Organoplatinum(ii) complexes containing chelating or bridging bis(N-heterocyclic carbene) ligands: formation of a platinum(ii) carbonate complex by aerial CO2 fixation

Abstract

ExperimentalThe 1 H, 13 C and 195 Pt NMR spectra were recorded on a Bruker Avance DRX 500-MHz spectrometer. The operating frequencies and references, respectively, are shown in parentheses as follows:1 H (500MHz, tetramethylsilane, SiMe 4 ), 13 C ((125 MHz, TMS), and 195 Pt (107 MHz, aqueous Na 2 PtCl 4 ). The chemical shifts and coupling constants are in parts per million and hertz, respectively. Electrospray ion mass spectra (ESI-MS) were recorded on a Hewlett-Packard Series 1100 spectrometer. 1-(tert-Butyl)imidazole and 1-(isopropyl)-imidazole were synthesized according to literature procedures. The non-hydrogen atoms were refined anisotropically. All of the hydrogen atoms were positioned geometrically and refined with the riding model approximation, with Uiso(H) = 1.2 or 1.5 Ueq(C). All calculations were carried out using the PLATON [Spek, A. L. Acta Cryst. 1990, A46, C34. PLATON, A Multipurpose Crystallographic Tool, Utrecht University, Utrecht, The Netherlands ]. For the molecular graphics the program SHELXTL was used. For complex 2, a series of similarity and same restraints were applied to model the disordered acetone molecule. Bis(imidazolium) SaltsThe 1-alkyl-imidazoles and dibromomethane(1/2 equiv) were heated neat overnight in a pressure tube at 120 °C. The resulting solid was triturated with CH 2 Cl 2 and washed with diethyl ether. Preparation of [PtMe 2Ag , 24.4; H, 4.1; N, 6; Found: C, 24.6; H, 4; N, 6.2

Reaction of carbon dioxide with a palladium–alkyl complex supported by a bis-NHC framework

“…The solid state IR spectrum obtained for (MDC Mes )Pd(CO 3 ) shows an intense stretching frequency at 1601 cm −1 , which matches that reported for similar complexes. 47,44,48–49 …”

Easy oxidative addition of the carbon–halogen bond by dimethylplatinum(II) complexes containing a related series of diimine ligands: Synthesis, spectral characterization and crystal structure

“…4). These results suggest that there are two different orientations for the PtCH a H b protons relative to the platinum atom [10,40,41]. It should be mentioned that there are three bpy resonances for trans isomer and six bpy resonances for cis isomer which they have overlapped.…”

Synthesis, Characterization, and Properties of a Carbonate‐Bridged Dinuclear Rhodium(III) Complex via Fixation of Atmospheric CO2

“…Similar proposals were also implied in some closely related studies. [6][7][8] a) The solvent used is water and CO 2 -free, which was degassed and dried in advance. b) Dried CO 2 .…”

“…The chloride-bridged complex [(ppy) 2 RhCl] 2 was obtained by reaction of ppy with RhCl 3 in glycerol according to the published procedure (Scheme 1a). [6] Into a Single flask containing complex 1 (0.179 g, 0.2 mmol), sodium methoxide (0.054 g, 1.0 mmol) was added CO 2free CH 2 Cl 2 solvent (30 mL) (Scheme 1b). The mixture was stirred at room temperature for 72 h in the atmosphere.…”

“…[3][4][5] For example, Jamali et al reported recently the formation of [Pt(CO 3 )(bis-NHC)] (NHC = N-heterocyclic carbene) from hydration of aerial CO 2 . [6] Choi et al reported the reaction of the rhodium(I) ethylene complex RhCl(CH 2 =CH 2 ) 2 (PMe 3 ) 2 with excess carbon dioxide in the presence of water, which afforded a dinuclear ethyl μ-carbonato complex. [7] In addition, the μ-CO 3 bridged nickel(II) complex [{Ni(mcN 3 )} 2 (μ-CO 3 )](PF 6 ) 2 (mcN 3 = 2,4,4,9-tetramethyl-1,5,9-triazacyclododec-1-ene) was reported to be generated by reaction of [Ni(mcN 3 )(μ-OH)] 2 (PF 6 ) 2 with carbon dioxide.…”