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Naming Hydrocarbons . Formic acid. Acetone. Acetylene. Naming: C ommon vs. IUPAC. Common names used in the 1800’s are still used for some compounds today:. The International Union of Pure and Applied Chemistry (IUPAC) was established in 1900s Frequent revisions to nomenclature
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Formic acid Acetone Acetylene Naming: Common vs. IUPAC • Common names used in the 1800’s are still used for some compounds today: • The International Union of Pure and Applied Chemistry (IUPAC) was established in 1900s • Frequent revisions to nomenclature • Systematic method allows an infinite number of compounds to be named given a few rules
How will you name this compound ? Side chain /alkyl group Parent chain
HYDROCARBON NOMENCLATURE PREFIX + ROOT +SUFFIX • PREFIX – tells name and location of each branch on the main carbon chain • ROOT – tells the number of carbon atoms in the main chain or ring • SUFFIX – tells type of compound (i.e. alkanes get the suffix ane, alkenes get ene and alkynes get yne
HYDROCARBON NOMENCLATURE STEPS IN NAMING 1.Find Root –find/count longest chain, -if cyclic add “cyclo” before root - if double or triple bonds are present, the longest chain must include it.
HYDROCARBON NOMENCLATURE 2.Find suffix – ane, ene or yne for aliphatic compounds. – If more than 1 double or triple bond exists, use di, tri before suffix (add a after root) 3. Give each carbon a # in the main chain, – give lowest possible # to double/triple bond (if any) – If no double/triple bond, then # so that branches have lowest possible #
HYDROCARBON NOMENCLATURE 4. Prefix – Name each alkyl group (branch) and give position # – If more than 1 branch, list in alphabetical order – Position of double/triple bonds come after positions and names of branches NOTE: Use commas between numbers and hyphens between numbers and words
HYDROCARBON NOMENCLATURE Example 1: Name the following compound Step 1: Determine longest chain - 5 Carbons Root: pent-
HYDROCARBON NOMENCLATURE Step 2: Determine the suffix: - Alkane compound - Suffix: -ane Root+ Suffix= pentane
HYDROCARBON NOMENCLATURE Step 3: Number the carbon, so the branches have lowest possible number
HYDROCARBON NOMENCLATURE Step 4: Prefix- Name each alkyl group (branch) and give position # Prefix: 2-methyl Alkyl group Prefix+ Root+ Suffix = 2-methylpentane
HYDROCARBON NOMENCLATURE Example 2: Multiple Branches Step 1: Root: pent Step 2: suffix: ane Step 3: number the carbon Step 4:- Two branches - write in alphabetical order Prefix : 3-ethyl-3-methyl 3-ethyl-3-methylpentane 1 2 3 5 4
HYDROCARBON NOMENCLATURE Example 3: Multiple Branches Step 1 and 2: Root +Suffix = nonane Step 3: Number the carbon Step 4: 3 methyl group and one propyl group – combine all 3 methyl groups together and use “tri” in front of methyl and number all the positions Prefix: 2,3,3-trimethyl-6-propyl 1 2 3 4 5 6 7 8 9 2,3,3-trimethyl-6-propylnonane
HYDROCARBON NOMENCLATURE Example 3: Double bonded carbons -For double or triple bonded carbons, we have to give the position # of the double bond 6 5 4 1 2 3 4-methyl -1- hex ene
HYDROCARBON NOMENCLATURE Example 3: Two or more double bond. -When there is two or more double bond, then add “di” or “tri” before ene in the suffix ( a after the root) and number both positions -Parent chain has to include both double bond 1 2 3 4 5 1,4- penta diene
HYDROCARBON NOMENCLATURE • Special alkyl groups: • Isopropyl- the main carbon chain is attached to the center carbon on the propyl group, rather then the edges. Example: 3-isopropylpentane or 3-ethyl-2methylpentane
HYDROCARBON NOMENCLATURE Hydrocarbon example: Fill in the table below 5-ethyl-2,4, 6-trimethyloctane 4-ethyl-7-methyl -2-nonene
HYDROCARBON NOMENCLATURE • Work on the handout in pairs. If you are down, check the answer and pick up another worksheet • Read chapter 1.2 and do practice question #1-8