Gold complexes utility

A multitude of related polynuclear gold complexes have been prepared utilizing a range of bridging ligands, and their spectroscopic properties have been examined [71]. An example involving 16 individual Au(I) ions deserves mention because of its extreme complexity [72],... 

Gold complexes can also be utilized as catalysts for the synthesis of pyrroles from 1,5-diynes. 2,5-Dimethylpyrrole is synthesized from the reaction of hexa-l,5-diyne and ammonia in the presence of a gold-carbene complex, Au-I [13] ... 

In addition, the byproduct acetylacetone is very easily separated from the other reaction product. We have shown the utility of [Au(acac)PPh3] and of PPN[Au(acac)2] [PPN = bis(triphenylphosphoranylidene)ammonium = N(PPh3)2] in the synthesis of a great variety of organometallic and coordination gold(I) complexes (see Scheme l).2 Laguna et al. have also found interesting applications for these complexes.3... 

The reported strategies utilized in DNA sensing include (1) sequence-specific hybridization processes based on the oxidation signal of most electroactive DNA bases, guanine and adenine [13,24] or (2) quasi-specific detection of small molecules capable of binding by intercalation or complexation with DNA, such as metal coordination complexes, antibiotics, pesticides, pollutants, etc. [17,18] or in the presence of some metal tags such as gold, silver nanoparticles, etc. [23,50,51]. 

The application of surface-enhanced Raman spectroscopy (SERS) for monitoring redox and other processes at metal-solution interfaces is illustrated by means of some recent results obtained in our laboratory. The detection of adsorbed species present at outer- as well as inner-sphere reaction sites is noted. The influence of surface interaction effects on the SER spectra of adsorbed redox couples is discussed with a view towards utilizing the frequency-potential dependence of oxidation-state sensitive vibrational modes as a criterion of reactant-surface electronic coupling effects. Illustrative data are presented for Ru(NH3)63+/2+ adsorbed electrostatically to chloride-coated silver, and Fe(CN)63 /" bound to gold electrodes the latter couple appears to be valence delocalized under some conditions. The use of coupled SERS-rotating disk voltammetry measurements to examine the kinetics and mechanisms of irreversible and multistep electrochemical reactions is also discussed. Examples given are the outer- and inner-sphere one-electron reductions of Co(III) and Cr(III) complexes at silver, and the oxidation of carbon monoxide and iodide at gold electrodes. 

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