Luminescent gold alkynyl complexes

With the more sophisticated dialkynylcalixarenes as ligands, tetranuclear gold alkynyl complexes 8a and 8b (Fig. 13), in which both a- and n-coordinated gold centers are present and exhibit short intramolecular Au Au contacts of 3.1344(8) and 3.2048(8) A, were obtained [104], The complexes were found to be strongly luminescent at 591-616 nm in the solid state, whereas in chloroform solution or 77 K CHCl3-MeOH-EtOH glass... 

Syntheses and luminescence studies of mixed-metal gold(I)-copper(l) and -silver (I) alkynyl complexes. The tuming-on of emission upon d metal ion encapsulation. Dalton Transactions, 1830-1835. 

The luminescence behavior of a binuclear gold(I) alkynyl complex with a bridging dppf ligand, [(dppf)Au2 C=CC(Me)=CH2)2], was also reported... 

Other work has demonstrated that it is possible to switch ON and OFF luminescence by reduction/oxidation, and it has been demonstrated that such switching is possible inside an OTTLE cell. Many alkynyl complexes, especially those of rhenium, platinum,copper, silver or gold " are highly luminescent from their excited MLCT or metal perturbed 71 states. This opens up the possibility to significantly influence their emissive properties by redox processes. An interesting example is found in recent work of Wong et Unlike other rhenium(I)-alkynyl complexes, heterobimetallic... 

With the recent developments and growing interest in metal-based chemosen-sors [196-198], some work toward the utilization of the luminescent Au(i) system in chemosensing has been described [199]. A series of gold(i) calix[4]crown-5 alkynyl complexes has been reported by Yam et al. [200, 201]. These calix[4]crown-5 alkynyl complexes were found to bind K+ ions preferentially over Na+ ions with UV-vis absorption spectral changes. It is noteworthy that the crown size of these alkynyl complexes could be fine-tuned by a subtle change in the steric demands on the triarylphosphine ligands, providing a firm basis for the further development of these classes of selective metalloreceptors for various metal ions. 

Gd-Rubio J, Camara V, Bautista D, Vicente J. Dinuclear alkynyl gold(I) complexes containing bridging N-heterocycHc dicarbene ligands new synthetic routes and luminescence. Organometallics. 2012 31 5414-5426. 

FIGURE 5.7 Luminescent tetranuclear gold(I) alkynyl complexes with a novel planar Tj, Tj -coordination mode. 

Gold(l) alkynyl derivatives containing the water-soluble PTA and DAPTA phos-phane ligands (see examples 34-36 in Figure 4.10) are cytotoxic in cancer cells and their cellular uptake was confirmed by fluorescence microscopy using the luminescent properties of these organometallics [117]. As expected, the complexes lack... 

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