DOI

Reaction of [Ir(μ-Cl)(ppy) 2] 2 (1) with 4 equivs of CNC 6H 4X (X = F 2a, Cl 2b, Br 2c, I 2d) in the presence of 2 equivs of AgOTf in dichloromethane at 20-25 °C furnished the bisisocyanide complexes [Ir(ppy) 2(CNC 6H 4X) 2](OTf) ([3a-d](OTf); 72-87%). Reaction of [3a-d](OTf) with an excess of gaseous ammonia at room temperature gave the bisdiaminocarbene species [Ir(ppy) 2{C(NH 2)NHC 6H 4X} 2](OTf) [5a-d](OTf) (73-83%); the two-step addition proceeds through an intermediate formation of appropriate monocarbene complexes [4a-d](OTf). Further reaction of [5a-d](OTf) with an excess of gaseous ammonia at 50 °C led to the cleavage of one diaminocarbene ligand to the cyanide ligand in [Ir(ppy) 2(CN){C(NH 2)NHC 6H 4X}] (6a-d) and this transformation is accompanied with the elimination of a substituted aniline. Treatment of [5a-d](OTf) with N(CH 2CH 2OH) 3 at 50 °C resulted in the cleavage of the diaminocarbene ligand to the isocyanide and uncomplexed NH 3; isocyanide remains bound to the iridium(iii) center in [Ir(ppy) 2{C(NH 2)NHC 6H 4X}(CNC 6H 4X)](OTf) (4a-d). All isolated compounds were characterized by elemental analyses (C, H, N), molar conductivity measurements, TG/DTA, HRESI +/--MS, FTIR, 1D ( 1H, 13C{ 1H}, 19F{ 1H}) and 2D ( 1H, 1H-COSY, 1H, 13C-HMQC/ 1H, 13C-HSQC, 1H, 13C-HMBC) NMR, and also by X-ray diffraction (for the bisisocyanide 3, the diaminocarbene/isocyanide 4, the bisdiaminocarbene 5, and the diaminocarbene/cyanide 6 type complexes).

Original languageEnglish
Pages (from-to)7571-7582
Number of pages12
JournalDalton Transactions
Volume48
Issue number22
DOIs
StatePublished - 1 Jan 2019

    Research areas

  • ACIDITIES, BLUE PHOSPHORESCENCE, BOND ACTIVATION, COMPLEXES, CRYSTAL-STRUCTURES, ISOCYANIDE, ISONITRILES, N-HETEROCYCLIC CARBENES

    Scopus subject areas

  • Inorganic Chemistry

ID: 42533881