Polychlorotriphenylmethyl Radicals: Towards Multifunctional Molecular Materials - Stable Radicals: Fundamentals and Applied Aspects of Odd-Electron Compounds - page 70

Cl

H

Fe

Cl

Cl

H

H Cl

H

H Cl

Cl

Fe H Cl

H Cl

Cl H H N

Cl H

Cl

Cl

Cl

N H H Cl

N

2

Cl H

Cl

Cl

h n

Cl H

H

Cl

Cl H

H

Cl

H

Cl

Fe

H

H

Cl

Cl

h n

2 trans

(cis ) 2

S = 0

S = 2·1/2 ∆

2·

∆

"off state"

"on state"

Figure2.31 PossibleisomerizationsofthePTMSchiffbaseradical 35 .(Reprintedwithpermissionfrom[128a].
Copyright2001Wiley-VCHVerlagGmbH&Co.KGaA.)

2.3.2 Redox switchable molecular systems
2.3.2.1 Switching multifunctional PTM radicals in solution

Presented here is a multifunctional redox switchable molecular system showing simultaneous changes of
three different outputs - the linear optical, nonlinear optical and magnetic properties - which is based on
the rich electrochemical behaviour of radical 18 (Scheme 2.6), previously described and for which the

Cl

Cl Cl

Cl

Cl Cl

Cl

Cl Cl

Cl

Cl Cl

Cl Cl

Cl Cl Cl Cl

Cl
Cl

Cl
Cl

Cl
Cl

•

•

+ e − + e −

Cl Cl

Cl Cl

e − − e −

Cl Cl

−

Fe

Fe Cl Fe

Cl Cl Cl

Cl Cl

Cl

Cl Cl

18 18

18

Cl

Cl Cl

H + OH −

Cl

Cl

Cl

Cl

Cl

Cl

H

Cl
Cl

Cl Cl

Fe Cl

Cl

Cl

H -18

Cl

Scheme 2.6 The four states of the molecular switch: 18 − , 18 , 18 + and H- 18