A long-standing issue regarding the local and long-range structure of V(2)O(5)*nH(2)O xerogel has been successfully addressed. The full three-dimensional structure of the lamellar turbostratic V(2)O(5)*nH(2)O xerogel was determined by the atomic pair distribution function technique. We show that on the atomic scale the slabs of the xerogel can be described well as almost perfect pairs (i.e., bilayers) of single V(2)O(5) layers made of square pyramidal VO(5) units. These slabs are separated by water molecules and stack along the z-axis of a monoclinic unit cell (space group C2/m) with parameters a = 11.722(3) A, b = 3.570(3) A, c = 11.520(3) A, and beta = 88.65 degrees. The stacking sequence shows signatures of turbostratic disorder and a structural coherence limited to 50 A.

The molecular building block approach was employed effectively to construct a series of novel isoreticular, highly porous and stable, aluminum-based metal–organic frameworks with soc topology. From this platform, three compounds were experimentally isolated and fully characterized: namely, the parent Al-soc-MOF-1 and its naphthalene and anthracene analogues. Al-soc-MOF-1 exhibits outstanding gravimetric methane uptake (total and working capacity). It is shown experimentally, for the first time, that the Al-soc-MOF platform can address the challenging Department of Energy dual target of 0.5 g/g (gravimetric) and 264 cm3 (STP)/cm3 (volumetric) methane storage. Furthermore, Al-soc-MOF exhibited the highest total gravimetric and volumetric uptake for carbon dioxide and the utmost total and deliverable uptake for oxygen at relatively high pressures among all microporous MOFs. In order to correlate the MOF pore structure and functionality to the gas storage properties, to better understand the structure–property relationship, we performed a molecular simulation study and evaluated the methane storage performance of the Al-soc-MOF platform using diverse organic linkers. It was found that shortening the parent Al-soc-MOF-1 linker resulted in a noticeable enhancement in the working volumetric capacity at specific temperatures and pressures with amply conserved gravimetric uptake/working capacity. In contrast, further expansion of the organic linker (branches and/or core) led to isostructural Al-soc-MOFs with enhanced gravimetric uptake but noticeably lower volumetric capacity. The collective experimental and simulation studies indicated that the parent Al-soc-MOF-1 exhibits the best compromise between the volumetric and gravimetric total and working uptakes under a wide range of pressure and temperature conditions.

tors (17). The resulting density matrix has only positive eigenvalues, and hence it represents a physically possible state. Its fidelity with respect to the expected Bell state, |Y -〉 from Eq. 2, is F = 86.0(4)%, with 0.5 < F ≤ 1 proving entanglement (18). From the density matrix, following (16), we derive a concurrence of C = 0.73(7), with 0 < C ≤ 1 also proving entanglement. Because of technical imperfections, e.g., of polarizers in the detection setups, the observed fidelity/concurrence sets a lower bound for both the atom-photon and photon-photon entanglement achieved. The same measurements were done for B = −0.13 G and t S = 2.8 ms for which the atomic superposition state accumulates a p phase shift (compare to Fig. 3). Therefore, a density matrix corresponding to the Bell stateis expected. This is indeed observed (Fig. 4B) with a fidelity of F = 82.9(6)% and a concurrence of C = 0.72(13). The state evolves between the two photon detections as a result of the constant magnetic field.Future experiments could produce a timeindependent |Y + 〉 Bell state by applying a pulsed magnetic field to the atom between entanglement generation and state mapping. Moreover, partial driving of the Raman transition in combination with atomic state manipulation should allow production of highly entangled multiphoton states (12). Our technique applied to a quasi-permanently trapped intracavity atom (3, 19) will push the probability of success even further, making the scheme truly deterministic. Two (or more) such systems operated in parallel are perfectly suited for teleportation and entanglement experiments in a quantum network (20)(21)(22) or quantum gate operations in a distributed and, hence, scalable quantum computer (23, 24). Inorganic porous materials are being developed for use as molecular sieves, ion exchangers, and catalysts, but most are oxides. We show that various sulfide and selenide clusters, when bound to metal ions, yield gels having porous frameworks. These gels are transformed to aerogels after supercritical drying with carbon dioxide. The aerogels have high internal surface area (up to 327 square meters per gram) and broad pore size distribution, depending on the precursors used. The pores of these sulfide and selenide materials preferentially absorb heavy metals. These materials have narrow energy gaps (between 0.2 and 2.0 electron volts) and low densities, and they may be useful in optoelectronics, as photocatalysts, or in the removal of heavy metals from water.