chemistry of the covalent compounds of carbon h b n o si p s f cl br i h c nof pscl br i si organic...
TRANSCRIPT
CHEMISTRY OF THE COVALENTCOMPOUNDS OF CARBON
H B N O Si P S F Cl Br I
H C N O F
P S Cl
Br
I
Si
Organic Chemistry Organic Chemistry
COMBINED WITH A FEW OTHER COMMON ELEMENTS:
B
Millions of things Millions of things contain organic contain organic
molecules….molecules….
UNIQUE PROPERTIES OF CARBONUNIQUE PROPERTIES OF CARBON
Carbon is TETRAVALENT - whichmeans it bonds four times….
Carbon is one of the few elements that can form chainswith itself…
C-C-C-C-C-C-C-C-C
Carbon can also form BRANCHED NETWORKS and RINGS
C
CCC
CC
CC C C C
C C C
C C
Most organic Most organic molecules have no molecules have no
charge….charge….
Most organic molecules contain C-C and C-H bonds which are non-polar…water, which has slight charge, is polar
Because of this, most organic molecules do not dissolve in water – For example, oil and water do not mix!
Most organic molecules are gases or quickly evaporating liquids at room temperature because they have no charge – they have weak physical bonds (London Dispersion bonds)
Organic molecules will not have charge unless they contain a bond with polarity
Those that do have slightly charged bonds – like C-O or O-H bonds (as in alcohols) dissolve well in water!
Water - has slight charge…is a liquid
Methane – has no charge…is a gas
NO ATTRACTION
Methanol – Has slight charge – is a liquid and dissolves well in water
ATTRACTION!
Water - has slight charge…is a liquid
Hydrocarbons – contain hydrogen and carbon bonds
Aliphatic hydrocarbons – chains of carbons and hydrogens
Aromatic hydrocarbons – contain benzenec
Alkanes – all single bonds
Alkenes – has some double bonds
Alkynes has some triple bonds
saturated unsaturated
Functional groups – altered hydrocarbons
-Ether-Ester-Aldehyde-Ketone-Carboxylic acid-alcohol
Aliphatic HydrocarbonsAliphatic Hydrocarbons
• Hydrocarbons are compounds composed Hydrocarbons are compounds composed of carbon and hydrogen in chainsof carbon and hydrogen in chains
• Aliphatic – meaning chains of carbons – Aliphatic – meaning chains of carbons – either straight or branched chainseither straight or branched chains
Aliphatic HydrocarbonsAliphatic Hydrocarbons
• Unsaturated:Unsaturated: contains carbon-contains carbon-carbon double or carbon double or triple bonds.triple bonds.
C C C
H H
H
H
H
H
• Saturated:Saturated: contains contains all all carbon-carbon carbon-carbon single bonds.single bonds.
C C
H
H
H
H
H
H
Common Hydrocarbon TypesCommon Hydrocarbon Types
C CC C
C
H
H
H
H
HH
H H
H
H
H
HC C
C
C
C
H
H
H
H
H
H
H
H
H H
H
H
C C
H
CH
C
H
H
H
HH
H
C C CH H
H
H
C C C C
H
H
H
C
H
H
H
H
H
H C C C C
H
H H
H
H
H H
ALKANESALKANESCCnnHH2n+22n+2
ALKENESALKENESCCnnHH2n2n
ALKYNESALKYNESCCnnHH2n-22n-2
onlyonlysinglesinglebondsbonds
at leastat leastoneonedoubledoublebondbond
at leastat leastoneonetripletriplebondbond
Structural Formulas – show the Structural Formulas – show the structure of the atomsstructure of the atoms
CondensedStructuralFormulas
CH3CH2CH2CH2CH3
somebondsshown
Unbranched(“linear”) Alkane
Branched Alkane
CHCH CH3CH3CH2
CH3CH3
CH3CHCH2CHCH3
CH3 CH3
CH2CH2 CH3CH3CH2
Molecular Formula – Tells me nothing about Structure – just how manyof each element there are!
C7H16C5H12
CH3CH(CH3)CH2CH(CH3)CH3
StructuralFormulas
C C CH H
H
H
H C C C C
H
H H
H
H
H H
CH3CH2CH=CH2
CH3CH2-CH=CH2
H-C C-CH3
HC CCH3
CH CCH3
or
Condensed NotationCondensed Notation
Alkene
Alkyne
CH3 CH
CH3
CH
CH2
CH2 CH3
CH3
CH3CH(CH3)CH(CH2CH3)CH2CH3
EVEN COMPLICATED BRANCHED STRUCTURESEVEN COMPLICATED BRANCHED STRUCTURESCAN BE WRITTEN ON A SINGLE LINECAN BE WRITTEN ON A SINGLE LINE
Condensed NotationCondensed Notation
for this reason manyhandbooks usecondensed notation
note use of parentheses -these atoms are attached to the Carbon atom that they follow
BranchedAlkane
C C CH3H CH3 C C CH2CH3
CH3CH2CH2CH2CH3 CH3 C CH3
CH3
CH3
C C CH3CH3
H
H
CH3CH2CH CH2
Skeleton NotationSkeleton Notation
Cyclic MoleculesCyclic Molecules
• For some molecules, the carbon For some molecules, the carbon chain may close on itself to form a chain may close on itself to form a ring.ring.
• These types of substances are called These types of substances are called cyclic molecules.cyclic molecules.
• These do not follow the general These do not follow the general formulas for alkanes, alkenes, and formulas for alkanes, alkenes, and alkynes (Calkynes (CnnHH2n+22n+2, C, CnnHH2n2n, and C, and CnnHH2n-22n-2))
Examples of Cyclic Examples of Cyclic MoleculesMolecules
C C
C
CH2 CH2
CH2
H H
H
HH
H
C
C C
C CH2
CH2 CH2
CH2
H
H
H
H
H H
HH
C C
C
C
C
CH2 CH2
CH2
CH2
CH2
H H
H
H
H
H
HH
HH
Cyclopropane C3H6
Cyclobutane C4H8
Cyclopentane C5H10
Testosterone
How to name compounds…How to name compounds…
Prefixes for organic are different than traditional naming…
Endings: -ane = single bonds – ene = double bonds – yne = triple bonds
Groups are named according to the number of carbon chains in the group….
The group has the ending –yl if it is a carbon group – the group has the ending –o if it is a halogen
-CH3 methyl group -CH2CH3 ethyl group
C
-Cl chloro group
Longest chain….? Six carbons….
Bond types….? All single bonds….
Hex….
-ane….
Attached groups…? -CH3 = methyl
Number from what side…?
The right….
Why…?The group is attached to carbon 3, and not carbon 4
3-methyl hexane
• Nomenclature for other types of hydrocarbons…Nomenclature for other types of hydrocarbons…
1, 1 dimethyl cyclobutane
•Longest chain…?
•Did you include the entire double bond…?
•Start numbering from what end…?
•Is the double bond or attached groups more important…?
•How many groups are attached…?
•What are they?
•Remember to report the groups alphabetically….!
•Longest chain…?
•Did you include the entire double bond…?
•Start numbering from what end…?
•Is the double bond or attached groups more important…?
•How many groups are attached…?
•What are they?
•Remember to report the groups alphabetically….!
5-chloro 7-methyl - 3 – nonene
CHC CCH2 CH2
CH2CH2CH2CH3CH3
C CH3
Name this sucker….! 4-butyl 2-methyl 1, 5 heptene-yne
• Important things to remember…Important things to remember…
• Double and triple bonds are Double and triple bonds are most most important when counting the longest important when counting the longest chainchain
• Always include Always include bothboth the double and triple bond in the longest chain – even the double and triple bond in the longest chain – even if it isn’t the most number of carbons!if it isn’t the most number of carbons!
• Start counting from the end closest to the double or triple bond – Start counting from the end closest to the double or triple bond – whichever has the lowest numberwhichever has the lowest number
• If there is a tie, and only then, do double bonds take priority over triple If there is a tie, and only then, do double bonds take priority over triple bondsbonds
• If there isn’t a double or triple bond, find the longest continuous chain of If there isn’t a double or triple bond, find the longest continuous chain of carbons, and start counting from the end closest to an attached group – carbons, and start counting from the end closest to an attached group –
• It doesn’t matter what the group is – all groups have the same importance It doesn’t matter what the group is – all groups have the same importance – CH– CH33, -CH, -CH22-CH-CH33, -Cl, etc., -Cl, etc.
• If there is a tie, start counting from the end that has the If there is a tie, start counting from the end that has the mostmost groups on groups on the lowest numberthe lowest number
Which end do you number from? Cl
CH3CCH2CH2CCH3
CH3
CH3
Cl
CH3CCH2CH2CCH3
CH3
CH3
• Great websites for tutorials….Great websites for tutorials….
http://www.chem.ucalgary.ca/courses/351/orgnom/index.html
http://www.cem.msu.edu/~reusch/VirtualText/nomen1.htm
http://en.wikipedia.org/wiki/IUPAC_nomenclature_of_organic_chemistry
http://chemistry.boisestate.edu/people/richardbanks/organic/nomenclature/organicnomenclature1.htm
http://www.chembio.uoguelph.ca/educmat/chm19104/nomenclature/quizes.html
http://www.quia.com/jg/65803.html
http://eppe.tripod.com/orgtable.htm
http://www.cem.msu.edu/~reusch/VirtualText/Questions/Nomencl/nomencl.htm
http://www.chemguide.co.uk/atoms/bonding/vdw.html
Boiling points of various hydrocarbons…
Why do they increase…?
•Boiling point as we halogenate, or add a halogen to a hydrocarbon, goes….
•Up! Why????
•Methane = -1620C
•Fluoromethane = -78.20C
•Difluoromethane = -51.60C
•Trifluoromethane = -50C
•Tetrafluoromethane = -1280C
•Why would we want to halogenate a hydrocarbon…?
•Does it matter what halogen you add…?
1.The compressor compresses cool Freon gas1.The compressor compresses cool Freon gas, causing it to become , causing it to become hot, hot, high-pressure Freon gashigh-pressure Freon gas (red in the diagram above). (red in the diagram above).
2.This hot gas runs through a set of coils so it can dissipate its heat, and it 2.This hot gas runs through a set of coils so it can dissipate its heat, and it condenses into a condenses into a liquidliquid..
3.The Freon liquid runs through an expansion valve, and in the process it 3.The Freon liquid runs through an expansion valve, and in the process it evaporates to become evaporates to become cold, low-pressure Freon gascold, low-pressure Freon gas (light blue in the (light blue in the diagram above).diagram above).
4.This cold gas runs through a set of coils that allow the gas to absorb heat 4.This cold gas runs through a set of coils that allow the gas to absorb heat and cool down the air inside the building.and cool down the air inside the building.
Halogenated hydrocarbons are used as refrigerants…
CH3
CH2CH2 CH3CH3CH2 CH2 CH2
Structural Isomers…
Molecules that have the same molecular formula, meaning same numbers of carbons and hydrogens, but different structures…
CH2CH2CH3CH3
CH2 CH2 CH2 CH2
Isomers of octane…..there are 18 different arrangements!
Octane
2-methyl heptane
Are these both octane though?
CH3
CH2CH2 CH3CH3CH2 CH2 CH2
Structural Isomers…
The problem is that some chemists generically refer to both of the following compounds as octane, since they both contain 8 carbons and 18 hydrogens…
CH2CH2CH3CH3
CH2 CH2 CH2 CH2
Octane
2-methyl heptane
The official naming system, the IUPAC naming system, does not call both of these molecules octane though!
Look at these two molecules - both of these molecules are generically referred to as structural isomers of hexane, because they both have 6 carbons and 14 hydrogens (C6H14). They don’t have the same IUPAC name at all – they are totally different molecules, with totally different properties!
CH3-CH2 - CH2-CH2-CH2-CH3CH3-CH2 - CH2-CH2-CH2-CH3
CH3
CH3-CH2 - CH-CH2-CH3
CH3
CH3-CH2 - CH-CH2-CH3
•Molecules that have the same molecular formula, but differ in how groups attached to the double bond are oriented
•Must have a double bond, and different groups on both the left and right sides!
Geometric Isomers
Cis means same side…
Trans means opposite side…
•This doesn’t happen with a single bond…
•The atoms are free to rotate around the single bond, to form both molecules….
•With a double bond, the atoms are locked into place by the p orbitals bonding in the double bond!
Geometric Isomers
Both are the same molecule!
1,2 dichloroethane
2 different molecules:
trans – 1,2 dichloroethene
cis – 1,2 dichloroethene
Geometric Isomers
Which are isomers, and which are the same molecule…?
H HCH3
C C
H H CH3
C C
H
HH HCH3
C C
H H CH3
C C
H
H
Same molecule..
CH2CH3H
H
CH3
C C
H
CH3
C C
HCH2CH3
CH2CH3H
H
CH3
C C
H
CH3
C C
HCH2CH3
Isomers!
To have geometric isomers:
1.You must have a double bond in the molecule2.You must have two different groups on the left hand side of the bond, and two different groups on the right hand side of the double bond. The left side groups do not have to be the same as the right side groups!
CH3
CH3
H
H CH3
C C
H
CH3
C C
HCH3
CH3
H
H CH3
C C
H
CH3
C C
H
Isomers!
H
H
CH3H
CH3
CH3
C C
CH3
C C
H
H
H
CH3H
CH3
CH3
C C
CH3
C C
H
Same molecule..
Stereoisomers
•Molecules that have the same molecular formula, have the same sequence of bonded atoms, but differ in their 3-d orientation!
•Stereoisomers can be non-superimposable mirror images!
•We call the carbons that they are attached to chiral, or asymmetric!
•This means they are non-symmetrical!
•Our hands are chiral!
- In nature, only one stereoisomer of biological molecules is usually present (example – amino - In nature, only one stereoisomer of biological molecules is usually present (example – amino acids)acids)- In medicine, different stereoiomers of a compound may have substantially different biological - In medicine, different stereoiomers of a compound may have substantially different biological effects.effects.- For example, for certain cancer drugs, such as cisplatin and leucovorin, only one of the two - For example, for certain cancer drugs, such as cisplatin and leucovorin, only one of the two stereoisomers are effective in combating cancer – the other stereoisomer is either ineffective or stereoisomers are effective in combating cancer – the other stereoisomer is either ineffective or poisonous!poisonous!- Robutissin contains D-methorphan – a powerful cough suppressant – the stereoisomer of this - Robutissin contains D-methorphan – a powerful cough suppressant – the stereoisomer of this molecule, L-methorphan, is an illegal opiate that has totally different effects in the body!molecule, L-methorphan, is an illegal opiate that has totally different effects in the body!- How do they separate stereoisomers, if their only difference is the fact that they are mirror - How do they separate stereoisomers, if their only difference is the fact that they are mirror images? Chemically, they look nearly identical!images? Chemically, they look nearly identical!
The two stereoisomers of the amino acid alanine…
D-methorphan D-methorphan L-methorphan L-methorphan
Benzene….Benzene….
•Any compound containing benzene is called an aromatic or arene compound…
•Any compound containing straight or branched chains of carbons is called aliphatic… Notice the resonance in the
benzene ring…
Common benzene compoundsCommon benzene compounds
toluene phenol anisole aniline xylene
cresol styrene benzoic acid salicylic acid
Benzene rings with two Benzene rings with two attached groups use a attached groups use a special naming system…special naming system…They use the ortho, meta, They use the ortho, meta, and para system…and para system…Ortho (o) means one Ortho (o) means one apart…apart…Meta (m) means two Meta (m) means two apart…apart…Para (p) means three Para (p) means three apart…apart…This only applies to This only applies to benzene rings with TWO benzene rings with TWO groups…groups…
Cl
CH3
p-bromo phenol
o-chloro toluene
Names…?Names…?
CH2CH3
CH3
Clm-ethyl anisole
2-chloro 3-ethyl toluene
1,4 dibromo aniline NH2
Br
Br
NH2
Br
Br
Benzene can also be called Benzene can also be called phenylphenyl when you when you want to treat it as an attached want to treat it as an attached
group….either name is acceptable!group….either name is acceptable!
3-ethyl-2-phenyl pentane 2-chloro-2-phenyl heptane
1,3,5 tri-nitro 1,3,5 tri-nitro toluene…toluene…
TNT!TNT!
CH3
NO2NO2
NO2
Dichloro-Diphenyl-Trichloroethane
DDT…
http://www.chem.ucalgary.ca/courses/351/orgnom/functional/func.htmlhttp://www.chem.ucalgary.ca/courses/351/orgnom/functional/func.html
CR
O
OR
CR
O
R
CR
O
OH
R O R
OHR
Functional Group Name Ending
•Alcohol -ol
•Aldehyde -al
•Ketone - one
•Ether - oxy (small) normal chain (large)
•Carboxylic Acid - oic acid
•Ester -yl -oate
CR
O
HCR
O
H
OH
CH3CHCH2CH3
CH2CH2CH2CH3C
O
H
CH2CHCH3C
O
alcohol…
Carboxylic acid…
aldehyde…
ketone…
2-butanol
1-pentanal
1-phenyl 1-butanone
CH3CH2CH2 C
O
HCH3CH2CH2 C
O
H
Aldehyde… 1-butanal
C
O
OHCH3CH2 C
O
OHCH3CH2 1-propanoic acid
Cl
CH2CHCH3C
O
CH3CH2
CH2CH2CH3C
O
CH3CH2
C
O
OHCH3CH2CH2
CH2CH3
O
CH3CHCH3
Carboxylic acid…
ketone…
ester…
ether…
ketone…
1-butanoic acid
3-hexanone
Ethyl butanoate
2-ethoxy propane
5-chloro 3-hexanone
OCH3CH2CH2 C
O
CH2CH3OCH3CH2CH2 C
O
CH2CH3
CH3C
O
OHCH3C
O
OH
H C
O
OHH C
O
OH
Ethanoic acid
Acetic acid (nickname!)
Methanoic acid
Formic Acid (nickname!)
H C
O
HH C
O
H
Methanal
Formaldehyde (nickname!)
Example Structures of complex organic molecules…
nicotine cholesterol
caffeine mescaline
CH3O
CH3O
OCH3
NH2N
N
N
N
O
O
CH3
CH3
CH3
HON
N
CH3H
Meth amphetamine
Think nomenclature is hard…?Think nomenclature is hard…?ZITHROMAX (azithromycin tablets and azithromycin for oral suspension) contain the active ingredient azithromycin, an azalide, a subclass of macrolide antibiotics, for oral administration. Azithromycin has the chemical name (2R,3S,4R,5R,8R, 10R,11R,12S,13S,14R)-13-[(2,6-dideoxy-3-C-methyl-3-O-methyl-α-L-ribo-hexopyranosyl) oxy]-2-ethyl-3,4,10-trihydroxy-3,5,6,8,10,12,14-heptamethyl-11-[[3,4,6-trideoxy-3- (dimethylamino)-β-D-xylo-hexopyranosyl]oxy]-1-oxa-6-azacyclopentadecan-15-one. Azithromycin is derived from erythromycin; however, it differs chemically from erythromycin in that a methyl-substituted nitrogen atom is incorporated into the lactone ring. Its molecular formula is C38H72N2O12, and its molecular weight is 749.00.