Structure and optical properties of gold(I) thiocyanate exciplexes

Aoyagi, Noboru   ; Shimojo, Kojiro   ; Ikeda, Atsushi*  ; Watanabe, Masayuki   ; Brooks, N. R.*; Binnemans, K.*; Kimura, Takaumi 

Metallophilic interactions in complexes of univalent ions of the coinage metals copper, silver and gold can lead to luminescent behavior. Particularly, gold(I) complexes are interesting from the point of view of their coordination chemistry, because they form supramolecular complexes with infinite chains, spirals, trigonal prismatic stacked aggregates, etc. Under photo-excitation, gold(I) complexes can undergo isomerization or contraction of the Au-Au bond distance due to the strong aurophilic interaction in the excited state. However, detailed studies of these photoeffects are very rare. We have synthesized low- melting thiocyanate complexes, which are free from lattice energy found in the solid state, to study the change in the coordination geometry of gold(I) thiocyanate complexes. The optical properties and the structure of the complexes in both the ground state and the excited state will be the central topic of this presentation.