When a solution of [Ru(η 6-C 6H 6)(η 6-[2 2](1,4)C 16H 16)][BF 4] 2 and [Os(η 6-C 6H 6((CH 3) 2CO) 3][BF 4] 2 in a mixed (CH 3) 2CO/CF 3CO 2H solvent is refluxed the paracyclophane ligand is transfered in part to the osmium ion. Pure samples of [Os(η 6-C 6H 6)(η 6-[2 2](1,4)C 16H 16)][BF 4] 2 are obtained by refluxing a solution of [Os(η 6-C 6H 6)((CH 3) 2CO) 3][BF 4] and paracyclophane in the mixed (CH 3) 2CO/CF 3CO 2H solvent. This new osmium(II) compound has been characterised by NMR spectroscopy and X-ray crystallography. The reaction of [Os(η 6-C 6-C 6H 6)((CH 3) 2-CO) 3][BF 4] 2 with [Ru(η 6-[2 2](1,4)C 16H 16) 2][BF 4] 2 in neat CF 3CO 2H yields the novel trinuclear heterometallic complex [(η 6-C 6H 6)Os(η 6,η 6-[2 2](1,4)C 16H 16)Ru(η 6,η 6-[2 2](1,4)C 16H 16)Os(η 6-C 6H 6)] [BF 4] 6, which has been isolated and characterised by 1H and 13C NMR spectroscopy.