Chelation sulfur-containing types

Among the sulfur-containing chelating ligands used in the electrosynthesis, it is necessary to mention dialkyldithiocarbamates and dialkyldithiophosphates, on whose basis complexes of the types 796 and 797, respectively, were prepared [554,587,588] ... 

Sulfur-bound L-Met, as opposed to S,N-chelated L-Met, is more reactive as a ligand on Pt(II) and can be slowly replaced by N7 of G (95, 96). Transfer of Pt onto DNA via Met-containing peptides or proteins may therefore be possible. Monofunctional adducts of the type [Pt(en)(G)(L-Met-S)] appear to be very stable (97) and so methionine may play a role in trapping these adducts. Also, the high trans influence of S as a Pt(II) ligand can lead to the facile labilization of trans-am(m)ine ligands and this allows cisplatin to react with GMP faster in the presence of L-Met then in its absence (98), which introduces another route to DNA platination. 

Additional types of k C-k E chelating ylide complexes merit mentioning here, in addition to the species already presented, and some of them are shown in Scheme 24. The first is formed by ylides containing a pyridine functionality as substituent of the ylidic carbon. This type of ligand has allowed the S3mthesis of many loose clusters (82) of Cu, Ag, and Au which show weak metal( / °)-metal( / °) interactions. These facts have prompted the definition of a new phenomenon numismophilicity) to account for these weak interactions, uniquely shared by the three coinage metals [164]. Nitrogen and sulfur keto-stabilized ylides have been reacted with Pt and... 

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