sp2 centres intro to aromatics Flashcards
1
Q
how does benzene react with bromine
A
only reacts when Br2 is with FeBr3 in a substitution reaction, heating system again allows disubstitution
2
Q
how do ring currents occur in benzene ring
A
protons inside ring: experience shielding small chemical shift
protons outside ring deshielding so higher chemical shift
3
Q
what peak does benzene give on HNMR
A
singlet at 7.27
4
Q
what is huckles rule
A
compounds which are planar and have a contagious cyclic array of p-orbitals perpendicular to the plane of ring: those with 4N+2 p electrons display special stabilisation eg aromatic
Thise with 4n p electrons display special inability anti-aromatic
5
Q
what happens is species is anti-aromatic
A
will be very unstable and so will have very slow ROR or no reaction will occur
