organic chemistry - How to determine number of structural …
May 17, 2019 · The number of alkanes ($\ce{C_nH_{2n+2}}$) as constitutional isomers (structural isomers) and as steric isomers is calculated by Polya's theorem (G. Polya and R. C. Read, Combinatorial Enumeration of Groups, Graphs, and Chemical Compounds, Springer (1987)). In the process of calculating constitutional isomers, one 2D structure (graph or ...
How to check for geometrical isomerism in cyclic compounds?
More formal: use the Cahn–Ingold–Prelog rules to rank both sides of the two carbon atoms of the double bond. If priorities are different, then you have different isomers (and you can actually assign them a name. In your particular example, the compound has another isomer, and the one you have drawn has the configuration.
How can I find all possible isomers of a given molecule?
Jan 24, 2022 · In the examples shown by you, molecular symmetry reduces the number of isomers possible. On paper, you might assume that any of the six hydrogen atoms at the two terminal carbon atoms may be replaced by a $\ce{-OH}$ group which already would lead to six isomers. No, this is not the case as they are all symmetry equivalent:
organic chemistry - What is metamerism - Chemistry Stack Exchange
Jul 14, 2017 · This term is generally applied to those cases if isomerism wherein compounds show identity of elementary composition, but belong to different types of classes (…). For example, it has long been a question whether ethylic acetoacetate is to be represented as $\ce{CH3-CO-CH2-CO2Et}$ or by the formula $\ce{CH3-C(OH)=CH-CO2Et}$ .
organic chemistry - Number of possible isomers (including optical ...
Thus I drew all possible isomers and listed accordingly: Consequently, I also counted 32 isomers (same as yours). When compared to your count, I realized your count of chain alcohols (6), ethers (5), and carbonyl compounds (3) are all correct. However, your count of three-membered ring alcohols (7) and three-membered ring ethers (6) are incorrect.
General rules for deciding volatility - Chemistry Stack Exchange
Volatility depends on four factors for organic compounds: 1) Branched chained hydrocarbons are more volatile than straight chained hydrocarbons. 2) The more branched an hydrocarbon is the more volatile it is. 3) Depending on the bonds i.e hydrogen bond, dipole-dipole intermolecular bond and van der Waals' forces.
organic chemistry - Number of geometrical isomers when a cyclic …
Isomers b and c have the same relative orientation of methyl groups, but in a global scope these are two different molecules, and thus two different geometrical isomers. Therefore, 1,2-dimethylcyclopentane has one cis and two trans isomers.
organic chemistry - What is the E/Z configuration of cyclic …
Apr 5, 2015 · It's not necessary to include the E/Z descriptors for these compounds, because the alternative geometries would be far too strained to be stable molecules. However, there is no reason that we can't apply the rules to these compounds and assign the E/Z descriptor. In each case, compare at the substituents on each side of the pi-bond.
organic chemistry - Is there a formula to determine the total …
Jun 26, 2015 · There seems to be some confusion here : in order to determine the number of stereo-isomers of a molecular formula (say C4H11N) you would need to first know the number of constitutional isomers as you need to know how many stereogenic centers across all …
Where can I find reliable data for melting points of organic …
Jan 29, 2019 · I can understand that especially for isomers of alkanes, pure samples can be difficult to obtain; but as basic a property as melting point ought to be well-established and easy to reference. For example, the m.p. listed for 3-methylpentane varies from -118 °C to -163 °C depending on source.