Cp*Ir(dab) (dab = 1,4-Bis(2,6-dimethylphenyl)-1,4-diazabutadiene): A Coordinatively Unsaturated Six-π-Electron Metallaheteroaromatic Compound?
- 1 January 1996
- journal article
- Published by American Chemical Society (ACS) in Inorganic Chemistry
- Vol. 35 (13) , 3998-4002
- https://doi.org/10.1021/ic9514814
Abstract
1,4-Bis(2,6-dimethylphenyl)-1,4-diaza-1,3-butadiene (dab) forms the structurally characterized iridium(III) complex [Cp*IrCl(dab)](PF6): C28H35ClF6IrN2P, orthorhombic, space group Pnma, a = 16.187(2) Å, b = 15.823(2) Å, c = 11.677(1) Å, V = 2990.8(6) Å3, Z = 4, and R = 0.0588. On reaction with NaBH3CN this compound does not form an iridium(III) hydride but the coordinatively unsaturated reduced product Cp*Ir(dab): C28H35IrN2, monoclinic, space group P21/n, a = 8.484(2) Å, b = 14.535(3) Å, c = 20.956(4) Å, β = 98.88(3)°, V = 2553.2(9) Å3, Z = 4, and R = 0.0586. The inverted relation dCC (=1.334(15) Å) < dCN (=1.379(13) and 1.366(14) Å) in the dab ligand of Cp*Ir(dab) suggests that the reduction has occurred primarily at that ligand to form an ene-1,2-diamido/iridium(III) moiety or, alternatively, a six-π-electron metallaheteroaromatic system. Abinitio pseudopotential calculations of model complexes [CpIr(HNCHCHNH)]0/2+ support this description of the bonding.Keywords
This publication has 64 references indexed in Scilit:
- A Tale of Two Complexes, [PtMen(RNCH-CHNR)] (n = 2 and n = 4, R = Cyclohexyl): Why do PtII and PtIV Complexes Exhibit Virtually Identical Redox Behavior and Colors?Chemistry – A European Journal, 1995
- Chemical and Electrochemical Generation of Hydride-Forming Catalytic Intermediates (bpy)M(CnRn): M = Rh, Ir (n = 5); M = Ru, Os (n = 6). Coordinatively Unsaturated Ground State Models of MLCT Excited States?Inorganic Chemistry, 1994
- Silylene complexes from a stable silylene and metal carbonyls: synthesis and structure of [Ni{(ButN–CHCH–NBut)Si}2(CO)2], a donor-free bis-silylene complexJournal of the Chemical Society, Chemical Communications, 1994
- Photocatalysis. Mechanistic studies of homogeneous photochemical water gas shift reaction catalyzed under mild conditions by novel cationic iridium(III) complexesJournal of the American Chemical Society, 1993
- Formiat-getriebene, nicht-enzymatische NAD(P)H-Regeneration bei der durch Alkohol-Dehydrogenasen katalysierten stereoselektiven Reduktion von 4-Phenyl-2-butanonAngewandte Chemie, 1992
- Monomeric (pentamethylcyclopentadienyl)iridium imido compounds: synthesis, structure, and reactivityJournal of the American Chemical Society, 1991
- Energy-adjustedab initio pseudopotentials for the second and third row transition elementsTheoretical Chemistry Accounts, 1990
- Elektrochemische und pulsradiolytische Reduktion von (Pentamethylcyclopentadienyl)(polypyridyl)rhodium‐KomplexenEuropean Journal of Inorganic Chemistry, 1989
- Bor‐organische RedoxsystemeEuropean Journal of Inorganic Chemistry, 1989
- Intramolecular coupling of .eta.2-iminoacyl and .eta.2-acyl functions at Group 4 and Group 5 metal centers: structure and spectroscopic properties of the resulting enamidolate and enediamide complexesJournal of the American Chemical Society, 1987