The new DO3A-derived dithiocarbamate ligand, DO3A-Bu-t-CS2K, is formed by treatment of the ammonium salt [DO3A-Bu-t]HBr with K2CO3 and carbon disulfide. DO3A-Bu-t-CS2K reacts with the ruthenium complexes cis-[RuCl2(dppm)(2)] and [Ru(CH=CHC6H4Me-4) Cl(CO)(BTD)(PPh3)(2)] (BTD = 2,1,3-benzothiadiazole) to yield [Ru(S2C-DO3A-Bu-t)(dppni)(2)](+) and [Ru(CH=CHC6H4Me-4)(S2C-DO3A-Bu-t)(CO)(PPh3)(2)], respectively. Similarly, the group 10 metal complexes [Pd(C,N-C6H4CH2NMe2)Cl](2) and [PtCl2(PPh3)(2)] form the dithiocarbamate compounds, [Pd(C,N-C6H4CH2NMe2)(S2C-DO3A-Bu-t)] and [Pt(S2C-DO3A-Bu-t)(PPh3)(2)]+, under the same conditions. The linear gold complexes [Au(S2C-DO3A-Bu-t)(PR3)] are formed by reaction of [AuCl(PR3)] (R = Ph, Cy) with DO3A-Bu-t-CS2K. However, on reaction with [AuCl(tht)] (tht = tetrahydrothiophene), the homoleptic digold complex [Au(S2C-DO3A-Bu-t)](2) is formed. Further homoleptic examples, [M(S2C-DO3A-Bu-t)(2)] (M = Ni, Cu) and [Co(S2C-DO3A-Bu-t)(3)], are formed from treatment of NiCl2 center dot 6H(2)O, Cu(OAc)(2), or Co(OAc)(2), respectively, with DO3A-Bu-t-CS2K. The molecular structure of [Ni(S2C-DO3A-Bu-t)(2)] was determined crystallographically. The tert-butyl ester protecting groups of [M(S2C-DO3A-Bu-t)(2)] (M = Ni, Cu) and [Co(S2C-DO3A-Bu-t)(3)] are cleaved by trifluoroacetic acid to afford the carboxylic acid products, [M(S2C-DO3A)(2)] (M = Ni, Cu) and [Co(S2C-DO3A)(3)]. Complexation with Gd(III) salts yields trimetallic [M(S2C-DO3A-Gd)(2)] (M = Ni, Cu) and tetrametallic [Co(S2C-DO3A-Gd)(3)], with r(1) values of 11.5 (Co) and 11.0 (Cu) mM(-1) s(-1) per Gd center. DO3A-Bu-t-CS2K can also be used to prepare gold nanoparticles, Au@S2C-DO3A-Bu-t, by displacement of the surface units from citrate-stabilized nanoparticles. This material can be transformed into the carboxylic acid derivative Au@S2C-DO3A by treatment with trifluoroacetic acid. Complexation with Gd(OTf)(3) or GdCl3 affords Au@S2C-DO3A-Gd with an r(1) value of 4.7 mM(-1) s(-1) per chelate and 1500 mM(-1) s(-1) per object.