Structural versatility of 5-methyltetrazolato complexes of (η5-pentamethylcyclopentadienyl)iridium(III) incorporating 2,2′-bipyridine, N,N-dimethyldithiocarbamate, or 2-pyridinethiolate ligands

Mai Kotera, Yusuke Sekioka, Takayoshi Suzuki

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23 Citations (Scopus)


Several new mono- and dinuclear η5- pentamethylcyclopentadienyl (Cp*) iridium(III) complexes bearing 5-methyltetrazolate (MeCN4-) have been synthesized and their molecular and crystal structures have been determined. For complexes incorporating 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen), both mononuclear κN2-coordinated and dinuclear μ-κN 1:κN3-bridging MeCN4 complexes were obtained: [Cp*Ir(bpy or phen)(MeCN4-κN 2)]PF6 (1 or 3) and [{Cp*Ir(bpy or phen)} 2(μ-MeCN4-κN1:κN 3)](PF6)3 (2 or 4), respectively. It was confirmed by X-ray analysis that the dinuclear complex in 2 has a characteristic structure with a pyramidal pocket constructed from a μ-κN 1:κN3-bridging MeCN4- and two bpy ligands. In the case of analogous complexes with N,N-dimethyldithiocarbamate (Me2dtc-), yellow platelet crystals of mononuclear κN1-coordinated complex, [Cp*Ir(Me2dtc) (MeCN4-κN1)]·HN4CMe (5·HN4CMe), and yellow prismatic crystals of dinuclear μ-κN1:κN4-bridging one, [{Cp*Ir(Me2dtc)}2(μ-MeCN4- κN1: κN4)]PF6 (6), were deposited. The κN1- and κN1:κN4-bonding modes of MeCN4- in these complexes presumably arise from the compactness of the Me2dtc- coligand. 6 is the first example in which tetrazolates act as a μ-κN1:κN 4-bridging ligand. Furthermore, the molecular and crystal structures of dinuclear complexes having μ-κ2S,N:κS-bridging 2-pyridinethiolate (2-Spy-) or 8-quinolinethiolate (8-Sqn -) ligands have been determined: [(Cp*Ir)2(μ-2- Spy or 8-Sqn-κ2S,N:κ)2] (7 or 8). These thiolato-bridging complexes were stable toward the addition of 5-methyltetrazole (HN4CMe), owing to the characteristic intramolecular stacking interaction between the pyridine or the quinoline rings. The 2-Spy complex of 7, however, reacted with an excess amount of Na(N4CMe), resulting in cleavage of the Ir-N(py) bond and coordination of MeCN4- in the μ-κN2:κN3-bridging mode: [(Cp*Ir)2(μ-2-Spy-κS:κS)2(μ- MeCN4-κN2:κN3)]PF6 (9). This bridging mode of MeCN4- was also observed in the triply bridging MeCN4 complex: [(Cp*Ir)2-(μ- MeCN4-κN2:κN3)3]PF 6 (10). In these various MeCN4 complexes, the structural parameters of the MeCN4 moiety were not perturbed by the difference in the bonding modes.

Original languageEnglish
Pages (from-to)3498-3508
Number of pages11
JournalInorganic Chemistry
Issue number9
Publication statusPublished - May 5 2008
Externally publishedYes


ASJC Scopus subject areas

  • Inorganic Chemistry

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