2,5-Dimethylthiophene (2,5-Me2T) and Tp(Me2)Ir(C2H4)(2) react at 60 degreesC to give a mixture of two products, 3 and 4. Both derive from initial aromatic C-H bond activation, but the organic ligand of 4 results from additional aliphatic C-H cleavage and C-C coupling of the activated C-ar with a C-2 unit from the starting Ir compound. In the presence of 2,5-Me2T, 4 reacts further to yield a more complex structure 5 (characterized by X-ray methods) which, upon protonation, releases the elaborated dithiophene 6. (C) 2002 Elsevier Science B.V. All rights reserved.