Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
178 Cards in this Set
- Front
- Back
amide
|
carbonyl and amine
|
|
geminal dihalide
|
carbon with two halogens bonded to it
|
|
vicinal dihalide
|
two adjacent carbons both bonded to halogens
|
|
alkoxy
|
-OR
|
|
hemiacetal
|
carbon with an -OH and -OR group along with one -R group
|
|
hemiketal
|
carbon with an -OH and -OR group along with two -R groups
|
|
mesyl group
|
sulfur with single bonded methyl group and two double bonded oxygens
|
|
tosyl group
|
sulfur with single bond to aromatic cyclohexane group and two double bonded oxygens
|
|
acetyl group
|
carbon with a carbonyl group as well as a terminal methyl group
|
|
acyl group
|
carbon with a carbonyl group and an R group
|
|
anhydride group
|
Two carbons each connected to R groups as well as carbonyls, connected together via an oxygen
|
|
aryl group
|
aromatic cyclohexane
|
|
benzyl group
|
aromatic cyclohexane bonded to a methyl group
|
|
hydrazine
|
two nitrogens bonded together via single bonds
|
|
hydrazone
|
nitrogen double bonded to an R group as well as a single bond to another nitrogen
|
|
vinyl group
|
two double bonded carbons
|
|
vinylic group
|
two double bonded carbons with a halogen bonded to one
|
|
allyl
|
two double bonded carbons with a methyl group bonded to one
|
|
nitrile
|
carbon triple bonded to a nitrogen
|
|
enamine
|
carbon single bonded to an R group and single bonded to an NRH, and double bonded to a CR2.
|
|
imine
|
a tautomer of en enamine, wherein the double previously double bonded CR2 group's double bond shifts to a single bond, providing electrons for a C=N-R group to be created
|
|
oxime
|
carbon single bonded to two R groups, and a =N-OH group.
|
|
nitro
|
carbon single bonded to one oxygen and double bonded to another
|
|
nitroso
|
a nitrogen double bonded to an oxygen
|
|
conformational isomers
|
different spatial arrangements of the same molecule. rotations around a sigma-bond
|
|
structural isomers
|
same molecular formula but different bond-to-bond connectivity
|
|
chirality
|
molecules that differ in reflections
|
|
achiral
|
exactly the same reflections of molecules
|
|
dextrotorary
|
rotates plane polarized light clockwise
|
|
levorotary
|
rotates plane polarized light counter clockwise
|
|
stereoisomers
|
two molecules with the same molecular formula and the same bond-to-bond connectivity that are not the same compound
|
|
what are two examples of stereoisomers?
|
enantiomers and diastereomers
|
|
what is resolution?
|
the separation of enantiomers
|
|
how do enantiomers relate chemically and physically?
|
they have the same chemical and physical characteristics except with reactions with other chiral compounds and reactions with polarized light
|
|
what are diastereomers?
|
they have the same molecular formula, have the same bond-to-bond connectivity, are not mirror images of eachother and are not the same compound
|
|
what is a geometric isomer?
|
they exist due to hindered rotation about a bond. Cis-isomers and Trans-isomers are examples
|
|
Do geometric isomers have different physical properties?
|
Yes they do.
|
|
Which, cis or trans, have a dipole moment?
|
cis has a dipole moment, while trans does not.
|
|
Which has stronger intermolecular forces?
|
Cis has stronger forces due to the dipole moment.
|
|
What does stronger intermolecular forces pertaining to geometric isomers infer about their physical properties?
|
Cis molecules have higher boiling points
|
|
What does a lack of symmetry among cis molecules infer about their physical properties?
|
They are unable to form crystals as readily due to their lack of stackability
|
|
Which has higher heats of combustion due to steric hindrance?
|
Cis molecules have higher heats of combustion because they have higher energy levels due to steric hindrance
|
|
Do diastereomers have different physical properties?
|
They have different rotation of plane-polarized light, as well as different melting and boiling points as well as solubilities.
|
|
What is the maximum number of optically active isomers found via?
|
The equation is 2^n, where n is the number of chiral centers
|
|
What are meso compounds?
|
They are compounds where two chiral centers can offset eachother creating an optically inactive molecule
|
|
Are meso compounds achiral?
|
Yes
|
|
Why are meso compounds considered achiral?
|
Because they have an internal plane of symmetry
|
|
What are epimers?
|
They are diastereomers that differ at only one chiral carbon
|
|
What are anomers?
|
They are the two possible diastereomers that form during an epimeric ring closure.
|
|
What is the chiral carbon of an anomer called?
|
Anomeric carbon
|
|
When the hydroxyl group on the anomeric carbon on glucose is oriented in the opposite direction to the methyl group, what is the anomer labeled as?
|
alpha
|
|
What about when the hydroxyl group is in the same direction?
|
It is labeled beta.
|
|
What governs boiling point trends in alkanes?
|
Intermolecular forces
|
|
When carbons are added to a single chain alkane, the molecular weight goes up increases intermolecular forces concurrently. What happens to the boiling point?
|
It goes up.
|
|
What does branching do to boiling point in alkanes?
|
It lowers the boiling point
|
|
Does melting point go up or down in alkanes with increased molecular weight?
|
It goes up
|
|
What does branching due to melting point of alkanes?
|
It increases it
|
|
Are alkanes soluble in water?
|
No
|
|
What are alkanes soluble in?
|
They are solube in benzene, carbon tetrachloride, chloroform, and other hydrocarbons
|
|
If an alkane contains a polar functional group, what happens to the polarity of the entire molecule and its solubility as the carbon chain is lengthened?
|
It goes down
|
|
Do alkanes have low density?
|
Yes
|
|
What happens during combustion?
|
An alkane reacts with oxygen, producing CO2, H2O and most importantly heat
|
|
Is combustion spontaneous?
|
No, it requires heat to occur, usually via a flame.
|
|
What type of reaction is combustion?
|
It is a radical reaction
|
|
If a molecule has a high heat of combustion, is it more or less stable than a similar molecule with a smaller heat of combustion?
|
A high heat of combustion correlates to the energy level of a molecule, inferring a less stable molecule
|
|
What happens if you react an alkane with F, Cl, and Br in the presence of heat or light?
|
Halogenation
|
|
Well what happens first in halogenation?
|
The first step is initiation.
|
|
What happens during initiation?
|
Light or heat cleaves a covalent bond between a two bound halogens. They both split leaving two identical radicals
|
|
What happens to these radicals after that, and what is the step called?
|
The next step is called propagation, and what happens is the halogen radical removes a hydrogen from the alkane, resulting in an alkyl radical.
|
|
What can this alkyl radical do to get rid of its radicalness?
|
It can hookup with a diatomic halogen molecule creating an alkyl halide and a new halogen radical.
|
|
Is this the end of our halo-radicals?
|
No! This reaction can continue indefinately, or it can go through the third and final step of halogenation.
|
|
What the third and final step of halogenation?
|
Termination
|
|
So what exactly happens in the termination step of halogenation?
|
Several things could happen. Two akyl radicals could react, the last halo-radicals can react with alkyl-radicals to form alkyl halides, or two halo-radicals can hookup
|
|
Is halogenation an endothermic or exothermic process?
|
It is exothermic
|
|
What is the stability chart for an alkyl radical?
|
3>2>1>Methyl
|
|
What type of geometry do alkyl radicals exhibit?
|
They exhibit trigonal planar geometry
|
|
When is the majority of product formed during halogenation?
|
The majority of the alkyl halides are formed during propagation
|
|
Are Pi-bonds more or less stable than Sigma-bonds?
|
They are less stable
|
|
Does this mean alkenes are more or less reactive than alkanes?
|
They are more reactive.
|
|
When dealing with alkenes, what should I keep in mind about the Pi-bonds?
|
They are electron hungry
|
|
What does this infer about acidity values of alkenes versus alkanes?
|
Alkenes are more acidic as a result of the willingness to gain electrons
|
|
What happens when a proton is moved away from a Pi-bond?
|
The Pi-bond of the alkene absorbs some of the negative charge
|
|
What does this do to the conjugate base?
|
It stabilizes it
|
|
How does substitution relate to thermodynamic stability of alkenes?
|
They more highly substituted, the more stable the alkene.
|
|
You're wrong! How come when you have addition reactions dealing with electrophiles the most substituted are the most reactive, it should be the opposite right?
|
Well a paradox exists due to the carbocation intermediate. A tertiary alkene will be a more stable carbocation, so it will proceed with greater frequency.
|
|
So which is right?
|
When dealing with electrophilic addition reactions of alkenes, the most reactive are the more substitituted
|
|
How do physical properties of alkenes work?
|
They work the same way as alkanes
|
|
Are alkenes soluble in water?
|
Slightly, and they have a lower density than water.
|
|
Which is more acidic, alkanes or alkenes?
|
Alkenes
|
|
What happens in an elimination reaction?
|
One or two functional groups are eliminated or removed to form a double bond.
|
|
What type of reaction is dehydration of an alcohol?
|
It is an E1 reaction
|
|
What happens in dehydration of alcohol reactions?
|
An alcohol forms an alkene in the presence of hot concentrated acid
|
|
Since it's an E1 reaction, that means it depends on the concentration of only one reactant, but which reactant does it depend on, the acid or the alcohol?
|
It depends on the concentration of the alcohol in this case.
|
|
What happens in the first step of dehydration of alcohols?
|
The acid protonates the hydroxyl group
|
|
What does this produce, and what was the purpose of protonating this new thing?
|
It produces water, which is a good leaving group. It wants to dump off the compound.
|
|
What happens next, and whats so special about this step?
|
This is the rate-determining step- the water drops off, forming a carbocation
|
|
Woo, carbocation. When I see carbocation I should think what?
|
Rearrangement possibilities exist, and stability of intermediate
|
|
What does carbocation stability follow the trend of?
|
It follows th same trend as radical stability?
|
|
What's that trend again?
|
3>2>1>methyl
|
|
So when would rearrangement occur?
|
It would only occur if a more stable carbocation could be made
|
|
What happens in the final step of dehydration of an alcohol?
|
A water molecule deprotonates the carbocation and the alkene is formed
|
|
What will the predominant product be a result of?
|
It will be the more stable, most substituted alkene.
|
|
What does the Saytzeff rule say?
|
It says that the major product of elimination will be the most substituted alkene.
|
|
What is dehydrohalogenation?
|
It's what happens when you take an alkane with a halogen and dump the halogen off in favor of making an alkene.
|
|
What are the two possibility routes for dehydrohalogenation to occur?
|
It can occur via E1 or E2
|
|
When would dehydrohalogenation occur via E1?
|
It would happen if a strong base is there
|
|
When would dehydrohalogenation occur via E2?
|
It would happen is there is a high concentration of a strong, bulky base
|
|
What happens first in the E1 reaction?
|
The halogen drops off in the first step.
|
|
What happens second in the E1 reaction?
|
The hydrogen is removed in the second step via the weak power of our weak base.
|
|
So the E1 reaction is multi-step or single-step?
|
Multi
|
|
What happens in E2 reaction?
|
The base removed a proton from the carbon next to the halogen-containing carbon and the halogen drops off, leaving an alkene.
|
|
So is the E2 reaction single or multi-step?
|
It is single step.
|
|
What does the bulky base of this E2 mechanism prevent?
|
It prevents an SN2 reaction, but if the base is too bulky, the Saytzeff rule is violated, leaving the least substituted alkene.
|
|
So what's an important thing to notice about the difference between these two pertaining to the power of the bases?
|
Well the E2 mechanism has a strong base, and it's so pimped out that it can pull the hydrogen off even without the decreased stability of an intermediate state like what occurs in the E1 mechanism.
|
|
What type of reaction of catalytic hydrogenation?
|
It is an addition reaction?
|
|
What type of catalyst is used in catalytic hydrogenation?
|
A heterogenous catalyst
|
|
What type of addition occurs usually?
|
Syn-addition
|
|
What are possible catalysts?
|
Ni, Pd, or Pt
|
|
So what actually happens?
|
You take an alkene and you turn it into an alkane
|
|
Is hydrogenation an endothermic or exothermic reaction?
|
It is an exothermic reaction.
|
|
Is it spontaneous?
|
No, it has a high energy of activation
|
|
What are heats of hydrogenation used to measure?
|
They are used to measure the relative stabilities is alkenes.
|
|
If something has a low heat of hydrogenation, is it unstable?
|
No it is considered stable
|
|
What happens with syn addition of an alkynes via hydrogenation?
|
It creases a cis alkene.
|
|
What does oxidation of an alkene produce?
|
It may produce glycols or it may cleave the alkene at the double bond
|
|
What is an example of a cleavage such as this?
|
Ozonolysis
|
|
If you add 1) O3 and 2) Zn,H2O, what happens to an alkene?
|
It will cleave the alkene at the double bond, producing two carbonyl groups
|
|
What happens to alkynes when they undergo ozonolysis?
|
They produce carboxylic acids
|
|
What is an electrophile?
|
It is an electron-loving species
|
|
What types of things are usually electrophiles?
|
Things with a positive charge, even if it is only from a momentary dipole.
|
|
What does the double bond of alkene function as pertaining to electrophiles?
|
It is an electron-rich environment, which will attract electrophiles
|
|
What rule is followed when you had a hydrogen halide to an alkene?
|
Markovnikov's rule
|
|
What does Markovnikov's rule state?
|
It states the hydrogen will add to the least substituted carbon of the double bond
|
|
What is the first step of electrophilic additition of a hydrogen halide to an alkene?
|
The hydrogen halide is a Bronsted-Lowry acid, so it will create a positively charged proton, which acts as an electrophile.
|
|
What is the second step of electrophilic additition of a hydrogen halide to an alkene?
|
The newly formed carbocation picks up the negatively charged halide ion.
|
|
Which is the slow step?
|
The first step is the slow step, and it determines the rate
|
|
What happens during this reaction is peroxide (ROOR) is present?
|
Bromine will add to the least substituted carbon
|
|
What is this known as?
|
Anti-markovnikov addition.
|
|
Will the other halides perform anti-markovnikov addition?
|
No, they still do Markovnikov, even in the presence of ROOR.
|
|
What are the most reactive alkenes, and why?
|
The most reactive are the most thermodynamically stable, because they also have the lowest activation energy and form carbocations the easiest.
|
|
What is hydration of an alkene?
|
It takes place when water is added to an alkene in the presence of an acid.
|
|
Does hydration of an alkene follow Markovnikov's rule?
|
Yes it does.
|
|
What is this reaction the reverse of?
|
It is the reverse of dehydration of an alcohol.
|
|
What circumstances drive an alkene toward alcohol formation?
|
Low temperatures and dilute acid
|
|
What circumstances drive an alcohol toward alkene formation?
|
High temperatures and concentrated acid
|
|
What is oxymercuration/demercuration?
|
It is another reaction which creates an alcohol from an alkene
|
|
Is oxymercuration/demurcuration a one or two step process?
|
Two step process
|
|
Does it usually result in rearrangement of the carbocation?
|
Very rarely.
|
|
What happens in the first step of oxymercuration/demurcuration?
|
The mercury-containing reagent partially dissociates to +Hg(OAc)
|
|
What does the +Hg(OAc) do once its formed?
|
It acts as an electrophile creating a mercurinium ion
|
|
What does water do to the mercurinium ion?
|
It attacks the mercurinium ion to form the organomercurial alcohol.
|
|
What type of addition is this?
|
Anti-addition
|
|
What is the second step?
|
It is the demercuration to form the alcohol
|
|
How is this performed?
|
By the addition of a reducing agent and base.
|
|
What is hydroboration?
|
It is another mechanism to produce an alcohol from an alkene
|
|
Does it follow Markovnikov?
|
No, it is anti-markovnikov
|
|
What type of addition is it?
|
It is syn addition
|
|
So what happens in hydroboration?
|
Take an alkene and add a hydrogen and alcohol to the same side of two carbons, via anti-markovnikov.
|
|
What happens if you add Br2 or Cl2 to an alkene?
|
They add via anti-addition to form vicinal dihalides
|
|
What is an important difference between a similar reaction involving alkanes?
|
Oh, you mean halogenation, right? Well alkene halogenation doesn't require heat or light
|
|
What happens if you perform alkene halogenation in the presence of water?
|
Water will act as a nucleophile instead of a bromide/chloride ion.
|
|
What does this produce?
|
It produces an anti-addition halohydrin
|
|
Does benzene undergo addition or substition?
|
It only undergoes substitution
|
|
Is benzene flat?
|
Yes, it has to be considering its aromatic
|
|
What happens when an electron withdrawing group is in the R position of a benzene?
|
It deactivates the ring and directs any new substituents to the meta position
|
|
What do electron donating groups do to the wring?
|
They active the ring and direct any new substituents to the ortho and para positions.
|
|
What is the exception to this rule, and why?
|
Halogens are an exception because they are electron withdrawing and deactivate the ring as expected but they are ortho-para directors.
|
|
What are the strongly electron donating groups?
|
|
|
What are the moderately electron donating groups?
|
|
|
What are the weakly donating groups?
|
|
|
What are strongly electron withdrawing groups?
|
|
|
What are moderately withdrawing electron groups?
|
|
|
What are weakly withdrawing electron groups?
|
|
|
What is phenol?
|
It is a benzene with an alcohol substituent.
|
|
What is aniline?
|
It is a benzene with an amino substituent.
|
|
What is toluene?
|
It is a benzene with a methyl substituent..
|
|
What is benzoic acid?
|
It is a benzene with a carboxylic acid
|
|
What is nitrobenzene?
|
It is a benzene with a nitro group.
|