We demonstrate that fluorous metal-organic frameworks (FMOFs) are highly hydrophobic porous materials with a high capacity and affinity to C(6)-C(8) hydrocarbons of oil components. FMOF-1 exhibits reversible adsorption with a high capacity for n-hexane, cyclohexane, benzene, toluene, and p-xylene, with no detectable water adsorption even at near 100% relative humidity, drastically outperforming activated carbon and zeolite porous materials. FMOF-2, obtained from annealing FMOF-1, shows enlarged cages and channels with double toluene adsorption vs FMOF-1 based on crystal structures. The results suggest great promise for FMOFs in applications such as removal of organic pollutants from oil spills or ambient humid air, hydrocarbon storage and transportation, water purification, etc. under practical working conditions.

A doubly interpenetrated semiconducting MOF Zn(4)O(2,6-NDC)(3)(DMF)(1.5)(H(2)O)(0.5)·4DMF·7.5H(2)O (UTSA-38) of a cubic net has been constructed, which exhibits photocatalytic activity for the degradation of methyl orange in aqueous solution.

The ability of high oxidation potential zinc porphyrins acting as electron donors in photoinduced electron-transfer reactions is investigated. Donor−acceptor dyads were assembled via metal−ligand axial coordination of either pyridine or phenylimidazole functionalized fulleropyrrolidine with zinc porphyrin functionalized with different numbers of halogen substituents on the meso-aryl rings. Optical absorption studies on complex formation revealed relatively higher binding constants. Efficient quenching of fluorescence was observed for the newly assembled dyads, revealing their ability to undergo photoinduced events. Differential pulse voltammetry studies were performed to understand the structure−activity relationships with respect to the electron deficient nature of the porphyrins and to utilize these data to estimate free-energy change for charge-separation and charge-recombination processes. The absolute value of free-energy change for charge separation was found to be lower for halogenated porphyrins with higher oxidation potentials expecting to form high-energy radical ion pairs. Using femtosecond transient techniques, evidence for charge separation and kinetics of charge separation and recombination were obtained in toluene. The kinetic data obtained by analyzing the time profiles of the radical ions revealed occurrence of ultrafast charge separation and relatively slower charge recombination processes in the dyads. Notably, electron-transfer rates did not exactly follow the trends predicted based on Marcus theory of electron transfer. Donor− acceptor geometry and populating the triplet excited states of the sensitizers during charge recombination are considered to be possible reasons for this behavior.

An experimental and computational study of correlations between solid-state structure and optical/electronic properties of cyclotrimeric gold(I) carbeniates, [Au3(RN═COR')3] (R, R' = H, Me, (n)Bu, or (c)Pe), is reported. Synthesis and structural and photophysical characterization of novel complexes [Au3(MeN═CO(n)Bu)3], [Au3((n)BuN═COMe)3], [Au3((n)BuN═CO(n)Bu)3], and [Au3((c)PeN═COMe)3] are presented. Changes in R and R' lead to distinctive variations in solid-state stacking, luminescence spectra, and conductive properties. Solid-state emission and excitation spectra for each complex display a remarkable dependence on the solid-state packing of the cyclotrimers. The electronic structure of [Au3(RN═COR')3] was investigated via molecular and solid-state simulations. Calculations on [Au3(HN═COH)3] models indicate that the infinitely extended chain of eclipsed structures with equidistant Au--Au intertrimer aurophilic bonding can have lower band gaps, smaller Stokes shifts, and reduced reorganization energies (λ). The action of one cyclotrimer as a molecular nanowire is demonstrated via fabrication of an organic field effect transistor and shown to produce a p-type field effect. Hole transport for the same cyclotrimer-doped within a poly(9-vinylcarbazole) host-produced a colossal increase in current density from ∼1 to ∼1000 mA/cm(2). Computations and experiments thus delineate the complex relationships between solid-state morphologies, electronic structures, and optoelectronic properties of gold(I) carbeniates.

The photophysical behavior of the polycyclic aromatic hydrocarbon peropyrene is studied both in dilute solution and in the solid state, with the goal of evaluating this molecule as a singlet fission (SF) material. In solution, the fluorescence quantum yield is consistently in the range 0.90−0.95, while the fluorescence lifetime changes from 3.2 to 5.5 ns. Analysis of the solvent dependence of the radiative rate provides evidence that the bright 1 B u singlet state mixes with a second, optically dark state. The presence of a dark state slightly above the 1 B u state in energy is confirmed using two-photon fluorescence excitation spectroscopy. The crystal structure of solid peropyrene consists of a herringbone arrangement of π-stacked molecular pairs, similar to the αpolymorph of perylene. There are two emitting species, centered at approximately 550 and 650 nm, both of which are formed within the 15 ps time resolution of the experiment, and which relax independently via biexponential decays. We find no evidence for rapid SF in the peropyrene crystals, most likely due to the large shift of the singlet state to lower energy where it no longer fulfills the energy condition for SF. These results demonstrate how both energetics and crystal packing influence the ability of a molecule to function as a SF material.