Crystal structure of di-μ-chlorido-bis[1-(2-(4-nitrophenyl)amidoethyl)-3-(2,4,6-trimethylphenyl)imidazol-2-ylidene-κC]di(dichlorido)dipalladium(II)) (Pd–Pd) dichloro methane solvate, C43H46Cl6N8O6Pd2

Stefan Warsink, Andreas Roodt
2013 Zeitschrift für Kristallographie - New Crystal Structures  
C 43 H 46 Cl 6 N 8 O 6 Pd 2 ,triclinic, P1 (no. 2), a =12.4700(4) Å, b =12.4810(3) Å, c =18.0322(5) Å, a =71.609(1)°, b =76.951(1)°, g =71.537(1)°, V =2501.3 Å 3 , Z =2, R gt (F) =0.0332, wR ref (F 2 ) =0.0867, T =100 K. Source of material To ad ichloromethane solution of [1-(2-(4-nitrophenyl)amidoethyl)-3-(2,4,6-trimethylphenyl)imidazol-2-ylidene]chloridosilver(I) [2]( 78 mg, 0.15 mmol) was added 1e quivalent of dichloridobis(acetonitrile)palladium(II) (35 mg). The resulting orange suspension
more » ... orange suspension wasfiltered over apad of celite, after which the solvent was allowed to evaporate slowly, yielding yellow crystals (94% yield). Experimental details The structure contains solvent accessible voids (153 Å 3 /unit cell), filled with disordered solvent molecules. Their contribution to thestructure factors(43 electrons/unit cell)was securedbyback-Fourier transformation with the SQUEEZE routine of the PLATON software [9] . Discussion In the course of our research in N-heterocyclic carbene (NHC) chemistry, we developed anew ligand scaffold, bearing an amide-moiety, for use in rhodium-mediated iodomethane oxidative addition [1].Aside from rhodium(NHC)complexes, we were interested in the coordination chemistry of these ligands with palladium [2]. It was shown thatakinetically stable trans-isomer was obtained when two equivalents of NHC were coordinated to palladium [3] .When only one equivalent is used, the dinuclear species is formed preferentially over thee xpectedm ononuclear species in which the ligand coordinates bidentate [4] [5] [6] . However, theamide does play arole, in contrast to earlier reports [3] . It stabilizesthe solidstate structure by engaging in intramolecular hydrogen bonding with the terminal chlorido ligands of the core (H···Cl: 2.63(4) and 2.75(4) Å). Further hydrogen bond stabilization occurs intermolecularly between the oxygen atomso ft he -NO 2 group and the hydrogen atomso nt he NHC backbones. These hydrogen bonds create athree-dimensional network. The coordination sphere around the palladium centers is square planar, slightly distorted by the dinuclear character of the complex. All other values such as the NHC-Pd bond lengths and the Pd-Pd distance are within literature values [3] .
doi:10.1524/ncrs-2014-0006 fatcat:5gov2cn2jna4pm5melwhmmfq5e