A new coordination polymer, [Zn(HBTC)(BPE)0.5(H2O)]n·nH2O (1) with an extended 1D ladderlike metal-organic framework (MOF) has been synthesized and structural characterized by single-crystal X-ray diffraction method. Structural determination reveals that, in compound 1, the Zn(II) ion is four-coordinated in a distorted tetrahedral geometry, bonded to one nitrogen atom from one BPE ligand, and three oxygen atoms from two monodentate carboxylate groups of two HBTC(2-) ligands and one coordinated water molecule. The HBTC(2-) acts as a bridging ligand with a bis-monodentate coordination mode, connecting the Zn(II) ions to form a one-dimensional (1D) [Zn(HBTC)] chain. Two 1D chains are then interlinked via the connectivity between the Zn(II) ions and anti-BPE liagnds to complete the 1D ladderlike MOF. Adjacent 1D Ladders are further extended to a 2D hydrogen-bonded layered network through the intermolecular O-H · · · O hydrogen bond between the carboxylic group and carboxylate group of interladder HBTC(2-) ligand. Adjacent 2D layers are then packed orderly in an ABAB-type array via the intermolecular interactions of combined π-π interaction and O-H · · · O hydrogen bonds to form a 3D supramolecular architecture exhibiting 1D channels intercalated with guest water molecules. The reversible solid-state structural transformation between crystalline 1 with 1D ladderlike framework and its dehydrated powder 2, [Zn(HBTC)(BPE)0.5]n, with 2D framework via the displacement of coordinated water molecule to HBTC(2-) ligand, by thermal de/rehydrated processes has been verified by PXRD measurements. The emission of 1 and 2 is ascribed to a ligand-based transition.

Using synchrotron powder X-ray diffraction (PXRD) and small-angle X-ray scattering (SAXS), we have studied the structures of the two CdSe/CdTe and CdTe/CdSe type II quantum dots (QDs), including the crystalline structure, particle shape and size, as well as phase separation of the two components. The X-ray results suggest that the spherical CdTe/CdSe QDs of the size ∼8 nm, synthesized in a two-step procedure with CdTe nanoparticles (4 nm) as nuclides, have the structure of a CdTe-rich core enclosed by a CdSe shell. On the other hand, the spherical CdSe/CdTe QDs of the size ∼9 nm, synthesized via a similar two-step procedure but with CdSe nanoparticles (∼3 nm) as nuclides, show mainly one-phase structure with a relatively uniform distribution of CdSe and CdTe. The phase separation of the two components CdSe and CdTe inside each of the two QDs, a decisive factor in the photovoltaic applications, is furthermore examined using anomalous SAXS (ASAXS) for a consistent conclusion. For comparison, single-phase nanoparticles CdSe and CdTe are also examined. The correlation between the synthesis procedures and the corresponding structures of the QDs is discussed.

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The crystal structure of Gd(CO3)OH was solved using synchrotron powder X‐ray diffraction. Gd(CO3)OH was known to exist in a form Gd2O(CO3)2·H2O and its powder pattern has been listed in JCPDF (#430604) for decades, but the crystal structure has not yet been elucidated. The crystal structure is solved with simulated annealing and the DASH program. The final Rietveld refinement converged to Rwp =6.28%, Rp = 4.47%and χ2 = 1.348, using the GSAS program. Gd(CO3)OH crystallizes in orthorhombic system with lattice parameters a = 7.08109(9), b = 4.88436(7), c = 8.45010(13)Å and space group P nma. Gd(CO3)OH forms a three‐dimensional framework with an eight‐membered ring, a one‐dimensional channel and OH− in the cavity. XANES of Gd LIII‐edge indicates that the oxidation state of Gd is 3+. Two phase transitions of Gd(CO3)OH were found at 500 and 650 °C to yield Gd2O2CO3 and Gd2O3 respectively.

Page s 114 isotope is concerned and deuteration is unfeasible (true for many materials, e.g. hydrogen storage materials, proton conductors, ferroelectrics, etc.). Improvements in neutron and detector technology have changed this long-standing view and a range of hydrogenous materials have now been characterised successfully with PND. [1-6] There are limitations though, naturally dependent on the 1 H content, complexity and thermal motion of the material under study. The general reduction of information inherent in PND data (from both the nature of the powder data and the often high incoherent background contribution from hydrogen-containing materials) can be partially overcome by the inclusion of single crystal X-ray diffraction (SXD) data in joint PND and SXD refinements. Also, imaging proton densities from difference Fourier maps is an old but equally powerful tool to obtain qualitative information about proton behaviour. We intend to show what appears possible today, but also point out the limitations we have found on the basis of recent datasets collected at the high intensity powder diffractometer D20 at ILL, Grenoble, and the recently upgraded HRPD at ISIS, UK. The materials studied include both inorganic and organic, and vary in 1 H content, complexity and data collection temperature.