intro to organic

• Hydrocarbon is a compound consisting of only hydrogen and carbon
• saturated contain single carbon-carbon bonds only
• unsaturated contains a c=c double bond
• molecular formula shows actual number of each type of atom
• empirical formula shows simplest whole number ratio of atoms of each element in a compound
• general formula is algebraic formula for homologous series

  e.g: CnH2n
• structural formula shows the minimal details for arrangement of atoms in a molecule

  e.g: butane is CH3CH2CH2CH3
• Displayed formula shows all covalent bonds and atoms present in a molecule

  
• each carbon has 4 bonds
• skeletal formula shows the simplified organic formula, shown by removing hydrogen atoms from alkyl chains, leaving just a carbon skeleton and associated functional groups

  
• functional group is an atom or group of atoms which when present in different molecules causes them to have similar chemical properties
• homologous series are a family of organic compounds with the same functional group and general formula
• homologous series

  • show a gradual change in physical properties
  • each member differs by CH2
  • same chemical properties
• Alkane is CnH2n+2

  has the suffix ane

  functional group

  
• alkene is CnH2n

  suffix ene

  functional group

  
• alcohol is CnH2n+1OH

  prefix is hydroxy- and suffix is -ol

  functional group

  
• halogenoalkane have the prefix bromo, chloro, iodo

  functional group is

  
• aldehyde has the suffix -al and prefix -formyl

  functional group is

  
• ketone has suffix -one and prefix -oxo

  functional group is

  
• carboxylic acid has the suffix -oic acid

  functional group is

  
• esters have -yl -oate

  functional group is

  
• when naming, the highest precedence group takes the suffix (lowest number on carbon chain) and the rest take prefix form, however double and triple C-C bonds only take suffix form

  order of priority highest first:

  Carboxylic acids >aldehydes>ketones>alcohols>alkenes>halogenoalkanes
• naming carbon chains

  1. find the longest carbon chain and name
  2. find any branched chains and count their carbons for the prefix
  3. add any other functional groups, if there are two or more name appropriately with di, tri etc.
• number of carbons

  1. meth
  2. eth
  3. prop
  4. but
  5. pent
  6. hex
  7. hept
  8. oct
  9. non
  10. dec
• naming alkenes

  1. name position of double bond from smaller carbon
  2. may start with E or Z to show type of stereoisomer
  3. if more than one double bond, suffix ends with diene or triene and stem ends in a
• multiple functional groups and side chains are listed in alphabetical order
• if a compound has an OH group and another functional group with higher priority, the priority group gets the suffix and OH is named using hydroxy prefix
• when ketones have 5C's or more in a chain then it needs a number to show the position of the double bond
• homolytic fission

  each atom gets one electron from the covalent bond

  one headed arrow shows movement of electron

  when a bond breaks by homolytic fission, two free radicals form that do not have a charge
• free radical is a reactive species which possess an unpaired electron
• heterolytic fission produces ions where one atom gains both electrons

  two headed arrow shows movement of pair of electrons
• curly arrows are used in mechanisms to show the movement of an electron pair breaking or forming a covalent bond

  a curly arrow always starts from a lone pair on centre of a bond
• structural isomers have the same molecular formula but different structural formula
• structural isomerism can arise from chain isomerism, position isomerism and functional group isomerism
• chain isomers are compounds with the same molecular formulas but different structures of the carbon skeleton
• position isomers are compounds with the same molecular formula but different structural formula due to different positions of the same functional group on the same carbon skeleton
• functional group isomers are compounds with the same molecular formula but with atoms arranged to give different functional groups
• functional group isomer examples

  • aldehyde and ketone
  • alkene and cycloalkane
  • alcohol and ether
  • carboxylic acid and ester
• stereoisomers have the same structural formula but different arrangement of atoms in space
• alkenes exhibit e-z isomerism