Presentation on theme: "UNIT 6 Theories of Covalent Bonding and Intro to Organic Chemistry: Nomenclature of Alkenes, Alkynes, Alcohols."— Presentation transcript:
UNIT 6 Theories of Covalent Bonding and Intro to Organic Chemistry: Nomenclature of Alkenes, Alkynes, Alcohols
Structural Isomers Have the Same Molecular Formula Draw the line angle structure of: The molecular formula of this compound is C 8 H 18. Draw three more structural isomers of octane.
...... :O = S = O: Valence Bond Descriptions What orbitals overlap to form each of the bonds in SO 2 ? The S-O sigma bond in each double bond is formed by the overlap of an O sp 2 hybrid orbital with a S sp 2 hybrid orbital. Each S-O pi bond is formed by the overlap of the S 3p z orbital with the O 2p z orbital. Two sp 2 orbitals on each of the O’s and one sp 2 orbital on the S are not involved in any bond.
Nomenclature of Alkenes Number the C chain from the end that brings you to the double bond sooner, then use the alkane naming rules and -ene. IUPAC (common) H 2 C=CH 2 ethene (ethylene) H 2 C=CH-CH 3 propene (propylene) Planar geometry around the double bond 120° bond angles to the C atoms in the double bond
Nomenclature of Alkenes geometric isomers All four are structural isomers. What are the bond angles? trans-but-2-ene bp = 1°C cis-but-2-ene bp = 4°C methylpropene bp = - 7°C but-1-ene bp = -6°C
Nomenclature of Alkenes 6,6-dichloro-5-ethyl-4-methylhept-1-ene Name this alkene. Give a VB description of the C-Cl bond. Draw the line angle structure for 1-chloro-3-methyl-1,3-butadiene
Alkynes Contain at least one C≡C bond. Alkynes are unsaturated molecules. The two π bonds make the geometry through the triple bond linear. The triple bond is highly reactive, so alkynes are not found widely in nature, though they are used as intermediates in industrial processes.
Nomenclature of Alkynes Number the C chain from the end that brings you to the triple bond sooner, then use the alkane naming rules and -yne. IUPAC (common) HC≡CHethyne (acetylene) HC≡C-CH 3 propyne Linear geometry around the triple bond 180° bond angles to the C atoms in the triple bond
Alkynes Draw the condensed structural formula and line angle structure for 4-methylpent-2-yne. CH 3 - C ≡ C - CH - CH 3 | CH 3 CH 3 C≡CCH(CH 3 ) 2 * What is the hybridization on the starred C? What is the geometry? Give a VB description of one of the C- C pi bonds.
Alcohols Contain the -OH (hydroxyl) group. Alcohols are NOT bases. In fact, some can be acidic (phenol). Can be soluble in polar solvents such as water (hydrocarbons are not soluble in water). Primary (1°) alcohols: R – CH 2 - OH Secondary (2°) alcohols:R - CH - R' | OH Tertiary (3°) alcohols: R″ | R - C - R' | OH R,R',R″ designate the rest of the molecule. R represents an alkyl group.
Nomenclature of Alcohols Number the C chain from the end that brings us to the -OH group sooner, then use the alkane naming rules and -ol. 1° alcoholsIUPAC (common) CH 3 CH 2 OH ethanol (ethyl alcohol) CH 3 CH 2 CH 2 OH propan-1-ol (n-propyl alcohol) or 1-propanol * CH 3 OH*M ethanol is not primary, it’s a methyl alcohol.
Nomenclature of Alcohols Number the C chain from the end that brings us to the -OH group sooner, then use the alkane naming rules and -ol. 2° alcoholsIUPAC (common) CH 3 CHCH 3 propan-2-ol (isopropyl alcohol) |or 2-propanol OH CH 3 CHCH 2 CH 3 butan-2-ol or 2-butanol | OH
Nomenclature of Alcohols Which are primary? Secondary? Tertiary? isopropyl alcohol IUPAC: propan-2-ol or 2-propanol t-butyl alcohol IUPAC: methylpropan-2-ol ethylene glycol IUPAC: ethane-1,2-diol
Nomenclature of Alcohols 1°? 2°? 3°? Give the IUPAC name of each. Give a VB description of one of the O-H bonds.
Nomenclature of Alcohols phenol IUPAC: phenol propylene glycol glycerine, glycerol IUPAC: propane-1,2,3-triol Draw the line angle structure for 2-methyl-3-butyn-2-ol
Nomenclature of Alcohols IUPAC: 10,13-dimethyl-17-(6-methylheptan-2-yl)- 2,3,4,7,8,9,11,12,14,15,16,17- dodecahydro-1H-cyclopenta[a]phenanthren-3-ol What is the H-C-C bond angle for either of the “dashed” H’s?