Photochemistry and Photophysics of Coordination Compounds

Photochemistry and Photophysics of Coordination Compounds: Copper 109
Fig. 38 The red-emitting complex [Cu(BTA)(hfac)] with BTA = bis(trimethylsilyl)acetylene
and hfac = 1,1,1,5,5,5-hexa-fluoroacetyl-acetonate
phosphorescence) [169], mononuclear and dinuclear azaindole-containing
systems (blue LC) [170, 171], heteroleptic diphosphine/diisocyanide ligands
(blue MLCT) [172], pyrazolylborates (blue LC phosphorescence) [173].
6
Conclusions and Perspectives
In recent years, the rationalization of the electronic and photophysical properties
of Cu(I) compounds has made considerable progress, in parallel with
a significant implementation of synthetic protocols to prepare both simple
and complex Cu(I)-based structures with satisfactory yields. Now we know
key design principles that allow one to make highly luminescent Cu(I) compounds
and supramolecular architectures with programmable cascades of
photoinduced processes. Such trends have taken Cu(I) complexes among the
key players in the realm of photoactive complexes, where other metals such
as Ru(II) and, more recently Ir(III) have traditionally played a prominent
role. The relentless quest for luminescent metal compounds to be utilized in
a variety of applications can find interesting answers among some classes of
Cu(I) complexes, as pointed out in this review article. Obviously, the need for
abundant, cheap, and environmentally friendly smart materials makes copper
compounds an attractive alternative to more traditional choices based on
precious metals. The current trends in literature and patenting [174] indeed
suggest that Cu(I) complexes are attracting increasing attention for technological
applications (e.g. OLEDs) and, although we are still at the level of
prototypes and proofs of principles, further important breakthroughs may be
anticipated in the years to come.