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97 Cards in this Set
- Front
- Back
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Atoms or Groups bonded by ... Can undergo... |
Atoms or Groups bonded by only sigma bonds can undergo rotation around the sigma bond. |
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Upon rotation (around sigma bond), the atoms or groups within a molecule will have... Some of these... |
Upon rotation (around sigma bond), the atoms or groups within a molecule will have different spatial arrangements. Some of these arrangements are more energetically favored than others. |
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Conformations or "" are the... |
Conformations or rotamers are the temporary structure that results from the rotation around the sigma bond. |
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Conformers are.... |
Conformers are each of the possible structures. |
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Conformational Analysis is the study... |
Conformational Analysis is the study of energy change associated with a molecule undergoing rotation around the sigma bonds. |
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The various ways to draw a 3D molecule are... (3) |
The various ways to draw a 3D molecule are: 1) Wedge & Dash 2) Saw-Horse 3) Newman Projection |
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In the Wedge & Dash method of 3D molecular drawing, Wedges represent... |
In the Wedge & Dash method of 3D molecular drawing, Wedges represents a bond coming out of the page. |
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In the Wedge & Dash method of 3D molecular drawing, Dashes represents.. |
In the Wedge & Dash method of 3D molecular drawing, Dashes represents bonds going into the page. |
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The Saw-Horse method of drawing a 3D molecule shows... |
The Saw-Horse method of drawing a 3D molecule shows a molecule at a diagonal view. |
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The Newman Projection method of drawing a 3D molecule represents... |
The Newman Projection method of drawing a 3D molecule represents the view of looking directly down the sigma bond of 2 atoms. |
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In Alkanes, the Newman Projection is most often used to... |
In Alkanes, the Newman Projection is most often used to determine the stability of different conformations. |
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A Dihedral angle (angle between 2 hydrogen atoms) separates... |
A Dihedral angle (angle between 2 hydrogen atoms) separates a bond of one atom from a bond on an adjacent atom. |
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In the Staggered Conformation of an alkane, the dihedral angle is... |
In the Staggered Conformation of an alkane, the dihedral angle is 60° |
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In the Staggered Conformation, all Hydrogen atoms are... |
In the Staggered Conformation, all Hydrogen atoms are as far apart as possible. |
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The Staggered conformation is most energetically favored because... |
The Staggered conformation is most energetically favored because there is minimal interaction between the Hydrogen atoms on Adjacent carbons. |
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In the Eclipsed conformation of alkanes, the dihedral angle is... |
In the Eclipsed conformation of alkanes, the dihedral angle is 0°. |
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The Eclipsed conformation is the highest in.... |
The Eclipsed conformation is the highest in ENERGY. |
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The Eclipse conformation is the highest in energy because... |
The Eclipsed conformation is the highest in energy because it contains the highest number on interactions between the Hydrogen atoms on adjacent carbon at and the overlap between sigma and antibonding sigma bond orbitals is no longer present. |
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At room temperature, 99% of most molecules exist in the... |
At room temperature, 99% of most molecules exist in the STAGGERED CONFORMATION. |
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Torsional Strain is defined as... |
Torsional Strain is defined as the difference in energy between the STAGGERED and ECLIPSE conformations. |
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Steric Interaction arises when... |
Steric Interaction arises when the Hydrogen atoms of a molecule are replaced by other atoms or molecules. |
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Steric interactions are based on the fact that.... When these atoms get too close... |
Steric interactions are based on the fact that atoms occupy a certain amount of space within a molecule. When these atoms get too close to each other there is a repulsion of electron clouds which costs energy. |
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When Hydrogen atoms are replaced by other atoms or groups, there are two forms of "" conformations known as: |
When Hydrogen atoms are replaced by other atoms or groups, there are two forms of staggered conformations known as anti and gauche. |
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The anti staggered conformation exists when... |
The anti staggered conformation exists when the largest groups are furthest apart (dihedral angles = 180°). |
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The gauche staggered conformation exists when.... |
The gauche staggered conformation exists when the largest groups are adjacent (dihedral angle = 60°) |
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All staggered conformations are preferred to... |
All staggered conformations are preferred to eclipse conformations which are always higher in energy. |
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For cyclic alkanes confined to a specific geometry,... This causes... |
For cyclic alkanes confined to a specific geometry, the bond angles may not correspond to desired 109.5° for sp3 carbons. This causes angular strain. |
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The size of the ring of a cyclic alkane determines... |
The size of the ring of a cyclic alkane determines how much angular strain a cyclic alkane will have. |
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Cycloalkanes also have varying degrees of... This is because.. &... |
Cycloalkanes also have varying degrees of torsional strain due to rigidity of their structures. This is because cycloalkanes do not have free rotation and the atoms attached to the carbons in the ring are locked in an eclipsed orientation. |
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"" is the most stable of all cycloalkanes. |
Cyclohexane is the most stable of all cycloalkanes. |
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Cyclohexane has a perfect "" conformation and bond angles of "" in the "" conformation. |
Cyclohexane has a perfect staggered conformation and bond angles of 109.5° in the chair conformation. |
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Cyclohexane has no... |
Cyclohexane has no angular or torsional strain in the chair conformation. |
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In the "" conformation for cyclohexane,there is... But no.. |
In the BOAT conformation for cyclohexane, there is torsional strain but no angular strain. |
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Cyclohexane has the ability to... Thus,... |
Cyclohexane has the ability to move more than smaller rings, thus it has various conformations. |
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The various conformations for cyclohexane are... |
The various conformations for cyclohexane are chair, half-chair, twist-boat, and boat. |
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All conformations for cyclohexane have... |
All conformations for cyclohexane have varying energy levels. |
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When cyclohexane exists in the "" conformation, all H atoms... &... |
When cyclohexane exists in the chair conformation, all H atoms are staggered and there is no torsional strain. |
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Cyclohexane exists primarily in "" conformation and very small amount in "" conformation. |
Cyclohexane exists primarily in chair conformation and very small amounts in twist-boat conformation. |
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Cyclohexane is made up of a ... |
Cyclohexane is made up of a 6 carbon ring. |
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Each carbon of cyclohexane is bonded to... These bonds are known as... |
Each carbon of cyclohexane is bonded to 2 other atoms or groups. These bonds are known as axial or equatorial. |
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A cyclohexane ring has "" bond and "" bonds. |
A cyclohexane has 6 axial bonds and 6 equatorial bonds. |
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All cyclohexane molecule have two "" conformation because... When "" occurs,... |
All cyclohexane molecules have two chair conformations because the cyclohexane can "ring flip". When "ring flip" occurs, all axial substituents become equatorial and all equatorial bonds become axial. |
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Any 6 membered ring that has a substituent requires drawing both... |
Any 6 membered ring that has a substituent required drawing both the chair and flip chair. |
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In cyclohexane, the substituents retain their..., the only change is... |
In cyclohexane, the substituents retain their relative positions in both chair conformations, the only change is whether they are axial or equatorial. |
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Isomers are defined as... The two types of isomers are... |
Isomers are defined as different compounds with the same chemical formula. The two types of isomers are structural and stereo. |
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A structural isomer is defined as... |
A structural isomer is defined as an isomer whose atoms have different connectivity. |
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Stereo Isomers are defined as... The two types of stereo isomers are... |
Stereo Isomers are defined as isomers that have the same atomic connectivity but differ in the arrangement of their atoms in space. The two types of stereo isomers are enantiomers and diastereomers. |
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A Geometric Isomer is known as... |
A Geometric Isomer is known as a diastereomer that has a different arrangement due to the rigidity of a molecule. |
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A Racemic Mixture is an... |
A Racemic Mixture is an equal mixture of a pair of enantiomers, considered optically inactive. |
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A Meso Compound are known as... |
A Meso Compound are known as stereo isomers that are mirror images of each others ; they are super-imposable. |
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The "" of structural isomers can be very different. |
The physical properties of structural isomers can be very different. |
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Alkanes with "" have no isomers. However, as the number of "" increases,.. |
Alkanes with 3 or less carbon atoms have no isomers. However, as the number of carbon atoms increases, the number of isomers increases greatly. |
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Geometric Isomers, a type of "", have the same... But... |
Geometric Isomers, a type of stereoisomer, have the same molecular formula but have different spatial arrangements due to the rigidity of the molecule. |
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To name alkenes with more than 2 types of substituents, we use the... Which is based on... |
To name alkenes with more than 2 types of substituents, we use the E & Z naming system which is based on the Cahn-Ingold Prelog priority rules. |
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The Cahn-Ingold-Prelog Rules are (3): |
1) The atom with higher atomic number receives the higher priority. 2) For isotopes, the isotope with higher mass receives the higher priority. 3) If the atoms directly attached are the same; explore outward until he 1st point of difference. At the first point of difference, the atom with higher atomic number receives a higher priority. |
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In the E & Z naming system, an "E" molecule will have... |
In the E & Z naming system, an "E" molecule will have higher priority substituents on opposite sides. |
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In the E & Z naming system, a "Z" molecule will have... |
In the E & Z naming system, a "Z" molecule will have higher priority substituents on the same side. |
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In Geometric Isomers, when a substituent contains a "" or "" atom they must be... |
In Geometric Isomers, when a substituent contains a sp2 or sp atom they must be "artificially" transformed into sp3 atoms. |
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A molecule is known as chiral when... |
A molecule (stereoisomer)is known as chiral when it cannot be super-imposed on its mirror image. |
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A molecule is known as achiral when... |
A molecule is known as achiral when it can super-impose on its mirror image. |
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Enantiomers are defined as... |
Enantiomers are defined as a pair of stereoisomers that are non-superimposable mirror images. |
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The central atom of a stereoisomer is known as.. Or... |
The central atom of a stereoisomer is known as the stereocenter or asymettric atom. |
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A molecule is always chiral if it has... |
A molecule is always chiral if it has only one stereocenter. |
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The importance of chirality is... In which... |
The importance of chirality is that these molecules (enantiomers) are different. In which they may have the same physical properties but behave differently on chiral environments (Ex:biological systems) |
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When identifying chiral atoms, there are two requirements which are... |
When identifying chiral atoms, there are two requirements which are: -chiral atom must be bonded to 4 different substituents - chiral atom will be sp3 hybridized. |
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The nomenclature naming system for enantiomers is known as... Which also follows the... |
The nomenclature naming system for enantiomers is known as thr "R - S" system which also following the CIP priority rules. |
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After determining the priority atoms & rotating the enantiomer so that...., if the path is clockwise, the enantiomer is given... |
After determining the priority atom & rotating the enantiomer so that the lowest priority group is point back, if the path is clockwise, the enantiomer is given the "R" prefix. |
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After determining priority and rotating the enantiomer so that..., if the path is counterclockwise, the enantiomer is given.. |
After determining priority and rotating the enantiomer so that the lowest priority group is pointing back, if the path is counter clockwise then the enantiomer is given the "S" prefix. |
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Pairs of enantiomers always have the opposite... |
Pairs of enantiomers always have the opposit "R-S" designation such that one enantiomer is "R" and the other enantiomer is always "S". |
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A pair of enantiomers will have the same... |
A pair of enantiomers will have the same physical properties. |
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Enantiomers will rotate... |
Enantiomers will rotate plane-polarized light in equal but opposite directions. |
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Optical Rotation can be described as... This molecule is said to have... |
Optical Rotation can be described as when plane-polarized light interacts with a chiral molecule, the plane of polarization of the light will rotate to the left or to the right. This molecule is said to have optical activity. |
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Optical activity is measured using a... |
Optical activity is measured using a polarimeter. |
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Specific rotation is a.... |
Specifix rotation is a physical property of chiral molecules. |
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Pairs of enantiomers will have ... Of specific rotation. |
Pairs of enantiomers will have equal but opposite valiues of specific rotation. |
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The maximum number of stereoisomers a molecule can having is expressed by the equation,... |
The maximum number of stereoisomers a molecule can have is expressed by the equation, 2^n in which n represents the number of stereocenters. |
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A diastereomer is a... |
A diastereomer is a stereoisomer that is not a mirror image molecule. |
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Unlike "", diastereomers have... |
Unlike enanteomers, diastereomers have different physical properties such as MP or BP. |
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When naming molecules with more than one stereoisomer, the ... naming system is used. This is because.. |
When naming molecules with more than one stereoisomer, the "R-S" naming system is used. This is because these molecules still contain chiral atoms. |
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Each "" (in a molecule with more than one stereoisomer) must be examined individually to determine if... Also,... |
Each chiral atom (in a molecule with more than one stereoisomer) must be examined individually to determine if "R" or "S. Also, the location of the chiral atom must be stated in naming. |
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A Fisher Projection takes a.. |
A Fisher Projection takes a wedge-dash diagram and converts it into a line diagram. |
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In a Fisher Projection, each intersection... |
In a Fisher Projection, each intersection of horizontal and vertical lines represents an asymmetrical carbon atom. |
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In Fisher Projection, each horizontal line represents.. |
In Fisher Projection, each horizontal line represents a bond coming out of page. |
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In Fisher Projection, each vertical line represents... |
In Fisher Projection, each vertical line represents a bond going into page. |
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In Fisher Projection, it is important that... |
In Fisher Projection, it is important that the proper groups are drawn on the top and the bottom. |
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In Fisher Projection, if one group bonded to a chiral atom is a... |
In Fisher Projection, if one group bonded to a chiral atom is a carbon group, it is drawn on top and bottom. |
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In Fisher Projection, if 2 or more "", then... |
In Fishes Projection, if 2 or more carbon groups are present, then the one bonded to more oxygen atoms is drawn on top and bottom. |
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In Fisher Projection, the "" is on the "" line. |
In Fisher Projection, the lowest priority group is on the horizontal line (bond going out of page) |
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In Fisher Projection, when doing "R-S" naming, rotate.. |
In Fisher Projection, when doing "R-S" naming, rotate the lowest priority group to the back. |
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A Meso Compound is a molecule that... |
A Meso Compound is a molecule that has chiral atoms, but its mirror image is super imposable. |
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Alkenes can also be classified as... |
Alkenes can also be classified as diastereomers (DO NOT CONFUSE WITH STRUCTURAL ISOMERS) |
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When considering the isomers of cyclic compounds, we must consider... Also watch out for... |
When considering the isomers of cyclic compounds, we must consider both structural isomers and stereoisomers; including enantiomers and diastereomers. Also, watch out for meso compounds aswell. |
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"" are very common in cyclic molecules. |
Planes of symmetry are very common in cyclic molecules. |
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A chiral molecule is a molecule... |
A chiral molecule is a molecule with a non-superimposable mirror image. |
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Generally, for a molecule to be considered chiral... However, there is an exception... |
Generally, for a molecule to be considered chiral, it must contain at least 1 chiral atom ( sp3 atom attached to four different substituents). However, this is an exception which are allenes. |
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Allenes contain... |
Allenes contain 3 consecutive Carbon atoms that are bonded by double bonds. |
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In Allenes, when the terminal Carbon atoms are... |
In Allenes, when the terminal Carbon atoms are attached to 2 different atoms, the mirror images becoming non-superimposable and are now chiral. |
