[chem] notes on organic reactions
[notes.git] / chem / organic-2.md
index 05cfd7482b539ba567f82d30cd7b16a1e9eb24d0..c0fadf2c65b10361e146a44c4f290bbc7968d564 100644 (file)
@@ -1,12 +1,15 @@
 ---
+geometry: a4paper, margin=2cm 
 header-includes:
 - \usepackage{mhchem}
+- \usepackage{chemfig}
 - \usepackage{tabularx}
 ---
 
 # Organic Chemistry
 
 Large number of compounds due to:
+
 - 4 valence pairs
 - single / double / triple bonds
 - cyclic (ring) structures
@@ -32,16 +35,74 @@ Alkynes: \ce{C_{$n$} H_{$2n-2$}}
 - Indicate number of branches with di-, tri- etc.
 - Longest unbranched carbon chain includes function group
 
-
-
 ## Functional groups
 
-\begin{tabularx}{\textwidth}{rX}
-  Alcohols & \ce{-OH} \\
-  Aldehydes & \ce{-CHO} \\
-  Ketones & \ce{-CO-} \\
-  Carboxylic acids & \ce{-COOH} \\
-  Amines & \ce{-NH2} \\
-  Amides & \ce{-CONH2} \\
+\setchemfig{atom sep=2em}
+\renewcommand{\arraystretch}{3}
+\begin{tabularx}{0.5\textwidth}{rlX}
+  \hline
+  Alcohols & \ce{-OH} & \chemfig{{\color{blue}R}-OH}\\\hline
+  Esters & \ce{-OCO-} & \chemfig{{\color{blue}R}-C(=[:-30]O)-[:30]O-{\color{blue}R}}\\\hline
+  Aldehydes & \ce{-CHO} & \chemfig{{\color{blue}R}-C(-[:-30]H)=[:30]O}\\\hline
+  Ketones & \ce{-CO-} & \chemfig{C(-[:150]{\color{blue}R})(-[:-150]{\color{blue}R})=O}\\\hline
+  Carboxylic acids & \ce{-COOH} & \chemfig{{\color{blue}R}-C(=[:-30]O)-[:30]O-H}\\\hline
+  Ethers & \ce{-O-} & \chemfig{{\color{blue}R}-[:210]O-[:-30]{\color{blue}R}}\\\hline
+  Amines & \ce{-NH2} & \chemfig{{\color{blue}R}-N(-[:-30]H)(-[:30]H)}\\\hline
+  Amides & \ce{-CONH2} & \chemfig{{\color{blue}R}-[:30]C(=[:90]O)-[:-30]N(-[:30]H)(-[:-30]H)}\\\hline
 \end{tabularx}
 
+
+## Isomers
+
+* **Structural isomers** - same molecular formula, different arrangement  
+* **Stereoisomers** - same structural configuration, different orientation  
+  * **Opotical isomers** - chiral centre, 4 groups bonded to C, non-superimposable mirror image
+  * **Geometric isomers** - \ce{C=C} double bond, 2 groups bonded to carbon atoms
+    + **Cis** - same horizontal plane
+    + **Trans** - diagonal
+
+\begin{center}\setlength\tabcolsep{1cm}
+\begin{tabularx}{0.5\textwidth}{cc}
+  cis & trans \\
+  \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}}} &
+  \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$^\prime$}}}
+\end{tabularx}\end{center}
+
+## Reactions
+
+**Cracking** - split moluecules with heat/pressure/catalyst
+
+### Alkanes
+
+- Relatively inert
+- Non-polar solvent
+- Non-soluble in \ce{H2O}
+- Combusts in \ce{O2} (forms \ce{CO2 + H2O})
+- Reacts with halogens (**substitution** of \ce{H})
+
+### Alkenes
+
+- More reactive than alkanes
+- **Addition reactions**: \ce{C=C} bond is broken (energy released)
+- **Addition polymerisation**
+
+### Alcohols
+
+- Can be formed from haloalkane substitution reaction
+- **Oxidation** (combustion)
+- Oxidation state $\propto$ no. of atoms connected to \ce{C}
+- **Substitution** of functional group, e.g. \ce{ROH + NH3 -> RNH2 + H2O}
+- Primary alcohols oxidise to aldehydes then carboxylic acids
+- Secondary alcohols oxidise to ketones
+
+### Carboxylic acids
+
+- Weak acids
+- **Hydrolysis**: \ce{RCOOH + H2O <=> RCOO^{-} + H2O^{+}}
+- Rxn with amines - carboxylic acid + amine $\rightarrow$ ammonium salt $\rightarrow$ amide + water
+
+### Esterification
+
+- **Condensation reactions** (esterification): \ce{RCOOH + R^{$\prime$}OH -> RCOOR^{$\prime$} + H2O}
+- This is reversed by **hydrolysis**: ester + water $\rightarrow$ carboxylic acid + alcohol
+- Polyesters