4.3 Carbocation Structure p102 and stability Carbocations are planar and the tricoordinate carbon is surrounded by only 6 electrons in sp2 orbitals The fourth orbital on carbon is a vacant p- orbital The stability of the carbocation is increased by the presence of alkyl substituents Therefore stability of carbocations 3°>20>1°>+CH4.3 Carbocation Structure and Stability • Carbocations are planar and the tricoordinate carbon is surrounded by only 6 electrons in sp2 orbitals • The fourth orbital on carbon is a vacant p￾orbital • The stability of the carbocation is increased by the presence of alkyl substituents • Therefore stability of carbocations: 3º > 2º > 1º > +CH3 p.102