Preparation and x-ray powder structure solution of a novel aluminum phosphate molecular sieve, (AlPO4)3.cntdot.(CH3)4NOH

Rudolf, P. R.; Saldarriaga-Molina, C. H.; Clearfield, Abraham

doi:10.1021/j100281a014

Cited by 59 publications

(17 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In recent years it has been shown that crystal structures can also be determined ab initio (without any prior structural knowledge) by powder diffraction (Rudolf, Saldarriaga & Clearfield, 1986;Cheetham, 1993). Unfortunately, most of !hese compounds do not grow as single crystals, hence, it is necessary to use powder diffraction methodology.…”

Section: Introductionmentioning

confidence: 99%

Ab initio powder structure determination and thermal behavior of a new lead(II) phenylphosphonate, Pb(O₃PC₆H₅)

Cabeza¹,

Aranda²,

Martı́nez-Lara³

et al. 1996

Acta Crystallogr Sect B

View full text Add to dashboard Cite

The crystal structure of Pb(O3PC6Hs) has been solved from X-ray powder diffraction data. Crystal data: triclinic, a = 13.6907 (5), b --9.3327 (4), c --7.0432A, ct = 106.188(3), /3 --94.927, y --96.97T, V = 851.04 (8)A 3, space group P1 and Z = 4. Initial positional parameters for Pb atoms were obtained from direct methods using 556 structure factors in the 20 range 9-63 °. All remaining non-H atoms were located from successive difference-Fourier maps. The final agreement factors were Rwp = 0.055, Rp = 0.042 and R F = 0.017. There are 22 atoms in the asymmetric part of the unit cell and 66 positional parameters have been refined with the help of soft constraints. The lead coordination environment is irregular due to a marked inert pair effect. The three-dimensional structure of this organic-inorganic compound is layered with inorganic layers built up from CPO 3 tetrahedra and PbO 6 units. 31p MAS and CP-MAS (cross-polarization magic-angle spinning) NMR studies have been carried out to confirm the triclinic symmetry with two independent structural units. In optimum conditions two 31p resonance signals are observed, indicating that there are two crystallographically independent P atoms with closely similar environments. The thermal behavior of this material has been studied and the thermal decomposition products identified.

show abstract

Section: Introductionmentioning

confidence: 99%

Ab initio powder structure determination and thermal behavior of a new lead(II) phenylphosphonate, Pb(O₃PC₆H₅)

Cabeza¹,

Aranda²,

Martı́nez-Lara³

et al. 1996

Acta Crystallogr Sect B

View full text Add to dashboard Cite

show abstract

“…The powder patterns of these samples showed good quality Bragg reflections with high resolution. Although these compounds consist of 18 nonhydrogen atoms in the asymmetric unit which is a relatively difficult problem to be attempted by powder methods, we were encouraged by our previous results (Rudolf et al, 1986) in which a 26 atom problem was solved by ab initio methods. Therefore it was decided to undertake the structure solution of these compounds to demonstrate the power of powder diffraction data in resolving the structure of compounds containing a large number of atoms.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and crystal structures of aluminum and iron phosphites

Poojary

Zhang²,

Cox³

et al. 1994

J Chem Crystallogr

Self Cite

View full text Add to dashboard Cite

The hydrated forms of aluminum and iron phosphite were prepared and their structure was solved using X-ray powder diffraction data. The diffraction data for the aluminum phosphite powder sample was collected using synchrotron radiation (~. = 1.3087 A,) while that for iron phosphite was obtained from a rotating anode X-ray source. Both compounds crystallize in the monoclinic space group, P2~. Unit ceil parameters for the AI compound: a = 8.0941(1), b = 9.9137(1), c = 7.6254(1) A., ~ = 111.95~ Fe compound: a = 8.2548(1), b = 10.1814(1), c = 7.7964(1) (A,), fl = 111.94(1)". The Rietveld refined formula is M2(PO3H)3"4H20 (M=AI, Fe). There are two independent metal atoms in the structure and both are six-coordinated. One of them is coordinated by two water molecules and four phosphite oxygens. The other atom is surrounded by one water molecule and five phosphite oxygens. All the phosphite oxygens are involved in bridging the AI atoms. The geometry about AI, Fe, and P atoms is normal and they display expected bond parameters. The Lattice water is located in the cavity and is hydrogen bonded to phosphite'oxygen and water molecules.

show abstract

“…A few structures have already been solved ab initio from powder diffraction data. These investigations have involved both Patterson (Berg & Werner, 1977;Westman, Werner, Schuler & Raldow, 1981;Adels-k61d, Werner, Sundberg & Uggla, 1981;Clearfield, McCusker & Rudolf, 1984;Rudolf & Clearfield, 1985;Attfield, Sleight & Cheetham, 1986) and direct methods (Nolang & Tergenius, 1980;Christensen, Lehmann & Nielsen, 1985;Cheetham, David, Eddy, Jakeman, Johnson & Torardi, 1986;Rudolf, Saldarriaga-Molina & Clearfield, 1986;Lehmann, Christensen, Fjellv~g, Feidenhans'l & Nielsen, 1987), and include conventional X-ray, synchrotron and 0021-8898/88/040305-06503.00 © 1988 International Union of Crystallography neutron sources. Several have been known structures or simple derivatives of known structures, and in only one instance was a zeolite-like material studied.…”

Section: Introductionmentioning

confidence: 99%

Theab initiostructure determination of Sigma-2 (a new clathrasil phase) from synchrotron powder diffraction data

McCusker¹

1988

J Appl Cryst

117

View full text Add to dashboard Cite

The structure of Sigma‐2 ([Si64O1 28].4C10H17N), a new clathrasil phase, has been determined directly from synchrotron X‐ray powder diffraction data using no prior structural information. The high‐resolution data were collected at the NSLS in Brookhaven, and then processed through a series of computer programs assembled and modified for this purpose. There are four Si and seven O atoms in the asymmetric unit, and nine of the 11 framework‐atom positions appeared in the direct‐methods solution. Eight of these were used to generate a Fourier map which clearly showed the remaining three oxygen positions. A whole‐pattern refinement in the space group I41/amd [a = 10.2387(1) and c = 34.3829(1) Å] converged with RF = 0.100, Rwp = 0.225 and Rexp = 0.190. The designation SGT for this new zeolite structure type has been approved by the IZA Structure Commission. Neither of the two cages which make up Sigma‐2 has been encountered previously. The 1‐aminoadamantane used in the synthesis was found to be disordered in the large cage. The JCPDS Diffraction File No. is PDF39‐2000.

show abstract

Preparation and x-ray powder structure solution of a novel aluminum phosphate molecular sieve, (AlPO4)3.cntdot.(CH3)4NOH

Cited by 59 publications

References 0 publications

Ab initio powder structure determination and thermal behavior of a new lead(II) phenylphosphonate, Pb(O₃PC₆H₅)

Ab initio powder structure determination and thermal behavior of a new lead(II) phenylphosphonate, Pb(O₃PC₆H₅)

Synthesis and crystal structures of aluminum and iron phosphites

Theab initiostructure determination of Sigma-2 (a new clathrasil phase) from synchrotron powder diffraction data

Contact Info

Product

Resources

About

Preparation and x-ray powder structure solution of a novel aluminum phosphate molecular sieve, (AlPO4)3.cntdot.(CH3)4NOH

Cited by 59 publications

References 0 publications

Ab initio powder structure determination and thermal behavior of a new lead(II) phenylphosphonate, Pb(O3PC6H5)

Ab initio powder structure determination and thermal behavior of a new lead(II) phenylphosphonate, Pb(O3PC6H5)

Synthesis and crystal structures of aluminum and iron phosphites

Theab initiostructure determination of Sigma-2 (a new clathrasil phase) from synchrotron powder diffraction data

Contact Info

Product

Resources

About

Ab initio powder structure determination and thermal behavior of a new lead(II) phenylphosphonate, Pb(O₃PC₆H₅)

Ab initio powder structure determination and thermal behavior of a new lead(II) phenylphosphonate, Pb(O₃PC₆H₅)