Ch. 10: Organic ChemistryButane versus NaClLearning CheckBondingMolecular GeometryClasses of Organic CompoundsMethods for Writing FormulasMethods for Writing FormulasIUPAC NomenclatureAlkane Base NamesBranched AlkanesIUPAC NomenclatureIUPAC NomenclatureIUPAC NomenclatureCycloalkanesIUPAC NomenclatureHaloalkanesNames to FormulasProperties of AlkanesCrude OilCrude OilCrude OilFunctional GroupsFunctional GroupsFunctional GroupsFunctional GroupsFunctional GroupsFunctional GroupsFunctional GroupsFunctional GroupsFunctional GroupsFunctional GroupsThe chemistry of carbon compounds.Mainly carbon and hydrogen atoms.Many organic compounds occur naturally.Thousands more can be synthesized by man.Ch. 10: Organic ChemistryButane versus NaClInorganicOrganicNaCl, 58.5 g/molBonding is ionicM.P. = 801oCB.P. = 1413oCDissolves in waterWill not burnC4H10, 58.1 g/molBonding is covalentM.P. = -138oCB.P. = 0oCNot soluble in waterWill burn in airDecide whether the property is that of pentane (C5H12) or sodium sulfide (Na2S).1. Liquid at room temperature.2. Dissolves in water.3. Floats on the surface of water.4. Has a melting point of 1176oC.5. Burns in air easily.Learning CheckThe bonding in all organic molecules is covalent.Carbon has 4 valence electrons and hydrogen has 1. • • C • H • •Carbon achieves an octet by forming four bonds.BondingWhen carbon is bonded to four other atoms, it has a tetrahedral geometry. Molecular GeometryClasses of Organic CompoundsAliphatic AromaticSaturated UnsaturatedAlkanes Cycloalkanes Alkenes AlkynesBenzene RingMolecular formula – shows the number of C and H atoms.Ex) Propane, C3H8.Complete structural drawing – shows every single bond. H H H   H – C – C – C – H    H H HMethods for Writing FormulasCondensed structural formula – writes each C atom along with the number of H’s bonded to that carbon atom.CH3 – CH2 – CH3This is the preferred method for showing structures in this course.Methods for Writing FormulasA set of rules for naming all organic compounds.Will not need to memorize the base names.Names for one through ten carbons.IUPAC NomenclatureAlkane Base NamesButane, C4H10, has more than one possible way to put four carbons together.These two forms are called structural isomers.Both can NOT be called butane!Branched AlkanesA substituent is any group that is attached to the longest chain of carbon atoms.CH4 = methane, -CH3 = methylCH3CH3 = ethane, -CH2CH3 = ethylCl = chloro, Br = bromo, I = iodoIUPAC Nomenclature1. Determine the longest continuous chain of carbon atoms. Because the alkanes have free rotation, the chain may bend and twist in many shapes!2. Determine the type of substituents located on the longest chain. These are named in alphabetical order.IUPAC Nomenclature3. Number the longest chain such that the substituents have the lowest numbers.4. Name the substituents first followed by the base name. If two or more of the same substituent, then use prefixes.5. Every substituent MUST have a number in front of it indicating the position on the chain.IUPAC NomenclatureA ring structure can be constructed from alkanes of three or more carbons by removing two hydrogen atoms.Because they form a geometric shape, a shorthand method for their structure is that shape.CycloalkanesFor ring structures, a mono-substituted ring does not need a number.Why???For di-substituted ring structures, number starting from the location of one the substituents and then go CW or CCW to give the next one the lowest number.IUPAC NomenclatureA haloalkane is placing a halogen (group 7A) atom in place of a hydrogen atom.Naming uses the fluoro, chloro, bromo, and iodo names.Haloalkanes are used as refrigerants (CF3CH2F) and anesthetic agents (CF3CHClBr).HaloalkanesWhen converting a name to a condensed formula, you may want to do it in several steps.1. Base name = carbon backbone.2. Fill in substituent groups.3. Add H’s until each carbon has four bonds.4. Condense.Names to FormulasAlkanes are non-polar and, thus, do NOT dissolve in water.Alkanes typically have a density of 0.65 – 0.70 g/mL and will float on the surface of water.All alkanes can be burned to produce energy.Alkane + O2  CO2 + H2OProperties of AlkanesCrude oil contains a variety of alkanes that are separated at an oil refinery.The mixture is heated and then separated by fractions – that is, their differences in boiling points.The lightest alkanes have the lowest boiling points and go to the top of the column.Crude OilCrude OilCrude OilAlkanes are fairly unreactive and have little use to organic chemists.Addition of other atoms like O, N, and S change the reactivity and properties of the boring alkanes and these are called functional groups.Functional groups are classified into several common identifiers.Functional GroupsUse of the letter “R” in generic formulas.Alcohol – contain the hydroxyl (O-H) group.R-OHEx) CH3CH2OH, CH3CHCH3  OHFunctional GroupsEther – an oxygen atom separating two alkyl groups.R – O – R’Ex) CH3CH2-O-CH2CH3Carbonyl group, C=O, is found in a couple of different ways.Functional GroupsAldehyde – the carbonyl group is on the end of the chain.RCHOEx) CH3CH2C=O  HFunctional GroupsKetone – the carbonyl group is in the middle of the chain.R(C=O)R’Ex) CH3 – C – CH3  OFunctional GroupsCarboxylic acid – has both the carbonyl and the hydroxyl groups.RCOOHEx) CH3 – C – OH  OFunctional GroupsEster – combines the carbonyl group and the ether group.R-COO-R’Ex) CH3CH2CH2 – C – O – CH3  OFunctional GroupsAmine – is a nitrogen atom that can be bonded to one, two, or three alkyl groups.RNH2 , R2NH, and R3N (note: R groups can be different!).Ex) CH3 – NH2 , (CH3)3NFunctional GroupsThiol – is a sulfur atom with one H atom (usually).R-SHCH3CH2 – SH Functional GroupsAlkenes, alkynes, and aromatics can also be considered as a functional group.All of these will be discussed in greater details in the following chapters including naming, properties, and important reactions.Functional