This investigation presents a systematic examination of the late transition metal octaethylporphyrins MII(OEP) with M = Co, Ni, Cu, and Zn as cocrystallization agents for C60. In each case, the fullerene was dissolved in benzene and then layered over an equimolar dichloromethane solution of the porphyrin. A striking new columnar structural type for these systems is found for CoII(OEP) and ZnII(OEP) with stoichiometric ratios 6:5 for porphyrin/fullerene. In these cocrystals, one fullerene is surrounded by two porphyrins, one is adjacent to only one porphyrin, while one makes no contact with a porphyrin; yet, all three fullerenes are ordered at 90 K. A more typical, also new, 1:1 structure with CuII(OEP) and C60 shows back-to-back porphyrins with all eight ethyl groups embracing the fullerene. In these three structures only dichloromethane is found as the solvate. The NiII(OEP) structure is related to the known structure of NiII(OEP)·C60·2C6H6 but has incorporated ca. 5% dichloromethane. In these NiII(OEP)/C60 cocrystals, four of the ethyl groups embrace the fullerene, while the other four are displaced to the opposite side of the porphyrin plane where they do not make contact with a fullerene. The porphyrin core conformations of the different metal derivatives also differ, and their possible impact on cocrystal formation is discussed.

Direct synthesis of diamine radical cations in crystalline form proceeding through oxidation of triphenylamine followed by the formation of a new C−N bond is reported. Although the oxidative coupling of triphenylamine is well studied, diamine products are rarely captured in their radical cation state. The neutral diamine most frequently obtained from this reaction pathway is N,N,N’,N’‐tetraphenylbenzidine. Herein, the capture of radical cations of diamines in crystalline form in one step starting with neutral triphenylamine was demonstrated, and the formation of two products (the radical cations of N,N,N′,N′‐tetraphenyl‐1,4‐benzenediamine or N,N,N′,N′‐tetraphenylbenzidine) depending on the oxidizing agent used was observed. The radical species are characterized by single‐crystal X‐Ray diffraction, electron paramagnetic resonance spectroscopy, and optical spectroscopy.

Variations in crystallization conditions produce dramatic changes in the composition and geometry of solvated porphyrin-fullerene cocrystals. The products obtained by cocrystallization from a benzene solution of C60 with a solution of MII(OEP) (M = Co or Zn) in a variety of solvents have been analyzed crystallographically. The cocrystals fall into three categories: Class 1, ordered crystals with a 1:1 porphyrin/fullerene ratio (CoII(OEP)·C60·CS2 (1), ZnII(OEP)­·C60·CS2 (2), CoII(OEP)­·C60·C4H8O2 (5), CoII(OEP)­·C60·1.5C6H6 (8); Class 2, ordered crystals with a 2:1 porphyrin/fullerene ratio (2ZnII(OEP)­·C60·0.75CCl4 (4) and 2CoII(OEP)­·C60·C4H8O (7)); and Class 3, crystals involving a five-coordinate metal and a disordered fullerene cage (ClCoIII(OEP)­·C60·CCl4 (3) and (C4H8O2)­ZnII(OEP)­·C60·C4H8O2 (6)). Class 1 crystals form in three different space groups, yet all contain two packing motifs: columns with significant porphyrin/porphyrin, fullerene/porphyrin, and fullerene/fullerene interactions and zigzag chains of fullerenes. Class 2 crystals are isostructural. Class 3 crystals vary due to differing axial ligands. Whether crystals with a 1:1 or 2:1 porphyrin/C60 ratio form depends upon the solvent rather than the amounts of components present in solution. Cocrystallization using ZnII(OEP) and chlorinated solvents appears as the preferred combination to produce ordered C60 molecules, and this situation may pertain for other fullerenes.

Treatment of an open-cage fullerene, designated as MMK-9, with (Ph3P)4Pt in toluene solution at room temperature allows a Pt(PPh3)2 unit to be incorporated into the rim of the cage so...

Terbium has been added to the list of elements that form oxide clusters inside fullerene cages. Tb 2 O@C 2 (13333)-C 74 has been isolated as a byproduct of the electric arc synthesis of the azafullerene Tb 2 @C 79 N. Cocrystallization of Tb 2 O@C 2 (13333)-C 74 with Ni(OEP) (where OEP is the dianion of octaethylporphyrin) in toluene yielded black needles of Tb 2 O@C 2 (13333)-C 74 • Ni II (OEP)•1.5C 7 H 8 that have been examined by single-crystal Xray diffraction. The resulting structure shows that a nearly linear Tb−O−Tb unit is contained in a C 2 (13333)-C 74 , which has two sites where pentagons share an edge to form pentalene units at opposite ends of the fullerene. Unlike the usual situations where metal atoms in fullerenes that do not obey the isolated pentagon rule are situated within the folds of the pentalene units, the Tb atoms in Tb 2 O@C 2 (13333)-C 74 are positioned to the side of the pentalene units and near-neighboring hexagons. The magnetic properties of Tb 2 O@C 2 (13333)-C 74 have been examined starting from the experimental geometry, using ab-initio multiconfigurational methods. The computations predict that Tb 2 O@C 2 (13333)-C 74 will show strong axiality, which would make it a singlemolecule magnet with a large magnetic anisotropy barrier.