chem / organic-2.mdon commit [chem] optical & geometric isomers (126ab85)
   1---
   2geometry: a4paper, margin=2cm 
   3header-includes:
   4- \usepackage{mhchem}
   5- \usepackage{chemfig}
   6- \usepackage{tabularx}
   7---
   8
   9# Organic Chemistry
  10
  11Large number of compounds due to:
  12
  13- 4 valence pairs
  14- single / double / triple bonds
  15- cyclic (ring) structures
  16
  17## Properties of hydrocarbons
  18
  19- *Saturated* - all C-C bonds are single
  20- Insoluble in water
  21- Almost non-polar (similar electronegativities)
  22- Only dispersion forces (valence e-)
  23- Dispersion forces increase with length
  24- Branched molecules have lower density
  25
  26## Linear (aliphatic)
  27
  28Alkanes: \ce{C_{$n$} H_{$2n+2$}}  
  29Alkenes: \ce{C_{$n$} H_{$2n$}}  
  30Alkynes: \ce{C_{$n$} H_{$2n-2$}}
  31
  32## Naming hydrocarbons
  33
  34- Branches end with _-yl_
  35- Indicate number of branches with di-, tri- etc.
  36- Longest unbranched carbon chain includes function group
  37
  38## Functional groups
  39
  40\begin{tabularx}{\textwidth}{rX}
  41  Alcohols & \ce{-OH} \\
  42  Aldehydes & \ce{-CHO} \\
  43  Ketones & \ce{-CO-} \\
  44  Carboxylic acids & \ce{-COOH} \\
  45  Amines & \ce{-NH2} \\
  46  Amides & \ce{-CONH2} \\
  47\end{tabularx}
  48
  49
  50## Isomers
  51
  52* **Structural isomers** - same molecular formula, different arrangement  
  53* **Stereoisomers** - same structural configuration, different orientation  
  54  * **Opotical isomers** - chiral centre, 4 groups bonded to C, non-superimposable mirror image
  55  * **Geometric isomers** - \ce{C=C} double bond, 2 groups bonded to carbon atoms
  56    + **Cis** - same horizontal plane
  57    + **Trans** - diagonal
  58
  59\setlength\tabcolsep{1cm}
  60\begin{tabularx}{\textwidth}{cc}
  61  cis & trans \\
  62  \chemfig{[:60]{\text{\color{blue}R$^\prime$}}-C(-[:120]{\text{\color{red}R}})=[0]C(-[:-60]{\text{\color{blue}R$^\prime$}})-[:60]{\text{\color{red}R}}} &
  63  \chemfig{[:60]{\text{\color{blue}R$^\prime$}}-C(-[:120]{\text{\color{red}R}})=[0]C(-[:-60]{\text{\color{red}R}})-[:60]{\text{\color{blue}R$^\prime$}}}
  64\end{tabularx}
  65