CHEM 3331 1nd Edition Lecture 4Outline of Last Lecture I. LCAOII. Bonding and anti-bondingIII. HybridizationIV. Drawing compounds additional informationV. RotationVI. Constitutional isomersVII. stereoisomersOutline of Current Lecture I. Polarity of moleculesII. Supramolecular interactionsIII. SolubilityIV. Classes of organic compoundsCurrent LectureI. Polarity of moleculesWhen talking about the polarity of a molecule, we relate it to a dipole moment μ. If a substance is non-polar, i.e. H3C-CH3 then μ=0. In the case of H3C-NH2, H3C-OH, and H3C-F μ increases due to the increasing difference in electronegativities.μ is calculated as δ*d. Where δ= amount of charge and d= distance between charges.C-O μ= 0.86C-N 0.22C-F 1.51C-Cl 1.54C-H 0.30H-O 1.53These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.C=O 2.40C≡N 3.60μ is also a vector quantity, it is characterized by direction and numeric value. If μ1 points to the right and μ2 points to the right, then μtotal= μ1+μ2.If μ1 points to the right and μ2 points to the left, then μtotal= μ1-μ2.For CO2 μ=0 because the charge vectors point in opposite directions and have the same quantity they cancel out. For the cis- isomer of C2H2Br2 μ=1.9, but for the trans- isomer μ=0 because the vectors cancel out. Trans- isomers are less polar than cis- isomers.Lone pairs count as well towards μ because they possess charge. For H2O, μ=1.9.II. Supramolecular interactionsDipole-dipole moments are between molecules with dipoles, such as CH2O. If CH2O binds to itself in the right order it can create a dipole-dipole moment.A high boiling point means there is a strong interaction between molecules, whereas a low boiling point symbolizes a weak interaction.Induced dipoles are also known as London Dispersion forces. These are the weakest. The larger the surface area the stronger the dispersion forces. Elongated molecules will have a higher boiling point and thus a stronger interaction than a spherical molecule will. Spherical molecules have only one contact point with each other, therefore the molecule breaksapart easier. With elongated molecules they have a larger surface area of contact and are harder to break giving it a higher boiling point.Hydrogen bonding is the bond between hydrogen and F, O, or N.CH3CH3OH has a boiling point of 78˚C CH3OCH3 has a boiling point of -25 ˚CHydrogen bonding is a strong interaction that gives a higher boiling point. III. SolubilityLike dissolves like. We also use the equation ΔG=ΔH-TΔS. ΔH= enthalpy and ΔS= entropy. NaCl dissolves in H2O because both are polar molecules and because it is highly favored by the equation. Hexane will not dissolve in H2O becaue hexane is non-polar and is not strong enough to break the hydrogen bonds in H2O. It is based on the reorganization of water and is highly unfavored. Therefore, hexane will not dissolve. A compound similar to wax and hexane will dissolve because they are both non-polar and has no strong interaction with self. Hexane does not need to reorganize with addition of this wax compound so this is favored.NaCl in hexane will not dissolve. NaCl has a strong ionic bond with itself and hexane only has London dispersion forces. Hexane cannot split apart the ionic bonds. Therefore, this is unfavored. IV. Classes of organic compoundsHydrocarbons are a class that contain only C and H. Within this class are subclasses.Alkanes contain only single bonds between carbon atoms.CH4=methane, C2H6= ethane, C3H8= propane, C4H10= butane, C5H12= pentane, C6H14= hexane, C7H16= heptane, C8H18= octane, C9H20= nonane, C10H22= decane.These are used to derive other classes of compounds simply by removing a hydrogen to bond toa functional group (OH, NH2, Cl). The first part of the compound is known as the alkyl group or rgroup. For example, butyl, ethyl, methyl, etc.Next are Alkenes which have double bonds between one or more carbons.H2C=CH2 (ethane- the simplest alkene)H3C-CH=CH2 (propene)H3C-CH=CH-CH3 (2-butene) since it bonds on the second carbonThen there are alkynes which have triple bonds between at least one carbonH2C-C≡C-CH2 (butyne)HC≡CH (ethyne)Alcohols have the setup of R-OH with only single bondsCH3OH= methanolCH3CH2OH= ethanolEthers have the setup of R1-O-R2 with only single bondsCH3OCH3= dimethyl etherCH3CH2OCH2CH3= diethyl etherC=O is known as a carbonyl groupAldehyde is an r group attached to a carbonyl group that’s attached to a hydrogen.Ketone is R1 attached to a carbonyl group attached to R2.Carbosylic acids are an r group attached to a carbonyl group attached to OH. These are named in the form like ethanoic acid, methanoic acid, octanoic acid.Amines are an r group bonded to NH2.CH3NH2= methyl amineAmide is an r group attached to a carbonyl group attached to