The crystal structure of the title compound, C29H39N3O4S4, was determined at 97 K and possesses normal geometric parameters.

Copper(II) complexes were prepared with the new N2S(thioether) ligand 2-methylthio-N-(2-pyridylmethyl)acetamide (2-HLN2S). [Cu(2-LN2S)Cl(MeOH)], which formed in the presence of excess triethylamine, is a distorted square pyramidal complex containing the ligand with the amide nitrogen deprotonated. The structurally analogous complex, [Cu(2-HLN2S)Cl2], which formed in the absence of triethylamine, contains 2-HLN2S in the tautomeric imidic acid form. Neutral copper(II) N2S(thioether)S(thiolate) species were generated by addition of alkyl or aromatic thiolates to [Cu(2-LN2S)Cl(MeOH)] and an unusual decomposition pathway was discovered.

Triazacyclononane (TACN) was coupled to glycine (L(Gly)), alanine (L(Ala)), and phenylalanine (L(Phe)) via standard solution phase peptide coupling techniques. Copper(II) complexes of these new ligand-amino acid conjugates, [(CuL(Gly))(2)](ClO(4))(4) (1), [(CuL(Ala))(2)Cl](ClO(4))(3) (2), and [Cu(2)L(Phe)Cl(4)] (3), were synthesized and characterized. The X-ray crystal structures of 2 and 3 were determined. Complex 2 is a dimeric species where L(Ala) bridges between copper ions via its two TACN amine nitrogen atoms to one copper while the Ala terminal amine and carbonyl oxygen bind to the other copper. Complex 3 is bimetallic but only contains one L(Phe) ligand that bridges between the copper ions.