Search

Treatment of an open-cage fullerene, designated as MMK-9, with (Ph3P)4Pt in toluene solution at room temperature allows a (PPh3)2Pt unit to be incorporated into the rim of the cage so that it becomes an integral part of the carbon cage skeleton. The structure of the adduct has been determined by single crystal X-ray diffraction and reveals that the platinum atom has planar PtC2P2 coordination, rather than the usual η2-bonding to an intact C–C double bond of the fullerene.

Variations in crystallization conditions produce dramatic changes in the composition and geometry of solvated porphyrin-fullerene cocrystals. The products obtained by cocrystallization from a benze...

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.

Treatment of an open-cage fullerene, designated as MMK-9, with (Ph

Ion recombination in the gas phase plays an important role in plasma science and chemistry that is closely related to various applications in combustion and materials processing. Due to the lack of robust theoretical models of three body ion recombination, this project intends to develop a Langevin dynamics-based ion recombination rate constant model that is applicable for a broad pressure and temperature range combination taking into account the effect of ionic structure (especially for polyatomic ions). At high pressures, Langevin Dynamics is commonly considered to be efficient model for ion-neutral gas interactions and the implementation of LD enables the trajectory analysis and obtaining the ensemble averaged estimates of the of ion recombination rate constant. Ion recombination or mutual neutralization is modeled within the framework of classical physics and thus does not explicitly model the quantum nature of electron transfer kinetics from the anion to the cation. We hypothesized that electron transfer takes place with near certainty when two atoms (one part of the cation and the other part of the anion) when their separation is less than or equal to σ - distance σ between two atoms at which the potential energy (due to van der Waals or polarization interaction) between the ions is zero. The comparison with experimental data 1 – 5 for several ion pairs reveals an agreement of ±50% with most of the tested ion pairs. At low pressure end, a good agreement is observed as well between ion pairs that consist of polyatomic ions.

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 ful...

Purified samples of Ho3 N@C2 (22010)-C78 and Tb3 N@C2 (22010)-C78 have been isolated by two distinct processes from the rich array of fullerenes and endohedral fullerenes present in carbon soot from graphite rods doped with Ho2 O3 or Tb4 O7 . Crystallographic analysis of the endohedral fullerenes as cocrystals with Ni(OEP) (in which OEP is the dianion of octaethylporphyrin) shows that both molecules contain the chiral C2 (22010)-C78 cage. This cage does not obey the isolated pentagon rule (IPR) but has two sites where two pentagons share a common C-C bond. These pentalene units bind two of the metal ions, whereas the third metal resides near a hexagon of the cage. Inside the cages, the Ho3 N or Tb3 N unit is planar. Ho3 N@C2 (22010)-C78 and Tb3 N@C2 (22010)-C78 use the same cage previously found for Gd3 N@C2 (22010)-C78 rather than the IPR-obeying cage found in Sc3 N@D3h -C78 .

Seven crystal structures of five first-row (Fe, Co, Ni, Cu, and Zn) and one second-row (Cd) transition metal–4-picoline (pic)–sulfate complexes of the form [M(pic) x ]SO4 are reported. These complexes are catena-poly[[tetrakis(4-methylpyridine-κN)metal(II)]-μ-sulfato-κ2 O:O′], [M(SO4)(C6H7N)4] n , where the metal/M is iron, cobalt, nickel, and cadmium, di-μ-sulfato-κ4 O:O-bis[tris(4-methylpyridine-κN)copper(II)], [Cu2(SO4)2(C6H7N)6], catena-poly[[bis(4-methylpyridine-κN)zinc(II)]-μ-sulfato-κ2 O:O′], [Zn(SO4)(C6H7N)2] n , and catena-poly[[tris(4-methylpyridine-κN)zinc(II)]-μ-sulfato-κ2 O:O′], [Zn(SO4)(C6H7N)3] n . The Fe, Co, Ni, and Cd compounds are isomorphous, displaying polymeric crystal structures with infinite chains of M II ions adopting an octahedral N4O2 coordination environment that involves four picoline ligands and two bridging sulfate anions. The Cu compound features a dimeric crystal structure, with the CuII ions possessing square-pyramidal N3O2 coordination environments that contain three picoline ligands and two bridging sulfate anions. Zinc crystallizes in two forms, one exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a tetrahedral N2O2 coordination containing two picoline ligands and two bridging sulfate anions, and the other exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a trigonal bipyramidal N3O2 coordination containing three picoline ligands and two bridging sulfate anions. The structures are compared with the analogous pyridine complexes, and the observed coordination environments are examined in relation to crystal field theory.

The crystal structures of the first-row transition-metal series of tris(ethylenediamine-κ2 N,N′)metal(II) diacetate, [M(C2H8N2)3](CH3CO2)2, with M = Mn, Fe, Co, Ni, Cu, and Zn, are reported. The complexes are all isostructural, crystallizing in a centrosymmetric triclinic cell and possessing an asymmetric unit composed of one [M(en)3]2+ cation and two symmetrically independent acetate anions. In the unit cell, the two complex cations are inversion-generated enantiomers, possessing the energetically favoured Δ(λλλ) and Λ(δδδ) configurations. The complex cations and acetate anions combine through a series of N—H...O hydrogen bonds to generate a three-dimensional network in the crystals. The other notable feature of the series is a significant Jahn–Teller distortion for the d 9 Cu2+ complex.

A strategy to generate crystalline coordination polymers with strong, covalent metal-linker bonds is presented. 1,6-Pyrenedi(2-ethylhexylmercaptopropionate) (1) is converted to 1,6-pyrenedithiolate (PDT) via a base-mediated deprotection allowing for rate control of the metal-linker self assembly. This leads to the formation of a single-crystalline, flexible 2D coordination polymer, [Cd(PDT)2][Cd(en)3] (3).

Purified samples of Ho

Open-cage fullerenes, fullerenes with orifices created by breaking some of the C-C bonds in a fullerene such as C60, are molecules that allow chemical access to both the external and the internal surfaces of the carbon cage. We have found such molecules to be challenging to crystallize and thereby fully structurally characterize through single crystal X-ray diffraction studies. We have also found that the reactivity of these open cage fullerenes can differ significantly from that of the parent fullerene (see A. Aghabali, S. Jun, M. M. Olmstead, A. L. Balch, Silver(I)-Mediated Modification, Dimerization, and Polymerization of an Open-Cage Fullerene. J. Am. Chem. Soc. 2016, 138, 16459-16465.) This talk will report recent studies of the crystallographically determined structures and reactivities of several open-cage fullerenes with particular attention given to the accessibility of the cage opening to chemical reactions.

The structure of Sc3N@D 3h -C78, which has been examined crystallographically and found to obey the isolated pentagon rule (IPR), will be discussed and compared to other related endohedral fullerenes. The effect of the composition of the interior M3N unit in this and other endohedral fullerenes will be shown to influence cage structure, sometimes in a predictable fashion. Structural studies of other fullerenes will also be presented.

Seven crystal structures of five first-row (Fe, Co, Ni, Cu, and Zn) and one second-row (Cd) transition metal-4-picoline (pic)-sulfate complexes of the form [M(pic)

The crystal structures of three first-row transition metal-pyridine-sulfate complexes, namely catena-poly[[tetrakis(pyridine-κN)nickel(II)]-μ-sulfato-κ

The crystal structures of the first-row transition-metal series of tris(ethylenediamine-κ

Cocrystallization of endohedral fullerenes and empty cage fullerenes with Ni(octaethylporphyrin) has become a widely used method to obtain X-ray structural information on these molecules. However, the stoichiometry of composition of these materials is difficult to predict. here we will report some new structures and studies of factors that effect the composition of these cocrystals.

The title compound, C6H6BrN, has half of a molecule in the asymmetric unit, as it sits on a crystallographic plane of symmetry. In the crystal, weak C—H...N interactions link the molecules, forming chains along [100]. No π–π interactions are observed.