Organic Chemistry
Organic Chemistry Topics 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Intro Recap bonding and Lewis diagrams Covalent bonding Alkanes and cycloalkanes (isomers), naming and chemistry Alkenes (isomers), naming and chemistry Functional groups, naming and interconversion Alkynes, naming Benzene and aromaticity, naming and chemistry Comparative acidity of organic molecules Spectroscopy – use the interaction of light with organic molecules.
Introduction • • • • •
Organic molecules tend to not be volatile. One of the most important uses of organic chemistry at the moment is in the plastic industry. Plastic is made from fossil fuels. Drugs and medicines are made from organic chemistry. DNA is a massive organic molecule. All life on earth is based on carbon. There are billions of types of life on earth and as of yet no one has found a non-carbon based life form. Also, all possible signs of life off earth are carbon based.
So why do we study carbon? The key chemical requirements: • Functionality –able to form multiple bonds to other atoms (and itself) this allows complexity (polymers) AND allows multiple reactive sites at the same time. Carbon is a multivalent element • Stability – molecules must have reasonable lifetimes to ensure the survival of the species as a whole BUT • Reactivity – we need to be able to both make and break bonds at the ambient temperature. Bond strength with multiple elements must fit within a certain window • Recycle mechanism – death is inevitable (on earth this equates to oxidation) and the element must be made available again. Carbon is a mobile species Organic chemistry involves the chemistry of carbon and a few other elements - hydrogen, oxygen and nitrogen, (these 3 make up about 95% of the human body) and sometimes sulfur, phosphorus and halogen (fluorine, chlorine, bromine and iodine)
The majority of what we know as “chemistry” is about what electrons are doing as constituents of atoms and, ultimately, matter. Bonding isn’t even, hence why atoms react.
Electrons determine: • 3 D structure of molecules and compounds • How molecules change i.e. react • Whether molecules react easily or are very stable • Whether a material conducts electricity or not To understand how molecules react, we must first know about the valence electrons in the outer shell.
Electrons • • • • • •
One of the main things electrons are involved in is bonding. o Holding atoms together to form molecules and compounds Covalent bonding - TWO electrons are shared equally between two atoms to form ONE bond. Ionic bonding - atoms lose or gain electrons to form oppositely charged ions which attract each other. The number of bonds an organic atom will make depends on the number of valent electrons they have and the octet rule Most bonds in organic molecules are covalent, sharing electrons more or less equally. In chemistry, the bonds where sharing between atoms is less equal are more interesting because this is where molecules are most likely to react.
Electronegativity •
A measure of the force of an atom’s attraction for electrons that it shares in a chemical bond with another atom.
Intro Recap bonding and Lewis diagrams Covalent bonding Alkanes and cycloalkanes (isomers), naming and chemistry Alkenes (isomers), naming and chemistry Functional groups, naming and interconversion Alkynes, naming Benzene and aromaticity, naming and chemistry Comparative acidity of organic molecules Spectroscopy – use the interaction of light with organic molecules.
Introduction • • • • •
Organic molecules tend to not be volatile. One of the most important uses of organic chemistry at the moment is in the plastic industry. Plastic is made from fossil fuels. Drugs and medicines are made from organic chemistry. DNA is a massive organic molecule. All life on earth is based on carbon. There are billions of types of life on earth and as of yet no one has found a non-carbon based life form. Also, all possible signs of life off earth are carbon based.
So why do we study carbon? The key chemical requirements: • Functionality –able to form multiple bonds to other atoms (and itself) this allows complexity (polymers) AND allows multiple reactive sites at the same time. Carbon is a multivalent element • Stability – molecules must have reasonable lifetimes to ensure the survival of the species as a whole BUT • Reactivity – we need to be able to both make and break bonds at the ambient temperature. Bond strength with multiple elements must fit within a certain window • Recycle mechanism – death is inevitable (on earth this equates to oxidation) and the element must be made available again. Carbon is a mobile species Organic chemistry involves the chemistry of carbon and a few other elements - hydrogen, oxygen and nitrogen, (these 3 make up about 95% of the human body) and sometimes sulfur, phosphorus and halogen (fluorine, chlorine, bromine and iodine)
The majority of what we know as “chemistry” is about what electrons are doing as constituents of atoms and, ultimately, matter. Bonding isn’t even, hence why atoms react.
Electrons determine: • 3 D structure of molecules and compounds • How molecules change i.e. react • Whether molecules react easily or are very stable • Whether a material conducts electricity or not To understand how molecules react, we must first know about the valence electrons in the outer shell.
Electrons • • • • • •
One of the main things electrons are involved in is bonding. o Holding atoms together to form molecules and compounds Covalent bonding - TWO electrons are shared equally between two atoms to form ONE bond. Ionic bonding - atoms lose or gain electrons to form oppositely charged ions which attract each other. The number of bonds an organic atom will make depends on the number of valent electrons they have and the octet rule Most bonds in organic molecules are covalent, sharing electrons more or less equally. In chemistry, the bonds where sharing between atoms is less equal are more interesting because this is where molecules are most likely to react.
Electronegativity •
A measure of the force of an atom’s attraction for electrons that it shares in a chemical bond with another atom.
