Questions tagged [geometrical-isomerism]

Also known as cis/trans isomerism, configurational isomerism, or E/Z isomerism when referring to alkenes.

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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 ...
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confusion regarding stereoisomers [closed]

I am a high school student and I am very confused in optical isomerism My confusions are: 1)Is the carbon shown in the image is a chiral carbon or pseudo-chiral carbon? 2)will this compound show ...
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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 ...
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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 ...
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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 ...
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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?
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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 ...
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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?
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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-...
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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...
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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 ...
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362 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 ...
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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 ...
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Doubt in conditions for 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 ...
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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 ...
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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 ...
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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. ...
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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 ...
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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?
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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 ...
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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 !
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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
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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 ...
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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 ...
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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-...
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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, ...
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Geometric isomerism in substituted cycloalkenes?

My book says the first and third molecules only will show geometrical isomerism. Why is this so? I can understand how the third will show (both the methyl groups can be into the screen or one can be ...
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Number of geometrical isomers?

How many geometrical isomers will exist for compound of this type which has cycloalkene having carbon atoms greater or equal to 8 in the middle of chain? I know that due to ring in middle of chain ...
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3answers
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Melting point of trans-4-methylhex-4-enoic acid and cis-4-methylhex-4-enoic acid

My book said that the cis isomer has a higher melting point. But I dont understand isn't that the trans isomer can pack more efficiently, because the trans isomer less bulky/ create less 'kink' than ...
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225 views

Number of total stereoisomers of a piperazine derivative

How do I find out the total number of stereoisomers of 3,6-dimethylpiperazine-2,5-dione? As far as I can see, the compound has two chiral carbons. Would the nitrogens make a difference? They seem ...
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Does dihydroimidazole show geometrical isomerism?

Does dihydroimidazole (above) exhibit geometrical isomerism? Does the fact that the lone pair is involved in conjugation with a double bond affect anything? As far as I know, it does not exhibit ...
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Number of stereoisomers of tetramethylspirononane

The above compound – 2,3,7,8-tetramethylspiro[4.4]nonane – clearly exhibits both optical and geometrical isomerism. The question is, how many stereoisomers does it have in all? As the number of ...
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What is the relation between the following two optical isomers?

I think they should be diastereomers, but the answer to this question is enantiomers, if it is enantiomers then how?
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Why is cis-1,2-dichloroethene more stable than trans-1,2-dichloroethene?

Why is cis-1,2-dichloroethene more stable than trans-1,2-dichloroethene? Usually, trans compunds are more stable than cis ones, due to less strain and its non-polarity. But, in this case it's quite ...
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Does CHT=CHT have a geometric isomerism because of tritium atoms?

Is the radioisotope of hydrogen considered as a new atom? Can you detect it with an H NMR?
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What is it meant by two different groups in stereoisomerism?

I understand there are some properties in an organic compound that allow stereoisomerism. double bond can't rotate two double bonded carbon atoms each have two different atoms or groups attached I'm ...
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Why dichlorobenzene doesn't show geometrical(cis/trans) isomerism? [duplicate]

As it has restricted rotation due to the presence of a double bond, it should show geometrical isomerism. Then, why doesn't it show cis/trans isomerism?
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Why is tautomers not possible in benzoquinone? [closed]

1,4-Benzoquinone, commonly known as para-quinone, is a chemical compound with the formula $\ce{C6H4O2}$ When there are alpha Hydrogen's why can't it show tautomerism?
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Does 1-ethylidene-2-(propan-2-ylidene)cyclobutane show geometrical isomerism?

I think it should be yes, but my book says no. I think the two geometrical isomers are Z-isomer E-isomer
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Is a carbon chiral it two of its groups are cis - trans isomers? [duplicate]

For example: In this image, the two groups sticking to a carbon are cis-trans isomers. So does that make the carbon chiral, exhibiting optical properties? What if the two groups were both having ...
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Why does 1,3-dimethylcyclopent-1-ene have geometric isomerism while 1-bromo-2-chlorobenzene doesn't?

The bottom compound has bromine and an R group connected to one of its SP2 double bond carbons, and chlorine and the same R group connected to the other. This fact, it would seem, indicates cis-trans ...
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Which of the following is more stable?

In this image, does the arrows indicate correct rate of reactions? The upper arrow is longer and lower is shorter. According to me Chair is more stable than Twist Boat. Does axial and equatorial ...
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Geometric isomers of substituted methylidenecyclohexane?

My thoughts on the problem: I am sort compound of sure C and D will not show geometric isomerism because of the same groups (H and H) attached. In compound A and B, suppose I swap the positions of H ...
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2answers
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Why does having identical groups on either side of the pi bond lead to no geometrical isomerism?

As far as I was taught, cis and trans isomers were categorised under stereoisomers and sub category of geometric isomers. Qualifying properties like, rigid and restricted double bond rotation (due to ...
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Determining geometry of trisubstituted alkene

The way I know to tell whether an alkene is E or Z -is to look at the coupling constant of the protons across the doble bond. Large value (16 Hz) indicates an (E)-alkene where as smaller values (11 Hz)...
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Can cis and trans isomers have widely different flash points?

Sigma seems to have two products listed for sale as "Cinnamic Aldehyde". One compound clearly seems the trans isomer but the other one seems like an unspecified mixture. (They even have two different ...
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How to determine if an alkene is an E or Z isomer?

Is the molecule below an E or Z isomer? From what I believe I would say E isomer because the two priority halides Cl and Br are on opposite sides of the double bond. But I'm not 100% sure. Because ...
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What theoretically is the smallest cyclic trans hydrocarbon to correspond to a local potential energy minimum?

Trans-cyclooctene is isolatable at room temperature. Trans-cycloheptene is also known at low temperature. Ab Initio Conformational Analysis of trans-Cyclohexene (1995) says that there is ...
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693 views

How many cis-trans isomers does 1-O-stearoyl-2-O-arachidonyl-phosphatidyl-inositol-4',5'-bisphosphate have?

I saw an exam that had a question asking the number of cis-trans-isomers of 1-O-stearoyl-2-O-arakidonyl-phosphatidyl-inositol-4',5'-bisphosphate: The "correct" answer in the exam is 1023, but this is ...
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Are glucose and galactose cis-trans isomers of each other?

Glucose and galactose are diastereomers of each other. However, is it correct to say that they are cis-trans isomers of each other? Does it make a difference with regard to terminology if glucose and ...