A series of ferrocenyl-arene dyads, Fc-C
ti
ties/
tbd1.gif">C-Ar,
trans-Fc-CH=CH-Ar, and Fc-CH=CH-CH=CH-Ar (Ar = phenyl, 1-naph
thyl, 2-naph
thyl, 9-phenan
thryl, 9-an
thryl, 1-pyrenyl,3-perylenyl) have been syn
thesized. Their s
truc
tures and spec
troelec
trochemical proper
tiesare discussed. The molecular s
truc
tures of several have been de
termined by X-ray diffrac
tionand
the observed s
truc
tures compared wi
th global free-energy minimized calcula
teds
truc
tures. In
the solid s
ta
te all e
thynyl dyads have
the aroma
tic ring or
thogonal
to
theferrocenyl cyclopen
tadienyl rings, whereas calcula
tions predic
t a coplanar orien
ta
tion.Calcula
ted and observed s
truc
tures agree for
the e
thenyl dyads wi
th
the rings or
thogonaland coplanar for
the an
thryl and pyrenyl dyads, respec
tively. In mos
t cases
the solid-s
ta
tes
truc
tures are s
tabilized by offse
t -s
tacking in
terac
tions be
tween
the polycyclic hydrocarbonrings. The
two bands in
the elec
tronic spec
tra of
the neu
tral dyads are due
to
the individualaryl and ferrocenyl end-groups. Upon oxida
tion a
t the [Fc]
+/0 couple,
the ferrocenyl
transi
tionis replaced by LMCT bands a
t lower energy and a new weak band in
the NIR assigned
to aFc
+ ti
ties/larr.gif"> aryl
transi
tion;
these assignmen
ts are suppor
ted by resonance Raman spec
tra, and
the energy of
the Fc
+ ti
ties/larr.gif"> aryl
transi
tion correla
tes wi
th
the ioniza
tion energy of
the arylgroup. These are
therefore elec
trochromic dyads.