Microwave heating was employed to promote arene displacement in reactions of [{(p-cymene)RuCl2}(2)] or [{(1,3,5-C-6,H(3)iPr(3))RuCl2}(2)] with neutral chelate ligands L-L' [L-L': 1,1'-bis(diphenylphosphanyl)methane, 1,1'- bis(diphenylphosphanyl)ferrocene, (S)-BINAP, (S,S)-DIOP, N,N'-bis(2,4,6- trimethylphenyl)-1,2-ethanediylidenediamine], (R)-Ph-PHOX, and 3-(phenylsulfanylpropyl)diphenylphosphane. The reactions gave complexes of the general formula [(arene)Ru(mu-Cl)(3)- RuCl(L-L')] in good yield. The synthesis of [(p-cymene)Ru(mu-Cl)(3)RuCl{PPh2(CH2)(3)NH2} (22) was accomplished in two steps via the intermediate [{(p-cymene)RuCl2}(2){mu- PPh2(CH2)(3)-NH2}] (21). The structures of [(1,3,5-C(6)H(3)iPr(3))Ru(mu-Cl)(3)RuCl- (dppf)] (16), [(1,3,5-C(6)H(3)iPr(3))Ru(mu-Cl)(3)RuCl{(S)-BINAP]} (17), and [(p- cymene)Ru(mu-Cl)(3)RuCl(MesNCHCHNMes)] (18) were determined by single- crystal X-ray diffraction. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)