3.1 intro to organic chem Flashcards
what is a functional group?
group of atoms responsible for a molecules characteristic reactions
what is molecular formula?
giving the actual number of atoms of each element in a molecule
eg c2h6
what is structural formula?
shows atoms carbon by carbon withe attached h and functional groups
eg ch3ch2ch3
what is displayed formula?
shows how all atoms are arranged and bonds between them
what is empirical formula?
simplest whole number ratio of atoms of each element in a compound
eg ch3
what is general formula?
an algebraic formula describing any member of a family of compounds
eg cnh2n
what is a homologous series?
family of compounds w same general formula, same functional group and consecutive members increase by ch2 so phys properties change slightly but chem same so react similar
what is skeletal formula?
shows bonds of carbon skeleton only with any functional groups. h and c arent shown- c is at each junction
alkanes
CnH2n+2
suffix- ane
prefix- number of c atoms
saturated (all carbons has 4 single bonds)
eg C3H8
halogenoalkanes
alkane but one or more H atoms replaced by a halogen
prefix- bromo, chloro etc
eg CH3Cl
cycloalkanes
CnH2n
suffix-ane
prefix- cyclo
ring of c with 2 h attached to each
branched alkanes
alkanes where all C arent in straight line
main chain with carbons coming off-branches are alkyl groups
eg 2-methylbutane
alkenes
CnH2n
suffix-ene
prefix- no of C
hydrocarbons w c=c
unsaturated- C on either end of = only bond to 3 others
alcohols
CnH2n
suffix-ol
prefix-hydroxy
OH (hydroxyl functional group)
aldehydes
R-CHO
suffix-al
prefix-oxo
one of end C has double bond to O and single bond to H
ketones
R-CO-R’
suffix- one
prefix-oxo
C=O bond but not on end C
R and R’ are alkyl groups with may/not be same
carboxylic acid
R-COOH
suffix- oic acid
double bond to o and single to OH
why do we need IUPAC names?
so scientists across the world can communicate and understand
how do you number chain?
so you use the lowest numbers eg instead of 6-methylhexane you could number from other side to have 1-methylhexane
priority in nomenclature
(which to give lowest number)
halogens (low priority)
alkyl groups
alkenes
others (high priority)
what is a mechanism?
breaks reaction into sequence of stages
use curly arrows to show where bonds are made/broken
where do curly arrows start and end?
start at bond or lone pair
end where new bond formed
what is an isomer?
molecules with same molecular formula but put together in diff way
what is a structural isomer?
same molecular formula but diff structural formula
3 types of structural isomer
chain, position, functional group
what is chain isomerism?
same functional group, diff arrangement of C skeleton
what is position isomerism?
same skeleton and same atom/group of atoms attached but attached to diff carbons
what is functional group isomerism?
same atoms arranged into diff functional groups
which functional groups are functional group isomers of each other? 4
alcohol and ether
aldehyde and ketone
carboxyllic acid and ester and hydroxylaldehyde and hydroxyketone
cycloalkane and alkene
what is a stereoisomer?
same structural formula but different arrangement of atoms in space
what is an E/Z isomer?
a stereoisomer that occurs in a molecule with a c=c double bond
what shape are c=c and atoms around in a e/z isomer?
C=C bond and atoms bonded to them lie in same plane- trigonal planar
smaller alkenes eg ethene- planar
larger alkenes- only c=c planar
atoms attached to each c form equilateral triangle
can atoms rotate around a c=c bond?
no
e/z isomerism in alkenes
caused by restricted movement
if C=C have diff species attached, arrangement is important
E-isomer
matching groups across double bond from each other
Z-isomer
matching groups both above/below double bond (zame zide)
when do you have to use Cahn-Ingold-Prelog priority rules?
when c=c surrounded by 4 diff species
Cahn-Ingold-Prelog priority rules:
Assign priority of 2 atoms to each side of double bond by looking at atoms directly bonded to C
Atom w higher atomic number on each side has priority
If same, look at next atom
If highest priority on same size-z if not-e