Chlorination-Supported Shrinkage of C60 Fullerene to Non-classical C58 Cages.

We provide important novel insights into skeletal transformations of fullerene by reporting new cases of cage shrinkage in the most abundant C60 fullerene via a C2 loss. High-temperature (400-500 oC) chlorination of IPR C60 with SbCl5 or SbCl5/SbCl3 mixtures predominantly gives non-IPR C60Cln compounds via Stone-Wales rearrangements, but the present study further reveals non-classical C58Cln chlorofullerenes as by-products. The new C58(NC1)Cl20 and C58(NC1)Cl24 chlorides have been isolated by air-free HPLC and structurally characterized by X-ray crystallography.

Photoisomerization Paths of α,ω-Diphenylpolyenes: Reaction Rate Dependence on Temperature, Excitation Wavelength, and Deuteration.

The photoisomerization rate of -stilbene (tS) and trans-trans-diphenylbutadiene (ttD) is studied in solution and compared to that in jet/gas. Rice-Ramsperger-Kassel-Marcus (RRKM) theory correctly predicts the tS rate in jet, = exp(-/) with = 1398 cm, and = 1.8 ps corresponding to frequency ν = 60 cm of the reactive mode, being the molecular temperature.

Effect of exohedral functionalization on the magnetic properties in the dysprosium-containing endohedral fullerene DyScN@C(CF).

We present a quantum-chemical study of the effect of exohedral functionalization with a CF group on the lowest electronic states and the zero-field splitting pattern in a potential single-molecule magnet (SMM) compound DyScN@C(CF). Multiconfiguration perturbational methodology is applied to various spin states of the endohedral compound, comparing different active spaces and state-averaging schemes in order to check for the possible involvement of orbitals other than 4f-Dy in the nondynamical electronic correlation and to suggest the most appropriate computational parameters. Combining the spin-orbit coupling calculations with perturbational corrections, we demonstrate that the interactions within the endohedral cluster and with the fullerene cage exert only a small effect on the non-relativistic approximation to the electronic states of the Dy ion, yet they are significant enough to alter the parameters of zero-field splitting depending on the orientation of the DyScN cluster inside the fullerene cage.

Nonclassical C and C Chlorofullerenes via Complex Chlorination-Promoted Skeletal Transformations of IPR Isomers of C and C.

Upon high-temperature (340-360 °C) chlorination with VCl, an isolated-pentagon-rule (IPR) -C(33) fullerene is just chlorinated to C(33)Cl and C(33)Cl, but a VCl/SbCl mixture promotes a five-step cage transformation to nonclassical C(2)Cl with two heptagons and five pairs of fused pentagons. Another chlorination-promoted seven-step transformation of an IPR fullerene removes as many as four C2 fragments from C to give a nonclassical C(1)Cl with cage heptagon and six fused pairs of pentagons. We discuss the driving forces behind the observed transformations and probable detailed pathways thereof.

Oxidative cage opening in the C fullerene facilitated by preceding trifluoromethylation.

Two novel derivatives of the C fullerene with 9- and 10-membered cage openings were obtained by means of oxidation and decarbonylation of C(CF). The major product, C(O)(CF)O, features a cleaved C-C bond transformed into two carbonyl functions plus an ether bridge. The second product, CO(CF)O, has one of the carbonyls replaced with another ether bridge.