The hierarchical Yen−Mullins model of Athabasca oil-sands asphaltene is strongly supported by solution-state 1 H NMR relaxation measurements and 2D HSQC-NMR spectroscopy. For the first time, the 1 H T 1 and T 2 relaxation behaviors of specific sites in asphaltene molecules have been studied, and it is shown that the relaxation behavior is in agreement with the hierarchical molecule-nanoaggregate-cluster model proposed by Mullins (Energy Fuels 2012, 26, 3986). The size of the asphaltene nanoaggregate clusters was determined from the biexponential T 2 relaxation behavior of the 1 H nuclei. Assignment of overlapping 1D NMR signals was made possible via HSQC methods, where elusive hallmark long-range aromatic−aliphatic heteronuclear correlations were observed. Alicyclic structures were shown to be more closely associated with the aromatic core than what has been proposed for most archipelago-type structures. The NMR parameters obtained from the deconvolution analysis indicate an average of 6−7 pericondensed aromatic rings present in each molecule, in agreement with the island model. The average molecular weight was determined at ∼720 g/mol, which would be typical for island model structures, hence lending strong support for the Yen−Mullins model.

The fluoride ion acceptor properties of OsO4 and OsO3F2 were investigated. The salts [N(CH3)4][OsO4F] and [N(CH3)4]2[OsO4F2] were prepared by the reactions of OsO4 with stoichiometric amounts of [N(CH3)4][F] in CH3CN solvent. The salts [N(CH3)4][OsO3F3] and [NO][OsO3F3] were prepared by the reactions of OsO3F2 with a stoichiometric amount of [N(CH3)4][F] in CH3CN solvent and with excess NOF, respectively. The OsO4F- anion was fully structurally characterized in the solid state by vibrational spectroscopy and by a single-crystal X-ray diffraction study of [N(CH3)4][OsO4F]: Abm2, a = 7.017(1) A, b = 11.401(2) A, c = 10.925(2) A, V = 874.1(3) A3, Z = 4, and R = 0.0282 at -50 degrees C. The cis-OsO4F2(2-) anion was characterized in the solid state by vibrational spectroscopy, and previous claims regarding the cis-OsO4F2(2-) anion are shown to be erroneous. The fac-OsO3F3- anion was fully structurally characterized in CH3CN solution by 19F NMR spectroscopy and in the solid state by vibrational spectroscopy of its N(CH3)4+ and NO+ salts and by a single-crystal X-ray diffraction study of [N(CH3)4][OsO3F3]: C2/c, a = 16.347(4) A, b = 13.475(3) A, c = 11.436(3) A, beta = 134.128(4) degrees, V = 1808.1(7) A3, Z = 8, and R = 0.0614 at -117 degrees C. The geometrical parameters and vibrational frequencies of OsO4F-, cis-OsO4F2(2-), monomeric OsO3F2, and fac-OsO3F3- and the fluoride affinities of OsO4 and monomeric OsO3F2 were calculated using density functional theory methods.

The previously recognized "extremely explosive" carbonyl diazide, OC(N(3))(2), was prepared as a pure compound and unambiguously characterized by gas-phase IR, matrix IR, and Raman spectroscopy and X-ray crystallography for the first time. The pure substance shows remarkable kinetic stability at room temperature in the gaseous, liquid, and solid states. A melting point of 16 °C and vapor pressure of 5.6 mbar at 0 °C were determined. Two planar conformers were found in the gas phase, and a composition of 12% anti-syn versus 88% syn-syn conformer in the gaseous equilibrium mixture at room temperature was estimated by matrix IR spectroscopy. In the crystal structure, only the more stable syn-syn conformer was observed. The preference of the syn-syn configuration was supported by DFT calculations.