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Relative stability of cis and trans cycloalkenes
Usually trans-olefins are more stable than their cis isomers for steric reasons, like you suggested. However in small and medium size rings this is not the case; here the cis-cycloalkene is more ...
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What is the perfect definition for chirality?
The correct definition of chirality is given in the IUPAC gold book as follows:
chirality
The geometric property of a rigid object (or spatial arrangement of points or atoms) of being non-...
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29
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How to determine number of structural isomers?
It isn't easy but it is an interesting research topic
Determining the number of possible structures for a given range of chemical formulae isn't simple even for saturated hydrocarbons. The number of ...
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What is the perfect definition for chirality?
I think Martin has provided an excellent answer, and I would like to supplement it with a few additional details and examples that might prove insightful.
So as I already mentioned in the comments, ...
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How to determine number of structural isomers?
(1) As for the number of alkanes ($\ce{C_nH_{2n+2}}$), Table 1, which is extracted from the data reported in
S. Fujita, MATCH Commun. Math. Comput. Chem., 57,
299--340 (2007) (access free),
shows ...
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How is exact racemization possible?
Racemization isn't "exact," but rather very very close to equality. It is just simple probability.
Think of flipping a coin, p=probability for heads, and q=probability of tails. Now for a fair flip ...
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17
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Why do we insert a numeric multiplier after group positions when naming an isomer?
take 2,3-dimethylbutane
In the case of different substituents on different or the same atom, we use a combination of the position and the name of the substituent, such as in
2-chloro-3-methoxy...
3-...
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Why are conformational isomers considered as isomers?
Gaurang's answer deals well with the theory part I just wanted to give a visual aid.
(Taken from Atropisomerism of naphthyl alcohol)
Let's call the rotating substituent on the naphtahlene a fan.
The ...
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How to calculate the number of geometrical isomers in allenes?
If we have one double bond in a hydrocarbon compound we have an olefin or alkene. Ethylene is the simplest example of this class of compounds. The carbons in the double bond and the 4 atoms attached ...
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Why are conformational isomers considered as isomers?
I was taught that geometric (cis-trans) isomers are considered isomers because there is a high energy barrier to breaking the double bond...
There's a problem here. Geometrical isomers are isomers ...
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Is light a reactant in photochemical reactions?
It is neither reactant nor catalyst, and equilibrium concepts do not apply
There are processes other than photochemistry that to go in a direction away from equilibrium. They require mechanical or ...
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13
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Difference between Epimers and Diastereomers
This scheme I just drew up specifically for you should answer your question.
Diastereomers are stereoisomers that are not enantiomers of each other. That includes conformers (geometric isomers that ...
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Number of stereoisomers of tetramethylspirononane
Here is another approach to @loong's solution to the seven stereoisomers of this tetramethyl spiro[4.4.0]nonane. [This question is akin to one recently asked about tetramethylspiropentanes].
Using ...
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How is plane polarized light rotated by chiral compounds?
Circularly polarized light is like a helix that twists through space. The two components are mirror images of each other.
Now, every molecule interacts with both the left-handed twisting light and the ...
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Difference between Epimers and Diastereomers
epimers as compounds which differ by configuration at only one carbon
Yes, at only one centre.
However isn't that the same thing as diastereomers?
No, not completely. Diastereomers differ at ...
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What is the reason of the color difference for the cis/trans isomers of tetraamminedichloridocobalt(III) chloride?
If you search a library for a copy of Inorganic Chemistry by Miessler and Tarr, they have an excellent diagram showing which explains the phenomenon.
$\ce{Cl-}$ ligands have lone electrons that can ...
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Isomers with molecular formula C₄H₇Cl
There are 12 different constitutional isomers:
There is also the further possibility of stereoisomerism in some of the compounds above.
3: Two diastereomers (cis- and trans-) are possible.
7, 8, 9: ...
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For molecules to be enantiomers, do the groups have to be non-superimposable mirror images even when rotated around C-C single bonds?
Real molecules surely do rotate around their single C-C bonds all the time(*). So yes, if two models can be superimposed after an internal rotation of such sort, this means they represent the same ...
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What is the error in the number of aromatic isomers of C7H8O?
You are completely correct - the furan derivatives you've drawn display unquestionable aromatic character, though the "strength" of their aromaticity is somewhat lower than various other ...
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How to assign E/Z configuration according to the Cahn-Ingold-Prelog rules when subsituents differ only by stereochemistry
I remember that when all the basic rules end up in a tie (including the ghost atoms), the following priority is used:
$R > S$
$cis > trans$
$Z > E $
So R is given higher priority and ...
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Predicting the products of the radical chlorination of propane
Let me give you two helpful hints.
Propane
If you use an internet search tool of your choice, you should quickly find out that propane is $\ce{C3H8}$, which has the structure $\ce{CH3CH2CH3}$. The ...
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Polymerization Isomerism In Transition-Metal Complexes Not True Isomerism?
I’m pretty sure that polymerisation isomerism should mainly be considered a historical term nowadays. Going back in the history of science, all people knew at some point was which elements a specific ...
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What is the seventh plane of symmetry in benzene?
Have a look at this picture which shows some of the symmetry axes and planes. You should be able to see other similar ones. Taken from www.molecule-viewer.com.(You can also use this site to practice ...
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