Term
| a reaction in which two species combine to make a third |
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Definition
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Term
| a reaction in which the reactant seperates to form two products |
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Definition
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Term
| a reaction in which two reactants exchange substituents in order to form two different products |
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Definition
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Term
| a reaction in which an isomer is formed |
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Definition
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Term
a reaction where each neutral reactant supplies an equal part of the bond (one electron)
vs.
a reaction in which one reactant supplies an electron pair |
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Definition
homolytic reaction
vs.
heterolytic reaction |
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Term
| what is another word for an asymmetrical/heterolytic reaction? |
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Definition
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Term
| what are the three steps of radical reactions? |
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Definition
1. initiation
2. propagation
3. termination |
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Term
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Definition
an atom that can be influenced by its environment (have its electron field manipulated) and therefore can become more polar
- LARGER atoms are more polarizable
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Term
| a reaction in which an electrophilic species bonds with a nucleophilic one |
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Definition
| electrophilic addition reaction |
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Term
| what you get if you divide the products of a reaction by the reactants |
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Definition
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Term
which reaction will be faster:
K = 1.5
K = 0.5 |
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Definition
| it's impossible to say! Activation energy determines rate of reaction, NOT the equilibrium constant |
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Term
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Definition
| ΔH; how much heat is stored in the bond |
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Term
| equation for Gibbs free energy |
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Definition
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Term
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Definition
| how much energy is stored in a bond - i.e. the enthalpic change when a bond is broken or formed |
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Term
| methylene, vinylic, allylic |
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Definition
methylene: H2C=
vinylic: H2C=C-H
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allylic:
H2C=C-CH-CH2- |
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Term
| What happens to stability of an alkene as they become more highly substituted and why? |
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Definition
More highly substituted alkenes are more stable.
1. hyperconjugation (stabilizing interactions between the pi bond and neighboring C-C sigma bond
2. sp3-sp2 are more stable than sp3=sp3 |
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Term
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Definition
- the rich get richer
- regiospecificity |
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Term
| when specific parts of a reactants end up on certain places in the product |
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Definition
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Term
| why are carbocations more stable when highly substituted? |
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Definition
- hyperconjugation (stabilization of empty p orbital and nearby, properly oriented sigma bonds)
- inductive effect (alkyl groups are larger; therefore more polarizable; therefore their charge shifts to the carbocation and stabilizes it) |
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Term
| How do you explain the fact that a more stable carbocation intermediate means that the activation energy is lower and the reaction happens faster? |
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Definition
Hammond Postulate: the transition state will physically resemble the species closest to it in energy.
--> reaction to become a carbocation is endothermic, therefore the TS resembles the carbocation intermediate, therefore it is more stable, therefore it takes less energy to form, therefore it forms faster |
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Term
| in a magnetic field (B0), number of possible electron spin states |
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Definition
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Term
| when the nuclei have been irradiated so that they are all spinning in the antiparallel, high energy state |
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Definition
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Term
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Definition
| strength of the external applied magnetic field applied to flip parallel electrons antiparallel (resonant) |
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Term
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Definition
| radio frequency - the energy required to bring 1H into resonance |
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Term
| what is the difference between B0 and Rf? |
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Definition
first one: is the energy applied to get all the electrons spinning either antiparallel or parallel
second one: energy needed to get the parallel spinning ones to spin antiparallel instead (resonate) |
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Term
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Definition
| location of a nuclear signal on the x-axis based on electron shielding |
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Term
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Definition
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Term
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Definition
1. broadband decoupled shows ALL carbon shifts
2. DEPT-90 shows ONLY CH
3. DEPT-135 shows CH and CH3 above and CH2 below the x-axis |
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Term
| if replaced with X, the molecule would be identical to others |
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Definition
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Term
| replacement of a proton would create a chiral center |
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Definition
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Term
| replacement with a proton would create a SECOND chiral center |
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Definition
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Term
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Definition
| the distance between coupling peaks; two groups coupled to each other will have the same J |
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