f-Block complexes of a m-terphenyl dithiocarboxylate ligand.

Straightforward syntheses are provided for the m-terphenyl dithiocarboxylic acid 2,6-(C6 H4 -4-t Bu)2 C6 H3 CS2 H (TerphCS2 H, 2) and its lithium and potassium salts, TerphCS2 Li(Et2 O)2 and TerphCS2 K (1·Et2 O and 4, respectively). These compounds can be isolated in good yields on multi-gram scales starting from Terph-I without isolating intermediates. Salt metathesis and protonolysis reactions provided access to the homoleptic actinide(iv) complexes (TerphCS2 )4 An (An = Th (5) and U (6)). Electrochemical and reactivity studies revealed that the dithiocarboxylate ligand is incompatible with U(iii). The homoleptic lanthanum(iii) complex (TerphCS2 )3 La and its η6 -toluene adduct (7 and 7·tol, respectively) were also structurally characterized. Binding of toluene to 7 was shown to displace intramolecular La-Carene close contacts that are facilitated by a distortion from the usual geometry of bound dithiocarboxylate ligands.