Cyclometalated Ruthenium Compounds Containing 2‐(2′‐Pyridyl)‐ 4‐methylphenyl and Benzo[ h ]quinolyl Ligands

Transmetalation of Hg(ptpy) 2 [Hptpy = 2‐(4‐tolylpyridine) with Cp*Ru(NO)Cl 2 (Cp* = η 5 ‐C 5 Me 5 )] gave [Cp*Ru(NO)(ptpy)] 2 [Hg 2 Cl 6 ] ([ 1 ] 2 · Hg 2 Cl 6 ) whereas that with [Cp*RuCl 2 ] x gave the dinuclear Ru II –Ru IV compound [Cp*Ru(μ‐η 6 :η 2 ‐ptpy)RuCl 2 Cp*][Hg 2 Cl 6 ] ( 2 ). Treatment of Ru(3‐phenylindenylid‐1‐ene)Cl 2 (PPh 3 ) 2 with Hg(ptpy) 2 resulted in coupling of ptpy with the 3‐phenylidenylid‐1‐ene ligand, and the formation of Ru(Ph‐ind‐ptpy)(PPh 3 )Cl {Ph‐ind‐tpy = 3‐phenyl‐1‐[2‐(4‐toyl)pyridyl]indenyl} ( 3 ), in which the chelated [Ph‐ind‐tpy] – ligand binds to Ru through the η 5 ‐indenyl ring and the pendant pyridyl group. Treatment of [Ru(CO) 2 Cl 2 ] n with [Hg(ptpy)Cl] 2 afforded [Ru(ptpy)(CO) 2 ] 2 (μ‐Cl) 2 ( 8 ). Irradiation of cis ‐[Ru(bzq) 2 (CO) 2 ] (Hbzq = benzo[ h ]quinoline) with UV light in MeCN afforded cis ‐[Ru(bzq) 2 (CO)(MeCN)] ( 9 ). Photolysis of cis ‐[Ru(bzq) 2 (CO) 2 ] in THF in the presence of PPh 3 and pyridine (py) afforded cis ‐[Ru(bzq) 2 (CO)(L)] [L = PPh 3 ( 10 ), py ( 11 )]. The crystal structures of complexes 1 – 3 , 8 , and 10 have been determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)