Fundamentals of Organic Chemistry CHONCCHONC bonds

What is organic chemistry? study of carbon, the compounds it makes, and the reactions it undergoes over 16 million carbon-containing compounds are known because the C-C single bond (348 kJ/mol) and the C-H bond (412 kJ/mol) are strong, carbon compounds are stable carbon can form chains and rings

Empirical, molecular & structural formulas 2

empirical formula – simplest ratio of atoms in a molecule molecular formula – actual numbers of atoms in a molecule Empirical Formula Molecular Formula CH 4 CH 3 C2H6C2H6C2H6C2H6 CH 2 O C 6 H 12 O 6 CH 2 C4H8C4H8C4H8C4H8 C 8 H 16

structural formula unambiguously shows how the atoms are bonded together can use condensed structural formulas – bonds are omitted, repeated groups put together, side chains put in brackets CH 3 CH 2 CH 2 CH 2 CH 2 CH 3 – or even CH 3 (CH 2 ) 4 CH 3 CH 3 CH(CH 3 ) CH 2 CH 3

condensed

skeletal formula – every vertex or end represents a carbon – hydrogens are implied

Isomers structural isomers: compounds with the same molecular formula but different structure (arrangement of atoms)

ifferent isomers have different and different such as melting point and boiling point different isomers have different chemical properties and different physical properties such as melting point and boiling point

Structural Formulas for C 4 H 10 O Isomers

hydrocarbon chains where all the bonds between carbons are SINGLE bonds hydrocarbon chains where all the bonds between carbons are SINGLE bonds therefore the chain is said to be saturated with hydrogen therefore the chain is said to be saturated with hydrogen draw out and write the structural formulas for all isomers that can be formed by: – CH 4 C 2 H 6 C 3 H 8 C 4 H 10 C 5 H 12 C 6 H 14 Richard Thornley 2:54 Structural formulas for the isomers of non- cyclic alkanes up to C 6 Alkanes

1.determine the longest carbon chain – use the prefix to denote the number carbons – ending is -ane Naming the isomers (IUPAC) of non-cyclic alkanes up to C 6 1 Meth- 2 Eth- 3 Prop- 4 But- 5Pent- 6Hex- Monkeys Eat Peeled Bananas

1.Richard Thornley 3:35Richard Thornley 3:35 2.Determine the longest carbon chain – Use the prefix to denote the number carbons Naming the isomers (IUPAC) of non-cyclic alkanes up to C 6 1 Meth- 2 Eth- 3 Prop- 4 But- 5Pent- 6Hex- Monkeys Eat Peeled Bananas

3.use the suffix “-ane” to indicate that the substance is an alkane 4.number the carbons in the chain consecutively, starting at the end closest to a substituent (groups attached to the main chain)…”most busy end”

5.name and number the location of each substituent – the name of the substituent will be written before the main chain – alkyl groups are the simplest substituents (yl ending) CH 3 is methyl C 2 H 5 is ethyl (CH 3 -CH 2 ) C 3 H 7 is propyl C 4 H 9 is butyl 6.use prefixes di-, tri-, tetra-, to indicate when there are multiple side chains of the same type 7.use commas to separate numbers and hyphens to separate numbers or letters. 8.name the side chains in alphabetical order

How about C 5 H 12 ? The isomers are: Pentane 2-methyl-butane 2,2-dimethyl propane

Nomenclature Practice Name this compound Step #1: For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon carbons = nonane

Nomenclature Practice Name this compound carbons = nonane Step #2: When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl. CH 3 = methyl chlorine = chloro

Nomenclature Practice Name this compound carbons = nonane CH 3 = methyl chlorine = chloro Step #3: The positions of substituent groups are specified by numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching. 19 NOT 91

Nomenclature Practice Name this compound carbons = nonane CH 3 = methyl chlorine = chloro Step #4: The location and name of each substituent are followed by the root alkane name. The substituents are listed in alphabetical order (irrespective of any prefix), and the prefixes di-, tri-, etc. are used to indicate multiple identical substituents. 2-chloro-3,6-dimethylnonane

Structural formulas for the isomers of straight chains alkenes have a double bond between two or more of the carbons (alkynes have a triple bond) the carbons are not as many hydrogens because double bonds are present the carbons are unsaturated, not as many hydrogens because double bonds are present Alkenes and Alkynes Richard Thornley (1:37)

1.suffix changes to “-ene” for alkenes and “- yne” for alkynes 2.when there are 4 or more carbon atoms in a chain, the location of the double/triple bond is indicated by a number 3.begin counting the carbons closest to the end with the double or triple bond – numbering the location of the multiple bonds takes precedence over the location of any substituents but-1-ene but-2-ene methyl propene Naming the isomers (IUPAC) of straight chain alkenes or alkynes up to C 6

ene Naming Practice!!! choose the correct ending

ene determine the longest carbon chain with the double bond

assign numbers to each carbon ene

assign numbers to each carbon ene

1-hexene ene attach prefix (according to # of carbons)

determine name for side chains 1-hexene ethyl methyl

2-ethyl-4-methyl-4-methyl-1-hexene ethyl methyl attach name of branches alphabetically

group similar branches 2-ethyl-4-methyl-4-methyl-1-hexene ethyl methyl

group similar branches 2-ethyl - 4,4 - dimethyl hex-1-ene ethyl methyl

Structural formulas for the isomers of the straight chain alkenes up to C 6 alkenes have a double bond between two or more of the carbons – chains are unsaturated suffix changes to -ene when there are 4 or more carbon atoms in a chain, the location of the double bond is indicated by a number begin counting the carbons closest to the end with the C=C bond Alkenes

draw the structural formulas for all isomers that can be formed by each – C 2 H 4 – C 3 H 6 – C 4 H 8 – C 5 H 10 – C 6 H 12 Richard Thornley (1:37) These are only straight chain isomers.

pent – 1 – ene pent – 2 – ene

Functional Groups a part of the molecule that stands out as an unusual or unique part of the molecule add these somewhere on alkanes and alkenes the molecule often has certain characteristics based on a functional group the entire class of compounds is often named according to the functional group they contain “R” in a structural formula of a molecule just stands for any other atoms other than the functional group website on functional groups click here

carboxyl - found in carboxylic acids - part of amino acids - putrid smelling

ester - found in esters - sweet smelling

carbonyl - found in ketones - sweet, minty, camphor smelling

hydroxyl - found in alcohols - sweet, camphor smelling

amino - found in amines - fishy smelling - in amino acids

humans can tell the difference between 10,000 different odors a more distant sense allowing us to detect small concentrations of airborne substances – must be a gas therefore cannot smell ionic compounds since they are normally solids at room temperature molecules fit into certain receptors sites in the human body as a result of their shape – signals are then sent to the brain Smells

compounds that have similar smells have similar structural formulas polar molecules may “stick” to receptor sites better than non-polar

the molecular subunits/building blocks of proteins (the essential building blocks for living organisms) 20 different amino acids are used to synthesize almost all the proteins in almost all living cells Amino Acids/Proteins

protein formation – link is between carboxyl group on one a.a. and the amino group on the other. – water is formed and remaining N and C link together called a peptide bond

Protein movie