Why is nitro deactivating

Wonderful strait-forward explanations. Thank you. You must provide Hard copies of your precious material…I surely bet…. Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Notify me via e-mail if anyone answers my comment.

This site uses Akismet to reduce spam. Learn how your comment data is processed. Previous Electrophilic Aromatic Substitution: Introduction. Notes Advanced References and Further Reading 1. Activating And Deactivating Groups Last post in this series we introduced electrophilic aromatic substitution. Measuring Reaction Rates Can Provide Insight Into The Mechanism As far as determining mechanisms is concerned, one of the best tools we have in our experimental arsenal is the ability to measure reaction rates.

Let me show you what I mean. We know that by adding nitric acid and H 2 SO 4 , benzene can undergo nitration to form nitrobenzene break C-H, form C-NO 2 We can even measure the rate of this reaction at a given temperature, concentration, and solvent. Using the exact same experimental conditions we can then measure the rate of the reaction when toluene methylbenzene, C 6 H 5 CH 3 is used as the substrate instead of benzene.

The nitration of toluene is 23 times faster than it is for benzene. The nitration of trifluoromethylbenzene is 40, times slower than it is for benzene 2. So it seems like a good hypothesis that activating groups are electron-donating relative to H , and deactivating groups are electron-withdrawing relative to H 5. Clearly, something else must be going on here besides the inductive effect of oxygen!

The same is true for nitrogen groups with lone pairs, such as amines and amides below. So how do we keep all of these factors straight? A Table of Activating and Deactivating Groups Now seems like the right time to present a big table of activating and deactivating groups.

Alkoxy, amide, ester groups less strongly activating. Alkyl Groups — with no electron withdrawing groups. Moderately activating through inductive effect. Halogens — Moderately deactivating. Electron withdrawing highly electronegative nature outweighs donation of electron density through a lone pair. Atoms with pi-bonds to electronegative groups — Strongly deactivating. All pi-acceptors. Electron withdrawing groups with no pi bonds or lone pairs — Strongly deactivating.

Pure inductive effect. So what does all of this tell us? Next Post: Electrophilic Aromatic Substitution: The Mechanism Notes Two other relevant points for determining the rate of electrophilic aromatic substitution. Unfortunately this paper does not have data comparing the rate of chlorination to benzene. Kinetics and mechanism of some electrophilic benzene substitution reactions Alan E.

Bradfield and Brynmor Jones Faraday Soc. Toluene is times as reactive as benzene. The kinetics of aromatic halogen substitution. Part IX. Relative reactivities of monosubstituted benzenes P.

Robertson, P. Swedlund J. This spans the gamut of extreme activating substituents N,N-dimethylaniline is 10 18 times more reactive than benzene! The influence of the methoxyl group in aromatic substitution P. Vernon J. Rates of Bromination of Anisole and Certain Derivatives.

Partial Rate Factors for the Bromination Reaction. Stock and Herbert C. However, the outcome was not conclusive, in particular about an importance of the resonance effect, that is the directing effect, in nitrobenzene. The quantitative KS-MO model together with the EDA have proven to be able to elucidate the nature of different types of bonds: the nature of resonance-assisted hydrogen bonding 8 and halogen bonding 9 has been defined.

Moreover, the KS-MO model was successfully used for explaining the organic reaction mechanism, 10 the concept of aromaticity and other properties of chemical compounds. Previously, Fernandez et al. Based on frontier molecular orbital theory to explain chemical reactivity, our quantitative KS-MO results together with the VDD charges clarify the orientation of the electrophilic aromatic substitution and the change in reactivity of the benzene ring caused by the NH 2 or NO 2 substituents.

The VDD method also allows us to analyze the electronic redistributions within two polyatomic fragments when a chemical bond is formed between these two molecular fragments.

As the molecular symmetry of aniline and nitrobenzene is C 2v , thus of higher symmetry than C s , the changes in the atomic charge can be split further into A2 and B1. The longer C—N distance in nitrobenzene is caused by the larger Pauli repulsion Compression of the C—N distance in nitrobenzene to the distance in aniline makes the Pauli repulsion go up from The shortening of the C—N distance in nitrobenzene results in an increase of Viewed 11k times.

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Or somehow the one pair conjugation and pi bond conjugation interconvert? Oscar Lanzi Oscar Lanzi Sign up or log in Sign up using Google. Posted January 21, Thanks for answering me.

I really appreciate your help on this! Posted January 24, Hi AllainU, I was going to send you a screenshot today, but when I opened Nitro, it asked me for my activation code, entered it and now its activated!

Thanks again! Allain Umailin Posted January 24, Hello bethpeters , Thanks for your response and patience. Posted January 30, Hi AllainU, Thanks for your directions! Works great! How many computers can I add this Nitro12 to? Appreciate you letting me know! Thanks, Beth. Allain Umailin Posted January 30, Hello bethpeters , Thanks for your patience. Hi AllainU! Thanks so very much for ALL of help! Beth Peters. Skemp Posted February 10, Posted February 10, Allain Umailin Posted February 11, Posted February 11, Hello Skemp , Thank you for reaching out to us through our Community Forums!

Are you installing Nitro Pro 11? Posted June 27, edited. Good afternoon, our company has a license of 11 activations, currently they are all activated but many computers are no longer in use, the former IT manager is no longer in the company, I need to deactivate several licenses that are not in use to be able to reuse them in other equipment, The help menu tells me that I should contact the support team to have them deactivated.

Correspond to Nitro Pro 8 my contact email is aromo xyz. Allain Umailin Posted June 27, Posted June 27, To further assist you with your concern, I responded to the support case you submitted. Posted June 30, edited.

Thanks, Beth Peters bethpeters yahoo. Posted June 1 edited. Thanks, Beth Peters. Report post. Posted June 3. Hi Beth bethpeters , Thanks for posting on our Community Forums! Please let me know how it goes. Jonathan Felt Posted July 6, Posted July 6,