Tuning the Extended Structure and Electronic Properties of Gold(I) Thienyl Pyrazolates

A series of thienyl pyrazole proligands
and gold­(I) thienyl pyrazolate cyclic trinuclear complexes (CTCs)
have been synthesized. The relationship between the structure and
emission properties of bridging thienyl pyrazolates within gold­(I)
cyclic trinuclear complexes suggests that the nature of dual emission
is sensitive to ligand conjugation length. Density functional theory
has been used to support the assignment of metal-sensitized, ligand-localized
phosphorescence from monothienyl complexes, while low-lying, ligand-localized
LUMOs present in bithienyl systems prohibit metal-sensitized phosphorescence.
Soluble n-hexyl derivatives have been synthesized
to explore the electrochemical properties of gold­(I) thienyl pyrazolates
CTCs, and conductive electropolymerized thin films were realized.