1.1 Alkanes 1.2 Alkenes & Alkynes

Introduction Originally the term “organic” referred to chemicals that were made by or obtained from living organisms. “Inorganic” referred to chemicals derived from mineral sources. However, in 1828, Fredrick Wholer (German) created urea (an organic compound) from potassium cyanate and ammonium chloride (inorganic compounds), which contradicted the general belief of the era that organic compounds could not be produced in a lab let alone from inorganic compounds.

The current definition of organic compounds is those substances that are primarily comprised of carbon. Inorganic compounds utilize the majority of elements and count compounds in the thousands, of which relatively few are new or recently created. Organic compounds include about half a dozen of the elements (N,O,P,S, & halides) and make hundreds of thousands of compounds with hundreds of new compounds occurring yearly. Organic compounds are a vital part of our life in fuel, food, medicine, materials (plastics, textiles), plants, animals, etc.

Functional Groups Organic compounds are named according to their functional groups and organized into “organic families”. Functional groups are useful to classify organic compounds – Compounds with the same functional groups have similar physical properties. – Compounds with the same functional groups behave similarly in chemical reactions (chemical properties).

Organic Families in this Course AlkanesThiols AlkenesAldehydes AlkynesKetones AromaticsCarboxylic acids AlcoholsEsters EthersAmines Alkyl halidesAmides

How do we deal them? IUPAC has devised a standardized method for naming organic compounds. The system generally follows the pattern: Prefix + Root + Suffix – Root - – Suffix - – Prefix –

Prefixes for Root Names Number of CarbonsPrefix

Alkanes (C n H 2n+2 ) contains only single bonds between carbon atoms in the chain this means the compound is saturated names end in –

Draw and name the following alkanes. Ex. 1 CH 4 Ex. 2 C 2 H 6 Ex. 3 C 3 H 8 Ex. 4 C 4 H 10

Try drawing C 4 H 10 a different way...

Isomers A chemical species with the same number and types of atoms as another chemical species, but possessing different properties. There are structural isomers, geometric isomers, optical isomers, and stereoisomers.

Ex. 5 Draw all the possible structural isomers for C 7 H 16

Hydrocarbon with Side chains! more complex hydrocarbons can have side chains name hydrocarbons with side chains by identifying the longest chain first, then the groups that are attached to it pick the numbering that gives the lowest combination of numbers any side chain uses the same prefixes as listed in table but the ending gets changed to –yl - e.g. meth  methyl multiple of the same type of side chain and we use the prefixes di, tri, tetra... When putting the name all together arrange multiple side chains in alphabetical order

Number of CarbonsSide Chain

Hydrocarbon with side chains! Try naming the following structures.

Cyclic Alkanes (C n H 2n ) named just like alkanes except the prefix cyclo- is added

Practice- Draw the following 3-methylhexane 2,3-dimethylhexane 3-ethyl-2-methylpentane

1.2 Alkenes (C n H 2n ) and Alkynes (C n H 2n-2 ) these are hydrocarbons with at least one double or triple bond double bond, name ends in –ene triple bond, name ends in –yne multiple of the same type of bond → use the prefixes di, tri, tetra... start numbering the carbons at the end that is closest to the multiple bond and insert the number before the suffix (ending)

Hydrocarbons - Nomenclature -C-C-C-C-C=C- C - C C

Hydrocarbons - Nomenclature Geometric isomers – The C=C bond does not rotate. – Groups attached to the double bonded carbons can form in two different positions. – Prefix cis- for “same side” and trans- “for opposite si -C-C-C=C-C- -C C-C-C=C-C- -C

Geometric Isomers