Wade:OrganicChemistryCh3
Terms
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- not cyclic
- acyclic
- hydrocarbon having only single bonds; a saturated hydrocarbon; general formula CnH2n+2
- alkane
- the group of atoms remaining after a hydrogen atom is removed from an alkane; an alkane-like substituent; symbolized by R-
- alkyl group
- the strain associated with compressing bond angles to smaller angles (less than 109.5); the strain associated with stretching bond angles to larger angles (greater than 109.5)
- angle strain or Baeyer strain
- a conformation with a 180 degree dihedral angle between the largest groups; usually the lowest energy conformation
- anti conformation
- hydrocarbon having a benzene-like aromatic ring
- aromatic hydrocarbon
- one of the six bonds (three up and three down) on the "chair" conformation of the cyclohexane ring that are parallel to the "axis" of the ring
- axial bond
- a compound containing two rings joined at nonadjacent carbon atoms
- bridged bicyclic compound
- the carbon atoms shared by two or more rings; three chains of carbon atoms connect them
- bridgehead carbons
- ring-flip; the process of one "chair" conformation of a cyclohexane flipping into another one (with all axial and equatorial positions reversed); the "boat" conformation is an intermediate for the chair-chair interconversion.
- chair-chair interconversion
- sterioisomers that differ only with respect to their cis or trans arrangement on a ring or double bond
- cis-trans isomers (geometric isomer)
- having two similar groups directed toward the same face of a ring or double bond
- cis isomer
- having two similar groups directed toward opposite faces of a ring or double bond
- trans isomer
- a rapid oxidation at high temperatures in the presence of air or oxygen
- combustion
- names that have developed historically, generally with a specific name for each compound; also called trivial name
- common name
- study of the energetics of different confirmations
- confirmational analysis
- structures that are related by rotations about a single bond; in most cases they interconvert at room temperature and are not true isomers
- conformations or conformers
- totally eclipsed conformation; usually the highest energy conformation
- dihedral angle equal to 0 degrees
- gauche confirmation; specific staggered confirmation; lower energy than eclipsed
- dihedral angle equal to 60 degrees
- "chair", "half-chair", "boat" and "twist boat"
- conformations of cyclohexane
- the most stable conformation of cyclohexane; with one part puckered up and another part puckered down
- "chair" conformation
- two hydrogens in the "boat" conformation pointing straight up
- flagpole hydrogens
- unstable conformation half way between the chair and the boat conformations of cyclohexane; part of the ring is flat in this conformation
- half-chair conformation
- isomers whose atoms are connected differently; they differ in their bonding sequence
-
constitutional isomers or
structural isomers - heating large alkanes to cleave them into smaller ones
- cracking
- cracking in the presence of a catalyst
- catalytic cracking
- catalytic cracking in the presence of hydrogen to give saturated mixtures of smaller alkanes
- hydrocracking
- containing a ring of atoms
- cyclic
- an alkane containing a ring of carbon atoms; general formula CnH2n
- cycloalkane
-
number of alkyl groups bonded to a carbon atom in a compound or an alkyl group:
primary(1st degree): C-R1
secondary (2nd degree): C-R2
tertiary (3rd degree): C-R3
quaternary (4th degree): C-R4 - degree of alkyl substitution
- strong steric hindrance between two axial groups on cyclohexane carbons with one carbon between them
- 1,3-diaxial interaction
- the angle between two specified groups in a Newman projection; differences in this angle result in the various conformations
- dihedral angle
- any conformation with bonds directly lined up with each other. one behind the other,in the Newman projection; dihedral angle equals zero
- eclipsed conformation
- one of the six bonds (three up and three down) on the cyclohexane ring that are directed out toward the "equator" of the ring
- equatorial bond
- molecule in which two or more rings share two adjacent carbon atoms
- fused-ring system
- a conformation with a 60 degree dihedral angle between the largest groups
- gauche conformation
-
the reaction of alkanes with halogens, in the presence of heat or light, to give products with halogen atoms substituted for hydrogen atoms
R-H + X2 -> R-X + HX X=F,CL,Br - halogenation
- heat given off when a mole of a compound is burned with excess oxygen to give CO2 and H2O in a bomb calorimeter; a measure of the energy content of a molecule
- heat of combustion
-
two compound that differ only by one or more -CH2- groups
example: C3H8 and C4H10 - homologs
- attracted to water; soluble in water
- hydrophilic
- repelled by water; insoluble in water
- hydrophobic
- the systematic names that follow the rules adopted by the International Union of Pure and Applied Chemistry
- IUPAC names
- a thin, volatile oil distilled from petroleum, with a boiling range higher than that of gasoline and lower than that of diesel fuel; once used for lanterns and heaters, but now most of this petroleum fraction is further refined for use as jet fuel
- kerosene
-
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-CH- group - methine group
- -CH2- group
- methylene group
- -CH3 group
- methyl group
- an alkane with all its carbon atoms in a single chain, with no branching or alkyl substituents
-
n-alkane or
normal alkane or
straight-chain alkane - method of drawing conformations of a molecule as if looking straight down the bond connecting two carbon atoms; reveals the eclipsed, staggered (skewed), gauche, and anti conformations
- Newman projections
- rating of the antiknock properties of a gasoline blend; the percentage of isooctane (2,2,4-trimethylpentane) in an isooctane/heptane blend that begins to knock at the same compression ratio as the gasoline being tested
- octane number
- another name for the larger alkanes that tend to be solid at room temperature
- paraffin "wax"
- the extra strain associated with the cyclic structure of a compound, as compared with a similar acyclic compound; composed of angle strain and torsional strain
- ring strain
- the strain associated with eclipsing of bonds in a ring; the resistance to twisting about a bond
- torsional strain
- having no double or triple bonds; having the maximum number of bonded hydrogen atoms in a hydrocarbon
- saturated
- a way of picturing conformations as if looking down at an angle toward the carbon-carbon bond
- sawhorse structures
- any conformation that is not precisely stagered or eclipsed (0,60,120,180 degrees)
- skew conformation
- bicyclic compounds in which the two rings share only one carbon
- spirocyclic compounds
- any conformation with the bonds equally spaced in the Newman projection
- staggered confirmation
- the interference between two bulky groups that are so close togather that their electron clouds experience a repulsion
-
steric hindrance or
steric strain - a side chain or appendage on the main (longest) chain of a hydrocarbon
-
substituent or
branch - the energy required to twist a bond into a specific conformation
-
torsional energy or
conformational energy - a conformation with a dihedral angle equal to zero between the largest groups; usually the highest-energy conformation
- totally eclipsed conformation