Sodalite Research Articles

Two polymorphs of a piperazinium zincophosphate with different interrupted SOD-type frameworks

Two polymorphous forms of the piperazinium zincophosphate (ZnPO) (C 4N 2H 12)[Zn 2P 3O 12H 3] have been obtained under mild hydrothermal conditions from mixtures of ZnCl 2, H 3PO 4 piperazine and H 3BO 3 in ethylene glycol/water solvents. Single-crystal X-ray structure analyses revealed that both polymorphs possess an open-framework structure with sodalite (SOD) topology. While polymorph I (formulation (C 4N 2H 12)[Zn 2(HPO 4) 3], space group P2 1/c, Z=8) is reported for the first time, polymorph II (formulation (C 4N 2H 12)[Zn 2(PO 4)(H 1.5PO 4) 2], space group C2/c, Z=4) is a known phase. Its structure has been reinvestigated in order to unambiguously determine the hydrogen bonds. The interruptions in the ZnPO host structures possess the form of distorted tetrahedral [H 3O 4(P) 4] groupings (hydroxyl nests). A diprotonated piperazine molecule is enclosed in every [4 66 8] cage. The polymorphs differ in the host–guest N–H⋯O and C–H⋯O interactions, the degree of condensation of the distinct phosphate tetrahedra, the hydrogen-bonding systems in the interruptions, and the long-range ordering of interruptions in the host frameworks. Considerable differences are seen for the donor–acceptor O⋯O distances (ranging from 2.47 to 3. 14 Å) in the total of three distinct [H 3O 4(P) 4] groupings.

MEGAKALSILITE, A NEW POLYMORPH OF KAlSiO4 FROM THE KHIBINA ALKALINE MASSIF, KOLA PENINSULA, RUSSIA: MINERAL DESCRIPTION AND CRYSTAL STRUCTURE

Megakalsilite, KAlSiO4, hexagonal, a 18.1111(8), c 8.4619(4) A, V 2403.7(2) A 3 , c:a = 0.4672, space group P63, Z = 24, R = 0.039 (for 3255 observed reflections collected with a four-circle X-ray diffractometer), is a new mineral species from Mount Koashva, Khibina alkaline massif, Kola Peninsula, Russia. It is of pegmatitic origin. Associated minerals are K-feldspar, sodal ite, cancrinite, natrolite, pectolite, aegirine, natrite, nacaphite, vitusite, fluorcaphite, belovite, umbite, lemmleinite-K, lomono sovite, lovozerite, phlogopite, sphalerite, and galena. The mineral was found in only one hand specimen of pegmatite rock as a corroded , irregularly shaped grain 2 � 3 mm across, intergrown with cancrinite, sodalite, and natrite. It is transparent, colorless with a white streak, a vitreous luster, and fluoresces pale whitish green under ultraviolet light. Megakalsilite has a Mohs hardness of 6, i s brittle with a conchoidal fracture, and has no cleavage. Dmeas is 2.58(2) g/cm 3 , Dcalc is 2.62 g/cm 3 . Megakalsilite is uniaxial negative, non-pleochroic, � 1.538(1), � 1.531(1). The strongest five reflections in the X-ray powder-diffraction pattern [ d in A(I)(hkl)] are: 3.091(100)(222), 2.612(70)(060), 1.240(60)(4.10.1,066,583), 3.18(50)(141), and 1.674(50)(173). An electron-microprobe analysis gives: K2O 29.73, Na2O 0.02, FeO 0.04, Al2O3 32.38, SiO2 37.96, TiO2 0.01, sum 100.14 wt.%. The corresponding empirical formula is K0.997Na0.001Fe0.001Al1.003Si0.998O4 (based on O = 4), ideally KAlSiO4. The name megakalsilite is derived from the Greek ����� (great) and kalsilite, in allusion to the fact that megakalsilite shares the same chemical formula with kalsilite, but its unit cell is 12 times larger than that of kalsilite. The crystal structure of megakalsilite, KAlSiO 4, has been solved by direct methods and refined to an R1 index of 3.82% based on 3255 observed [Fo > 4� (Fo)] unique reflections measured with

Incorporation of iron in sodalite structures and their transformation into other iron containing zeolites: Synthesis of Fe-NaA (LTA)

In the low temperature digestion of gibbsitic aluminium ores an iron content impurity phase, ‘desilication product’ (DSP), will be separated from the sodium aluminate liquor. Due to its main component: (hydroxy- or carbonate-) sodalite (SOD) and amount, reaching 7–10% of the feedstock, the DSP is an important raw material for synthesising various zeolites. Applying the sol–gel technique the authors developed synthesis methods to prepare iron content (chloride-) sodalites, in order to model how they can be transformed to commercially interesting types of zeolites (e.g. to NaA (LTA)). Using diluted mineral acids (e.g. 5 wt.% sulfuric acid) in amounts equivalent (or rather in 10% excess) to the ion exchange capacity, a heat-treatment at 100°C, lasting 3 h leads to an amorphous product which can easily be recrystallised to various zeolites. Outgoing from iron containing SOD, a new kind of NaA (LTA) could be prepared possessing various amounts of iron. Mössbauer, XP, ESR and UV–VIS spectroscopic investigations revealed that up to 3 wt.% total iron content, as an average, about 60–62% iron is sited in framework (FW) positions, in T h co-ordination. The other part is located in the voids, in extra-framework (EFW) positions, in O h co-ordination, as highly dispersed iron oxide. This component exhibits strong magnetic interaction which manifests itself in large linewidths when taking the ESR spectra. Mössbauer spectroscopy revealed that the FW/EFW iron ratio decreased with the total iron content. Due to the ‘chemistry’ of sol–gel technique, in alkaline environments complete iron incorporation into zeolitic frameworks can never be attained. Applying complexing agents or other methods EFW iron can be dissolved during the acid treatment permitting the synthesis of low module zeolites with uniform Fe(III) siting. The various kinds of iron content LTA zeolites may catalyse (biomimetic) selective oxidation reactions between reactants capable to enter the pore structure.

Heteroepitaxial Growth of a Zeolite T.W. and T.O. are grateful to H. Tsunakawa of the High Voltage Electron Microscope Laboratory, University of Tokyo (UT), and Prof. Y. Ikuhara, Engineering Research Institute, UT, for the 400-kV SAED experiments and their analyses, respectively. H. Shiga, T. Hayashi and T. Shiraki are acknowledged for preliminary experiments. This work was supported by a Grant-in-Aid

Heteroepitaxial Growth of a Zeolite T.W. and T.O. are grateful to H. Tsunakawa of the High Voltage Electron Microscope Laboratory, University of Tokyo (UT), and Prof. Y. Ikuhara, Engineering Research Institute, UT, for the 400-kV SAED experiments and their analyses, respectively. H. Shiga, T. Hayashi and T. Shiraki are acknowledged for preliminary experiments. This work was supported by a Grant-in-Aid

Wairakei geothermal silica; a low cost reagent for the synthesis of low, intermediate- and high-silica zeolites

A precipitated silica, produced as a waste product from the Wairakei geothermal field and power station in the central North Island of New Zealand, has been found to be active in the hydrothermal synthesis of a range of zeolite molecular sieves of various structure types: Sodalite (SOD), Linde type A (LTA), Linde type Y (FAU), Mordenite (MOR), ZSM-5 (MFI) and Beta (*BEA). The natural silica reagent contains reactive aluminium (Al) and iron (Fe) impurities that can be either included or excluded from the zeolite frameworks depending on the synthesis conditions. High alkalinity syntheses (SOD, LTA, FAU, MOR) tend to include Al, while Fe is excluded from the zeolite lattices. The crystalline zeolite products that result are white to off-white in colour. Lower alkalinity syntheses that require organic structure-directing agents (SDA), zeolites MFI and *BEA, include less Al but higher amounts of Fe, producing off-white to pale brown products. Both the crystallinities and compositions of zeolites MOR, MFI and *BEA are modified by rotation of the autoclave during synthesis.

Synthesis of ultramarine from synthetic molecular sieves

Methods of ultramarine production using synthetic zeothetic zeolites as substrates have been developed. In contrast to the conventional method the emission of sulfur oxides is almost negligible. Intense blu products having the sodalite (SOD) structure have been obtained by the calcination of zeolites A, X, Y and hydroxysodalite impregnated with sulfur compounds (mainly sodium polysulfides). An attempt has been made to introduce into zeolites the S 3 − radicals generated in DMSO solutions of polysulfides.

Remarks on symmetries occurring in the sodalite family

Remarks on symmetries occurring in the sodalite family

Synthesis, Structural and Optical Characterization of Zinc Chalcogentdes in Novel Solid State Hosts

ABSTRACTSeveral series of sodali te analogues of unit cell composition M8X2(TO2)12, where M is Zn or Cd, X is a chalcogen, and T is a tetrahedral cation B, or Be in combination with Si or Ge, have been prepared. An M4X tetrahedron, which is the first coordination sphere of the bulk semiconductor MX, sits at the center of each sodalite cage. These materials have been structurally characterized by solid state 77Se and 125STe MAS NMR and by powder X-ray diffraction. Diffuse reflectance optical absorption spectra are reported for each series. The borates have optical properties similar to the bulk MX whereas the beryllosilicates and germanates exhibit large blue shifts in the absorption spectra.

The Synthesis and Structure of Some New Sodalites: The Lithium Haloberyllophosphates and ‐Arsenates

The Synthesis and Structure of Some New Sodalites: The Lithium Haloberyllophosphates and ‐Arsenates

Infrared spectra of cathodochromic sodalite

Infrared spectra of cathodochromic sodalite

Sodalite colours

Sodalite colours

The Ice River Complex, British Columbia, is Precambrian Basement

ABSTRACT The Ice River complex, in Yoho and Kootenay National Parks, consists of plutonic basement rocks of Precambrian age (Gussow and Hunt, 1959), brought to the surface in two thrust sheets as a result of the Rocky Mountain orogeny. The basement rocks consist of nepheline and sodalite syenite, paragneisses, and crystalline limestones, which unconformably underlie rocks of Upper Cambrian age. The strata immediately overlying the basement are dove-gray limestones containing boulders and pebbles of basement rocks, and locally have a thin basal conglomerate or grit. The limestones thin by onlap on basement topography (, ). In recent years, other workers have postulated carbonatites, magmatic differentiation, and liquid immiscibility for their origin (Gussow, 1977).2 The Ice River controversy is dealt with in detail, by documenting the evidence for the true age of the complex, and reinterpreting the data of others in the light of this evidence.

On three new analyses of sodalite, from three new localities

On three new analyses of sodalite, from three new localities

On sodalite and elaeolite from Salem, Massachusetts

On sodalite and elaeolite from Salem, Massachusetts

On sodalite and cancrinite

On sodalite and cancrinite