ORGANIC CHEMISTRY The Chemistry of Carbon

Organic Molecules Molecules containing carbon and hydrogen, originally extracted from fossil fuels (coal, petroleum, natural gas), once living plants and animals. Many organic compounds also contain O, S, N, P, Si, halogens (locate on PT). Nearly all physiological molecules (biochemistry) are organic molecules.

History of Organic Chemistry In the early 19 th century, chemists started to synthesize organic molecules (vs extracting them from fossil fuels vs belief in “vital force”) – 1816: soap = fatty acids and glycerol – 1828: urea – 1856: Mauve dye – 1874: DDT Synthesis, Reactions and Mechanisms

Variety, Number and Uses Organic molecules take many shapes: chains, rings, helices, sheets, spheres, polymers Petrochemicals, Plastics, Pharmaceuticals, Biomolecules, Buckyballs, Nanochemistry There are over 10 million organic molecules with 10,000 being discovered or synthesized every year. Compounds-Using-the-IUPAC-Method Compounds-Using-the-IUPAC-Method

How Do We Organize and Name Them? Organic compounds are categorized by identifiable combinations of atoms called functional groups. IUPAC System of Nomenclature was adopted over 50 years ago.

Organic Functional Groups NameFunctional Group NameFunctional Group AlkaneC n H 2n+2 Esterhttp://home.clara.net/rod.beavon/efo.htm AlkeneC n H 2n EtherC-O-C AlkyneC n H 2n-2 Amidehttp:// Alcohol-C-OHAmine-NH 2 Carboxylic Acid -COOHAromatic (Benzene C 6 H 6 ) ext/react3.htm PAHhttp://chppm pdf

Biochemical Functional Groups NameFunctional Group CarbohydrateSugars, C n H m O p LipidsFats, Oils Proteinspolypeptides Nucleic AcidsRNA, DNA

POLYMERS Superglue, Time-Released Meds, Shatter-proof Glass, Contact Lenses

Polymers A long molecule made up of repeating units called monomers. The monomers are connected by chemical bonds. Propylene = H 3 C – CH = CH 2 Polypropylene =

Superglue (p 219) Superglue = Polymer = very strong adhesive Methyl α-cyanoacrylate (monomer; ester) + Water  Polycyanoacrylate (polymer)

Note Where does water come from? Methyl group at bottom of molecule can be replaced by many other groups thus changing the properties (time to adhere, temp range, strength) of the glue. Adhesion = f(smooth vs rough surface, H- bonding, strong IMF attractions)

Some History Another serendipitous discovery (1942 discovered but rejected  1951 properties recognized and valued  1958 commercialization) Remove Superglue with ______

Time-Released Meds (p. 208) Time-released medications produce a more constant dosage of medicine over a longer period of time. Coatings can be made from polymers or polysaccharides with added plasticizers, flavors and pigment.

Coating Variety a water-soluble polymer coating of different thicknesses (Contac) – Active ingredient is released when coating dissolves. a coating with pores (FMC Corp) – Monomer = ethyl cellulose; for release in stomach – Monomer = cellulose acetate phthalate for release in intestine (enteric, resists low pH environments) – Release is determined by diffusion through pores

Coating Variety a coating activated by temp and moisture – nitroglycerin patch: This compound hydrolyzes to form NO; NO activates an enzyme causing an increase in GMP; GMP decreases Ca 2+ levels leading to blood vessel dilation. – Motion sickness patch: Scopolamine blocks the neurotransmitter acetylcholine.

Hard and Soft Contact Lenses (p. 221) Desirable properties of lenses: optical transparency (clear), durability, wettability for comfort, scratch resistant, gas permeable for cornea health, corrective, does not dissolve foreign compounds, bacteria resistant

Hard Lenses Hard lenses are made of a polymer of nonpolar hydrophobic monomers. – 1948 monomer = MMA = methyl methacrylate (plexiglass; ester); not permeable to oxygen – 1975 monomer= MMA + monomer TRIS (Si, more oxygen permeability)  copolymer – 1980’s monomer = MMA + TRIS + HFIM (F); gas permeable

Soft Lenses Soft lenses are made of a polymer of polar hydrophillic monomers. – 1959 Monomer = HEMA = 2-hydroxyethyl methacrylate; polymer includes cross-linking – Water is absorbed into lens; hydrogel polymers by weight) – HEMA + MMA copolymer (58% water) – Extended wear (70% water, copolymer incl Si); ionic monomers increase water absorption