Hydrocarbons and Naming

  1. Hydrocarbons are a series of organic molecules that are made of only hydrogen and carbon
  2. The simplest series of organic compounds are the alkanes
  3. All carbon atoms are singly bonded, therefore saturated
  4. The alkanes make up a homologous series
  5. A set of compounds that differ by a CH2 group
  6. Homologous series have similar chemical properties by varying physical properties.
  7. For example, the alkanes are relatively inert (chemical property)
  8. Have low boiling points that increase within the series because of
  9. Higher mass and
  10. Increased dispersion forces due to larger molecules/more electrons

Naming:

  1. Organic structures are named through a system of prefixes and suffixes.
  2. Prefix = number of carbon atoms
  3. Suffix = functional group.
  4. – ane = saturated carbon chain made only of C and H

# C / Prefix / Alkanes -ane / Alkenes - ene / Alcohols - anol
1 / Meth- / Methane / Methene / Methanol
2 / Eth- / Ethane / Ethene / Ethanol
3 / Prop- / Propane / Propene / Propanol
4 / But- / Butane / Butene / Butanol
5 / Pent- / Pentane / Pentene / Pentanol
6 / Hex- / Hexane / Hexene / Hexanol
7 / Hept- / Heptane / Heptene / Heptanol
8 / Oct- / Octane / Octene / Octanol
9 / Non- / Nonane / Nonene / Nonanol
10 / Dec- / Decane / Decene / Decanol
  1. Naming Isomers
  2. A given molecular formula can have many possible structures – these are isomers
  3. Two isomers for C4H10 are:

butane2-methyl propane

  1. 2-methylpropane is a branched alkane
  2. Name the longest carbon chain
  3. Name the substituent
  4. find number of carbons and add –yl ending
  5. Number the carbons so that substituent is lowest number possible
  6. Name: #-(substituent)(carbon chain)
  7. Note the following is not 4-methylpentane
  1. What if there is more than one substituent?
  2. Same kind on same carbon
  3. Follow the steps as above but name
  4. (#,#)-(di)(substituent name)(carbon chain)
  1. Different kind on same carbon
  2. Follow steps above but name substituents in alphabetical order and separate numbers
  3. (#)-(substituent)-(#)-(substituent)(carbon chain)
  1. Different kind on different carbon
  2. Follow the steps above so that numbers of carbons are lowest number possible. The highest priority substituent should get the lowest number but with substituent groups that are the same functional group (alkanes, alcohols, etc) make numbers as low as possible.
  3. Put name of substituents in alphabetical order and separate numbers
  4. (#-substituent)-(#-substituent)(carbon chain)