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Thiocarbamoylbenzimidoyl chlorides, PhC(Cl)-N-(C-S)-NR¹R², react with 2-(iminodiacetic acid)benzylamine under formation of the potentially pentadentate ligands H3L (R¹, R² = Et) and H3L-COOEt (R¹ = Me, R² = C6H4-4-COOEt) in high yields. Hydrolysis of H3L-COOEt in NaOH/MeOH gives quantitatively another benzamidine ligand H3L-COOH. The novel ligands readily react with (NBu4)[MOCl4] (M = Re, Tc) under formation of stable complexes with the general composition [MO(L)], in which they are triply deprotonated and fully occupy the remaining five coordination positions of the {MO}3+ cores. In a "proof-of-principle" reaction for possible bioconjugations, the complex [ReO(L-COOH)] has been labeled with triglycine ethyl ester in high yields. [ABSTRACT FROM AUTHOR]

A series of novel neutral NHC gold halide complexes derivedfrom4,5-diarylimidazoles were synthesized, characterized, and analyzedfor biological effects. High growth inhibitory effects in MCF-7 andMDA-MB 231 breast cancer as well as HT-29 colon cancer cell linesdepended on the presence of the C4,C5-standing aromatic rings. Methoxygroups at these rings did not change the growth inhibitory properties,while F-substituents in the ortho-position (5d) increasedthe activity in MCF-7 and MDA-MB 231 cells. The substituents at thenitrogen atoms and the oxidation state of the metal play a subordinaterole. The most active bromo[1,3-diethyl-4,5-bis(2-fluorophenyl)-1,3-dihydro-2H-imidazol-2-ylidene]gold(I) (5d) was distinctlymore active than cisplatin. All complexes caused thioredoxin reductase(TrxR) inhibition (EC50= 374–1505 nM) distinctlylower than auranofin (EC50= 18.6 nM) excluding this enzymeas main target. Because of the low nuclear content, a participationof DNA interaction on the mode of action is very unlikely. The missingER binding and the missing correlation of growth inhibition and inactivationof COX enzymes exclude these targets, too. [ABSTRACT FROM AUTHOR]

The syntheses of four S6-cages with different cavity sizes are described. In regard of potential applications for radioimmunotherapy with 111Ag, their coordination behaviour towards Ag(i) was evaluated by studies of their reactivity in solution and of their crystal structures. All cages reacted differently with Ag(i). Whereas S6-cages based on 3,8,12,17,20,25-hexathiabicyclo[8.8.8]-hexacosane (14) and on 5,9,17,21,28,31-hexathiabicyclo[11.11.11]pentatriacontane (18) showed only external Ag(i) coordination, successive adaptation of the cage size, yielded ligand 24, based on 4,7,13,21,24,25-hexathiabicyclo[8.8.8]hexacosane, which gave a complex with internal-peripheral Ag(i) binding. [ABSTRACT FROM AUTHOR]