Reaction of C 63 NO 2 (Ph) 2 (Py) (1)w ith o-phenylenediamine and pyridine producesamixture of C 63 H 4 NO 2 (Ph) 2 (Py)(N 2 C 6 H 4 )( 2)a nd H 2 O@2.C ompound 2 is an ew open-cage fullerene containing a2 0-membered heterocyclic orifice, which has been fully characterizedb y NMR spectroscopy,h igh-resolution mass spectrometry, and X-ray crystallography.T he elliptical orificeo f2 spans 7.45 a long the major axis and 5.62 a long the minor axis, which is large enough to trap water and small organic molecules.T hus, heating am ixture of 2 and H 2 O@2 with hydrogen cyanidea nd formaldehyde in chlorobenzene affords HCN@2 and H 2 CO@2,r espectively.T he 1 HNMR spectroscopy reveals substantial upfield shifts for the endohedral species( d = À1.30 to À11.30 ppm), owing to the strong shielding effect of the fullerene cage.The interior space of fullerenesi sl arge enough to enclose atoms ands mall molecules.[1] Endohedralm etallofullerenes (for example,S c 3 N@C 80 )a re currently being prepared by evaporation of graphite/metal oxide composites, [2] while individual nitrogen atoms, lithium atoms, or noble gases have been incorporated into fullerenes by forced plasmao rh igh-pressurep rocesses.[3] The disadvantageso ft hesem ethods are the large amount of work involved, poor controlo fp roducts, and extremely low yields.[4] Recently,c reating ah ole on the fullerene cage surface by chemical methods provides ap romising approach. [5][6][7][8][9][10] Such open-cage fullerenes allow atoms,s mall molecules, or ions to enter and leave their inner sphere in ac ontrollable and reversible manner( Scheme 1). This molecularcontainer-like feature may find wide applications in sensors, molecular storagea nd transport,h azard sequestration, and biomedicines. [11] The first open-cage fullerene was reported in 1995b yW udl and co-workers.[12] Later,R ubin et al. synthesized ab islactam derivativeo fC 60 and successfully inserted aH eo rH 2 molecule into the cage, [13] though the filling ratio was low owing to as mall orifice size. Komatsu et al. subsequently prepared an ew derivative containing al arger orifice, which encapsulated H 2 quantitatively. [14] Up to now,n obleg ases (He, Ar, Kr), [13,15,16] N 2 , [15] H 2 , [13,14,15, 17,18] H 2 O, [18, 19] CO, [15,20] NH 3 , [21] CH 4 , [22] and HF [23] molecules have been effectively stored inside the open-cage fullerenes,a nd completion of "molecular surgery" [24] to reform the pristine C 60 cage was achieved for He@C 60 , [16] H 2 @C 60 , [17a] and H 2 O@C 60 . [19b] Yett he incorporation of organic compounds bearing functional groupsh as not been reported. In our continuing interest in fullerene chemistry, [25] herein we present the successful insertion of H 2 C=Oa nd HCNi nto an ew open-cage fullerene.The open-cage fullereneC 63 NO 2 (Ph) 2 (Py) (1)w ith a1 2-memberedh eterocyclic ring was prepared from C 60 according to the methodr eported by Komatsu and Murata.[26] Furthermore, following the Iwamatsu'sr ing-enlargement process, [19a] compound 1 was treated with o-phenyle...

[(2,6-(Ph(2)P(o-C(6)H(4))CH=N)(2)C(5)H(3)N)(2)Cu(2)](BF(4))(2) (2) has been prepared by treating 2,6-(Ph(2)P(o-C(6)H(4))CH=N)(2)C(5)H(3)N (1) with [Cu(NCMe)(4)]BF(4). Reaction of 2 and [Ph(3)PNPPh(3)]NO(2) produces (2,6-(Ph(2)P(o-C(6)H(4))CH=N)(2)C(5)H(3)N)Cu(NO(2)) (3), with the nitrite ligand in a unique eta(2)-O,O coordination mode. Protonation of 3 releases NO gas, which mimics the reactivity of the Type 2 Cu-NiRs.

Experiments are described that probe the stability of N-substituted derivatives of the azadithiolate cofactor recently confirmed in the [FeFe] hydrogenases (Berggren, G., et al. Nature 2013, 499, 66). Acid-catalyzed hydrolysis of bis(thioester) BnN(CH2SAc)2 gives [BnNCH2SCH2]2 rather than azadithiol BnN(CH2SH)2. Treatment of BnN(CH2SAc)2 with NaOtBu generates BnN(CH2SNa)2, which was trapped with NiCl2(diphos) (diphos = 1,2-C2H4(PR2)2; R = Ph (dppe) and Cy (dcpe)) to give fully characterized complexes Ni[(SCH2)2NBn](diphos). The related N-aryl derivative Ni[(SCH2)2NC6H4Cl](diphos) was prepared analogously from 4-ClC6H4N(CH2SAc)2, NaOtBu, and NiCl2(dppe). Crystallographic analysis confirmed that these rare nonbridging [adtR]2− complexes feature distorted square planar Ni centers. The analogue Pd[(SCH2)2NBn](dppe) was also prepared. 31P NMR analysis indicates that Ni[(SCH2)2NBn](dppe) has basicity comparable to typical amines. As shown by cyclic voltammetry, the couple [M[(SCH2)2NBn](dppe)]+/0 is reversible near −2.0 V versus Fc+/0. The wave shifts to −1.78 V upon N-protonation. In the presence of CF3CO2H, Ni[(SCH2)2NBn](dppe) catalyzes hydrogen evolution at rate of 22 s−1 in the acid-independent regime, at room temperature in CH2Cl2 solution. In contrast to the instability of RN(CH2SH)2 (R = alkyl, aryl), the dithiol of tosylamide TsN(CH2SH)2 proved sufficiently stable to allow full characterization. This dithiol reacts with Fe3(CO)12 and, in the presence of base, NiCl2(dppe) to give Fe2[(SCH2)2NTs](CO)6 and Ni[(SCH2)2NTs](dppe), respectively.

Treatment of the open-cage fullerene C H NO (Ph) (Py)(N C H ) (1) with methanol at 150 °C results in an orifice-enlargement reaction to give C H NO(CO Me)(Ph)(Py)(N C H ) (2). The overall yield from C to isolated 2 is 6.1 % (four steps). Compound 2 contains a 24-membered elliptic orifice that spans 8.45 Å along the major axis and 6.37 Å along the minor axis. The skeleton of 2 resembles the hypothetic C H (5,5)-carbon nanotube endcap. The cup-shaped structure of 2 is able to include water, hydrogen cyanide, and acetylene, forming H O@2, HCN@2, and C H @2, respectively. The molecular structures of H O@2 and HCN@2 have been determined by X-ray crystallography. The H NMR spectra reveal substantial upfield shifts for the endohedral species, such as δ=-10.30 (for H O), -2.74 and -14.26 (for C H ), and -1.22 ppm (for HCN), owing to the strong shielding effects of the fullerene cage.

Reactions of the open-cage fullerene C63NO2(Py)(Ph)2 (1) with [Ru3(CO)12] produce [Ru3(CO)8(μ,η(5)-C63NO2(Py)(Ph)2)] (2), [Ru2H(CO)3(μ,η(7)-C63N(Py)(Ph)(C6H4))] (3), and [Ru(CO)(Py)2(η(3)-C63NO2(Py)(Ph)2)] (4), in which the orifice sizes are modified from 12 to 8, 11, and 15-membered ring, through ruthenium-mediated C-O and C-C bond activation and formation.