Organic Chemistry

Carbon• Has 4 valence electrons• Can have sp3 hybridization where substituted

groups are at 109.5o to one another.• Other hybridizations are possible.• Usually shares electrons• Can easily bond to itself and many other

elements• Can make straight chains of carbons or

branched chains• Can form single, double, and triple bonds to

itself and to some selective other atoms• Can polymerize

Alkanes• Contain only carbon and hydrogen• Have only single bonds. • Tetrahedral geometry• Characteristic reactions

– Halogenation• R-H + X2 R-X + HX

• Chlorine >Bromine• Tertiary>Secondary>Primary

– Combustion• R-H + O2 CO2 + H2O

– Pyrolysis(cracking)• Alkane H2 + smaller alkanes + alkenes

Alkanes

• Nomenclature – ending is ane.– Meth– Eth– Prop– But– Pent– Hex– Hept– Oct– Non– Dec

Alkyl Groups

Alkenes

• Contain only carbon and hydrogen• Have one double bond between two carbons. • The double bond makes alkenes unsaturated with respect to

hydrogen. • Trigonal planar geometry • If there are two or three double bonds

– Alkadiene– Alkatriene

• Characteristic reactions– Addition– C=C + Y-Z C-C Y Z

Alkenes

Alkenes• Structural isomers are those which have the

same chemical formula but differ in how the atoms are attached to one another.

• A cis-isomer has the two substituted groups on the same side of the double bond.

• A trans-isomer has the two • substituted groups on • opposite sides of the double • bond.

Alkenes

• Characteristic Reactions– Addition of hydrogen– Addition of halogens– Addition of hydrogen halides– Addition of sulfuric acid– Addition of water

Alkenes• Nomenclature – end with ene

– Eth– Prop– But– Pent– Hex– Hept– Oct– Non– Dec

Alkynes

• Contain only carbon and hydrogen

• Contain one triple bond between carbons

• Linear geometry

• Characteristic reactions of alkynes– Addition of hydrogen– Addition of halogens– Addition of hydrogen halides– Addition of water

Alkynes

• Nomenclature – end with yne

Functional Groups

• Hydrocarbons may have functional groups substituted for hydrogens.

• Such substitutions give carbon the capacity to form many, varied compounds with different reactivities from the original hydrocarbon.

• The possibilities are nearly endless.

Alkyl Halides

• RX– Give the number of the carbon where the

halide(s) appear. – Give the name of the halide (chloro, bromo,

iodo)– Write the name of the longest chain of

carbons.– C5H10Cl2 dichloropentane (must have

structure to determine the numbers of carbons that are substituted)

Alcohols

• ROH– Give the name of the longest chain of carbons

and end with –ol.– Primary – carbon with OH is connected to one

other carbon– Secondary – carbon with OH is connected to two

other carbons– Tertiary – carbon with OH is connected to three

other carbons– C5H11OH – pentyl alcohol or

pentanol(structure needed to determine number)

Aldehydes

• RCHO– Write the name of the longest carbon chain

and add -al for the ending. – Remember that the functional group here

must be on the last carbon in the molecule.

– C5H10O - pentanal

Ketones

• RCOR`– Write the name of the longest carbon chain

and end with -one. – Remember that the functional group, the

carbonyl (C=O) cannot be on the end of the molecule.

– Example

Carboxylic Acids

• RCOOH– Write the name of the longest carbon chain

and end with –oic acid. – Remember that the functional group (COOH)

must be on the end of the molecule. – These are organic acids and they contain one

ionizable hydrogen. – Example

Esters

• RCOOR`

• Write the name of the group (R`) and end it with –yl.

• Then write the name of the R-C group and end it with –oate.

• Example

Ethers

• ROR`

• Write the name of one of the R groups and then the name of the other one in alphabetical order.

• End with –ether.

• Example

Cyclic compounds

• Cycloalkanes

• Cycloalkenes

• Cycloalkynes

• Example

Aromatic Compounds

• These must contain a benzene ring.

• Benzene is C6H6 and may be indicated in several different ways.

• Positions on the ring may be indicated by ortho(1,2 positioning), meta(1,3 positioning), and para(1,4 positioning) prefixes.

• Examples

Amines

• RNH2 – primary amine• RNR` - secondary amine H• RNR` - tertiary amine R• These are organic bases. • They will combine with carboxylic acids to make

amino acids, the building blocks of proteins. • Examples

Amides

• RCONH2

• Write the name of the carbon chain and end with amide.

• Examples

Thiols

• RSH

• May be primary, secondary and tertiary.

• Analogs of alcohols so they will do the same reactions.

• Name the longest carbon chain and maintain the ending.

• Add the word thiol to it.