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Definition
Molecules that are not identical , but are mirror images
*Like a right hand is related to a left hand
* results when a tetrahedral carbon is bonded to four dif substituents |
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Definition
A molecule that is not identical to its mirror image
*Molecule with NO plane of symmetry
*Most commonly a Carbon connected to four different groups |
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Definition
Optically active molecules that rotate to the LEFT
*Given a (-) sign |
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Definition
Optically active molecules that rotate light to the RIGHT
*Given a (+) sign |
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Equation for Specific Rotation |
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Definition
[a]d = a/l x c
a=observed degrees
l= pathlength (dm)
c=concentration (g/cm3) |
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Term
Rank the following highest to lowest:
-H, -Cl, -Br, -CH3, -CH2OH, -NH2, -B, -O |
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Definition
| -Br, -Cl, -O, -NH2, -CH2OH, -CH3, -B, -H |
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Definition
Stereoisomers that are not mirror images
*Similar but not identical
* Have oppsosite configuration at some chirality centers but the same at others within the same chiral molecule |
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Difference between Enantiomers and Diastereomers |
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Definition
| enantiomers have opposite configurations at ALL chirality centers, diasteromers have opposite configurations at SOME (one or more) chirality centers but the same congfiguration at others. |
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Definition
| Diasteriomers that differ by configuration at only one chirality center |
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Definition
| ACHIRAL (non-chiral compound) that contain chirality centers |
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Definition
*50/50 mixture of enantiomers
*Reacts with non-chiral molecules to form racemic mixture of enantiomeric products.
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Definition
*Process of seperating racemic mixture
*employs chiral enantiopure resolving agents
*enantiopure reagents react with racemic mixture to form diastereomeric salts, which have diff physical properties and are seperated by crystallization |
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Definition
Compounds whose atoms are connected differently (same molecular formula) |
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Definition
compounds whose atoms are connected in the same order but with different arrangements in space
(enantomers, diastereomer [cis and trans]) |
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Configurational Stereoisomer |
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Definition
| A configurational stereoisomer is a stereoisomer of a reference molecule that has the opposite configuration at a stereocenter (e.g., R- vs S- or E- vs Z-) |
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Definition
Molecule that can be converted from achiral to chiral in a single chemical step (Changing a molecule with out affecting priority of other atoms)
*Have two faces Re (clockwise) Si (counterclock wise)
*Sp3 hybirdized prochiral atom can be Pro-S (replacement leads to a S chiral center) or Pro-R (replacement leads to R center) |
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What type of reaction is this?
[image] |
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Definition
| Addition Reaction: 2 Reactants combine to form one product |
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Term
What type of reaction is this?
[image] |
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Definition
| Elimination Reaction: one reactant splits to form two products |
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Term
What type of reaction is this?
[image] |
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Definition
| Substitution reaction: 2 reactants exchange substitients to form 2 new products |
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Term
What type of reaction is this?
[image] |
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Definition
| Rearrangement reaction: single reactant rearranges its bonds. Mirgration of sigma bonds from 1->3 would be called [1,3] |
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Term
| Types of Addition reactions: |
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Definition
–Hydrohalogenation of alkene
–Hydrogenation of alkene
–Addition of Nucleophile to Ketones and Aldehydes
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Types of elimination reactons: |
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Definition
–Dehydration of Alcohols
-Dehydrohalogenation of Alkyl halides (haloalkanes |
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Types of Substitution reactions |
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Definition
–Esterification of Carboxylic Acid
–Hydrolysis of Ester |
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Definition
*symmetrical cleavage
*Radical
*one bonding electron stays with each product
[image] |
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Heterolytic Bond cleavage |
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Definition
*unsymmetrical bond breaking
*polar
*two bonding electrons stay with one product
[image] |
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Definition
| process that involves symmetrical bond-breaking and bond making |
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Definition
| a neutral chemical species taht contains an odd number of electrons and thus has a single, unpaired electron in one of its orbitals |
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Definition
* involves unsymmetrical bond breaking and bond making
*involve species that habe an even number ofelectrons |
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Term
Initiation step in methane chlorination |
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Definition
UV Light breaks weak CL-CL bond to give a few reactive chlorine radicals
[image]
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Term
Propagation step in methan chlorination |
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Definition
chloring radical collides with methane molecule abstracting a hydrogen atom to give HCl and methyl radical (CH3)
* Methyl radical reacts furthar with Cl2 in second propagation step to give product chloromethane plus new chlorine radical, which repeats.
*once initiated it becomes self sustaining / chain reaction
[image] |
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Term
Termination of Methane chlorination |
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Definition
* When two radicals collide and combine to form a stable product.
*Cycle is broke and chain is ended
[image]
[Possible terminations] |
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Term
What is a polar reaction? |
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Definition
* an electron pair is moved from electron-rich center(atom or bond) to electron-poor center.
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Term
Name 3 characteristics of a Nucleophile |
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Definition
NUCLEUS LOVING
* Negatively polarized electron rich atom
*form bond by donating pair of electrons to postively charges electron poor atom.
*Can be Neutral or Negative
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Name 3 characteristics of an Electrophile |
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Definition
ELECTRON LOVING
*positively polarized, electron poor atom
*forms bond by accepting pair of electrons from nucleophile
*Can be neutral or positvely charged |
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Term
What is the equation for Keq (equilibrium constant)? |
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Definition
product concentrations multiplied together divided by the reactant concentrations mulitplied together with each concentrations raised to the power of its coefficient
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Term
Gibbs free energy change (ΔG) equation
What is the favorable outcome?
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Definition
* equal to the free energy of the products minus the free energy of the reactants:
* A negative value is more favorable
*energy is lost by the chemical sytem and released =exergonic (negative value)
ΔG = Gproducts - Greactants
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Definition
•The energy exchange between bonds and the surrounding during this process is measured by enthalpy, ΔH (ΔH is primarily determined by the energy required to homolytically break a bond, also bond dissociation energy) |
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Definition
•The total change in enthalpy during bond breaking and bond forming reaction is called heat of formation. |
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Is heat absorbed or released during bond breaking/and formation |
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Definition
–Bond breaking (heat absorbed)
–Bond forming (heat release) |
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What is degree of unsaturation and how can you figure it out? |
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Definition
*# of rings and/or multiple bonds in molecules
*One degree = one double bond or one ring
*2 degree= two double bonds, or one double bond and a ring, or two rings, or one triple bond
Formula: DU= C-1/2(H+X-N)+1 |
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Is Cis or Trans alkenes more stable? why? |
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Definition
•Trans- alkenes are more stable than cis- alkenes because cis- alkenes have larger steric strain from the substituents. Therefore, alkenes always prefer the trans-siomers |
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Which bond is stronger Sp3-sp3 or Sp2-sp3? |
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Definition
–Bond Strengths: sp2–sp3 carbons bond is stronger than sp3–sp3 carbons bond. |
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Definition
Bromine and Chlorine add rapidly to yield 1, 2 Dihalides
Chorine = cis or trans
Bromine=Always trans |
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Definition
1,2 disubstituted haloalcohol (X and OH)
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Term
[image]
What is this reaction? |
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Definition
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Term
Oxymercuration-demercuration |
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Definition
*Alcohol adds to the most substituted Carbon
*Reacts with (Hg[Oac]2) followed by addition of sodium borohydride
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Term
[image]
What is this reaction? |
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Definition
Oxymercuration-demercuration
*OH is added to the most substituted Carbon |
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Term
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Definition
*nonmarkovnikov addition of OH group (adds to least substituted)
*Uses addition of BH3, in THF solvent, followed by addition of H2O2(hydrogen peroxide), and NaOH(sodium hydroxide) |
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[image]
What reaction is this? |
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Definition
Hydroboration
*adds OH to least substituted carbon |
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Definition
*alkene converted to alkane
*usually with (Pd/C) or platinum (Pt)
*Hydrogen added across the double bond
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Term
[image]
What reaction is this? |
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Definition
Hydrogenation
turns alkene to alkane with adding Hydrogen |
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Term
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Definition
*Decreases electron density on carbon by
1. forming a carbon bond with O, N, or X(halogen)
2. Breaking a Carbon bond with Hydrogen |
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Definition
*Increses electron density on carbon by
1.Forming carbon bond with Hydrogen
2.Breaking carbon bond with [O, N, and halogen] |
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Definition
| *add 2 hydroxyl groups using OsO4 & H2O2 |
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Term
[image]
What reaction is this? |
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Definition
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