Synthesis, structure, and reactivity of iridium perfluorocarbene complexes: regio- and stereo-specific addition of HCl across a metal carbon double bondElectronic supplementary information (ESI) available: Details of all DFT calculated structures. CCDC 1406693-1406699. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5dt02275d

Reductive activation of an α-fluorine in the perfluoroalkyl complexes Cp*(L)( i )Ir-CF 2 R F using Mg/graphite leads to perfluorocarbene complexes Cp*(L)Ir&z.dbd;CFR F (L = CO, PMe 3 ; R F = CF 3 , C 2 F 5 , C 6 F 5 ). New complexes E-Cp*(PMe 3 )Ir&z.dbd;CFC 2 F 5 and E-Cp*(CO)Ir&z.dbd;CFC 6 F 5 have been characterized by single crystal X-ray diffraction studies, and a comparison of metric parameters with previously reported analogues is reported. Experimental NMR and computational DFT (B3LYP/LACV3P**++) studies agree that for Ir&z.dbd;CFR F complexes (R F = CF 3 , CF 2 CF 3 ) the thermodynamic preference for the E or Z isomer depends on the steric requirements of ligand L; when L = CO the Z -isomer (F cis to Cp*) is preferred and for L = PMe 3 the E -isomer is preferred. When reduction of the precursors is carried out in the dark the reaction is completely selective to produce E - or Z -isomers. Exposure of solutions of these compounds to ambient light results in slow conversion to a photostationary non-equilibrium mixture of E and Z isomers. In the dark, these E / Z mixtures convert thermally to their preferred E or Z equilibrium geometries in an even slower reaction. A study of the temperature dependent kinetics of this dark transformation allows Δ G ‡ 298 for rotation about the Ir&z.dbd;CFCF 3 double bond to be experimentally determined as 25 kcal mol −1 ; a DFT/B3LYP/LACV3P**++ calculation of this rotation barrier is in excellent agreement (27 kcal mol −1 ) with the experimental value. Reaction of HCl with toluene solutions of Cp*(L)Ir&z.dbd;CFR F (L = CO, PMe 3 ) or Cp*(CO)Ir&z.dbd;C(CF 3 ) 2 at low temperature resulted in regiospecific addition of HCl across the metal carbon double bond, ultimately yielding Cp*(L)Ir(CHFR F )Cl and Cp*(CO)Ir[CH(CF 3 ) 2 ]Cl. Reaction of HCl with single E or Z diastereomers of Cp*(L)Ir&z.dbd;CFR F gives stereospecific cis -addition to give single diastereomers of Cp*Ir(L)(CHFR F )Cl; addition of HCl to several different E / Z ratios of Cp*(L)Ir&z.dbd;CFR F affords ratios of diastereomeric products Cp*(L)Ir(CHFR F )Cl identical to the original ratio of starting material isomers. The addition of HCl is therefore demonstrated to be unambiguously regio- and stereo-specific. The observed product regiochemistry of addition of HCl to Ir&z.dbd;CF 2 , Ir&z.dbd;CFR F , and Ir&z.dbd;C(CF 3 ) 2 ligands is the same and is not dependent on the ground state energy preference (singlet or triplet) for the free perfluorocarbene. DFT ca