Presentation on theme: "ORGANIC CHEMISTRY Organic chemistry is the study of carbon chemistry and the compounds of carbon. Majority of chemical compounds on earth are organic."— Presentation transcript:
1ORGANIC CHEMISTRYOrganic chemistry is the study of carbon chemistry and the compounds of carbon.Majority of chemical compounds on earth are organic.The main elements involved in organic chemistry are C, H, O, N, HC = hydrocarbonOrganic chemistry reminds us of plants and animals but is not limited to such.Natural medicines: penicillian, cortisone, streptomycinManmade medicines: novocaine, sulfa drugs, aspirin.Natural textile fibers: nylon, dacron, lytex, rayonPolymers: saran, teflon, styrofoam, plastics, polyethylene, PBC’s
2FUNDAMENTAL ASPECTS OF CARBON CARBON WILL HAVE 4 COVALENT BONDSNITROGEN WILL HAVE 3 COVALENT BONDSOXYGEN WILL HAVE 2 COVALENT BONDSHYDROGEN WILL HAVE 1 COVALENT BONDREMEMBER TO MAKE SURE THESE ATOMSALWAYS HAVE THE ABOVE # OF BONDS
4BONDING IN ORGANIC CHEMISTRY 1. Carbon forms four covalent bonds. Carbon has either 4 attached groups (single bonds), or three attached groups (two single bonds and a double), or two attached groups (both double bonded or one single plus one triple).H H H H HH - C - H H - C - C - H C = C H - CC - Hmethane ethane ethene ethyne2. Nitrogen forms three covalent bonds and has one unshared pair of electrons. The bonds may either be three singles, or one single plus a double, or a triple bond.H - N - H H - O - N = O H - C N N N:Hammonia nitrous acid hydrogen cyanide nitrogen molecule
5BONDING IN ORGANIC CHEMISTRY 3. Oxygen forms two covalent bonds and has two unshared pairs of electrons. The bonds may either be two singles or one double.H :O: H :O: . .H - O - H H - C - .O. - H H - C - H H - C - C - .O. - H H Hwater methanol methanal acetic acid(methyl alcohol) (formaldehyde)Hydrogen forms one covalent bond and it is always single bonded.SATURATED: a hydrocarbon in which all carbon atoms are bonded to the maximum number of hydrogen atoms. There are no carbon-carbon double or triple bonds.UNSATURATED: a hydrocarbon which contains double or triple carbon-carbon bonds, the compound does not have the maximum number of hydrogen atoms.
6ISOMERSSTRUCTURAL - compounds with the same molecular formula but different structures.C5H12 - Structural HH - C - HH H H H - C - H H - C - C - C - H H H H H H H H H H H H - C - C - C - C - C - H H - C - C - C - C - H H - C - H H H H H H H H H H HPentane, b.p. 36° C Methylbutane, b.p. 28° C 2,2-Dimethylpropane, b.p. 9.5°CFractional DistillationN - butane MP = -138ºC BP = -.5ºCisobutane MP = -160ºC BP = ºCbranched boils at higher BP, requires more energy to boil.
7GEOMETRIC - different orientation of ligands in space C2H2Br2 ISOMERSGEOMETRIC - different orientation of ligands in spaceC2H2Br2Br Br H BrC = C C = CH H Br Hcis trans
8SHAPE, GEOMETRY, STRUCTURE Since Organic chemistry is limited to a small number of elements, why are there so many molecules and compounds possible?Structure & geometry are very important. Remember molecules exist in 3-D and Chem Rx occur because the approach is easiest (requires less energy) - use molecules to show difficulty of approach (steric hindrance)Different geometry, shape or structure will give molecules different physical or chemical properties.Most common geometry for carbon compounds:Linear, trigonal planar, tetrahedral, cycloStability can be demonstrated by using models and feeling the amount of stress needed to make the model.
9ORGANIC CHEMISTRY - THE CHEMISTRY OF CARBON # of carbon name exampleatoms1 Meth Methane CH42 Eth Ethane C2H63 Prop Propane C3H84 but Butane C4H105 pent pentane C5H126 hex hexane C6H147 hept heptane C7H168 oct octane C8H189 non nonane C9H2010 dec decane C10H22
10THE FIRST TEN CONTINUOUS-CHAIN ALKANES Name Molecular formula Number ofpossible isomersMethane CHEthane C2HPropane C3HButane C4HPentane C5HHexane C6HHeptane C7HOctane C8HNonane C9HDecane C10H
11Physical Properties of Selected Alkanes MOLECULAR MELTING BOILING DENSITY ATNAME FORMULA POINT (°c) POINT (°C) °C (g/mL)Methane CH (Gas)Ethane C2H (Gas)Propane C3H (Gas)Butane C4H (Gas)Pentane C5HHexane C6HHeptane C7HOctane C8HDecane C10HDodecane C12HTetradecane C14HHexadecane C16HOctadecane C18H (Solid)Eicosane C20H (Solid)
12ALKANESSaturated hydrocarbons “single bonds” (CnH2n + 2)Butane Octane HexaneProperties- non polar molecules- insoluble in water- less dense than H2O- dissolves fats, oils and waxes- fuel
13Cyclic HydrocarbonsThe names of cyclic hydrocarbons begin with the prefix cyclo- followed by the name of the alkane with the same number of carbon atoms.
14ALKENES & ALKYNESUnsaturated Hydrocarbons “Double & Triple” Bondsbutene octene hexenebutyne octyne hexyneProperties- Insoluble in water- Nonpolar molecules- Undergo many chemical RxAddition Rx: C2H H2 C2H6- Add to form polymers
15NOMENCLATURE1. Find longest chain- separate body from branches2. Name body based on #1 chain- use prefixes3. Determine type of bonds between carbon atoms4. If functional group present- number carbons5. Name compound using lowest numbering- body contains functional groups- branches are represented by prefix & - yl
16AROMATIC HYDROCARBONS BenzeneProperties- Insoluble in water- used as solvents or fuels- narcotic vapors (cancerous)
17Chlorinated Hydrocarbons When hydrogen atom or atoms of a hydrocarbon are substituted by chlorine, a chlorinated hydrocarbon is formed. Chlorinated hydrocarbons have many useful properties.Dichloromethane is used as a solvent and paint remover.Trichloromethane (chloroform) is also a solvent and at one time was used as an anesthetic. It is now considered hazardous.
18CHLORINATED HYDROCARBONS CH3Cl methyl chloride - make siliconesCH2Cl methylene chloride - solvent for paint removerCHCl chloroform - anestheticCCl carbon tetrachloride - dry cleaning solventCCl4 + H2O COCl2 + HClphosgene, poison gas WWICFC’sDDT (dichloro diphenyl tri chloro ethane)PCB (polychlorinated biphenyls)Properties- slightly polar- does not dissolve in H2O, dissolves in fats and oils
19TYPES OF ORGANIC REACTIONS 1. Addition Rxan unsaturated reactant becomes a saturated productR-CH=CH-R + -y R-CH-CH-R2. Elimination Rxa saturated reactant becomes an unsaturated productR-CH-CH2 R-CH=CH2 + - y3. Substitution Rxan atom (or group) from an added reactant substitutes for one in the organic reactant
20Functional GroupsAtoms or groups of atoms attached to hydrocarbon skeletons give the compounds characteristic chemical and physical properties and are known as functional groups. Double and triple bonds as well as halogen substituents are examples of functional groups.
21ORGANIC NOMENCLATURE FUNCTIONAL GROUPS containing oxygen R - OH -ol alcoholR - O - R ether ethercarbonyl C=OR- HC = O -al aldehydeR - C = O -one ketonelRR - C - O-H -oic acid carboxylic acidllOR - C - O - R -oate ester
22ORGANIC NOMENCLATURE R – NH2 -amine amine R – C=O -amide amide l NH2 FUNCTIONAL GROUPS containing nitrogenR – NH2 -amine amineR – C=O -amide amidelNH2
24MeOH – wood alcohol – methanol CH3OH - oxidized in body to formaldehyde- 1oz MeOH causes blindnessEtOH – grain alcohol – ethanol C2H5OH- not poisonous in low concentrations- 500 mL 200 proof rapidly ingested will killIPA – Isopropyl alcohol (rubbing alcohol)- C3H7OH 2-propanol-toxic (dosage) causes nerve damage, blindness and/or death, it’s a poison.- FAS- depressant- heavy drinking alter brain cell functions, causes nerve damage, shortens life span
25ALDEHYDES/KETONES- formaldehyde- makes plastic- embalming- disinfectant- benzaldehyde (oil of almond)- maraschino cherry flavor- perfume, flavoring- acetone C3H6O- nail polish remover; common solvent for fats, rubber, plastics, & varnishes. Used in paint and varnish removers.- MEK – methyl ethyl ketone – solvent in oil paints and glues. Also formed in the blood stream in ketosis (a problem in diabetes).
26Ketone functional group Ketone functional group is basis for soft contact polymerCarbonyl group is C=OKetone contains two hydrocarbon chains attached to carbonyl group
27Naming ketones Obtain root name Remove –e and replace with –one Count total number of C atomsRemove –e and replace with –oneLocation of carbonyl groupCount carbon atoms from shortest end
28- react w/O2 to form unstable peroxides ETHERS- solvent- flammable- react w/O2 to form unstable peroxides- Diethyl ether anesthetic 1842; side effects include nausea & vomiting.- MODERN ANESTHETICS include methy propyl ether (Neothyl) and methoxyflurane (penthrane; CHCl2CF2OCH3)- MTBE (methyl tert-butyl ether) – reduce CO emissions in automobiles but is a suspected carcinogen.- ethylene oxide (C2H4O; cyclic) is used to make ethylene glycol which in turn is used to make polyester fibers and antifreeze.
29Naming EthersWhen the hydrocarbon groups are different, the name orders the two group alphabetically and ends in ether.Butyl methyl ether: H3CCH2CH2CH2-O-CH3When the groups are the same the prefix di- is used.Dimethyl ether: H3C-O-CH3
30-formic acid – methanoic acid - ant sting - CH2O2 CABOXYLIC ACIDS- carboxylic acids are polar and form hydrogen bonds thus leading to higher boiling points. (formic acid; 46 g/mol has bp of 101oC whereas ethanol; 46 g/mol has bp of 78oC). They are weak acids and react with bases to form salts.-formic acid – methanoic acid - ant sting - CH2O2-acetic acid – ethanoic acid - vinegar - CH3COOH-butyric acid – butanoic acid – rancid butter-benzoic acid – Listerine-citric acid – sour flavor in oranges, lemons, & limes-lactic acid – imparts tartness to pickles, sauerkraut, & sweat. -cause of muscle pain & soreness after exercise.
32The name game Ester contains two name parts First: attached to O atom in main chainSecond: all C atoms in main chain, subtract -e and add-oate
33Carboxylic acid + amine = amide + H2O AMINES/AMIDESOrganic bases – similar to ammonia NH3 in odor and basicity. Many amines have unpleasant odors like trimethylamine (smell of rotting fish) & putrescine (component of decaying animal flesh) H2N-(CH2)4-NH2Amines are biologically important for example some illicit drugs like amphetamine & methamphetamine are amines and amino acids & proteins contain amines/amides. Nylon is a polyamide.Carboxylic acid + amine = amide + H2O