title: The first triple thiol-thiolate hydrogen bond versus triple diselenide bond that bridges two metal centers.
abstract: Treatment of fac(S)-[Rh(aet)3] (aet = 2-aminoethanethiolate) with aqueous HBF4 in air led to the protonation at coordinated thiolato groups to give a rhodium(III) dimer, [{Rh(aet)2(Haet)}{Rh(aet)(Haet)2}](BF4)3 ([1](BF4)3). On the other hand, similar treatment of fac(Se)-[Rh(aes)3] (aes = 2-aminoethaneselenolate) produced a dinuclear rhodium(III) complex, [Rh2(selenocystamine)3](BF4)6 ([2](BF4)6), because of the autoxidation of coordinated selenolato groups by air. The crystal structures of [1](BF4)3, DeltaDelta-[1](BF4)3, and [2](BF4)6 were determined by X-ray crystallography. In [1]3+ two RhIII octahedrons are connected through a strong triple thiol-thiolate S-H...S hydrogen bond, while two RhIII octahedrons are directly joined by a triple diselenide bond in [2]6+. The cyclic voltammetry indicated that in acidic media the RhIII center in fac(Se)-[Rh(aes)3] is more easily oxidized to RhIV than that in fac(S)-[Rh(aet)3], which is responsible for the formation of coordinated diselenide bonds.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Konno
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Haneishi
authors.forename: Masakazu
authors.initials: M
authors.lastname: Hirotsu
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Tasuku
authors.initials: T
authors.lastname: Ito
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshimura
mesh_terms: D003035:Cobalt / Q000737:chemistry; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D007495:Iridium / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry; D012643:Selenium / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D013438:Sulfhydryl Compounds; D003035:Cobalt; D007495:Iridium; D012238:Rhodium; D012643:Selenium