Fluxionality and Stereoisomerism Flashcards
Conformations/conformers
structures that differ only because of rotations around single bond; not isomers
Nomenclature of alkanes
first identify longest chain of C atoms, then add prefixes to the name of the longest chain to indicate positions of substituents, numbered based on which C they are connected to
2 carbon chain name
ethane
3 carbon chain name
propane
4 carbon chain name
butane
5 carbon chain name
pentane
6 carbon chain name
hexane
7 carbon chain name
heptane
8 carbon chain name
octane
9 carbon chain name
nonane
10 carbon chain name
decane
Stereoisomers
molecules that have the same molecular formula and the same atomic connectivity (from the same structural isomer)
Geometric isomers
distinguishable arrangement in space around bonds that cannot rotate freely (double bonds or rings)
Cis isomer
both methyl groups on the same side of the double bond
Trans isomer
methyl groups on opposite sides
Characteristics of geometric isomers
different physical properties, different substances
Enantiomers
molecules that are mirror images of each other but cannot be superimposed; chiral
Chiral
non superimposable mirror images of each other
How to determine a chiral center
Find sp3 hybridized atoms bonded to four distinct groups
Characteristics of enantiomers
same chemical and physical properties, differences occur when substances interact with other chiral molecules or chiral environments
Chiral center
atom bonded to 4 different groups
Intermolecular forces
any attractive forces between molecules
Viscosity
measure of a liquid’s resistance to flow
Patterns of LDFs
increase with increasing electrons, linear shapes have greater surface area so greater LDFs, compact molecular geometry has weaker LDFs
