Chp 1 Introduction Carbon Compounds

• Organic Chemistry: Carbon Compounds and Chemical Bonds is a course titled BIOL 103 Session 1 Introduction to Organic Chemistry.
• The chemistry of the compounds of carbon is the focus of Organic Chemistry.
• The human body is largely composed of organic compounds.
• Organic chemistry plays a central role in fields such as medicine and bioengineering.
• Vitalism was a belief that organic compounds could only be made by living things through the intervention of a “vital force”.
• Fredrich Wöhler disproved vitalism in 1828 by making the organic compound urea from the inorganic salt ammonium cyanate by evaporation.
• Halogen is attached to: •If the carbon is attached to one other carbon that carbon is primary (1 o) and the alkyl halide is also 1 o.
• If the carbon is attached to two other carbons, that carbon is secondary (2 o) and the alkyl halide is 2 o.
• If the carbon is attached to three other carbons, the carbon is tertiary (3 o) and the alkyl halide is 3 o.
• Central Premises in Structural Theory include Valency: atoms in organic compounds form a fixed number of bonds and Carbon can form one or more bonds to other carbons.
• Isomers are different molecules with the same molecular formula.
• Constitutional isomers are one type of isomer.
• Constitutional isomers are different compounds that have the same molecular formula but different connectivity of atoms.
• Constitutional isomers often differ in physical properties such as boiling point, melting point, and density.
• Constitutional isomers also often differ in chemical properties.
• Virtually all molecules possess a three-dimensional shape which is often not accurately represented by drawings.
• In 1874, van’t Hoff and le Bel proposed that the four bonds around carbon were not all in a plane but rather in a tetrahedral arrangement.
• Alkene, alkynes, aromatics contain fewer than maximum number of hydrogens per carbon and are capable of reacting with H2 to become saturated.
• Alkanes are the principle sources of alkanes are natural gas and petroleum and smaller alkanes (C1 to C4) are gases at room temperature.
• Methane is a component of the atmosphere of many planets, a major component of natural gas, and is produced by primitive organisms called methanogens found in mud, sewage and cows’ stomachs.
• Ethene (ethylene) is a major industrial feedstock used in the production of ethanol, ethylene oxide and the polymer polyethylene.
• Propene (propylene) is also very important in industry and its molecular formula is C3H6.
• Ethyne (acetylene) is used in welding torches because it burns at high temperature and many alkynes are of biological interest.
• Capillin is an antifungal agent found naturally.
• Dactylyne is a marine natural product.
• Ethinyl estradiol is a synthetic estrogen used in oral contraceptives.
• Benzene is the prototypical aromatic compound and the Kekulé structure is a six-membered ring with alternating double and single bonds.
• Polar covalent bonds occur when a covalent bond is formed between two atoms of differing electronegativities, with the more electronegative atom developing a partial negative charge and the less electronegative atom developing a partial positive charge.
• A bond which is polarized is a dipole and has a dipole moment.
• Functional group families are characterized by the presence of a certain arrangement of atoms called a functional group, which is the site of most chemical reactivity of a molecule.
• Alkyl groups are obtained by removing a hydrogen from an alkane and often more than one alkyl group can be obtained from an alkane by removal of different kinds of hydrogens.
• In alkyl halides, halogen (F, Cl, Br, I) replaces the hydrogen of an alkane and they are classified based on the carbon the halogen replaces.
• Charges in Resonance: One resonance contributor is converted to another by the use of curved arrows which show the movement of electrons.
• The use of these arrows serves as a bookkeeping device to assure all structures differ only in position of electrons.
• A calculated electrostatic potential map of carbonate clearly shows the electron density is spread equally among the three oxygens.
• Areas which are red are more negatively charged; areas of blue have relatively less electron density.
• Individual resonance structures exist only on paper.
• Only electrons are allowed to move between resonance structures.
• All structures must be proper Lewis structures.
• The energy of the actual molecule is lower than the energy of any single contributing form.