Concept explainers
Interpretation:
The relative energy levels of the seven π molecular orbitals of cycloheptatrienyl system are to be show. How these seven orbitals are filled in the cation, radical and anion is to be indicated. Further the
Concept introduction:
The number of molecular orbitals formed is equal to the number of orbitals overlapping. The available orbitals are filled by the electrons in the increasing order of their energies. Each moleclar orbital can accommodate two electrons with opposite spin. Electrons occupy the orbitals individually first before they get paired in the same orbital.
The cycloheptatrienyl cation has six electrons to be filled in molecular orbitals.
The cycloheptatrienyl radical has seven electrons to be filled in molecular orbitals.
The cycloheptatrienyl anion has eight electrons to be filled in molecular orbitals.
To show:
The relative energy levels of the seven π molecular orbitals of cycloheptatrienyl system.
To indicate:
How these seven orbitals are filled in the cation, radical and anion.
To explain:
The aromatic character of the cycloheptatrienyl cation.
Want to see the full answer?
Check out a sample textbook solutionChapter 15 Solutions
Organic Chemistry
- Peroxides are often added to free-radical reactions as initiators because the oxygen–oxygen bond cleaves homolytically rather easily. For example, the bond-dissociation enthalpy of the O¬O bond in hydrogen peroxide (H¬O¬O¬H) is only 213 kJ>mol (51 kcal>mol). Give a mechanism for the hydrogen peroxide-initiated reaction of cyclopentane with chlorine. The BDE for HO¬Cl is 210 kJ>mol (50 kcal>mol).arrow_forwardSubstituents on an aromatic ring can have several effects on electrophilic aromatic substitution reactions. Substituents can activate or deactivate the ring to substitution, donate or withdraw electrons inductively, donate or withdraw electrons through resonance, and direct substitution either to the ortho/para or to the meta positions. From the lists of substituents, select the substituents that correspond to each indicated property. The substituents are written as –XY, where X is the atom directly bound to the aromatic ring. These substituents activate the ring These substituents withdraw electrons towards substitution. through resonance. -CN -COOH -CH, O -OCH, -NO, O -NH, -NHCOCH, -CN Incorrect These substituents give ortho/para-directed substitution. -F -CH,arrow_forwardWhat type of substituent effect do you expect a -CC12-CC12-CC13 (perchloropropyl) group to have upon aromatic electrophilic substitution reactions? Resonance electron donor; activating substituent; ortho/para director Inductive electron donating; activating substituent; ortho/para director Resonance electron withdrawing; deactivating substituent; ortho/para director Inductive electron withdrawing; deactivating substituent; meta directorarrow_forward
- Substituents on an aromatic ring can have several effects on electrophilic aromatic substitution reactions. Substituents can activate or deactivate the ring to substitution, donate or withdraw electrons inductively, donate or withdraw electrons through resonance, and direct substitution either to the ortho/para or to the meta positions. From the lists of substituents, select the substituents that correspond to each indicated property. The substituents are written as -XY, where X is the atom directly bound to the aromatic ring.arrow_forwardSubstituents on an aromatic ring can have several effects on electrophilic aromatic substitution reactions. Substituents can activate or deactivate the ring to substitution, donate or withdraw electrons inductively, donate or withdraw electrons through resonance, and direct substitution either to the ortho/para or to the meta positions. From the lists of substituents, select the substituents that correspond to each indicated property. The substituents are written as -XY, where X is the atom directly bound to the aromatic ring. These substituents activate the ring towards substitution. These substituents withdraw electrons through resonance. O -OCOCH; O -OH -CI O -COOH O -NH, O -CH, O -so,H O -CN These substituents give ortho/para-directed substitution. I -F O -NHCOCH, O -COOH O -NO,arrow_forwardExplain why the bond dissociation enthalpy of a C-H bond in benzene is significantly greater than that in alkanesarrow_forward
- Define Protons on Benzene Rings ?arrow_forwardFollowing the instructions for drawing the energy levels of the molecular orbitals for the compounds shown in Figure 8.17, draw the energy levels of the molecular orbitals for the cycloheptatrienyl cation, the cycloheptatrienylanion, and the cyclopropenyl cation. For each compound, show the distribution of the p electrons. Which of the compounds are aromatic?arrow_forwardThe pentadienyl radical, H2C“CH¬CH“CH¬CH2#, has its unpaired electron delocalized over three carbon atoms.(a) Use resonance forms to show which three carbon atoms bear the unpaired electron.(b) How many MOs are there in the molecular orbital picture of the pentadienyl radical?(c) How many nodes are there in the lowest-energy MO of the pentadienyl system? How many in the highest-energy MO?(d) Draw the MOs of the pentadienyl system in order of increasing energy. (continued)762 CHAPTER 15 Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy(e) Show how many electrons are in each MO for the pentadienyl radical (ground state).(f) Show how your molecular orbital picture agrees with the resonance picture showing delocalization of the unpairedelectron onto three carbon atoms.(g) Remove the highest-energy electron from the pentadienyl radical to give the pentadienyl cation. Which carbon atomsshare the positive charge? Does this picture agree with the resonance picture?(h) Add an…arrow_forward
- When exactly 1 mole of methane is mixed with exactly 1 mole of chlorine and light is shone on the mixture, a chlorination reaction occurs. The products are found to contain substantial amounts of di-, tri-, and tetrachloromethane, as well as unreacted methane. Explain how a mixture is formed from this stoichiometric mixture of reactants, and propose mechanisms for the formation of these compounds from chloromethane.arrow_forwardThe chlorination of ethane produces many by-products. One by-product that forms in small amounts is 2-chlorobutane. Suggest a mechanism for the formation of 2-chlorobutane from the radical chlorination of ethane. (NOTES: intermediates can only have one radical, 2-chlorobutane should be the product of your termination step, any intermediate radical formed during the propagation phase can be used in the termination step)arrow_forwardCyclopropenones are described as having aromatic character. How would you account for this, given that the ring contains three ℼ-electronarrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning