Cationic rhodium(I) complexes containing 4,4′-disubstituted 2,2′-bipyridines: A systematic variation on electron density over the metal centre

Phosphonate‐Mediated Immobilization of Rhodium/Bipyridine Hydrogenation Catalysts

“…[40,41] Solution-state 1 H, 13 C, and 31 Ps pectra were recorded in deuterated solvents with aB ruker Avances pectrometer operating at 300 or 400 MHz. The protocols for the synthesis of the mono-4-C12, mono-5-C12, mono-6-C12, 4,4'-C12, 5,5'-C12,a nd 6,6'-C12 ligands are detailed in the Supporting Information.…”

“…Previously described methods were used for the preparation of [Rh(bipy) 2 ] + BF 4 À . [40,41] Solution-state 1 H, 13 C, and 31 Ps pectra were recorded in deuterated solvents with aB ruker Avances pectrometer operating at 300 or 400 MHz. Solid-state 31 PM AS NMR experiments were performed with aB ruker Avance III spectrometer operating at 9.4 T( 1 Ha nd 31 PL armor frequencies of 400 and 161.9 MHz, respectively) by using a4mm double-resonance MAS probe.…”

“…In the first step, [Rh(COD)Cl] 2 (COD = 1,5-cyclooctadiene) was treated with AgBF 4 in THF for 16 h [40,41] to form am ore reactive species, namely,[ Rh(COD)(solvent) 2 ] + BF 4 À ,a fter removal of the AgCl precipitate. The resulting solution was then mixed with an aqueous solution of mono-4-C12, mono-5-C12, mono-6-C12, 4,4'-C12, 5,5'-C12,o r6,6'-C12 (water/THF = 1:1, v/v,R h/ ligand = 1:2), and the mixture was stirred for 2d for complete formation of the expected RhL 2 complexes.T hen, immobilization of the resulting complexes was performed by ap reviously optimized heterogenization protocol, [15] based on the reaction of the phosphonic acid groups on the ligandsw ith titanium oxide particles generated in situ (Scheme 1).…”

“…[40] The mixture was stirred overnight and then filtered through aM illipore apparatus to remove AgCl. [40] The mixture was stirred overnight and then filtered through aM illipore apparatus to remove AgCl.…”

“…AgBF 4 (0.06 mmol) was added to as olution of [Rh(COD)Cl] 2 (14.8 mg;0 .03 mmol) in THF (5 mL). [40] The mixture was stirred overnight and then filtered through aM illipore apparatus to remove AgCl. The filtrate was then added to the desired ligand (0.12 mmol) suspended in 5mLo fw ater,a nd the mixture was stirred for 48 ha tr oom temperature.…”