CHEM 2211 1st Edition Lecture 5 Outline of Last Lecture I II III I II What are cycloalkanes Rules for Nomenclature Alcohols How alcohols are formed Rules for Nomenclature Outline of Current Lecture I Alkyl Halides II Ethers III Amines IV Conformational Isomers Vocabulary Alkyl Halides Conformational Isomer Ether Eclipsed Conformer Amine Staggered Conformer Current Lecture I Alkyl Halides a Much like alcohols alkyl halides are considered a primary secondary or tertiary if they are attached to a primary secondary or tertiary carbon b When using the common naming system for Alkyl Halides we use the alkyl group name plus fluoride chloride bromide or iodide Butyl Fluoride c When using the IUPAC naming system we name the halide first and the alkane group second 5 bromo 6 butyl 4 7 dimethyldecane II Ethers a Ethers are one oxygen molecule bonded to two alky groups b Symmetric ethers have the same substituent on both sides while asymmetric ethers have different substituents on both sides c The common name for an ether is to add the names of the two alkyl groups followed by ether Ethyl methyl ether d The IUPAC way of naming is to add the oxy to the name of the alkyl group in place of the yl The last name of the compound is the alkane name i The shortest alkyl substituent gets the oxy ending 1 ethoxy 3 methylpentane III Amines a Amines unlike alcohols ethers and alkyl halides are determined to be primary secondary tertiary or quaternary by the number of groups attached to the nitrogen Primary Amine Secondary Amine Tertiary Amine Quaternary Amine b For the common naming system the alkyl substituents are named in alphabetical order then the name amine is added to the end N ethyl 3 hexanamine c For IUPAC the e at the end of the alkane name is replaced with amine Any group bonded to nitrogen instead of a carbon is preceded by an italicized N 4 butyl 3 nonamine d Nitrogen compounds bonded to four different groups are called quaternary ammonium salts Without the H ion the nitrogen atom has a positive formal charge i To name we put the alkyl function group name together and then add the ending ammonium plus the name of the accompanying anion Tetramethylammonium hydroxide IV Conformational Isomers a Carbons to carbon single bonds have bond rotation in which each carbon can spin around the bond b Conformation Isomers are the different spatial arrangements one molecule can have when rotating about the axis c Newman Projections show a carbon to carbon bond lengthwise in which the hydrogens on the first carbon are drawn to intersect each other in the middle and the hydrogens on the second carbon are drawn from the outer ring of the first carbon d An eclipsed conformer is when the second molecule cannot be seen behind the first molecule because they are lined up perfectly with each other Ethane A Newman projection of the ethane molecule and an example of an eclipsed molecule e A staggered conformer on the other hand is a rotation of one carbon by 60 to produce a molecule that is in essence staggered An example of a staggered conformer
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