Probing the donor strength of yldiide ligands: synthesis, structure and reactivity of rhodium complexes with a PC_ylideN pincer ligand

Abstract

Control of the metal ligand interaction by changes in the ligand protonation state is vital to many catalytic transformations based on metal-ligand cooperativity. Herein, we report on the coordination chemistry...

From a mercury(ii) bis(yldiide) complex to actinide yldiides

“…[25][26][27][28][29] Analogous complexes with transition metals are rare, [30][31][32][33] but have demonstrated the unusual donor strength of the respective phosphonio-carbene/yldiide ligands. [34][35][36] Likewise phosphonio-carbene complexes of the actinides have been reported, but only with the parent phosphoranomethylide ligand (C and D), [37][38][39][40] which was synthesized in the coordination sphere of the metal and was shown to produce short actinide-carbon bonds with some degree of multiple bonding character. Albeit in the meantime various yldiides have been isolated, [41][42][43][44] no actinide complexes have been prepared from these precursors, so that the impact of the substitution pattern on the bonding situation remains completely unclear.…”

Rhodium(III) and Iridium(III) Complexes of a Neopentyl-Substituted PNP Pincer Ligand that Feature Agostic Interactions

“…To quantify the relative donor strength of the PNP-Np ligand, M­(I) carbonyl derivatives were prepared for analysis by IR spectroscopy (Scheme ). , The new rhodium variant 5 was obtained in good yield by reaction of [Rh­(CO) 2 Cl] 2 with PNP-Np in fluorobenzene, using Na­[BAr F 4 ] as the halide abstracting agent, and fully characterized in solution ( C 2 v symmetric; δ 31P 17.4, 1 J RhP = 121 Hz) and the solid state (Figure A) . The iridium carbonyl complex [Ir­(PNP-Np)­(CO)]­BF 4 has been reported previously, and [BAr F 4 ] − analogue 6 was prepared using a variation of the reported two-step procedure, employing [Ir­(COD) 2 ]­[BAr F 4 ] (COD = 1,5-cyclooctadiene) as the metal precursor and 1,2-difluorobenzene (DFB) as the solvent.…”

Reactivity umpolung (reversal) of ligands in transition metal complexes

“…Other methods of estimating the d electron energies are Tolman's electronic parameters, 13 electrochemistry, 23,24 photoelectron spectroscopy and IR spectroscopy of complexes containing diatomic ligands such as CO and N 2 . 25,26 Many organometallic reactions have been probed by varying the steric and electronic properties of the ligands. 13,15,[27][28][29] Varying the bite angle of chelating ligands can also significantly affect complex reactivity.…”