OCTAHEDRAL IRIDIUM CLUSTERS - SYNTHESIS, ELECTROCHEMICAL MECHANISMS OF FORMATION, AND SOLID-STATE STRUCTURES OF [IR-6(CO)(14)(MU-TEPH)](-) AND [IR-6(CO)(13)(MU-TEPH)(2)]

The diphenyl ditelluride PhTeTePh reacts with [Ir-6(CO)(15)](2-) (in r efluxing tetrahydrofuran) or Ir-6(CO)(16) (in toluene) yielding [Ir-6( CO)(14)(mu-TePh)](-) or [Ir-6(CO)(13)(mu-TePh)(2)], respectively. Anal ogous mono-and disubstituted iridium compounds were prepared with othe r diaryl disulfides or diselenides. Electrochemical experiments confir m the different reactivity of PhTeTePh and PhSSPh showing that the dit elluride adds to the electrogenerated transient radical [Ir-6(CO)(15)] (-.) and the disulfide to [Ir-6(CO)(15)](0). The two clusters consists of octahedra of iridium atoms with one or two edges bridged by phenyl tellurolate ligands. The Ir-Ir bonds trans to the TePh unit are remark ably short.