Inhis2004PriestleyMedal address.published in Chemical and EngineeringNews,[4] E. J. Corey writes,"On May4,1964,I suggested to mycolleague R.B. Woodward a simple ex-planation involving the symmetry of theperturbed (HOMO) molecular orbitalsfor the stereoselective cyclobutene/l,3-butadieneand1,3,5-hexatriene/cyclohexadiene conversions that provided thebasisforthefurther developmentoftheseideas into what became known as theWoodward-Hoffmann rules."6
6
When Woodward and I spoke of thematter-again.Icannotrememberwhen it was--I asked him directly ifCorey had a role in this work. He saidInthelettertomeof November16.“no"this was our(R.B.W.and R.H.)1981, E. J. Corey says that he told me inwork.May1964that hehad suggested toR.B.Woodwardthe HOMO explanation forI believe that E.J. Corey's percepthe stereochemistry of electrocyclic re-tion of the consequences of what hetoldactions.andthatBobhadtakenovertheR.B. Woodward is just that-what he.idea from him.I spoketo Corey often inCorey,believes.Based on the argumentsthatperiod,butIhavenorecollection ofI made above,and on what I remember.such a conversation;I think CoreysIdon't thinkthat the conversation instatement would have been so strikingquestion influenced in any significant(especially the part about Woodwardway the beginning of the orbital symtakingtheideafromCorey)thatIwouldmetry control story. And given thathaverememberedit.Corey's claim was (and is being)madeafterWoodward'sdeath-whentheclaim could havebeenmadefor15yearsin Woodward's lifetime-that claim isalso deeply and fundamentally unfair.7
7
80W.nJmsTwwiloomJaF.B.ThnlluJACS8S,3309((963)1969TulkanthWuduend-to7方DLCxpomun?Figure1.May5,1964,entryin RoaldHoffmann's notebook.Theyear in thedate waswritten in8sometimelater
8
Shapes of molecules IELECTRONPAIRREPULSIONThe shape of a molecule can be worked out using the followingrules about electron pairs:(i) the pairs of electrons in a molecule (both shared and lonepairs) behave as though they repel each other and move as farapart as possible;(i) lone pairs repel more than bonding pairs9
9 Shapes of molecules I The shape of a molecule can be worked out using the following rules about electron pairs: ELECTRON PAIR REPULSION (i) the pairs of electrons in a molecule (both shared and lone pairs) behave as though they repel each other and move as far apart as possible; (ii) lone pairs repel more than bonding pairs
ShapesofmoleculesISo, the number of electron pairs decides the shape as the tableshows:ShapeNameof shapeNo. of charge clouds2000lineartrigonal3planar4tetrahedraltrigonal5bipyramidaloctahedral610
10 Shapes of molecules I So, the number of electron pairs decides the shape as the table shows: Shape No. of charge clouds Name of shape 2 3 4 5 6 linear trigonal planar tetrahedral trigonal bipyramidal octahedral