(Cyclopentadienyl)chromiumtricarbonyl dimers as a source of metal-centered free-radicals to form stable η2-bonded spin-adducts with fullerenes

Coordination Modes and Different Hapticities for Fullerene Organometallic Complexes

“…A possible problem for the η 6 coordination would appear to be the curvature of the fullerenes [13,60]. One way to avoid this situation would be to prepare organometallic compounds of fullerenes larger than C 60 and C 70 .…”

Anionic coordination complexes of C60 and C70 with cyclopentadienyl and pentamethylcyclopentadienyl molybdenum dicarbonyl

“…Metal-centered free radicals [CpM(CO) 3 ] • generated photochemically from the {CpM(CO) 3 } 2 dimers (M = Cr, Mo) also coordinate to fullerenes C 60 and C 70 and single-wall carbon nanotubes to form EPR active radical adducts. 16,17 Similarly, metal-centered radicals formed from Re 2 (CO) 10 and {CpRu(CO) 2 } 2 under thermal or photolytic conditions add to C 60 to form coordination complexes {Re(CO) 5 } 2 (C 60 ) 18 and {η 1 -CpRu(CO) 2 } 2 (C 60 ). 19 Potentially charge transfer from metals to fullerenes can provide high conductivity at appropriate packing of fullerene anions in a crystal.…”

Sidewall Functionalization of Single‐Walled Carbon Nanotubes by Organometallic Chromium‐Centered Free Radicals

“…It happened that the radical-adduct was quite stable, indeed. However, both signals in the ESR spectrum of the Cr-modified SWNT had g-factors much lower than those observed for the fullerene radical-adducts (g ¼ 2.0134) (11). This suggests greater transfer of electron density from metal to nanotube, making the product more like cation-radicals (e.g., g-factor for bis(benzene)chromium cation, (C 6 H 6 ) 2 Cr þ , g ¼ 1,9863, a( 53 Cr) 19.0 G) (15).…”

“…Recently we have reported the addition of the organometallic chromiumcentered free radicals to fullerenes C 60 and C 70 and found the h 2 -structure of the spin-adducts stable in solution from ESR spectroscopy and quantum-chemical calculations (10,11). In this paper, we wish to describe the extension of this approach for SWNT to afford the first chromium-derived nanotubes.…”