Reactivity of Tris(1-pyrazolyl)methane Towards Ru⁰ Complexes

Graphical Abstract

Ru⁰ complexes can undergo a cyclometalation reaction with tris(1-pyrazolyl)methane to yield a stable Ru^II hydride species, the structure of which has been studied by NMR techniques. This complex reacts with chloroform to give the analogue containing a chlorido in place of the hydrido ligand, but with different structural features.

Abstract

By treating tris(1-pyrazolyl)methane (tpm) with suitably activated [Ru(cod)(cot)] and [Ru(cod)(nap)] (cod = η⁴-cycloocta-1,5-diene, cot = η⁶-cycloocta-1,3,5-triene, nap = η⁶-naphthalene) the (hydrido)Ru^II species [Ru(N²,N^2′,C^5″-tpm)(cod)H] with cyclometalated tpm was obtained. This complex reacted with chloroform at room temperature to give [Ru(N²,N^2′,C^5″-tpm)(cod)Cl] and dichloromethane. The coordination and symmetry of the novel complexes were elucidated by ¹H and ¹³C NMR spectroscopy.