Structural formulas for isomers

Table 2. Illustrates the Structural Formulas for Isomers of Pentane.

Figure 1. Illustrates the structural formulas for isomers of butane and pentane.

Wnte a structural formula for the CFI3NO isomer characterized by the structural unit indi cated None of the atoms in the final structure should have a formal charge... 

Wnte structural formulas for all the constitutional isomers of molecular formula C3HgO that contain... 

Now write structural formulas for the remaining three isomers Be sure that each one IS a unique compound and not simply a different representation of one writ ten previously... 

In Problem 2 5 you were asked to write structural formulas for the five isomeric alkanes of molecular formula C6H14 In the next section you will see how the lUPAC rules generate a unique name for each isomer... 

Excluding compounds that contain methyl or ethyl groups write structural formulas for all the bicychc isomers of (a) CsHg and (b) CgHjo... 

Photochemical chlorination of pentane gave a mixture of three isomenc monochlorides The pnncipal monochlonde constituted 46% of the total and the remaining 54% was approximately a 1 1 mixture of the other two isomers Write structural formulas for the three monochlonde iso mers and specify which one was formed in greatest amount (Recall that a secondary hydrogen is abstracted three times faster by a chlonne atom than a pnmary hydrogen)... 

How many isomers of CsHs can you write" An article in the March 1994 issue of the Journal of Chemical Educa tion (pp 222-224) claims that there are several hun dred and draws structural formulas for 25 of them... 

In the realm of chemical enumeration we note Polya s equation (4.4) which gives the generating function for stereoisomers of the alkyl radicals, or equivalently, alcohols — that is, equation (5.2) of this article. His equation (4.3) gives the corresponding result for the structural isomers of these compounds. His equations (4.2) and (4.5) correspond, respectively, to the cases of alcohols without any asymmetric carbon atoms and the number of embeddings in the plane of structural formulae for alcohols in general. The latter problem is not chemically very significant. 

Draw structural formulas for all the isomers of ethylene (QH ) in which two of the hydrogen atoms have been replaced by deuterium atoms. Label the cis and the irons isomers. 

We have now found all possible structural formulas for the ethanol molecule. The oxygen atom is either directly bonded to one carbon atom or to two carbon atoms. Once a choice between these two possibilities is made, the structure of the rest of the molecule can be determined from the molecular formula and the bonding rules. The two possible structures are shown in Figure 18-2. Such compounds with the same molecular formula but different structural formulas are called structural isomers. The existence of the two compounds I and 2 was known long before their structures were clarified. Hence the existence of these isomers perplexed chemists for decades. Now we recognize the crucial impor-... 

Draw a structural formula for the fructose molecule (remember that fructose is an isomer of glucose). Explain why fructose cannot be oxidized to a six-carbon acid. 

Self-Test 18.4B Halogen atoms can substitute for hydrogen atoms in hydrocarbons. Write the condensed structural formulas for the four isomers with the molecular formula C4H9Br. 

Write the structural formulas for and name (a) at least 10 alkene isomers having the formula C(1HI2 (b) at least 10 cycloalkane isomers have the formula CftH12. 

Write the structural formulas for and name all the isomers (including geometrical isomers) of the alkenes (a) C4H8 (b) C5H10. 

Methane, CH4, has one carbon atom. The next two members of the alkane family are ethane, C2H6, and propane, C3H8. Molecules of these compounds contain chains of two carbon atoms and three carbon atoms, respectively. Alkanes with more than three carbon atoms have more than one isomer. There are two structural formulas for butane, C4H10, and three structural formulas for pentane, C5H12. 

Draw the structural formula for each isomer and label it with the correct IUPAC name. 

Write structural formulas for the three isomers of pentane. 

In this question consider organic molecule with no rings or carbon-to-carbon double or triple bonds, (a) Show that ethers can be isomers of alcohols but not of aldehydes, (ft) Show that aldehydes and ketones can be isomers of each other, but not of acids or alcohols, (c) Write the structural formula for an alcohol isomeric with diethyl ether. 

The ratio between the values of the TRE or between those of the HSRE for the isomer pairs (88)-(93) is analogous to that between the values of the CCMRE (given in eV under the structural formulae) for the positional isomers of azulenofurans, azulenopyrroles, and azulenothiophenes (87H2025). 

Draw structural formulas for the isomers of heptane. Name the isomers by the IUPAC system. 

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