III. Isomers - compounds with the same molecularformula that have different structural arrangements.
A. The simplest alkane that can have isomers isbutane, with a molecular formula of C4H10:
structuralformula
ball and stick
normal-butaneaka n-butane
isobutaneaka i-butane
Isobutane as a gas for refrigeration systems, especially in domestic refrigerators and freezers, and as a propellant in aerosol sprays. When used as a refrigerant or a propellant, isobutane is also known as R-600a. Some portable camp stoves use a mixture of isobutane with propane, usually 80:20. Isobutane is used as a feedstock in the petrochemical industry, for
Butane gas is sold bottled as a fuel for cooking and camping. When blended with propane and other hydrocarbons, it is referred to commercially as LPG. It is also used as a petrol component, as a feedstock for the production of base petrochemicals in steam cracking, as fuel for cigarette lighters and as a propellant in aerosol sprays such as deodorants.
n-butanei-butane
n-butane:b.p. = -0.5 0C
i-butane:b.p. = -12 0C
B. Isomers have different chemical and physical properties.
Ex. Which isomer of butane has a higher boiling point?
C. As the number of carbon atoms increases,the number of possible isomers increases. This is one reason why there are so many organiccompounds.
Ex. butane (C4H10) has 2 isomersoctane (C8H18) has 18 isomersdecane (C10H22) has 75 isomers
ibuprofen is made of 2 isomers:
V. Functional Groups Many new organic compounds are formed when atoms other than C and H replace H in a hydrocarbon. These atoms or groups of atoms are called functional groups. The unchanged part of the remaining hydrocarbon is shown with an R:
R
rest of the hydrocarbon functional group goes here
Each type of functional group produces a uniqueclass (type) of compound and gives the compound distinct chemical and physical properties.
bond
A. Halides Functional group: F, Cl, Br, I
When the halogens (F, Cl, Br, I) replace a H atom in a hydrocarbon, the compound is called an organic halide or halocarbon.
Ex. Take methane CH4 and replace an H with a Cl
It was used as a refrigerant and is now used to
make polymers.
formula:methane
becomes
Cl
CH3Cl
PVC = polyvinylchlorides:
ethylene + chlorene = chloroethylene
9000 shellfishto produce1 gram ofTyrolian purple
Rubens: The discovery ofTyrolian purple
PCBs
Uses:plasticisers in paints and cementscasting agentsfire retardant fabric treatments and heat stabilizing additives for PVC electrical insulationadhesivespaints and water-proofingrailway sleepers
capacitorsinsulating fluids in transformersvacuum pump fluidshydraulic fluids
Between approximately 1947 and 1977, GE released up to 1,300,000 pounds (590,000 kg) of PCBs into the Hudson River
Polychlorinated biphenyl
TOXIC
A brominated flame retardant. It consists of twelve carbon, eighteen hydrogen, and six bromine atoms tied to the ring. Its primary application is in polystyrene foam that is used as thermal insulation in the building industry. Other uses are upholstered furniture, automobile interior textiles, car cushions and insulation blocks in trucks, packaging material, video cassette recorder housing and electric and electronic equipment.
1,2,5,6,9,10-Hexabromocyclododecane
TOXI
C
Ex. Chloroform. Used to be used as an anesthetic,but is toxic. Now used as a solvent and to produce dyes and pesticides. Replace 3 H’s with Cl’s.
methane
becomes
Cl|
Cl |Cl
H— C—
Ex. CFCs (chlorofluorocarbons) cause the ozone layer to be destroyed.
methane
Freon-22
DDT:
dichlorodiphenyltrichloroethane
TOXIC
C
C
Polytetrafluoroethylene: Teflon
TOXIC
B. Alcohols R—____Functional Group = ___________ group = OH
The OH group makes alcohols polar. Alcohols dissolve in water because H2O is polar:
Alcohol names all end in –___.
Start with:
HO
H
OH
Replace anH with an-___ group:
Ex:
End up with:
H
H
H
C H
____________
H
H
H
C
__________ ormethyl alcohol
OH
hydroxyl
ol
+-
+
-
+
methane
OHOH
CH3OH
Ex. __________ (ethyl alcohol) = drug, solvent, fuel
H
H
H
C
H
H
C H
___________ ________ or ethyl alcohol
Replace anH with an-OH group:
H
H
H
C
H
H
C
Ex. __________ alcohol (rubbing alcohol)
H
H
H
C
H
H
C H
___________ _________ or Isopropyl alcohol
Replace a_________H with an-OH group:
H
H
C H
H
H
C
H
C H
H
H
C
ethanol
ethane
OH
CH3CH2OH
isopropyl
propane
middle
OH
CH3CHOHCH3
ethylene glycol
Ethylene glycol is widely used as an automotive antifreeze and a precursor to polymers. In its pure form, it is an odorless, colorless, syrupy, sweet-tasting liquid. Ethylene glycol is toxic, and ingestion can result in death.
OH
OH
H
H
C
H
C H
Glycerin (glycerol):--> clear, sweet tasting, oily liquid--> used to keep dried fruits and pastry fillings moist, in toothpaste, hand creams, eye and ear drops,suppositories (for laxatives, eg), and as an antifreeze
H2SO4 for drying
aka nitroglycerin(dynamite)Also:
glycerin + nitric acid --> glycerol trinitrate