CHEM305 Organic Chemistry I Introduction Dr. Ralph C. Gatrone Department of Chemistry and Physics Virginia State University Fall, 2009 Fall, 2009 1 Objectives • Discuss syllabus • Discuss course requirements • Review general chemistry Fall, 2009 2 Organic Chemistry I CHEM305-01-081 • Office Hours – T: 2:00 – 5:00 and W: 9:00 – 12:00 – by appointment (524-5762) • Office: HM239Nb • Email: rgatrone@vsu.edu • I only respond to an email address that ends in @vsu.edu Fall, 2009 3 Organic Chemistry 1 Course Description • • • • • • Survey of compounds composed of carbon Nomenclature Structure Physical properties Reactions Mechanisms Fall, 2009 4 Course Emphasis • Organic reactions • Molecular orbital theory • Organic Mechanisms • Molecules of biological importance • Critical thinking skills • Skills necessary to do well on • MCAT, PCAT, OAT, DAT, others Fall, 2009 5 Roles • My role • Professor • Guide • Your Role • Student • Understand the material! Fall, 2009 6 The Teacher versus the Professor • A teacher conveys information to provide a • • • student with certain skills and a knowledge base. A professor professes the truth about their area of expertise while providing the student with the skills to accept or refute that truth. Ideally the professor imparts a sense of wonder such that the student will push the limits of our understanding. The student develops the necessary skills and knowledge base to succeed. Fall, 2009 7 Requirements and Prerequisites • • • • Course Materials Text: Organic Chemistry A Biological Approach, John McMurry You must purchase the book. A study guide is available. It is not required. • Prerequisites • CHEM101 or 111, 102 or 112 • Associated Laboratories • • • • • • Foundation from General Chemistry Quantum mechanics Solution chemistry Acid Base Chemistry Kinetics Thermodynamics Fall, 2009 8 Prerequisites are critical • You must have passed these courses • If you have not passed these courses • You must drop the course immediately • If not sooner! Fall, 2009 9 Homework • Every problem in the Text is recommended. • However, – – – – They will not be graded. They will not be collected. They will not be discussed in class. They are available to you to determine if you understand the material. – If you choose not to do the problems it is nearly a guarantee that you will not pass this class. Fall, 2009 10 Evaluation • Test 1: Chapters 1 – 6 • Test 2: Chapters 1 – 7 • Test 3: Chapters 1 – 10 • Final Exam Chapters 1 – 10 100pts 100pts 100 pts 200pts • Total Possible 500pts Fall, 2009 11 Evaluation – Grade Calculation • Final Grades will be computed: – Earned Points >450 400 – 449 325 – 399 250 – 324 <249 Fall, 2009 Final Grade A B C D F 12 Extra Credit • No extra credit will be given. • If you follow my instructions • You will not need it. • If you do not follow these instructions • It will not help. Fall, 2009 13 Special Consideration • • • • • • • • • • • • • Grades are earned. Grades are not awarded Grades cannot be negotiated. Grades cannot be influenced by factors such as: I like you You like me (rare circumstance) I feel sorry for you You are a nice person in good standing with the university. You will lose a scholarship You will forfeit some tuition reimbursement A previously excellent GPA will be ruined You will be sent back to a repressive country You will not graduate on time! Fall, 2009 14 Attendance • • • • • • • • Assumption: you are adult students Attendance in lecture is expected Do not ask me to re-lecture material you missed. Regardless of your excuse for missing class you made a choice not to attend and you are responsible for the material you missed. Attendance at examinations is required. A missed examination will receive a zero. No excuse will be accepted. A missed final exam will receive a zero. Fall, 2009 15 A Word on Examinations • Examinations will consist of several short answer • • questions. The final examination will contain 100 multiple choice questions. These will be similar to the questions encountered on the MCAT, DAT, PCAT, etc. Fall, 2009 16 A Word on the Final Exam • The final exam is scheduled by the university. • This schedule minimizes conflicts between • • rooms and courses. If the scheduled date and time happens to be inconvenient for you, please withdraw from the course today. There is no excuse that I will accept that would permit you take the exam early. Fall, 2009 17 Communication in Class • Turn your cell phone off. • Turn your desire to communicate with anyone • • but me off. An offending cell phone (includes text messaging) will result in the cancelation of that day’s lecture. If a class is cancelled because of an offensive cell phone the class will be held responsible for the material not covered me by in that class. Fall, 2009 18 Expectations - Students • • • • • • • • A professional student is expected to attend class purchase course materials study do the homework be prepared for class be prepared for tests do well Fall, 2009 19 Expectations - Faculty • I am expected to • attend class • prepare lecture materials • present lecture materials • prepare and grade tests • be available for outside consultation • keep accurate records Fall, 2009 20 Important Note • I am not expected to • Provide extra credit • Negotiate grades Fall, 2009 21 Doing Well • • • • • • • • • • • Read the chapter before lecture Attend lecture Take notes Do not rely on copies of Power Points Re-read the chapter after lecture Review lecture notes daily Rewriting the lecture notes is strongly suggested Keep, maintain, and study note cards Do homework problems. Form a study group Learn the functional groups Fall, 2009 22 The Functional Groups • • • • • • • • Families of Organic Compounds Millions of compounds Thousands discovered every year Task of knowing the chemistry would be overwhelming However, compounds can be grouped into families Based upon common structural features Suggests common reactivity You must know the Table of Functional Groups provide by me. Others will come along during the semester • This course is a survey the chemistry and properties of organic compounds • It is taught as a tour of the functional groups Fall, 2009 23 Functional Groups R R CH3 alkane X CH2 alkyl R R halide R alkene alkyne (X = F, Cl, Br, I R OH R R S R R S O sulfoxide phenol Fall, 2009 R SH sulfone R S R sulfide thiol O O O OH R ether alcohol arene O R R S OH O sulfonic acid 24 Functional Groups O O H R R O R R carboxylic acid R carboxylic acid chloride carboxylic acid anhydride O O R R Cl R O O O OH R ketone aldehyde O O ester H3C R NH2 amide N nitrile Fall, 2009 25 Wow! • That’s a lot of stuff to learn and you expect me to know it. • Do you believe that this is the only course I am taking? • This is an important question which we must answer! • You may not like the answer. Fall, 2009 26 Is this the only course I am taking? • • • • • • • • • YES Time invested = Desired grade Average professional – 60 hours/week Professional student ~18 hours/week in class 60 – 18 = 42 42hours/6 days = 7 hours per day Or approximately 2 hours/class Time invested = Desired grade Fall, 2009 27 Why? • Your Role: • The job of understanding the material is yours. • • • • • My Role: Guide I’ve been here. I’ve done it. I have the t-shirt (at least a C and a B in Organic I and II) • Best advice I can give you! • If you choose to study organic chemistry like other courses you have taken you might do well, but the odds are against it. Fall, 2009 28 Major Complaint • I can’t possibly learn this stuff. • I can’t learn all of those functional groups. • Why? Again you aren’t going to like the answer. • You don’t study enough. • Average of 42 hours per week beyond your class is expected • To obtain a C - the average grade Fall, 2009 29 Comment • I have never met a student who could not learn organic chemistry. • Some students might make 3 or more attempts to learn the material. • The number of attempts required is dependent upon you. Fall, 2009 30 Why don’t students learn? • Fear • Wrong attributes • Lack of confidence • Too much confidence • Failure to follow through • Paralysis due to personal/family problems • Failure to imitate best practices • Lack of balance of social and academic life • Failure to appreciate delayed gratification. Fall, 2009 31 Guide’s Role You Fall, 2009 32 Study Sessions • Study sessions will be held • Tuesday and Thursday • 7 – 8 AM • They are not mandatory • The first one will be held next Tuesday. • The last one the first time I enter the room and no one is here. Fall, 2009 33 Important Goals of Organic Chemistry • Prepare you for MCAT, DAT, OAT, etc. • Assist in your transition from a student to a scholar. • This is done by – Mastery of content – Application of theoretical constructs – Developing skills to critique, analyze, research, discuss, write, and present. Fall, 2009 34 What is the minimum I need to do to get out of here? • Depends, what grade do you want? • W, F, or D – Attend class irregularly – Study just before each test – Rely upon your memory • C, B, or A – – – – – – – Never miss class Read the chapter before and after class Review lecture notes daily Study 2 hours per day, 6 days per week Make and use note cards Do all assigned homework problems See me for assistance early and often Fall, 2009 35 Why Study Organic Chemistry? • • • • • • • • • • Required for Major I will never need it. Required for Major I might need it someday. Elective I will certainly never need it. Best course on campus. Best instructor on campus Only class available at this forsaken time Need to lower my GPA. Fall, 2009 36 Who studies Organic Chemistry? • • • • • • • • • Chemistry Biology Pre-medicine Pre-dentistry Pre-pharmacy Animal Science Pre-veterinarian Nutrition Other programs not offered at VSU also require organic chemistry. Fall, 2009 37 A Common Thread • Sciences • Scientists do science • Scientists do NOT do sloppy work • Sloppy scientists fulfill Darwin’s principles! Fall, 2009 38 Some More Important Questions • • • • • • Is drop/add over? Are there any other instructors available? When is the last day to withdraw? What is the minimum I need to pass? What is organic chemistry? Before we start, let’s review some general chemistry concepts that are important for us because organic chemistry depends upon a fundamental understanding of general chemistry Fall, 2009 39 Important Note • If you decide to withdraw from the lecture • at any point in the semester, • You must withdraw from the laboratory! • Let’s review General Chemistry! Fall, 2009 40 Review of General Chemistry • • • • • • • • • • • • • To be here you met the pre-requisites. You have taken General Chemistry I and II. You have learned the following The Periodic Table Structure of the atom and electron configuration Lewis dot structures and bonding Basic chemical nomenclature Stoichiometry Energy and chemical reactions Chemical equilibrium, acids, bases Thermodynamics and basic kinetics Assumption for Organic Chemistry I You received an A in General Chemistry I and II. Fall, 2009 41 Review of General Chemistry • • • • • • • • • Nucleus Orbitals Electronic Configuration Chemical Bonding Ionic and Covalent Hybridization of Carbon’s Orbitals sp3, sp2, and sp hybridization Molecular Orbital Theory Formation of C-C sigma and pi bonds Fall, 2009 42 Review of General Chemistry • Electronegativity • F is the most electronegative atom • Electronegativity decreases down group • Electronegativity decreases right to left • Polar covalent bonding • Dipole moments • Formal Charge Fall, 2009 43 Review of General Chemistry • Review Resonance • Consider two structures • Acetate ion and Benzene Fall, 2009 44 Acetate Ion O O O • • • • O Two line structures are possible C=O and C-O bonds However, both C-O bonds are 127pm C=O is 120pm and C-O is 135pm Fall, 2009 45 Benzene • Two possible line structures • Neither is correct • C-C bonds in benzene are all 139pm • C-C bond is 154pm and C=C is 134pm • Problem encountered • Drawing these molecules • True structure can’t be drawn Fall, 2009 46 Drawing these Structures • We cannot draw the true structure • Therefore, we invoke idea – • resonance • Individual structures are resonance hybrids of true structure • We cannot draw the true structure Fall, 2009 47 Resonance Structures Resonance Hybrids O O O Fall, 2009 O 48 Resonance Guidelines • Individual resonance forms are not real • Resonance forms differ only in placement of electrons (pi or non-bonding) • Resonance forms do not have to be equivalent • Resonance forms obey valence rules • Hybrid is more stable than resonance forms Fall, 2009 49 Review of Acids and Bases • Two Definitions of Acids and Bases • Bronsted-Lowry • Lewis Fall, 2009 50 Bronsted – Lowry • Acid donates a proton • Base accepts a proton • Consider following reaction: HA + HOH H3O+ + A[H3O+] [A-] Keq = Fall, 2009 [HA] [HOH] 51 In dilute solution • [HOH] = 55.5M, nearly constant • Therefore, define the acidity constant HA + HOH H3O+ + A[H3O+] [A-] [HOH] Keq = [HA] [H3O+] [A-] Ka = Fall, 2009 [HOH] Keq = [HA] 52 Acid Strength HA + HOH H3O+ + A- Strong acids – equilibrium is to the right Ka is large Weak acids – equilibrium is to the left Ka is small Range of values is 1015 (strongest) to 10-60 (weakest) Fall, 2009 53 pKa Values • • • • • • • • pKa = -logKa Values range -7 (strongest) to 60 (weakest) As strength of acid increases Strength of base decreases HCl pka = -7 (a strong acid) Conjugate base: Cl- is very weak H-CH3 pKa = 60 (a weak acid) Conjugate base CH3- is very strong Fall, 2009 54 A Few pKa Values (learn this list as we will add to it) • EtOH • HOH • HCN • HOAc • Phosphoric Acid • Nitric Acid • HCl Fall, 2009 16 15.7 9.3 4.8 2.2 -1.3 -7 55 pKa Values • Learn values given in Table 2.3 (p 52) • Use these values to predict acid base reactions • Consider the following: HOAc + NaOH NaOAc + HOH Which is the stronger acid? pKa of HOAc = 4.76 pKa of HOH = 15.7 (conjugate acid of NaOH) HOAc = stronger acid than HOH, HO- = stronger base than AcOReaction proceeds to the right. Fall, 2009 56 Lewis Acids and Bases • Lewis Acids – accept an electron pair • Lewis Bases – donate an electron pair • The electron pair ends up shared by the acid-base as a covalent bond Fall, 2009 57 Lewis Acids • The Lewis definition of acidity includes metal cations • such as Mg2+ • Neutral Group 3A compounds • such as BF3 and AlCl3 • Neutral transition-metal compounds • such as TiCl4, FeCl3, ZnCl2, and SnCl4 • The combination of a Lewis acid and a Lewis base can shown with a curved arrow from base to acid Fall, 2009 58 Lewis Bases • Donate an electron pair • Molecules must contain an electron pair Fall, 2009 59 Lewis Acids and Bases • H+ is a Lewis acid • Accepts electron pair from water • Hydronium ion (H3O+) • Water is a Lewis base • Donates electron pair to the proton Fall, 2009 60 Illustration of Curved Arrows in Following Lewis Acid-Base Reactions Fall, 2009 61 Review of General Chemistry • Our review of general chemistry is done. • We have also covered Chapters 1 and 2 in • Organic Chemistry: A Biological Approach by John McMurry • Now, we can ask • What is organic chemistry? • Why am I studying this course? Fall, 2009 62 Organic Chemistry • is the study of the chemistry of compounds that contain carbon. • Carbon is a unique element in the Periodic Table in that • (1) it likes to bond to itself and • (2) The number of carbon atoms that can be bonded in a chain appear to be limitless. Fall, 2009 63 Organic Chemistry and Biology • Biological revolution • Biotechnological advances – Unprecedented scale – Foundation is organic chemistry • All organic molecules contain Carbon • 99% of 26 million molecules contain C • Possible because of Carbon’s electronic structure Fall, 2009 64 Questions to consider in CHEM305 • Why do organic molecules have certain • • • properties? Why do certain reactions occur? Why do other reactions not occur? What drives these processes? • Can we predict the presence or absence of • certain properties? Can we make new materials with other desired properties? Fall, 2009 65 Biological Organic Chemistry • • • • • • • • Know what and why something happened Molecular level Understanding is based on foundation Bonding Bond polarity Acid base behavior Hydrogen bonding Organic chemistry depends upon a fundamental understanding of general chemistry Fall, 2009 66