In order to investigate the coordination behaviour of the macrocyclic crown thioether bzo2-18S6 (2,3,11,12-dibenzo-1,4,7,10,13,16-hexathiacyclooctadecane) and the properties of its metal compounds, the ruthenium and silver complexes [Ru(bzo218S6)]2+ and [Ag(bzo218S6)]+ were synthesized. [Ru(bzo2 18S6)](PF62·2CH3NO2 crystallizes in space group P21/c with a=1151.7(4), b=554.1(2), c=2695.8(13) pm, β=100.00(4)°, Z=2 and Dcalc=1.90 g/cm3; R=0.072, Rw=0.052. The ruthenium center is surrounded by the six sulfur atoms of the ligand in almost ideal octahedral geometry. Reaction of bzo218S6 with [M(CO)3L3] (MCr, Mo, W; LCH3CN, EtCN) yields the corresponding complexes [M(CO)3(bzo2 18S6)], indicating that the crown thioether will not act as a hexadentate ligand, if the metal center carries strongly bound coligands. The tertiarybutyl derivative of bzo218S6, bubzo218S6 (2,3,11,12- bis(2′,4′-di-tertiarybutyl-benzo)-1,4,7,10,13,16-hexathiacyclooctadecane), is obtained by template alkylation of [Fe(CO)'buS5'] ('buS5'2- = 2,2′-bis(2-mercapto-3,5-di-tertiarybutyl-phenylthio)diethylsulfide(20-)) with bis(β-bromoethyl sulfide, followed by acidic hydrolysis of the primary product [Fe(bubzo218S6)]Br2. As the structure of [Fe(bubzo218S6)]Br2 remained uncertain, free bubzo218S6 was reacted with Fe(CF3SO3)2 to give [Febubzo218S6)](CF3SO3)2 which was characterized by NMR spectroscopy. © 1990.