Showing papers by "Thierry Loiseau published in 1996"
TL;DR: In this paper, the synthesis and single-crystal X-ray structure of ULM-16, a new fluorinated gallophosphate Ga4(PO4)4F2·1.5NC6H14·0.5H3O is described.
Abstract: The synthesis and single-crystal X-ray structure of ULM-16, a new fluorinated gallophosphate Ga4(PO4)4F2·1.5NC6H14·0.5H2O·0.5H3O is described. This material is prepared hydrothermally at 180 °C using cyclohexylamine as structuring agent. It crystallizes in the orthorhombic space group Pbcn(no. 60) with a= 27.329(4), b= 17.377(2), c= 10.2124(5)A, V= 4849.6(9)A3 and Z= 8, with R= 0.0477 for 3006 observed reflections [I > 2σ(I)]. The structure is built up from vertex-linked GaO4 and PO4 tetrahedra, GaO4F trigonal bipyramids and GaO4F2 octahedra forming hexameric and tetrameric units. The three-dimensional framework consists of one-dimensional circular tunnels delimited by sixteen polyhedra and is stable up to 800 °C.
59 citations
TL;DR: In this article, the synthesis and structural characterization of oxyfluorinated microporous gallophosphates with the ULM-3 type are presented, and the structures of the phases obtained with the variable organic chain lengths were examined by single-crystal X-ray diffraction (XRD) and 31P, 19F, 13C solid state nuclear magnetic resonance (NMR) spectroscopy.
26 citations
TL;DR: In this article, the synthesis and characterization of ULM-16, a new fluorinated gallophosphate Ga4(PO4)F2 • 1.5 NC6H14 • 0.5 H2O • 0.5 H3O, is described.
Abstract: The synthesis and characterization of ULM-16, a new fluorinated gallophosphate Ga4(PO4)F2 • 1.5 NC6H14 • 0.5 H2O • 0.5 H3O, is described. This material is hydrothermally prepared at 180°C using cyclohexylamine as the structuring agent. It cristallizes in the orthorhombic space group Pbcn (n° 60) with a = 27.329(4) A, b = 17.377(2) A, c = 10.2124(5) A, V = 4849.6 (9) A3 and Z = 8. The structure is built up from vertex-linked GaO4 and PO4 tetrahedra, GaO4F trigonal bipyramids and GaO4F2 octahedra forming hexameric units and infinite double crankshaft chains (called cc or UUDD). The hexameric unit is similar to that found in ULM-3, ULM-4, ULM-5 and ULM-8. The two types of building units are fully connected by vertex-sharing with respect to a strict Ga-P alternation. The 3-D framework consists of cylindrical tunnels delimited by sixteen and six polyhedra running along [001]. The cyclohexylamine molecules are trapped in the wider pores and interact with the bridging fluorine atoms and hydration water through hydrogen bonds. The ULM-16 topology is closely related to that of ULM-5 where, in ULM-16, the infinite crankshaft chains replace the isolated D4R cages of ULM-5. TGA curve (under argon) indicates that the ULM-16 structure is intact up to 800°C. Structural relationships will be stated explicitly for the different structures of the ULM-n series containing the hexameric units.
7 citations