Questions tagged [cis-trans-isomerism]
Stereoisomeric olefins, cycloalkanes, etc. which differ in the positions of groups relative to a reference plane: in the cis-isomer the atoms are on the same side, in the trans-isomer they are on opposite sides. An obsolete synonym, for which the usage is strongly discouraged, is geometric isomerism.
126
questions
-3
votes
0
answers
29
views
What is the Maximum number of stereoisomers that a pentagonal bipyramidal structure can have
For a pentagonal bipyramidal complex MABCDE, such as PFBrClIAt, if enantiomers are included as distinct stereoisomers, how many such stereoisomers exist?
- 89
0
votes
0
answers
45
views
Are meso compounds also included in optical isomers or are they just stereoisomers
Our teacher has taught us today about optical isomers . And at the end given a formula for finding number of optical isomers of a symmetrical molecule( n is number of chiral atoms and the n is odd for ...
2
votes
1
answer
161
views
Difficulty in E-Z nomenclature and counting number of geometrical isomers
I have found above four molecules as the geometrical isomers just by drawing them and checking if they are superimposable. I'm not sure that these are the only ones.
I have tried using E and Z but ...
- 169
2
votes
0
answers
104
views
stable conformation of 2,3-dimethylsuccinic acid
I was researching for answering this question on Kolbe's electrolysis of 2,3-butanedicarboxylic acid (succinic acid). Turns out, this compound is not very well researched in particular, and shows few ...
- 162
2
votes
0
answers
162
views
Is hydroxylamine monodentate or ambidentate ligand?
What is the total number of geometric isomers of the complex $\ce{[Pt(Cl)(py)(NH3)(NH2OH)]+}$?
If $\ce{NH2OH}$ acts as an ambidentate ligand, then there should be six geometric isomers. Or is it ...
- 29
-1
votes
1
answer
54
views
Why is the 'side' of a double bond defined across the double bond horizontally rather than vertically? [closed]
When we are determining cis-trans isomerism, we seem to refer to a molecule's 'side' in relation to the double bond in a horizontal manner, as if we had drawn a mirror line through it horizontally. ...
- 11
0
votes
0
answers
55
views
Why does 1-ethylidene-2,3-dimethylcyclopropane exhibit cis-trans isomerism?
I think the carbons 2 and 3 have different configuration according to the CIP rules which makes the groups different:
Am I correct? Is there any official criteria regarding these cases ?
- 185
8
votes
2
answers
369
views
Comparing acidic strength of crotonic and isocrotonic acids
Compare acidic strength of crotonic acid (1) and isocrotonic acid (2):
On comparing $\mathrm{p}K_\mathrm{a}$ values, cis-form $(4.44)$ turns out to be more acidic than the trans-form $(4.69)$.
Most ...
- 185
0
votes
2
answers
300
views
Why doesn't 2,3-pentadiene show geometrical/cis-trans isomerism?
There are two different groups bonded to each terminal C in the C=C=C system, and there is restricted rotation about the C=C=C. So why doesn't it show cis-trans isomerism?
The most common answer I get ...
- 11
1
vote
1
answer
94
views
How many geometrical isomers will be formed here?
Can someone help me calculate the number of geometrical isomers in this compound? According to me there should be 3 isomers here but according to my teacher, there are 4.I believe that both EZ and ZE ...
- 141
5
votes
1
answer
1k
views
The total number of stereoisomers of 1,2-dibromo-3,4-dichlorocyclobutane
I tried writing all the geometrical isomers for 1,2-dibromo-3,4-dichlorocyclobutane, and then saw if they were optical or not. And I am getting the answer as 10:
However, the given answer is 8. I can'...
- 61
7
votes
1
answer
4k
views
Does 1,4-dimethylcyclohexane have a chiral center?
My textbook says that 1,4-dimethylcyclohexane (cis or trans) does not have a chiral centre, since two groups on the tertiary carbon (that are the part of the ring) are identical, and thus the compound ...
user92687
3
votes
1
answer
1k
views
Why is [M(AB)2] a geometrical isomer?
Our teacher told us that for coordination number 4 and tetrahedral shape $\ce{[M(AB)2]}$ doesn't have a plane of symmetry, so it shows optical isomerism.
What if we take a plane passing through the ...
- 585
9
votes
2
answers
972
views
Determining if the product would be cis or trans after an anti elimination on fischer projections
I find these kind of problems really confusing for some reason, but I saw a way on the web and tried doing it that way:
I considered the basic Fischer operations (Vertical: Below the plane of paper, ...
- 1,198
0
votes
0
answers
74
views
Does this molecule show cis-trans isomerism? [duplicate]
I want to find if the above molecule shows cis-trans isomerism, per an assignment. I am assuming that such isomerism, if present, will be shown by the substituted chlorines.
It seems clear to me that ...
- 732
7
votes
1
answer
208
views
Stereoisomers of 1,3,4,6-tetramethylcyclohex-1,4-diene
How many stereoisomers are possible for following compound (1,3,4,6-tetramethylcyclohex-1,4-diene)?
My Approach
the 1,4 methyl groups lie in the plane, whereas 3,6 are possible chiral centers. ...
- 1,389
2
votes
1
answer
2k
views
Why is Maleic Acid more soluble in water than its trans isomer Fumaric Acid?
My teacher taught me that compounds having intramolecular H-Bonding are relatively less soluble in water as they will not involve in H-Bonding with water appreciably while those able to do ...
0
votes
0
answers
319
views
How many stereoisomers are present in octahedral complexes of type MA3B2C?
Does $\ce{MA3B2C}$ type have optical isomerism or just geometric isomerism? I was told that it has three isomers, two cis and one trans. Are the two cis isomers optically active?
0
votes
0
answers
91
views
Which would have higher priority according to CIP rule (Cyclic Substituents)? [duplicate]
So if we were to assign E-Z nomenclature to this compound :
then the Ethyl group would obviously have more priority than methyl group, but I am confused whether out of Cyclopropane and Cyclobutane ...
- 304
1
vote
0
answers
17
views
Why does hydrogenation of this compound not result in a diastereomeric mixture? [duplicate]
In a question, this compound was given and it was asked:
"Hydrogenation of the above compound in the presence of poisoned Palladium catalyst gives?"
When I was answering it, I thought that ...
- 119
-2
votes
1
answer
485
views
Why these compounds don't show and show Geometrical isomerism? [closed]
I was recently studying organic chemistry related to Isomerism. I have doubt based on an example that is,
Why Cumulenes show GI?
Why 1-chloro cyclohexene don't show GI?
- 89
2
votes
1
answer
123
views
Is there geometrical isomerism in case of 2-methylcyclopentanone?
How can 2-methylcyclopentanone show geometrical isomerism?
A ring and a double bond are in different planes, so even after having restricted rotation there will be no change in areal distance.
0
votes
1
answer
2k
views
Which are the Geometrical isomers of the complex [Cr(NH3)2Cl2(en)]+?Is it one or two?
I was recently studying coordination compounds and i came across optical isomerism shown by complexes.I think that the complex i gave above have 4 geometrical isomers(I think this is where I am wrong, ...
2
votes
0
answers
70
views
Synthesis of Pt(II) complex using trans effect
By making use of the trans-effect in platinum(II) complexes, show efficient routes for the synthesis of all the possible isomers of $\ce{[PtCl(NH3)2(py)]+}$ (where $\ce{py}$ = pyridine) from the ...
- 21
0
votes
0
answers
69
views
For a flat, planar molecule, how do you determine which side is up? Or down?
I was just reading about alpha and beta linkages in certain cyclic molecules, and it said that the alpha configuration was the one in which a hydrogen was sticking out above the plane, and an OH ...
- 1,765
4
votes
1
answer
178
views
Chiral centres with stereoisomeric substituents
The structure of one particular isomer of 4-chlorohepta-2,5-diene is shown here. I am confused about how two of the propenyl groups attached to the central carbon have the same atoms with different ...
- 222
-4
votes
1
answer
122
views
Terminologies used in isomerism [closed]
What is the difference between the terms constitutional isomers, stereoisomers, geometric isomers?
I know cis and trans-1,2-dichloroethane shows cis trans isomerism and 1,1 dichloroethene, 1,1,2 ...
- 65
7
votes
1
answer
3k
views
In what way trans alkenes are more symmetric than cis alkenes?
While providing the reason for the higher melting point of trans molecules, everyone says that trans molecules are more symmetric than cis molecules. An example can be found over here, where the OP ...
user88957
3
votes
1
answer
551
views
Number of Stereoisomers of C(CHClCH3)4
I am having trouble understanding why the structure
$$\ce{C(CHClMe)4}$$
has only five stereo isomers. According to my textbook, the stereo isomers correspond to the following series of absolute ...
- 52
18
votes
3
answers
2k
views
Can geometrical isomers be enantiomers?
I have just been pondering upon the question above. I have found this example and I am sure they are enantiomers, but do they also count as geometrical isomers?
- 183
-2
votes
1
answer
2k
views
MA3B3 isomers - is this same as meridional one? [closed]
I'm new to studying stereo chemistry. (Now I'm studying coordination complexes.)
In my class material and other some datas(from google), it says that there is two, fac and mer.
I want to know is ...
- 1
-1
votes
2
answers
364
views
Conversion of cis to trans isomer [closed]
why in cis and trans isomers the double bond cannot be broken once and again joined to convert them from cis to trans is this type of bond breaking not allowed or is this allowed?
2
votes
0
answers
311
views
Shortcuts for finding geometrical isomers
Our teacher provides us extra questions for pratice, so one of the questions was :-
Find number of products if following are reacted with excess $\ce{NH2OH}$ (hydroxyl amine):
Cyclohex -
(i) 1,4-...
- 254
-1
votes
1
answer
163
views
Optical activity of cis-trans isomers of a co-ordination compound [closed]
Why do geometrical (cis and trans) isomers of [Pt(NH3)(Br)(Cl)(py)] not show optical activity ? Thanks In Advance...
1
vote
1
answer
506
views
Conformers of a meso-compound [duplicate]
In a particular question in one of my reference book, I was asked if the given compound (meso-butane-2,3-diol) was a meso compound or not. In it’s solution part, to show that the compound was ...
- 31
1
vote
1
answer
998
views
Optical activity of cis coordination compounds
I came across a statement saying,
"Consider a Octahedral coordination compound of type [MA2X2]. Then,
if the compound is in a cis form, it shows optical activity as there
is no plane of ...
- 139
0
votes
2
answers
153
views
Why are we still using cis/trans system while the E/Z system is better than it?
I am currently learning about Alkenes. It is given that cis/trans isomerism is either ambiguous or doesn't even apply in cases where the alkene is trisubstituted or tetrasubstituted. To solve this ...
- 2,022
1
vote
1
answer
844
views
Do the groups involved in geometrical isomerism have to be in similar planes to show geometrical isomerism?
In my textbook, under the topic "Conditions for geometrical isomerism", the following has been given:
Groups responsible to show geometrical isomerism must be nearly in the same plane.
Is this ...
- 2,022
3
votes
0
answers
120
views
Will N,N‐diethylbenzamide show geometrical isomerism?
I know for a compound to show geometrical isomerism it should
have site of restricted rotation;
be connected to two different groups on either side of site of restricted rotation;
the distance ...
- 379
0
votes
0
answers
71
views
Plaster of Paris
One of my Chemistry professors said that the hard mass formed after adding water to Plaster of Paris, cannot be converted back into Plaster of Paris. However, he said that the original Gypsum can be ...
- 220
0
votes
1
answer
303
views
Trans vs. cis, or Z vs. E
I am new to organic chemistry and am confused regarding the following question:
Does the geometrical isomerism of 3-methyl-2-heptene fall into the category of trans vs. cis, or the category of Z vs. ...
- 131
-2
votes
1
answer
345
views
Can there be geometrical isomerism in resonating structures [closed]
If a double bond which has two different substituents on each of it's two ends is showing resonance with one of the substituents would the double bond exhibit Geometrical isomerism?..if yes how so ...
2
votes
2
answers
3k
views
Does 1,3‐dichloroallene show geometrical isomerism? [duplicate]
Since the attached groups are present in different planes, $\ce{ClCH=C=CHCl}$ should not show geometrical isomerism, but my book say that it does. Why?
- 131
2
votes
0
answers
148
views
What does the dissociative mechanism for cis/trans interconversion of [Mo(CO)4(PPh3)2] look like?
All I can find in the literature is that the cis→trans interconversion proceeds via dissociation of one of the PPh3 ligands resulting in a square-pyramidal Cs intermediate, with the remaining PPh3 in ...
- 91
0
votes
1
answer
651
views
E - Z configuration of cyclic substituents [closed]
The answer is coming out as Z but given is E.
I’m not sure where I’m wrong at this point as I moved along one chain at a time and wanted to follow heaviest atom as earliest as possible !
- 11
-2
votes
1
answer
218
views
Please explain plane of symmetry [closed]
i am getting option (a) but answer is (b) where i am going wrong please help
SO IT IS OPTION A ONLY FOR ME BUT HOW B HAS PLANE OF SYMMETRY PLEASE HELP
- 347
3
votes
1
answer
1k
views
How many stereoisomers are possible for 1,2-dimethyl-4-(propan-2-ylidene)cyclopentane?
How many stereoisomers (not counting different conformers) does 1,2-dimethyl-4-(propan-2-ylidene)cyclopentane have?
I think the answer should be 3. There are two geometrical isomers (cis and ...
- 183
-2
votes
1
answer
825
views
Total Structural Isomers of diphenyl chloromethane?
The maximum option is 8 available but while Drawing I found there are many more . Are there any other condition of structural formula except the fact that the compounds will have the same molecular ...
- 1,720
2
votes
2
answers
4k
views
Stability of geometrical isomers in cycloalkanes
Among the following, which should be the most stable compound?
1)Cis-cyclohexane-1,2-diol
2)Trans-cyclohexane-1,2-diol
3)Cis-cyclohexane-1,3-diol
4)Trans-cyclohexane-1,3-diol
My thought process is-...
- 25
1
vote
1
answer
2k
views
Are Anomers Epimers?
epimers are the class of stereoisomers which differ along configuration at any carbon in a carbohydrate(generally),
And anomers are the kind of stereo isomers that differ at the carbonylic carbon, ...
- 353