The reaction of 14e [L Me Rh-(coe)] (1; L Me ArNC(Me)CHC(Me)-NAr, Ar 2,6-Me 2 C 6 H 3 ; coe cis-cyclooctene) with phenyl halides and thiophenes was studied to assess the competition between s coordination, arene p coordination and oxidative addition of a CÀX bond. Whereas oxidative addition of the CÀCl and CÀBr bonds of chlorobenzene and bromobenzene to L Me Rh results in the dinuclear species [{L Me Rh(Ph)(m-X)} 2 ] (X Cl, Br), fluorobenzene yields the dinuclear inverse sandwich complex [{L Me Rh} 2 (anti-mh 4 :h 4 -PhF)]. Thiophene undergoes oxidative addition of the CÀS bond to give a dinuclear product. The reaction of 1 with dibenzo[b,d]thiophene (dbt) in the ratio 1:2 resulted in the formation of the s complex [L Me Rh(h 1 -(S)-dbt) 2 ], which in solution dissociates into free dbt and a mixture of the mononuclear complex [L Me Rh(h 4 -(1,2,3,4)-dbt)] and the dinuclear complex [{L Me Rh} 2 (m-h 4 -(1,2,3,4):h 4 -(6,7,8,9)-dbt)]. The latter could be obtained selectively by the 2:1 reaction of 1 and dbt. Reaction of 1 with diethyl sulfide produces [L Me Rh(Et 2 S) 2 ], which in the presence of hydrogen loses a diethyl sulfide ligand to give [L Me Rh-(Et 2 S)(H 2 )] and catalyses the hydrogenation of cyclooctene.