University:
Shippensburg University of Pennsylvania
Course:
CHM 121 | Chemical Bonding
Academic year:

2022
Views:

28

Pages:

6
Author:

GrabCapacity

Hyperconjugation (Baber & Nathan effect No bond resonculce (zero order resonance) os, conjugation or or second order resonance) Biber and Nathan carried out reaction between p-substitued pyridine where the Benzyl bromide curd pyridine gets proto -Wated by p- substituted benzge mation the rate of reactiong Gis of reaction sate casbo decreases electron attracting CN) and f Increasee if Ges electron donating (+ I group, alkyl groups) 7 The increasing rati of reaction by by +I because I understood Geralps stabilized duertasing its Inductivell effect nature Benzyl et (ur) by Since chor the electrondonating 2 from primary (1) incleasing from methyl group geral rate of Eencedase with 13° (Texttary) depye of reaction the same order, Bert practically they found. the rate of reverse order. It means group reaction fastest by its nature donating Which is Inductive sullaring nature the by effect. of explanation given Nathan that increase rate of electron donating elerdoon The electron cf-group beren they at &-carbon atom maximum Bakes and C-H they can -bords be donated (transfered) like electromeric effect and this type of Brown as electron donati Hyper confucation nature ne dnd! having two Alkyl group carbond atom Alpyl zero: C H The methyl (cy) group has three 20 bonds at hyperconfucation effect be maximum and C-H bonds So, electron donatry cf-group incrlase rate of reaction fastest. Suse, there is no definate d-carbon atom and atom no bond resonance or In the rate identities determining bond between so called zero order pesonance. step the two and Panion cation and exists suppose to some time so called second order resonance So the election donating different alkyl groups nature of can be given as below in which the tod -effects in opposite direction. so, the Hyperconjucation different reply groups structures of can be given Sach hyperconjugative delocaliestion Involving Hobonding Shital and the adjacent bonding orbital form I of can be given in the molecular orbithe picture In MO picture the explanation can be given as the &'e atom o molecular orbital C-H bond is adjacent parallel to the T MO of adjacent c=c system. It is sssumed that those troo and form ands formed Conjugation molecule and I MO conjugate parallely new delocalised and and chemical However, resonance tve conjugation practically affect peroperties effect This i observed in the both physical of become neaper than The effect of hypercornmation