In most other reactions of anthracene, the central ring is also targeted, as it is the most highly reactive. Which is more reactive naphthalene or anthracene? Case 3 reflects a combination of steric hindrance and the superior innate stabilizing ability of methyl groups relative to other alkyl substituents. MathJax reference. Naphthalene has two aromatic rings, but only 10 pi electrons (rather than the twelve electrons that it would prefer). 22: Arenes, Electrophilic Aromatic Substitution, Basic Principles of Organic Chemistry (Roberts and Caserio), { "22.01:_Nomenclature_of_Arenes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.02:_Physical_Properties_of_Arenes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.03:_Spectral_Properties_of_Arenes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.04:_Electrophilic_Aromatic_Substitution" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.05:_Effect_of_Substituents_on_Reactivity_and_Orientation_in_Electrophilic_Aromatic_Substitution" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.06:_Orientation_in_Disubstituted_Benzenes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.07:_IPSO_Substitution" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.08:_Substitution_Reactions_of_Polynuclear_Aromatic_Hydrocarbons" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.09:_Addition_Reactions_of_Arenes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.10:_Oxidation_Reactions" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.11:_Sources_and_Uses_of_Aromatic_Hydrocarbons" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.12:_Some_Conjugated_Cyclic_Polyenes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.13:_Fluxional_Compounds" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22.E:_Arenes_Electrophilic_Aromatic_Substitution_(Exercises)" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { "00:_Front_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "01:_Introduction_to_Organic_Chemistry" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "02:_Structural_Organic_Chemistry" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "03:_Organic_Nomenclature" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "04:_Alkanes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "05:_Stereoisomerism_of_Organic_Molecules" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "06:_Bonding_in_Organic_Molecules" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "07:_Other_Compounds_than_Hydrocarbons" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "08:_Nucleophilic_Substitution_and_Elimination_Reactions" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "09:_Separation_Purification_and_Identification_of_Organic_Compounds" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "10:_Alkenes_and_Alkynes_I_-_Ionic_and_Radical_Addition_Reactions" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "11:_Alkenes_and_Alkynes_II_-_Oxidation_and_Reduction_Reactions._Acidity_of_Alkynes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "12:_Cycloalkanes_Cycloalkenes_and_Cycloalkynes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "13:_Polyfunctional_Compounds_Alkadienes_and_Approaches_to_Organic_Synthesis" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "14:_Organohalogen_and_Organometallic_Compounds" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "15:_Alcohols_and_Ethers" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "16:_Carbonyl_Compounds_I-_Aldehydes_and_Ketones._Addition_Reactions_of_the_Carbonyl_Group" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "17:_Carbonyl_Compounds_II-_Enols_and_Enolate_Anions._Unsaturated_and_Polycarbonyl_Compounds" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "18:_Carboxylic_Acids_and_Their_Derivatives" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "19:_More_on_Stereochemistry" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "20:_Carbohydrates" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "21:_Resonance_and_Molecular_Orbital_Methods" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "22:_Arenes_Electrophilic_Aromatic_Substitution" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "23:_Organonitrogen_Compounds_I_-_Amines" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "24:_Organonitrogen_Compounds_II_-_Amides_Nitriles_and_Nitro_Compounds" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "25:_Amino_Acids_Peptides_and_Proteins" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "26:_More_on_Aromatic_Compounds" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "27:_More_about_Spectroscopy" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "28:_Photochemistry" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "29:_Polymers" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "30:_Natural_Products_and_Biosynthesis" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "31:_Transition_Metal_Organic_Compounds" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "zz:_Back_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, 22.8: Substitution Reactions of Polynuclear Aromatic Hydrocarbons, [ "article:topic", "showtoc:no", "license:ccbyncsa", "autonumheader:yes2", "authorname:robertscaserio", "licenseversion:40" ], https://chem.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fchem.libretexts.org%2FBookshelves%2FOrganic_Chemistry%2FBasic_Principles_of_Organic_Chemistry_(Roberts_and_Caserio)%2F22%253A_Arenes_Electrophilic_Aromatic_Substitution%2F22.08%253A_Substitution_Reactions_of_Polynuclear_Aromatic_Hydrocarbons, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), status page at https://status.libretexts.org. This stabilization in the reactant reduces the reactivity (stability/reactivity principle). Alternatively, a DielsAlder reaction with carbon atoms #9 and #10. 05/05/2013. Why? Why is phenanthrene more reactive than anthracene? When applied to aromatic halides, as in the present discussion, this mechanism is called SNAr. The correct option will be A. benzene > naphthalene > anthracene. Do Men Still Wear Button Holes At Weddings? Anthracene, however, is an unusually unreactive diene. The 5-membered ring heterocycles (furan, pyrrole, thiophene) are -electron rich aromatics (6 electrons over 5 atoms) This makes them more reactive than benzene (since the aromatics the nucleophilic component in these electrophilic substitution reactions) . Anhydrides are highly reactive to nucleophilic attack and undergo many of the same reactions as . The two structures on the left have one discrete benzene ring each, but may also be viewed as 10-pi-electron annulenes having a bridging single bond. These group +I effect like alkyl or . This makes the toluene molecule . Does Counterspell prevent from any further spells being cast on a given turn? Science Chemistry Give the diene and dienophile whose reaction at elecvated temperature produces the adduct shown below: I x OA. The recent ability to manipulate and visualize single atoms at atomic level has given rise to modern bottom-up nanotechnology. Electrophilic nitration and Friedel-Crafts acylation reactions introduce deactivating, meta-directing substituents on an aromatic ring. The 1,2 bonds in both naphthalene and antracene are in fact shorter than the other ring bonds, whereas the 9,10 bond in phenanthrene closely resembles an alkene double bond in both its length and chemical reactivity. In terms of activation, notice that maleic anhydride is a highly reactive dienophile, due to the presence of two electron- withdrawing carbonyl substituents. The resonance energy of anthracene is less than that of naphthalene. In anthracene the rings are con- However, ortho-chloroanisole gave exclusively meta-methoxyaniline under the same conditions. In previous studies, the origin of the higher stability of kinked polycyclic aromatic hydrocarbons (PAHs) was found to be better -bonding interactions, i.e., larger aromaticity, in kinked as compared . Stability can be compared only for isomeric or related compounds or at best for unsaturated hydrocarbons it is comp. Naphthalene is more reactive than benzene, both in substitution and addition reactions, and these reactions tend to proceed in a manner that maintains one intact benzene ring. Anthracene is actually colourless. It's a site that collects all the most frequently asked questions and answers, so you don't have to spend hours on searching anywhere else. Log In. Is phenanthrene more reactive than anthracene? Whereas chlorine atom involves 2p-3p overlap. Although the transition state almost certainly has less aromaticity than benzene, the . Examples of these reductions are shown here, equation 6 demonstrating the simultaneous reduction of both functions. I invite you to draw the mechanisms by yourself: It may be helpful to add that benzene, naphthalene and anthracene are of course Hckel-aromatic compounds; with 6, 10 or 14 -electrons they fit into the rule of $(4n + 2)$. Similarly, alkenes react readily with halogens and hydrogen halides by addition to give alkyl halides, whereas halogens react with benzene by substitution and . This increased reactivity is expected on theoretical grounds because quantum-mechanical calculations show that . Phenol has an OH group bonded to one of the carbons and this oxygen has two lone pairs in p-orbitals. Which is more reactive anthracene or naphthalene? Direct nitration of phenol (hydroxybenzene) by dilute nitric acid gives modest yields of nitrated phenols and considerable oxidative decomposition to tarry materials; aniline (aminobenzene) is largely destroyed. . The resulting N-2,4-dinitrophenyl derivatives are bright yellow crystalline compounds that facilitated analysis of peptides and proteins, a subject for which Frederick Sanger received one of his two Nobel Prizes in chemistry. In most other reactions of anthracene, the central ring is also targeted, as it is the most highly reactive.