Highly Regioselective Derivatization of Trimetallic Nitride Templated Endohedral Metallofullerenes via a Facile Photochemical Reaction

Abstract

Photochemically generated benzyl radicals react with Sc(3)N@C(80)-I(h) to produce a dibenzyl adduct [Sc(3)N@C(80)(CH(2)C(6)H(5))(2)] in 82% yield and high regioselectivity. The adduct's (1)H spectrum revealed high symmetry: only one AB pattern was observed for the methylene protons. The (13)C NMR spectrum suggested a C(2)-symmetrical structure. DFT calculations reveal that a 1,4-adduct is more favorable than a 1,2-adduct by >10 kcal/mol. The 1,4-structure on [566] ring junctions was unambiguously confirmed by X-ray crystallographic analysis. UV-vis spectra revealed that the removal of two p orbitals from the pi system of the cage together with the benzylic substituents change the electronic properties of the metallofullerene in a manner similar to those reported for disilirane and trifluoromethyl moieties. Under the same conditions from Lu(3)N@C(80)-I(h) we prepared (63% yield) Lu(3)N@C(80)(CH(2)C(6)H(5))(2), which demonstrated properties similar to the 1,4-dibenzyl adduct of Sc(3)N@C(80)-I(h).

Nitrated Benzyne Derivatives of La@C82: Addition of NO2 and Its Positional Directing Effect on the Subsequent Addition of Benzynes

“…As the presence of a nitro group facilitates nucleophilic aromatic substitution, the resulting La@C 82 NO 2 species would evidently favor the subsequent addition of benzyne; this proposed pathway is supported by the absence of the molecule ion peak of La@C 82 NO 2 in Figure 1. [23] After the addition of NO 2 , calculations on [18] This postulation is consistent with the reported higher reactivity of the pyramidalized carbons of C 70 to benzyne.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Cycloadduct derivatives of EMFs that contain closed five-or six-membered rings between the substituent and the fullerene cage have been synthesized using, for example, 1,3-dipolar additions or Diels-Alder reactions. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Cycloadduct derivatives of EMFs that contain closed five-or six-membered rings between the substituent and the fullerene cage have been synthesized using, for example, 1,3-dipolar additions or Diels-Alder reactions.…”

“…[10][11][12][13][14][15] This difference in stability cannot be explained simply by the higher ring-strain in a cyclopropyl ring, because the Bingel adducts of Sc 3 N@C 78 have closed structures. [18] However, the synthesis and characterization of EMF derivatives that have four-membered rings has not yet been achieved. [18] However, the synthesis and characterization of EMF derivatives that have four-membered rings has not yet been achieved.…”

Chemical, Electrochemical, and Structural Properties of Endohedral Metallofullerenes

“…Based on its crystal structure and DFT calculations, it was determined that Sc 3 N@C 80 (CH 2 C 6 H 5 ) 2 had a 1,4-structure at a [5,6,6] ring junction. [42] …”

“…[34, 35a, 68, 69b, 77, 81b, 136] [136] 0.10 À0.10 À0.55 À1.36 Y@C 82 -(Mes 2 Si) 2 CH 2 I(II) [136] À0.03 À0. 42 …”