Metal Chelates Based on Isoxazoline[60]fullerenes

Abstract

Fullerene C60 reacts with a variety of nitrile oxides, providing access to an array of fullerene-fused heterocycles bearing covalently linked chelate moieties. The improved chelating property of the newly synthesized isoxazoline[60]fullerene adducts toward transition metals allows the syntheses of octahedral and square-planar organometallic compounds of rhenium, iridium, and platinum. This new approach has great potential as a general route to other novel derivatives containing catalytically active transition metals.

Acid/Base‐Triggered Switching of Circularly Polarized Luminescence and Electronic Circular Dichroism in Organic and Organometallic Helicenes

“…J. 2015, 21, 1673 -1681 www.chemeurj.org carbaldehyde, [17,18] (benzo[g]phenanthren-3-ylmethyl)triphenylphosphonium bromide, [7] and cis-[(dmso) 2 PtMe 2 ] [19] were prepared according to literature procedures.…”

“…UV/Vis spectroscopy was conducted on a Varian Cary 5000 spectrometer. 2,2′‐Bipyridine‐6‐carbaldehyde,17, 18 (benzo[ g ]phenanthren‐3‐ylmethyl)triphenylphosphonium bromide,7 and cis ‐[(dmso) 2 PtMe 2 ][19] were prepared according to literature procedures.…”

“…The reaction mixture turned deep red and was then slowly warmed to room temperature. After 45 min, the reaction mixture was cooled again to −78 °C and then 2,2′‐bipyridine‐6‐carbaldehyde17, 18 (440 mg, 2.39 mmol) was added in one portion; the reaction mixture was warmed to room temperature and the color turned yellow‐white on stirring for 3 h. The reaction mixture was filtered through Celite, concentrated under vacuum, and the crude oily product was purified by column chromatography (silica gel, heptane/ethyl acetate, 7:3) to give the olefin 6‐[2‐(benzo[ c ]phenanthren‐2‐yl)vinyl]‐2,2′‐bipyridine ( cis and trans mixture) as a yellow solid (890 mg, 92 %). 1 H NMR (300 MHz, CD 2 Cl 2 ): δ =9.26 (s, 1 H), 9.20 (d, J= 8.5 Hz, 1 H), 9.17 (s, 0.45 H), 8.75 (d, J= 3.6 Hz, 1 H), 8.72 (s, 0.5 H), 8.65 (d, J= 7.8 Hz, 1.4 H), 8.33 (t, J= 7.4 Hz, 1.4 H), 8.15–7.73 (m, 14.5 H), 7.68 (t, J= 7.8 Hz, 2 H), 7.53 (dd, J= 14.4, 7.3 Hz, 1 H), 7.48–7.31 (m, 4 H), 7.28 (s, 0.3 H), 7.26–7.19 (m, 0.4 H), 7.16 (d, J= 12.3 Hz, 0.4 H), 6.93 ppm (d, J= 12.2 Hz, 0.4 H); elemental analysis calcd (%) for C 30 H 20 N 2 : C 88.21, H 4.93, N 6.86; found: C 87.98, H 4.85, N 6.80.…”

Iron(II) and Zinc(II) Complexes with Tetradentate Bis(pyrazolyl)methane Ligands as Catalysts for the Ring‐Opening Polymerisation of rac‐Lactide

“…Pyrazole, FeCl 2 , FeBr 2 , FeSO 4 , ZnCl 2 and ZnBr 2 were purchased from commercial suppliers. 3,5‐Methylpyrazole, 2,2′‐bipyridine‐6‐carbaldehyde, Fe(CF 3 CO 2 ) 2 , Fe(CH 3 SO 3 ) 2 and Zn(CF 3 CO 2 ) 2 were prepared according to literature methods. d , l ‐Lactide (Corbion Purac) was dried at 40 °C under vacuum for 3 d. The ligands and complexes were characterised by IR spectroscopy, mass spectrometry and X‐ray analysis.…”

Fullerenes

“…80 A facile synthesis of rhenium, iridium and platinum compounds of isoxazoline-C 60 fullerenes bearing covalently linked chelating moieties such as pyridine and phenol that enhance the coordinative capability of the nitrogen in the isoxazoline ring has been described. 81 The synthesis and full characterisation of novel four-membered aromatic systems consisting of planar cobalt trichalcogenide compounds protected inside a bowl-shaped confined space of pentaaryl-C 60 fullerene has been explored. 82 Pd and Ru-C 60 compounds were synthesised by doping 1 wt% of each metal on the pure C 60 fullerene followed by hydrogen sorption measurements at 300 bar and 298 K. The resulting complexes were characterised with TEM, XRD and Raman spectroscopic analyses.…”