model Kit (CD, Guide, and 3-D glasses) by Warren J. Hehre ISBN-13: 978-0-13-222044-6 ISBN-1 0: 0-13-222044-X SpartanModel'" puts chemistry at your fingertips. The workbook includes a software tutorial and numerous challenging exercises that help you solve problems involving structure building and analysis, using the tools included in the two pieces of Spartan software. SpartanModel Software supports teaching and learning organic chemistry at the molecular level. Extending the use of models in your chemistry course, SpartanModel provides 3-D construction and visualization of almost any chemical system. Framework Molecular Model Kit by George Brumlik ISBN-13: 978-0-13-330076-5 ISBN-1 0: 0-13-33007 6-5 This accurate, reasonably priced molecular model set enables users to represent all atoms having up to 12 electrons in their valence shells-including those which cannot be built with the most expensive sets (i.e., cyclopropane, cubane, etc.)
1 Introduction and Review The modern definition of organic chemistry is the chemistry of carbon compounds. 1-1 What is s The Origins of Organic atoms can he huilt un to form an endless variety of molecules it is this diversity of carbon compounds that provides the basis for life on Earth.Living creatures are Chemistry composed largely of complex organic compounds that serve structural,chemical, or the science the study of organisms and their natural products.Compounds such as sugar,urea,starch.waxes and plant oils were considered"organic,"and people accepted Vitalism,the belief that natural products needed a "vital force the study pound norgan be the nineteenth century.experiments sho ad that o organic compounds could be synthesized from inorganic compounds.In 1828,the German chemist Friedrich Wohler converted ammonium cyanate,made from ammonia and cyanic acid,to urea simply by heating it in the absence of oxygen. 0 NH:-OCN heat H.N-C-NH, Urea had always come from living organisms and was presumed to contain the vital force,yet ammonium cyanate is inorganic and thus lacks the vital force.Some nds reactio Since Vitalism was disproved in the early nineteenth century,you'd think it would be extinct by now.And you'd be wrong!Vitalism lives on today in the minds of those who believe tha natura 7ae 1
1 Introduction and Review px py px pz py pz 1 1-1 The Origins of Organic Chemistry The modern definition of organic chemistry is the chemistry of carbon compounds. What is so special about carbon that a whole branch of chemistry is devoted to its compounds? Unlike most other elements, carbon forms strong bonds to other carbon atoms and to a wide variety of other elements. Chains and rings of carbon atoms can be built up to form an endless variety of molecules. It is this diversity of carbon compounds that provides the basis for life on Earth. Living creatures are composed largely of complex organic compounds that serve structural, chemical, or genetic functions. The term organic literally means “derived from living organisms.” Originally, the science of organic chemistry was the study of compounds extracted from living organisms and their natural products. Compounds such as sugar, urea, starch, waxes, and plant oils were considered “organic,” and people accepted Vitalism, the belief that natural products needed a “vital force” to create them. Organic chemistry, then, was the study of compounds having the vital force. Inorganic chemistry was the study of gases, rocks, and minerals, and the compounds that could be made from them. In the nineteenth century, experiments showed that organic compounds could be synthesized from inorganic compounds. In 1828, the German chemist Friedrich Wöhler converted ammonium cyanate, made from ammonia and cyanic acid, to urea simply by heating it in the absence of oxygen. Urea had always come from living organisms and was presumed to contain the vital force, yet ammonium cyanate is inorganic and thus lacks the vital force. Some chemists claimed that a trace of vital force from Wöhler’s hands must have contaminated the reaction, but most recognized the possibility of synthesizing organic compounds from inorganics. Many other syntheses were carried out, and the vital force theory was eventually discarded. Since Vitalism was disproved in the early nineteenth century, you’d think it would be extinct by now. And you’d be wrong! Vitalism lives on today in the minds of those who believe that “natural” (plant-derived) vitamins, flavor compounds, etc. are somehow different and more healthful than the identical “artificial” (synthesized) compounds. NH4 OCN heat H2N9C9NH2 O urea (organic) ammonium cyanate (inorganic) The Jarvik 7 artificial heart, composed largely of synthetic organic materials. WADEMC01_0131478710.QXD 11/8/04 7:56 AM Page 1
2 Chapter 1:Introduction and Review As chemists,we know that plant-derived com 实 ompounds synthesized from aL平pO0op3 zsaulu&s nua为 naly is len htve hiah i4c content and are plant-derived.Such a sophistic ch f vor to thi still distin guished from inorganic compounds.The distinctive feature pounds is that hey all contain one or more carbon atoms.Still,not all carbon compounds are organic: substances such as diamond,graphite,carbon dioxide,ammonium cyanate,and sodium of nicotine's efferts is bonate are derived from minerals and have typical inorganic properties.Most of the increase concentration reward em. of this we are nourished by and reinforces the need to smoke. the n in our li ers.and the DNA in the nuclei of ou compounds.ur bodies are also regulated and defended by complex organic compounds icotin carmine morphine CH2OH OH HCOH O. glucose COOH 0 OH HO OH OH 0H0 mples of o nisms.Tobacc addictive alkaloid.Rose hips contain vitami nies contain morphine,a pain-relieving.addictive alkaloid. Chemists have learned to synthesize or simulate many of these complex mole ee prodcs serve sdrugs meacnes.Pasnc and fibers.M ny o es in me cine are actu ces I ugs are the goo propertie organic chemi New syn ties(highly addictive). s the study of c unds de ”and now gone full t gives us the drugs and materials we need to save or replace those organs
morphine O OH OH H N CH3 2 Chapter 1: Introduction and Review As chemists, we know that plant-derived compounds and the synthesized compounds are identical. Assuming they are pure, the only way to tell them apart is through dating: Compounds synthesized from petrochemicals have a lower content of radioactive and appear old because their has decayed over time. Plant-derived compounds are recently synthesized from in the air. They have a higher content of radioactive Some large chemical suppliers provide isotope ratio analyses to show that their “naturals” have high content and are plant-derived. Such a sophisticated analysis lends a high-tech flavor to this twenty-first-century form of Vitalism. Even though organic compounds do not need a vital force, they are still distinguished from inorganic compounds. The distinctive feature of organic compounds is that they all contain one or more carbon atoms. Still, not all carbon compounds are organic; substances such as diamond, graphite, carbon dioxide, ammonium cyanate, and sodium carbonate are derived from minerals and have typical inorganic properties. Most of the millions of carbon compounds are classified as organic, however. We ourselves are composed largely of organic molecules, and we are nourished by the organic compounds in our food. The proteins in our skin, the lipids in our cell membranes, the glycogen in our livers, and the DNA in the nuclei of our cells are all organic compounds. Our bodies are also regulated and defended by complex organic compounds. 14C 14C. CO2 14C 14C 14C N N CH3 nicotine OH O CH2OH HO HCOH H O vitamin C glucose OH OH COOH OH O O HO carmine Four examples of organic compounds in living organisms. Tobacco contains nicotine, an addictive alkaloid. Rose hips contain vitamin C, essential for preventing scurvy. The red dye carmine comes from cochineal insects, shown on prickly pear cactus. Opium poppies contain morphine, a pain-relieving, addictive alkaloid. Chemists have learned to synthesize or simulate many of these complex molecules. The synthetic products serve as drugs, medicines, plastics, pesticides, paints, and fibers. Many of the most important advances in medicine are actually advances in organic chemistry. New synthetic drugs are developed to combat disease, and new polymers are molded to replace failing organs. Organic chemistry has gone full circle. It began as the study of compounds derived from “organs,” and now it gives us the drugs and materials we need to save or replace those organs. One of the reasons chemists synthesize derivatives of complex organic compounds like morphine is to discover new drugs that retain the good properties (potent painrelieving) but not the bad properties (highly addictive). One of nicotine’s effects is to increase the concentration of dopamine, a chemical in the brain’s reward system. Release of this chemical makes smokers feel good and reinforces the need to smoke. WADEMC01_0131478710.QXD 11/8/04 7:56 AM Page 2
1-2 Principles of Atomic Structure 3 Before we begin our study of organic chemistry.we must review some basic prin-1-2 ciples.Many of these concepts of atomic and molecular structure are crucial to your understanding of the structure and bonding of organic compounds. Principles of Atomic Structure 1-2A Structure of the Atom " ed cloud of electrons sitive charge on the p h e he ma t n c moa e e ounding the nucleus (Figure 1-1).Protons and neutrons have similar nucleus,but it is the electrons that take part in chemical bonding and reactions acn element is leus (the atom eutrons is usually sin o the num of ons may or protons (nn) ind of carhon atom has siy roton mas thesm t protonsad euro)is1.and we writesymbol C About 1% ▲Figure1-1 of carbon atoms have seven neutrons:the mass number is 13.written ic atomic su cture.An atom has fraction of carbon atoms have eight neutrons and a mass number of 14.The surrounded by a cloud of electrons. material 000 years 1-2B Electronic Structure of the Atom An element's chemical properties are determined by the number of protons in the nucleus and the corresponding number of electrons around the nucleus.The electrons form bonds and determine the structure of the resulting molecules.Because they are the e ave mo liKe wa eoamclelarefond orbitals. e n the electron in a particular part of the orbital.An orbital,then,is an allowed energy state for an electron.with an associated probability function that defines the distribution of electron density in space. est. A n n th by a principal quantum numb estce5gDeToses nd can hold n iodic table indicating that their electrons are found in the first two electron shells.The first shel (n=1)can hold two electrons,and the second shell (n=2)can hold eight. The st electron she ell contains just the 1s orbital.All s orbitals are spherically meaning tha they are no ional ly a runc Th. sity c 19 m the s The le ht he ir ined as a cotton boll.with the cottonseed at the middle representing the nucleus.The density of the cotton is highest nearest the seed,and it becomes less dense at greater distances trom this "nucleus The second ele ctron shell ts of the 2s and 2p orbitals.The 2s orbital is spher me the Is orbi lle
cloud of electrons nucleus (protons and neutrons) Á Figure 1-1 Basic atomic structure. An atom has a dense, positively charged nucleus surrounded by a cloud of electrons. 1-2 Principles of Atomic Structure 3 1-2 Principles of Atomic Structure Before we begin our study of organic chemistry, we must review some basic principles. Many of these concepts of atomic and molecular structure are crucial to your understanding of the structure and bonding of organic compounds. 1-2A Structure of the Atom Atoms are made up of protons, neutrons, and electrons. Protons are positively charged and are found together with (uncharged) neutrons in the nucleus. Electrons, which have a negative charge that is equal in magnitude to the positive charge on the proton, occupy the space surrounding the nucleus (Figure 1-1). Protons and neutrons have similar masses, about 1800 times the mass of an electron. Almost all the atom’s mass is in the nucleus, but it is the electrons that take part in chemical bonding and reactions. Each element is distinguished by the number of protons in the nucleus (the atomic number). The number of neutrons is usually similar to the number of protons, although the number of neutrons may vary. Atoms with the same number of protons but different numbers of neutrons are called isotopes. For example, the most common kind of carbon atom has six protons and six neutrons in its nucleus. Its mass number (the sum of the protons and neutrons) is 12, and we write its symbol as About 1% of carbon atoms have seven neutrons; the mass number is 13, written A very small fraction of carbon atoms have eight neutrons and a mass number of 14. The isotope is radioactive, with a half-life (the time it takes for half of the nuclei to decay) of 5730 years. The predictable decay of is used to determine the age of organic materials up to about 50,000 years old. 1-2B Electronic Structure of the Atom An element’s chemical properties are determined by the number of protons in the nucleus and the corresponding number of electrons around the nucleus. The electrons form bonds and determine the structure of the resulting molecules. Because they are small and light, electrons show properties of both particles and waves; in many ways, the electrons in atoms and molecules behave more like waves than like particles. Electrons that are bound to nuclei are found in orbitals. The Heisenberg uncertainty principle states that we can never determine exactly where the electron is; nevertheless, we can determine the electron density, the probability of finding the electron in a particular part of the orbital. An orbital, then, is an allowed energy state for an electron, with an associated probability function that defines the distribution of electron density in space. Atomic orbitals are grouped into different “shells” at different distances from the nucleus. Each shell is identified by a principal quantum number n, with for the lowest-energy shell closest to the nucleus. As n increases, the shells are farther from the nucleus, higher in energy, and can hold more electrons. Most of the common elements in organic compounds are found in the first two rows of the periodic table, indicating that their electrons are found in the first two electron shells. The first shell can hold two electrons, and the second shell can hold eight. The first electron shell contains just the 1s orbital. All s orbitals are spherically symmetrical, meaning that they are nondirectional. The electron density is only a function of the distance from the nucleus. The electron density of the 1s orbital is graphed in Figure 1-2. Notice how the electron density is highest at the nucleus and falls off exponentially with increasing distance from the nucleus. The 1s orbital might be imagined as a cotton boll, with the cottonseed at the middle representing the nucleus. The density of the cotton is highest nearest the seed, and it becomes less dense at greater distances from this “nucleus.” The second electron shell consists of the 2s and 2p orbitals. The 2s orbital is spherically symmetrical like the 1s orbital, but its electron density is not a simple exponential function. The 2s orbital has a smaller amount of electron density close to the nucleus. 1n = 12 1n = 22 n = 1 14C 14C 13C. 12C. WADEMC01_0131478710.QXD 11/8/04 7:56 AM Page 3
4 Chapter 1:Introduction and Review distance 一dithe Figure 1-2 nucleus on de off exponentially with increasing in any direct Most of the electron density is farther away.beyond a region of zero electron density called a node.Because most of the 2s electron density is farther from the nucleus than that of the 1s.the 2sorbital is higher in energy.Figure 1-3 shows a graph of the 2s orbital. e seco lso contains three s,one orie each f the three spa e00 are slightly higher in enery than the 2s beca ause the ae e location of the electron in a 2p orbital is farther from the nucleus.Eachp orbital consists of two lobes one on either side of the nucleus.with a nodal plane at the nucleus.The nodal plane is aflat (planar)regifthe c with zero clecro .so they e erate orbi ows the electron density node nucleus ram of the 2s atomic orbital.The 2s orbital has a small nod s hu electron density is farther from the
4 Chapter 1: Introduction and Review electron density distance from the nucleus distance 1s » nucleus Figure 1-2 Graph and diagram of the 1s atomic orbital. The electron density is highest at the nucleus and drops off exponentially with increasing distance from the nucleus in any direction. » Figure 1-3 Graph and diagram of the 2s atomic orbital. The 2s orbital has a small region of high electron density close to the nucleus, but most of the electron density is farther from the nucleus, beyond a node, or region of zero electron density. electron density node node distance from the nucleus distance from the nucleus node node 2s nucleus Most of the electron density is farther away, beyond a region of zero electron density called a node. Because most of the 2s electron density is farther from the nucleus than that of the 1s, the 2s orbital is higher in energy. Figure 1-3 shows a graph of the 2s orbital. In addition to the 2s orbital, the second shell also contains three 2p atomic orbitals, one oriented in each of the three spatial directions. These orbitals are called the the and the according to their direction along the x, y, or z axis. The 2p orbitals are slightly higher in energy than the 2s, because the average location of the electron in a 2p orbital is farther from the nucleus. Each p orbital consists of two lobes, one on either side of the nucleus, with a nodal plane at the nucleus. The nodal plane is a flat (planar) region of space, including the nucleus, with zero electron density. The three 2p orbitals differ only in their spatial orientation, so they have identical energies. Orbitals with identical energies are called degenerate orbitals. Figure 1-4 shows the shapes of the three degenerate 2p atomic orbitals. 2pz 2p , y px, ,2 WADEMC01_0131478710.QXD 11/8/04 7:56 AM Page 4