Metalloligands: Rhodium(III) Cyclometallated Compounds Containing Multitopological Binucleating Ligands

The reaction of [Rh(2‐phenylpyridine) 2 Cl] 2 with secondary dithiooxamides H 2 R 2 C 2 N 2 S 2 (R = isoamyl, isopropyl, {S}‐phenylethyl, meso ‐phenylethyl) affords the contact ion pair [Rh(2‐phenylpyridine) 2 (H 2 R 2 C 2 N 2 S 2 κ‐ S , S ‐Rh)] + Cl – , which can be transformed into the neutral complexes [Rh(2‐phenylpyridine) 2 (HR 2 C 2 N 2 S 2 κ‐ S , S ‐Rh)]. The HCl exchange between the ion pairs and the corresponding neutral complexes has been studied by means of dynamic NMR spectroscopy techniques, and a mechanism for this exchange has been proposed. [Rh(2‐phenylpyridine) 2 {H(isoamyl) 2 C 2 N 2 S 2 κ‐ S , S ‐Rh}] reacts with chlorido‐bridged dimers [ML n Cl] 2 {ML n = Pd(η 3 ‐allyl), Rh(cyclooctadiene), ( n ‐propyl) 3 PClPd} and provides the heterobimetallic complexes [Rh(2‐phenylpyridine) 2 {μ‐(isoamyl) 2 C 2 N 2 S 2 }ML n ]. Heterobimetallic complexes having the same formula and the same structure are obtained by reaction of [ML n {H(isoamyl) 2 C 2 N 2 S 2 κ‐ S , S ‐M}] species [ML n = Rh(1,5‐cyclooctadiene), Pd(η 3 ‐allyl), PdCl(tri‐ n ‐propylphosphane), PtCl(diphenyl‐2‐pyridylphosphane)] with [Rh(2‐phenylpyridine) 2 Cl] 2 . The connectivity of the binucleating ligand diisoamyldithiooxamidate within the bimetallic complexes has been assessed. The linkage isomer obtainedis [Rh(2‐phenylpyridine) 2 {μ‐(isoamyl) 2 C 2 N 2 S 2 }ML n ] (κ‐ N , N ‐Rh III , κ‐ S , S ‐M).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)