Search

To study the cyclopentane sorption sites and the effect of sorption on the H-ZSM-5 structure, crystal of H-ZSM-5 were prepared by burning out the tetrapropylammonium cations in air. For the adsorption of cyclopentane into H-ZSM-5 crystal, the crystal was treated with zeolitically dried cyclopentane for 6 h at 297 K, and then evacuated for 600 s at this temperature and 1.1 × 10–4 Pa. The structure of a single crystal of cyclopentane sorption complex of dehydrated H-ZSM-5 (MFI, |H3.8(C5H10)1.47|[Al3.8Si92.2O192]-MFI, Si/Al = 24) has been determined crystallographically using synchrotron X-radiation in the orthorhombic space group Pnma; a = 20.141(4), b = 19.944(4), c = 13.439(3) A. It was refined using all intensities to the final error indice R1 = 0.072. The 1.47 cyclopentane molecules per unit cell are located between 5-rings in zigzag channel. The cyclopentane molecules are located perpendicular to the 10-rings of zigzag channel and parallel to the 5-rings of H-ZSM-5 framework at the center of them. Each cyclopentane molecule is held in place by 16 hydrogen bonds between all hydrogen atoms of cyclopentane and framework oxygen atoms of its 5- and 10-rings: C···O ca. 3.318 ~ 3.992 A.

The crystal structure of the new double CuII complex salt, [Cu(L)(H2O)2][Cu(L)]Br4·2H2O (L = 3,14-diethyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane, C22H44N4) has been determined using synchrotron radiation. The asymmetric unit contains one half of a [Cu(L)(H2O)2]2+ cation, one half of a [Cu(L)]2+ cation (both completed by crystallographic inversion symmetry), two bromide anions and one water solvent molecule. The CuII atom in the first complex exists in a tetragonally distorted octahedral environment with the four N atoms of the macrocyclic ligand in equatorial and two aqua ligands in axial positions, whereas the CuII atom in the second complex exists in a square-planar environment defined by the four nitrogen atoms of the macrocyclic ligand. The two macrocyclic rings adopt the most stable trans-III configuration with normal Cu—N bond lengths from 2.016 (3) to 2.055 (3) Å and an axial Cu—O bond length of 2.658 (4) Å. The crystal structure is stabilized by intermolecular hydrogen bonds involving the macrocycle N—H or C—H groups and the O—H groups of water molecules as donor groups, and the O atoms of water molecules and bromide anions as acceptor groups, giving rise to a one-dimensional network extending parallel to [100].

The Cd4S6+ and Cd2S2+ clusters in the sodalite cavities were synthesized by reaction of the fully Cd2+-exchanged zeolite Y (Si/Al = 1.56) and 0.1 M Na2S(aq) solution at 294 K for 2 days. The single-crystal structure was determined at 100(1) K by synchrotron X-ray diffraction techniques in the cubic space group Fd $$\overline{3}$$ m. The structure was refined using all intensities to the final error index R1/wR2 = 0.048/0.156 (for Fo > 4σ(Fo)). Approximately 13 Cd2+ and 53 Na+ ions per unit cell were found at two and four crystallographically distinct positions, respectively: two site-Iʹ positions (in the sodalite cavities opposite double 6-rings (D6Rs)) are occupied by 5 and 7.5 Cd2+ ions, respectively, per unit cell. The 0.5 Cd2+ ions per unit cell are at site IIʹ in the sodalite cavity. The 2 Na+ ion is located at the center of the D6R (site I). The 15.5 Na+ ions per unit cell are located at site Iʹ. Site-II position is occupied by 31.5 Na+ ions per unit cell. The remaining 4 Na+ ions per unit cell are located at sites IIIʹ near triple 4-rings in the supercage. Finally, 0.5 and 1.5 S2− ions per unit cell, associated with Cd2+ ions, were found at the center of sodalite cavity and opposite 6-ring in the sodalite cavity, respectively. The 1 S2− ion at the center of the sodalite cavity is coordinated to 4 Cd2+ ions at site Iʹ to give a centered-tetrahedral cationic cluster, Cd4S6+, and the other S2− ion opposite 6-ring in the sodalite cavity bridges between two Cd2+ ions at site Iʹ to give a cationic cluster with a bent arrangement, Cd2S2+, in 6.3% and 18.8% of the sodalite cavities of zeolite Y (Si/Al = 1.56), respectively.

The structures of fully Zn2+-exchanged zeolite Y, |Zn37.5|[Si117Al75O384]-FAU (Si/Al = 1.56), evacuated at 523, 623, 723, 773, and 823 K, were determined at 100 K by single-crystal synchrotron X-ra...

The extraframework sodium sulfide cationic cluster, Na4S2+, has been introduced into zeolite Y (FAU, Si/Al = 1.56). A single crystal of |Na73(Na4S2+)1.0|[Si117Al75O384]-FAU was prepared by allowing aqueous 0.1 M Na2S solution to flow past a |Na75|[Si117Al75O384]-FAU crystal, and followed by vacuum dehydration at 723 K. Its structure was determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd $$\overline{3}$$ m. The structure was refined using all intensities to the final error index R1/wR2 = 0.044/0.125. About 77 Na+ ions per unit cell are found at the crystallographically distinct positions, six. One Na+ ion per unit cell is at the center of double 6-ring. Two site-I′ positions are occupied by 26.5 and 4 Na+ ions, respectively, per unit cell. Thirty-two Na+ ions per unit cell are found at site II, in the supercage opposite single 6-rings. The remaining 4.5 and 9 Na+ ions per unit cell occupy two sites III′ near triple 4-rings in the supercage. Finally, one sulfide ion per unit cell, associated with Na+ ions, is found at the center of sodalite cavity. The 4 Na+ ions at site I′ coordinate to a sulfide ion at the center of sodalite cavity to give tetrahedral cationic cluster, Na4S2+. In |Na73(Na4S2+)1.0|[Si117Al75O384]-FAU, tetrahedral Na4S2+ ions center about 12.5% of the sodalite cavities.

An Al13 e-Keggin cluster, AlO4Al12(OH)24(H2O)127+, is a predominant intermediate during the hydrolysis and polymerization of aluminum as well as a highly toxic substance to plants and fishes. However, no one could clearly explain why and how a cage-like Al13 e-Keggin cluster is formed even though it could be readily synthesized by the forced hydrolysis of Al3+. We found that the Al13 e-Keggin cluster was spontaneously formed not in monocrystalline octosilicate but in polycrystalline magadiite by the cation-exchange reaction with unhydrolyzed Al3+. Furthermore, the Al13 e-Keggin cluster was hardly detected in disaggregated magadiite crystals whose morphology was changed into monocrystalline crystals like octosilicate. Our findings prove that Al13 formation is necessary to relieve localized inhomogeneity and rationalize that Al13 is formed by the simultaneous co-assembly of four planar trimers and one octahedral monomer. In addition, the spontaneous formation of Al13 in heterogeneous systems could be a vital clue to its evaluation in soils and sediments.

To study the Sr2+-ion selectivity of zeolite Y (Si/Al = 1.56) in binary solution with different Sr2+ and K+ concentration during exchange, two single-crystals of fully dehydrated, Sr2+- and K+-exchanged zeolites Y were prepared by the flow method using a mixed ion-exchange solution whose Sr(NO3)2:KNO3 mol ratios were 1:1 (crystal 1) and 1:100 (crystal 2), respectively, with a total concentration of 0.05 M, followed by vacuum dehydration at 723 K. Their crystal structures were determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group $$ Fd\bar{3}m $$, respectively, and were refined to the final error indices R1/wR2 = 0.0429/0.1437 and 0.0356/0.1239 for crystals 1 and 2, respectively. In the structure of |Sr28K19|[Si117Al75O384]-FAU (crystal 1), 28 Sr2+ ions per unit cell occupy four different crystallographically distinct sites; 15, 2, 2, and 9 are at sites I, I′, II′, and II, respectively, whereas, the K+ ions occupy only one site: 19 are at site II. In the structure of |Sr17K41|[Si117Al75O384]-FAU (crystal 2), 17 Sr2+ ions per unit cell occupy three equipoints; 10.5, 2, and 4.5 are at sites I, I′, and II, respectively. The residual 41 K+ ions per unit cell are found at four different sites; 8, 24, 3, and 6 are at sites I′, II, III′a, and III′b, respectively. The degrees of ion exchange are 74.7 and 45.3% for crystals 1 and 2, respectively. This result shows that the degree of Sr2+ exchange decreased sharply by decreasing the initial Sr2+ concentration and increasing the initial K+ concentration in the given ion-exchange solution.

The structure of a cyclohexane sorption complex of partially dehydrated, fully Mn2+-exchanged zeolite Y has been determined at 100(1) K by single-crystal synchrotron X-ray diffraction techniques. It was refined using all intensities to the final error indices R1 = 0.052 and wR2 = 0.174. Cyclohexane molecules of symmetry 3 ¯ 2/m (D3d, chair form) occupy 5.7 of the 16 12-rings per unit cell. Each cyclohexane molecule is held in place by 18 weak hydrogen bonds between its six equatorial hydrogen atoms and all 12 oxygen atoms of its 12-ring: C⋯O ca. 3.85 A. Mn2+ ions are found at four crystallographic sites, I, I′, II′, and II. Each of the 17.7(2) Mn2+ ions per unit cell at site II (opposite 6-rings in the supercage) coordinates tetrahedrally to three framework oxygen atoms and a water molecule. The cyclohexane molecules interact neither with the Mn2+ ions nor with the water molecules.

Three single-crystals of fully dehydrated and partially Sr2+-exchanged zeolites Y (Si/Al = 1.56) were prepared by the flow method using mixed ion-exchange solutions. The Sr(NO3)2:NaNO3 molar ratios of the ion exchange solution were 1:100 (crystal 1), 1:250 (crystal 2), and 1:500 (crystal 3) with a total concentration of 0.05 M. The single-crystals were then vacuum dehydrated at 723 K and 1 × 10−4 Pa for 2 days. The structures of the crystals were determined by single-crystal synchrotron X-ray diffraction technique in the cubic space group $$Fd\bar {3}m$$ , at 100(1) K, and were then refined to the final error indices of R1/wR2 = 0.044/0.167, 0.051/0.175, and 0.069/0.219 for crystals 1, 2, and 3, respectively. The unit-cell formulas of crystals 1, 2, and 3 were |Sr17Na41|[Si117Al75O384]-FAU, |Sr13Na49|[Si117Al75O384]-FAU, and |Sr9Na57|[Si117Al75O384]-FAU, respectively. In all three crystals, the Sr2+ ions preferred to occupy site I in the D6Rs, with the remainder occupying site II. The Sr2+ ions are also located at site I′ in crystal 1. On the other hand, the Na+ ions are located at sites I′, II, and III′ in all crystals. With increasing the molar concentration of Na+ in the given exchange solution, the occupancies of the Sr2+ ions at sites I, I′, and II decreased, whereas the occupancies of the Na+ ions at sites I′, II, and III′ increased.

Four single crystals of fully dehydrated and partially Zn2+-exchanged zeolites Y (Si/Al = 1.56) were prepared by the static ion-exchange method using a mixed ion-exchange solution in which Zn(NO3)2:NaCl mole ratios were 1:1 (crystal 1), 1:25 (crystal 2), 1:50 (crystal 3), and 1:100 (crystal 4), respectively, with a total concentration of 0.05 M, and followed by vacuum dehydration at 673 K. Their single-crystal structures were determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd $$\bar {3}$$ m and refined to the final error indices R1/wR2 = 0.0459/0.1454, 0.0449/0.1283, 0.0427/0.1284, and 0.0486/0.1680, respectively. Their unit-cell formulas are |Zn25Na25|[Si117Al75O384]-FAU (crystal 1), |Zn19.5Na36|[Si117Al75O384]-FAU (crystal 2), |Zn19.5Na36|[Si117Al75O384]-FAU (crystal 3), and |Zn7Na61|[Si117Al75O384]-FAU (crystal 4), respectively. The degree of Zn2+ exchange decreases from 67 to 19% as the initial concentration of Zn2+ decrease and the initial concentration of Na+ increases in given ion-exchange solutions.

Seven single crystals of fully dehydrated Ni2+-exchanged zeolite Y (Si/Al = 1.56) were prepared via cation exchange of Na75-Y (|Na75|[Si117Al75O384]-FAU) by flowing 0.05 M aqueous solutions of Ni(NO3)2·6H2O (pH = 4.9, at 294 K) with various ion-exchange time. Their crystal structures were completely determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd–3m at 100(1) K. In all seven structures, Ni2+ ions occupy sites I, I’, II, and sometimes II’ or a second II, or both, preferring site I; residual Na+ ions in crystals 1 and 2 are found at site III and/or a second III. The level of Ni2+ exchange monotonically increased from 75.2% to 89.6% (from 28.2(2) to 33.6(8) Ni2+ per unit cell) with increasing exchange time until 18 h. The dealumination of zeolite frameworks was observed in the center of sodalite cavities after 24 h, suggesting that this process occurs during ion-exchanges, or subsequent dehydration. H+ ions are present in all seven crystals for a charge balan...

The single-crystals of Ca2+, K+-exchanged zeolite Y, and Ca2+, Rb+-exchanged zeolite Y were prepared by using flow method with mixed ion-exchange solution, whose Ca(NO3)2:KNO3 mole ratios were 1:1 (crystal 1) and 1:100 (crystal 2), and Ca(NO3)2:RbNO3 mole ratios were 1:1 (crystal 3) and 1:100 (crystal 4), respectively, with a total concentration of 0.05 M. They were fully dehydrated by vacuum dehydration at 723 K and 1 × 10−6 Torr for 2 days. Their crystals were determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group $$Fd \overline{3}$$ m, respectively, and were refined to the final error indices R 1/wR 2 = 0.057/0.196, 0.073/0.223, 0.055/0.188, and 0.049/0.175 for crystals 1, 2, 3, and 4, respectively. In the structure of crystal 1 (|Ca23K29|[Si117Al75O384]-FAU), 23 Ca2+ ions per unit cell occupy sites I, II′, and II; 29 K+ ions per unit cell are at sites II′, II, and III′. In the structure of crystal 2 (|Ca18.5K38|[Si117Al75O384]-FAU), 18.5 Ca2+ ions per unit cell occupy sites I, I′, and II; 38 K+ ions are at sites I′, II, and III′. In the structure of crystal 3 (|Ca27Rb21|[Si117Al75O384]-FAU), 27 Ca2+ ions per unit cell occupy sites I, II′, and II; 21 Rb+ ions per unit cell are at sites II′, II, and III. In the structure of crystal 4 (|Ca18Rb39|[Si117Al75O384]-FAU), 18 Ca2+ ions per unit cell occupy sites I and II; 39 Rb+ ions per unit cell are at sites I′, II′, II, III, and III′. In the four crystals, the Ca2+ ion which has much smaller size and higher charge than other cations such as K+ and Rb+ energetically preferred at site I and so the first to be filled on it. Unlike Ca2+ ion, no K+ and Rb+ ions are found at site I, which are clearly less favorable for K+ and Rb+ ions.

Centered-tetrahedral cationic clusters are frequently found in the sodalite cavities of zeolites and in the cavities of analogues of the mineral sodalite. Examples are Mn4S6+, Fe4Te6+, Zn4Se6+, Cd4S6+, Cu4Cl7+, Na4Cl3+, Na4I3+, Na54+, In57+, Ga57+, and Sn512+.

The structures of the subnanometer clusters of CdS that form in zeolite Y (FAU), prepared as follows, have been determined. A single crystal of Cd2+-exchanged zeolite Y was prepared by the exchange of Na75–Y (|Na75|[Si117Al75O384]–Y with aqueous Cd(NO3)2 at 294 K, followed by vacuum dehydration at 723 K (crystal 1). A second crystal, similarly prepared, was exposed to 6.7 × 104 Pa of dry H2S(g) for 6 h at 294 K and evacuated (crystal 2). Their structures were determined crystallographically using synchrotron X-rays and were refined using all data to the final error indices (calculated using only Fo > 4σ(Fo)) of R1/wR2 = 0.040/0.156 and 0.049/0.186, respectively. In crystal 1, Cd2+ ions primarily occupy sites I and II. In crystal 2, |Cd27(Cd4S6+)0.6(Cd(SHCd)46+)0.9H12|[Si117Al75O384]–FAU, tetrahedral Cd4S6+ ions center about 7.5% of the sodalite cavities and tetrahedral Cd(SHCd)46+ ions center about 11% of the supercages. In Cd(SHCd)46+, a Cd2+ ion at the center of a supercage bonds tetrahedrally to four S...

To study the tendency of Cs+ exchange into zeolite Y (Si/Al = 1.56) dependence on Cs+ and Na+ concentration of aqueous solution during exchange, two single-crystals of fully dehydrated, Cs+-and Na+-exchanged zeolites Y were prepared by the flow method using a mixed ion-exchange solution whose CsNO3:NaNO3 mol ratios were 1:1 (crystal 1) and 1:100 (crystal 2), respectively, with a total concentration of 0.1 M, followed by vacuum dehydration at 723 K. Their crystals were determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd $$\overline{ 3}$$ m, respectively, and were refined to the final error indices R 1/wR 2 = 0.084/0.248 and 0.088/0.274 for crystals 1 and 2, respectively. In the structure of |Cs40Na35|[Si117Al75O384]-FAU (crystal 1), 40 Cs+ ions per unit cell occupy five different equipoints; 3, 3, 14, 9, and 11 are at sites I, II′, II, IIIa and IIIb, respectively, whereas, the remaining 35 Na+ ions occupy three different sites: 9, 11, and 15 are at sites I, I′, and II, respectively. In the structure of |Cs21Na54|[Si117Al75O384]-FAU (crystal 2), 21 Cs + ions per unit cell occupy three equipoints; 4, 6, and 11 are at sites II, IIIa, and IIIb, respectively. The residual 54 Na+ ions per unit cell are found at three different sites; 6, 20 and 28 are at sites I, I′, and II, respectively. The degrees of ion exchange are 53 and 28 % for crystals 1and 2, respectively. This result shows that the degree of Cs+ exchange decreased sharply by decreasing the initial Cs+ concentration and increasing the initial Na+ concentration in given ion-exchange solution.

The structures of partially dehydrated and partially Co2+-exchanged zeolites X (Si/Al = 1.40) and Y (Si/Al = 1.70) were determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd $$\overline{3}$$ m and were refined to the final error indices R 1/wR 2 = 0.0773/0.2152 and 0.0683/0.2184, respectively. Their unit-cell formulas are |Co26.1Na21(H3O)7.1(H2O)14.2|[Si112Al80O384]-FAU (a = 24.7892(2) A) and |Co29.3Na6.2(H3O)5.9(H2O)5.9|[Si121Al71O384]-FAU (a = 24.7346(2) A), respectively. In the structure of Co2+-X, Co2+ ions occupy sites I′, II′, II, and III′; the Na+ ions are at sites I′ and II. In the structure of Co2+-Y, Co2+ ions occupy sites I′, II′, II, and III′; the Na+ ions are at site I′. Because of the low pH of the Co2+ exchange solution, some H3O+ ions are observed in both structures. The number of Co2+ ions in zeolite was increased slightly as Si/Al ratio increased, and Na+ content and the unit cell constant of the framework were decreased.

To study the tendency of Zn2+ exchange into zeolite A, two single-crystals of fully dehydrated Zn2+-and Na+-exchanged zeolite A were prepared by the static ion-exchange method using a mixed ion-exchange solution whose Zn(NO3)2:NaNO3 mol ratios were 1:4 (crystal 1) and 3:2 (crystal 2), respectively, with a total concentration of 0.05 M, followed by vacuum dehydration at 623 K. Their single-crystal structures and chemical compositions were determined by single-crystal synchrotron X-ray diffraction techniques and electron probe microanalysis. Their structures were refined to the final error indices R 1/wR 2 = 0.0678/0.2154 and 0.0619/0.1938 for crystals 1 and 2, respectively. In both structures, the 4 Zn2+ ions are located in sodalite unit, whereas, the remaining 4 Na+ ions are located in large cavity. Unit-cell formula of two single-crystal structures is approximately |Zn4Na4|[Si12Al12O48]-LTA. This work shows that the degree of Zn2+ exchange by increasing the initial Zn2+ concentration and decreasing the initial Na+ concentration in given ion-exchange solution does not differ significantly.

Three single crystals of fully dehydrated, largely Co2+-exchanged zeolites X and Y were prepared by the exchange of Na80-X (|Na80|[Si112Al80O384]-FAU, Si/Al = 1.40), Na75-Y (|Na75|[Si117Al75O384]-FAU, Si/Al = 1.56), and Na71-Y (|Na71|[Si121Al71O384]-FAU, Si/Al = 1.70) with aqueous streams 0.05 M in Co(NO3)2, pH = 5.1, at 294 K for 3 days. This was followed by vacuum dehydration at 673 K. Their crystal structures were determined by synchrotron X-ray diffraction techniques in the cubic space group Fd $$\overline{3}$$ m at 100(1) K. In all three crystals Co2+ ions occupy the 6-ring sites I, I’, and II; Na+ ions occupy sites II’ and II. The number of Co2+ ions exchanging into the zeolite was about 30 per unit cell for all three crystals. The number of residual Na+ ions, however, decreased sharply as Si/Al ratio increased, and the number of H+ ions co-exchanging into the zeolite decreased nearly to zero. Some dealumination of the zeolite framework was seen in the first crystal (initial Si/Al = 1.40).

Single-crystal of fully dehydrated, Mg2+-exchanged zeolite Y, |Mg34.5Na6|[Si117Al75O384]-FAU (Si/Al = 1.56), was successfully prepared from undried methanol solution (water concentration 0.02 M). A crystal of Na-Y was treated with 0.05 M MgCl2 ·6H2O in the solvent at 333 K, followed by vacuum dehydration at 723 K and 1 × 10−6 Torr for 2 days. Its structure was determined by single-crystal synchrotron X-ray diffraction techniques, in the cubic space group $$Fd\overline{3} m$$ at 100 K. It was refined to the final error indices R 1/wR 2 = 0.0587/0.2210 with 1,294 reflections for which F o > 4σ(F o). In the structure of |Mg34.5Na6|[Si117Al75O384]-FAU, 34.5 Mg2+ ions per unit cell are found at four different crystallographic sites: 15 per unit cell are located at site I at the center of the hexagonal prism [Mg–O = 2.216(2) A], two are at site I’ in the sodalite cavity near the hexagonal prism [Mg–O = 2.20(3) A], only one is located at site II’ in the sodalite cavity [Mg–O = 2.197(23) A], and the remaining 16.5 are at site II near single 6-oxygen rings in the supercage [Mg–O = 2.103(3) A]. The residual 6 Na+ ions per unit cell are found at site II [Na–O = 2.218(7) A]. No water molecules are found in this structure.

A single crystal of excessively Ni2+-exchanged zeolite Y (FAU, Si/Al = 1.70) was prepared by exchange of |Na71|[Si121Al71O384]-FAU with an aqueous stream 0.05 M Ni(NO3)2 at 293 K and pH 4.9, followed by vacuum evacuation at room temperature and 1.3 × 10−4 Pa. Its crystal structure was determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd $$\overline{ 3}$$ m and was refined to the final error indices R 1/wR 2 = 0.0554/0.1557 for |Ni24.7(NiOH)12.1(Ni2O(OH)2)4.8(Ni4AlO4)1.7Na17.0(H3O)6.9|[Si117Al75O384]-FAU. Crystal has about 53 Ni2+ ions per unit cell, indicating the uptake of excess Ni(OH)2, perhaps as NiOH+ ions. Some dealumination of the framework occurred during Ni2+ exchange. In this structure, Ni2+ ions occupy sites I, I′, II′, II, and III′. The residual Na+ ions are found at sites II′ and II. Due to the low pH of the Ni2+ exchange solution, some H3O+ ions are observed. Nonframework oxygen atoms as oxide and hydroxide ions and orthoaluminate coordinate to some of Ni2+ ions to give NiOH+, Ni2O(OH)2, and Ni4AlO4 3+ groups.

K for 6 h, 12 h, and 18 h, respectively, followed by vacuum dehydration at 673 K. Their single-crystal structures were determined by synchrotron X-ray diffraction techniques in the cubic space group Fd3m at 100(1) K. They were refined to the final error indices R1/wR2 = 0.0437/0.1165, 0.0450/0.1228, and 0.0469/0.1278, respectively. Their unit-cell formulas are |Co29.1Na11.8H5.0|[Si117Al75O384]-FAU, |Co29.8Na11.0H4.4|[Si117Al75O384]-FAU, and |Co30.3Na9.5H4.9|[Si117Al75O384]-FAU, respectively. In all three crystals, Co 2+ ions occupy sites I, I' and II; Na + ions are also at site II. The tendency of Co 2+ exchange slightly increases with increasing contact time as Na + content and the unit cell constant of the zeolite framework decrease.

The single-crystal structure of fully dehydrated zeolite Y (FAU, Si/Al = 1.56) Mn2+ exchanged by flow method, |Mn31(Mn4AlO4)H10|[Si117Al75O384]-FAU, was determined by single-crystal synchrotron X-ray diffraction techniques. It was refined to the final error indices R 1/wR 2 = 0.0692/0.2026 in the cubic space group $$Fd\overline{3}m$$ at 100(1) K. In this structure, 35 Mn2+ ions per unit cell are found at four crystallographic positions: 11 and 7 are at the centers of the double 6-rings (site I) and in the sodalite cavity opposite the double 6-rings (site I′), respectively. The remaining 4 and 13 are found at sites II′ (near 6-ring in the sodalite cavity) and II (near 6-ring in the supercage), respectively. Some dealumination of the zeolite framework occurred during Mn2+ exchange. The four non-framework oxygen atoms coordinate to a aluminate ion at the center of sodalite cavity (site U) and 4 Mn2+ ions at site II′ to give Mn4AlO4 3+. The 10 H+ ions are required for charge balance in fully dehydrated Mn2+-Y. The single-crystal structure of fully dehydrated, partially dealuminated, and Mn2+-exchanged zeolite Y (FAU (Si/Al = 1.56) was determined by single-crystal synchrotron X-ray diffraction techniques.

Two single-crystals of fully dehydrated, partially Li+-exchanged zeolites X (Si/Al = 1.09, crystal 1) and Y (Si/Al = 1.56, crystal 2), were prepared by flow method using 0.1 M LiNO₃ at 393 K for 48 h, respectively, followed by vacuum dehydration at 673 K and 1 × 10 -6 Torr. Their structures were determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3and Fd3m at 100(1) K for crystals 1 and 2, respectively. They were refined to the final error indices R₁/wR₂ = 0.065/0.211 and 0.043/0.169 for crystals 1 and 2, respectively. In crystal 1, about 53 Li+ ions per unit cell are found at three distinct positions; 9 at site I’, 19 at another site I’, and the remaining 25 at site II. The residual 25 Na+ ions occupy three equipoints; 2 are at site I, 7 at site II, and 16 at site III’. In crystal 2, about 31 Li+ ions per unit cell occupy sites I’ and II with occupancies at 22 and 9, respectively; 3, 4, 23, and 3 Na+ ions are found at sites I, I’, II, and III’, respectively. The extent of Li+ ion exchange into zeolite X (crystal 1) is higher than that of zeolite Y (crystal 2), ca. 73% and 56% in crystals 1 and 2, respectively.

Complete exchange of Li+ into zeolite Na-X, |Na92|[Si100Al92O384]-FAU, was accomplished using undried methanol solvent (water concentration 0.02 M). A crystal of Na-X was treated with 0.1 M LiNO3 in the solvent at 333 K, followed by vacuum dehydration at 673 K and 1 × 10−6 Torr for 2 days. Its structure was determined by single-crystal synchrotron X-ray diffraction techniques, in the cubic space group $$ Fd\overline{3} $$ at 100(1) K. The 92 Li+ ions per unit cell are found at three different crystallographic sites. The 32 Li+ ions occupy at site I’ in the sodalite cavity: these Li+ ions are recessed 0.28 A into the sodalite cavity from their 3-oxygens plane [Li–O = 1.903(5) A and O–Li–O = 117.8(3)°]. Another 32 Li+ ions are found at site II in the supercage, being recessed 0.26 A into the supercage [Li–O = 1.968(5) A and O–Li–O = 118.3(3)°]. The remaining 28 Li+ ions are located at site III in the supercage [Li–O = 2.00(8) A].

A single crystal of fully dehydrated, largely Rb+-exchanged zeolite Y, |Rb59Na16|[Si117Al75O384]-FAU (Si/Al = 1.56), prepared by exchange of |Na75|[Si117Al75O384]-FAU with an aqueous stream 0.1 M RbOH at 293 K, followed by vacuum dehydration at 673 K and at 1 × 10−6 Torr. Its crystal structure was determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd $$\overline{3}$$ m and was refined to the final error indices R 1/wR 2 = 0.0392/0.1189. In the structure of |Rb59Na16|[Si117Al75O384]-FAU, about 59 Rb+ ions per unit cell occupy five different equipoints; 9 are at site I, 9 at site I′, 3 at site II′, 28 at site II, and the remaining 10 are at site III, preferring II. The residual 16 Na+ ions occupy three equipoints; 5 are at site I′, 3 at site II, and 8 are at site III. These Rb+ and Na+ ions filled full from hexagonal prism to supercage. This work achieved the highest level of Rb+-exchange (ca. 81 %) in the single-crystal structure of zeolite Y by conventional method using aqueous solution at room temperature. The distributions of Rb+ and Na+ ions in this structure, as compared to fully dehydrated partially Rb+-exchanged zeolite X, are different due to local Si/Al order among the T atoms. The single-crystal structure of fully dehydrated, largely Rb+-exchanged zeolite Y, |Rb59Na16|[Si117Al75O384]-FAU (Si/Al = 1.56), was determined by single-crystal synchrotron X-ray diffraction techniques.

A single crystal of excessively Pb2+-exchanged zeolite Y (|Pb 15.5 2+ (Pb4O4(Pb 16/19 2+ Pb 3/19 4+ )4)4.75|[Si117Al75O384]-FAU) was prepared by exchange of Na–Y (|Na75|[Si117Al75O384]-FAU, Si/Al = 1.56) with an aqueous stream 0.05 M Pb(C2H3O2)2 at 294 K, followed by vacuum dehydration at 1 × 10−6 Torr and 693 K. Its structure was determined at 100 K, by X-ray diffraction techniques in the cubic space group Fd $$ \overline{3} $$ m and was refined to the final error indices R 1/wR 2 = 0.0639/0.1323. About 53.5 Pbn+ ions per unit cell occupy three different equipoints; 26 are at site I′, 19 are at site II, and the remaining 8.5 are at another site II. Three Pb4+ ions at some of the positions must have higher oxidation states due to elevated dehydration temperature; Pb(IIa) is supposed to coexist with Pb2+ and Pb4+ ions assuming the charge balance of the zeolite framework. A distorted Pb4O4 cube, alternating Pb2+ at Pb(I′) and O2− at O(5), coordinates with four Pb2+ and/or Pb4+ ions through its oxygen atoms to give a [Pb 4 2+ O 4 2− (Pb 16/19 2+ Pb 3/19 4+ )4]176/19+ cluster in 4.75 of eight sodalite cavities per unit cell in zeolite Y.

The crystal structure of partially dehydrated fully Zn 2+ -exchanged zeolite Y was determined by X-ray diffraction techniques in the cubic space group Fd3m at 294(1) K and refined to the final error indices R₁/wR₂ = 0.035/0.119 for |Zn 35.5 (H₂O) 13 |[Si 121 Al 71 O 384 ]-FAU. About 35.5 Zn 2+ ions per unit cell are found at six distinct positions; sites I, I’, a second I’, II’, II, and a second II. In sodalite cavities, the 11 water molecules coordinate to Zn(I’b) and/or Zn(II’) ions; each of two H₂O bonds to a Zn(IIb) in supercages. Two different Zn 2+ positions near 6-oxygen ring are due to their Si-Al ordering in tetrahedral site by Si/Al ratio leading to the different kinds of 6-rings.

The structures of fully and partially dehydrated zeolite Y Co2+ exchanged at pH 5.1, were determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd 3 ¯ m and were refined to the final error indices R1/wR2 = 0.046/0.120 and 0.062/0.191, respectively. Two crystals were used; their unit-cell formulas are approximately |Co31Na8H5|[Si117Al75O384]-FAU and |Co30.5Na6(H3O)4(H2O)4H4|[Si117Al75O384]-FAU, respectively. In the fully dehydrated structure, Co2+ ions occupy sites I, I′ and II; the Na+ ions are also at site II. In the partially dehydrated structure, Co2+ occupies sites I′, II′, II, and III′; the Na+ ions are at site I′. Some H3O+ ions are seen in the partially dehydrated structure, and H+ ions must be present in both crystals for charge balance. Upon dehydration Co2+ ions move into the hexagonal prisms and Na+ ions move from sodalite cavities to supercages.

The single-crystal structure of fully dehydrated partially -exchanged zeolite Y, -FAU, was determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group at 100(1) K. Ion exchange was accomplished by flowing stream of 0.1 M aqueous for 2 days at 293 K, followed by vacuum dehydration at 623 K and Torr for 2 days. The structure was refined using all intensities to the final error indices (using only the 801 reflections with ( > ) . The 50 ions per unit cell are found at three different crystallographic sites. The 19 ions occupy at site I' in the sodalite cavity: the ions are recessed 0.30 into the sodalite cavity from their 3-oxygens plane (Li-O = 1.926(5) and ). The 20 ions are found at site II in the supercage, being recessed 0.23 into the supercage (Li-O = 2.038(5) and ). Site III' positions are occupied by 11 ions: these ions bind strongly to one oxygen atom (Li-O = 2.00(8) ). About 25 ions per unit cell are found at four different crystallographic sites: 4 ions are at site I, 5 at site I', 12 at site II, and the remaining 4 at site III'.

Two single crystals of fully dehydrated partially -exchanged zeolite X were prepared by the exchange of Na-X, (Si/Al = 1.09), with using aqueous 0.1 M at 293 (crystal 1) and 333 K(crystal 2), followed by vacuum dehydration at 623 K and Torr for 2 days. Their structures were determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group at 100(1) K. Their structures were refined using all intensities to the final error indices (using the 1281 and 883 reflections for which ( > ) = 0.075/0.244 and 0.074/0.223 for crystals 1 and 2, respectively. Their compositions are seen to be -FAU and -FAU, respectively. In crystal 1, 17 ions per unit cell are at site I', 15 another site I', 30 at site II, and the remaining 16 at site III; 2 ions are at site II and the remaining 4 at site III'. In crystal 2, 32 and 30 ions per unit cell fill sites I' and II, respectively, and the remaining 25 at site III'; 2 and 3 ions are found at sites II and III', respectively. The extent of exchange increases slightly with increasing ion exchange temperature from 93% to 95%.

The crystal structures of zeolite Y Ni2+ exchanged at pH 4.9, fully dehydrated (|Ni29.7(Ni4AlO4)1.1H12.3|[Si117Al75O384]-FAU) and partially dehydrated (|Ni14.1(NiOH2)16.4(Ni4AlO4)1.1(H3O)9.6|[Si117Al75O384]-FAU), were determined by single-crystal synchrotron X-ray diffraction techniques. They were refined to the final error indices R1/wR2 = 0.044/0.115 and 0.052/0.153, respectively, in the cubic space group Fd3m. Some dealumination of the zeolite framework occurred during Ni2+ exchange. In the fully dehydrated structure, Ni2+ ions primarily occupy sites I and II, with additional Ni2+ ions at site I′, site II′, and a second site II. In the partially dehydrated structure, Ni2+ occupies six different sites: I, I′, a second site I′, II, a second site II, and III′. Because of the low pH of the Ni2+ exchange solution, some H3O+ ions are observed in partially dehydrated Ni2+–Y; correspondingly, some H+ ions are required for charge balance in fully dehydrated Ni2+–Y. The nonframework oxygen atoms in water and or...

Two single crystals of fully dehydrated, mostly Cu2+-exchanged zeolite Y were prepared by the exchange of Na75–Y (|Na75|[Si117Al75O384]-FAU, Si/Al = 1.56) with an aqueous stream 0.05 M in Cu(NO3)2, pH = 4.2, at 294 K for 18 and 24 h, respectively, followed by vacuum dehydration at 673 K and 1 × 10–6 Torr. Their crystal structures were determined by synchrotron X-ray diffraction techniques in the cubic space group Fd3m at 100(1) K and were refined to the final error indices R1/wR2 = 0.050/0.165 and 0.050/0.163, respectively, for |Cu32.6Na5.3H4.5|[Si117Al75O384]-FAU and |Cu33.0Na3.9H5.1|[Si117Al75O384]-FAU, respectively. Cu2+ ions occupy the 6-ring sites I′ and II, preferring I′; Na+ ions also occupy sites I′ and II; neither site is filled. All Cu2+ ions in these structures coordinate not only to three trigonally arranged oxygen atoms of their 6-rings, but also to a fourth oxygen atom of those 6-rings to achieve planar, severely distorted square, 4-coordination. This result is in agreement with DFT calcula...

A single crystal of zeolite Y, 0.30 mm in diameter, fully exchanged with Mn2+ and fully dehydrated, was treated with zeolitically dry toluene at 298(1) K and a pressure of 1.3 × 10–4 Pa and evacuated for 2 h. The crystal structure, |Mn37.5(C7H8)17|[Si117Al75O384]-FAU (a = 24.5923(1) A), was determined by synchrotron X-ray diffraction techniques in the space group Fd3m at 100(1) K and was refined to the final error indices R1 = 0.083 and wR2= 0.230. Mn2+ ions occupy sites I, I′, II′, and II with occupancies at 14, 4, 2.5, and 17, respectively. The 17 Mn2+ ions per unit cell at site II each coordinates to three framework oxygen atoms at 2.213(6) A and extends into the supercage by 0.63 A from their plane. Each of these Mn2+ ions also interacts facially with a toluene molecule (Mn2+–toluene center = 2.62 A). The methyl group is somewhat off the plane of the ring, indicative of a net repulsive interaction with the zeolite framework.

The single-crystal structure of partially dehydrated partially -exchanged zeolite Y, []-FAU per unit cell, = 25.5060(1) , dehydrated at 723 K and Pa, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd m at 100(1) K. The structure was refined using all intensities to the final error indices (using only the 561 reflections with > ) = 0.0377 (Based on F) and = 0.1032 (Based on ). About 30.5 ions per unit cell are found at four different crystallographic sites. The 14 ions occupy at site I at the center of double 6-ring (Mg-O = 2.231(3) , O-Mg-O = and ). Four ions are found at site I' in the sodalite cavity; the ions are recessed 1.22 into the sodalite cavity from their 3-oxygen plane (Mg-O = 2.20(3) and O-Mg-O = ). Site II' positions (opposite single 6-rings in the sodalite cage) are occupied by 2.5 ions, each coordinated to an molecule (Mg-O = 2.187(20) and O-Mg-O = ). The 10 ions are nearly three-quarters filled at site II in the supercage, being recessed 0.12 into the supercage (Mg-O = 2.123(4) A and O-Mg-O = ). About 14 ions per unit cell are found at one crystallographic site; the ions are located at site II in the supercage (Na-O = 2.234(7) and O-Mg-O = ).

The single-crystal structure of a mesitylene sorption complex of fully dehydrated fully Mn 2+ -exchanged zeolite Y, |Mn 37.5 (C 9 H 12 ) 15 |[Si 117 Al 75 O 384 ]-FAU, has been determined by single-crystal synchrotron X-ray diffraction techniques in the space group Fd 3 ¯ m at 100(1) K. A fully dehydrated fully Mn 2+ -exchanged zeolite Y crystal (|Mn 37.5 |[Si 117 Al 75 O 384 ]-FAU, Si/Al = 1.56) was treated with zeolitically dried mesitylene at 297(1) K for 3 days. The structure of the resulting dark-brown crystal was refined using all intensities to the final error indices (using the 570 reflections for which F o > 4 σ ( F o )) of R 1 = 0.063 and wR 2 = 0.151. In this structure, 37.5 Mn 2+ ions per unit cell are found at four crystallographic positions: 14.5 are at the centers of the double 6-rings (site I) and three are in the sodalite cavity opposite the double 6-rings (site I′). The remaining 20 are found at two nonequivalent sites II, near 6-rings in the supercage with occupancies of 5 and 15, respectively. Fifteen mesitylene molecules per unit cell lie on threefold axes where these interact facially with the 15 Mn 2+ ions at the first site II (Mn 2+ -mesitylene center = ca. 2.65 A). Of the three hydrogen atoms per methyl group, one is calculated to be 2.14 A from a framework oxygen and another one is 2.48 A from another framework oxygen atom. Mesitylene appears to be slightly distorted in the same way.

Large colorless single crystals of analcime with diameters up to 0.20 mm have been synthesized from gels with the composition of : : 8.02NaOH : : 5.00TEA. The fully -exchanged analcime have been prepared with aqueous 0.1 M NaCl (pH adjusted from 6 to 11 by dropwise addition of NaOH). The single-crystal structure of hydrated -ANA per unit cell, a=13.703(3) , has been determined by single-crystal X-ray diffraction technique in the orthorhombic space group Ibca at 294 K. The structure was refined using all intenties to the final error indices (using only the 1,446 reflections for which > = 0.054/0.143. About 15 ions are located at three nonequivalent positions and octahedrally coordinated. The chemical composition is . The Si/Al ratio of synthetic analcime is 2.19 determined by the occupations of cations, 14.79, in the single-crystal determination work.

Three single crystals of zeolite Y, each 0.3 mm in diameter, fully exchanged with Mn2+ and fully dehydrated, were treated with zeolitically dry o-, m-, and p-xylene, respectively, at 297(1) K, followed by evacuation. Their crystal structures were determined by synchrotron X-ray diffraction techniques in the space group Fd3m at 100(1) K and were refined using all intensities to the final error indices R1/wR2 = 0.056/0.160, 0.080/0.217, and 0.066/0.177, respectively. In each structure, Mn2+ ions occupy sites I, I′, II′, and II. In each structure, 18 Mn2+ ions per unit cell at site II (on the 3-fold axes of the single 6-rings) each extend 0.63, 0.68, and 0.67 A into the supercage to coordinate facially to an o-, m-, and p-xylene molecule, respectively. The corresponding distances from Mn2+ to the centers of the xylene rings are 2.67, 2.65, and 2.63 A. The methyl groups are all somewhat off the planes of their rings, indicative of a net repulsive interaction with oxygen atoms of the zeolite framework. The h...

The single-crystal structure of a benzene sorption complex of fully dehydrated fully Mn2+-exchanged zeolite Y, |Mn37.5(C6H6)24|[Si117Al75O384]-FAU, has been determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd $$ \overline{3} $$ m at 100(1) K. A fully dehydrated and fully Mn2+-exchanged zeolite Y (|Mn37.5|[Si117Al75O384]-FAU, Si/Al = 1.56) was treated with zeolitically dried benzene at 297(1) K for 3 days. The structure was refined using all intensities to the final error indices (using the 544 reflections for which F o > 4σ(F o)) R 1 = 0.050 (based on F) and wR 2 = 0.147 (based on F 2). In this structure, Mn2+ ions occupy four crystallographic sites: 13.5 Mn2+ ions are at the centers of the double 6-rings; 4 Mn2+ ions are in the sodalite cavity opposite to the double 6-rings; the remaining 20 Mn2+ ions are found at two non-equivalent threefold axes in the sodalite cavity and supercage with occupancies of 2 and 18, respectively. The 24 benzene molecules are found at two distinct positions within the supercages. Eighteen benzene molecules are found on the threefold axes in the supercages where each interacts facially with one of site-II Mn2+ ions (Mn2+-benzene center = ca. 2.53 A). The remaining six benzene molecules lie on the planes of the 12-rings where each is stabilized by multiple weak electrostatic and van der Waals interactions with framework oxygens.

Single crystals of zeolite Y, |Na75|[Si117Al75O384]-FAU, were Sr2+ ion exchanged and fully dehydrated to generate |Sr37.5|[Si117Al75O384]-FAU (crystal 1) and next, benzene adsorbed to generate |Sr37.5(C6H6)33(H2O)15|[Si117Al75O384]-FAU (crystal 2, partially dehydrated). Crystal 1 was prepared by ion exchange in a flowing stream of aqueous 0.05 M Sr(ClO4)2 for 3 days followed by dehydration at 673 K and 1 × 10−6 Torr for 2 days. To prepare the benzene sorption complex (crystal 2), another dehydrated |Sr37.5|[Si117Al75O384]-FAU crystal was exposed to 50 Torr of benzene for 3 days at 294 K followed by evacuation for 30 min. at this temperature and 5 × 10−5 Torr. Their structures were determined crystallographically at 100(1) K using synchrotron X-radiation in the cubic space group Fd $$ \bar{3} $$ m. They were refined to the final error indices R 1/wR 2 = 0.051/0.125 and 0.057/0.154 using 598 and 590 reflections with F o > 4σ(F o) for crystals 1 and 2, respectively. In crystal 1, about 37.5 Sr2+ ions per unit cell are found at an unusually large number of crystallographically distinct positions, six. Eight Sr2+ ions per unit cell are at the centers of the double 6-rings (D6Rs, site I). Five additional Sr2+ ions are near site I. The site-I’ positions (in the sodalite cavities opposite D6Rs) are occupied by 2.5 Sr2+ ions per unit cell. Two Sr2+ ions are located at site II’ in the sodalite cavity. The remaining twenty Sr2+ ions are found at two nonequivalent sites II (in the supercages) with occupancies of 9 and 11 ions per unit cell, respectively. Each of these Sr2+ ions coordinates to three framework oxygens. In this crystal, all sites are only sparsely occupied. In crystal 2, all Sr2+ ions are located at four crystallographic sites and 33 benzene molecules are found at two distinct sites within the supercages. One Sr2+ ion is at the center of the D6R. Fifteen Sr2+ ions are located at site I’. The remaining 21.5 Sr2+ ions are found at two nonequivalent sites II with occupancies of 19 and 2.5 ions per unit cell. Nineteen benzenes lie on threefold axes in the supercages, where they interact facially with the latter 19 site-II Sr2+ ions; occupancy = 19 molecules/32 sites. The remaining fourteen benzene molecules are found in 12-ring planes; occupancy = 14 molecules/16 sites. Each hydrogen of these 14 benzenes is ca. 2.9 A from six 12-ring oxygens.

The polyatomic tetrahydroxytetraindium(III) cations, In4(OH)48+, have been synthesized in 94% of the sodalite cavities of zeolite Y (FAU, Si/Al = 1.69). In−Y (|In57.8[In5]1.8|[Si121Al71O384]−FAU or In66.8−Y) was prepared by the oxidative solid state ion exchange (OSSIE) method from In0 and single crystals of Tl−Y under anhydrous conditions at 623 K. One of these was exposed to the atmosphere and then zeolitically dry oxygen, both at 623 K, to give In−Y[In4(OH)4] (|In7.6[In4(OH)4]7.5[In(OH)2]2.0|[Si121Al71O384]−FAU or In39.6(OH)34.0−Y). The structures of In−Y and In−Y[In4(OH)4] were determined by single crystal crystallography with synchrotron X-radiation. They were refined in the space group Fd3m (a = 24.863(1) and 24.518(1) A) with all unique data to the final error indices R1 = 0.050 and 0.057 for the 1110 and 1037 reflections for which Fo > 4σ(Fo), respectively. The In in In−Y is mostly In+; some In57+ clusters are present in sodalite cavities. Upon oxidation in the presence of water, 41% of the In ex...

Summary of experimental and crystallographic datafirst crystal second crystalCrystal cross-section (mm) 0.28 0.30Ion exchange T (K) 343 343Ion exchange for Mn 2+ (day, mL) 20, 200 20, 200Dehydration T (K) 723 723Crystal color pale brown pale brownData collection T (K) 294(1) 294(1)Space group Fd 3 m Fd 3 m X-ray source Pohang Light Source, Beamline 4A MXWWavelength (A) 0.76999 0.76999Unit cell constant, a (A) 24.659(1) 24.657(1)2θ range in data collection (deg) 60.59 60.73Total reflections harvested 63,895 64,045No. of unique reflections, m 893 894No. of reflections with F o > 4σ( F o ) 878 875No. of variables, s 49 49Data/parameter ratio, m / s 18.2 18.2Weighting parameters, a / b 0.060/161.8 0.061/189.3Initial error indices R 1 / wR 2 ( F o > 4σ( F o )) a 0.3857/0.8159 0.3817/0.8138Final error indices R 1 / wR 2 ( F o > 4σ( F o )) a 0.0508/0.1468 0.0510/0.1487 R 1 / wR 2 (all intensities) b 0.0513/0.1482 0.0516/0.1504Goodness-of-fit c 1.270 1.245 a R 1 = Σ| F o -| F c

Large colorless single crystals of FAU-type zeolites were synthesized from gels with the composition xSiO2 : 2.0NaAlO2 : 7.5NaOH : 454H2O : 5.0TEA, where x = 2.0–6.0. FAU-type zeolite with Si/Al = 1.26(4) was nearly pure and the maximum size of the single crystals was ca. 150 μm. In case of FAU-type zeolites with Si/Al = 1.54(5), the maximum size of single crystals was ca. 200 μm and the ratio of FAU/impurity was 0.07. The framework Si/Al ratio of the as-synthesized FAU-type zeolite tended to increase with the Si/Al ratio of gel composition. All of the large single crystals had good crystallinities for single-crystal X-ray diffraction, leading to enough numbers of significant reflections which have strong intensity. The structure of a single crystal of dehydrated zeolite Na-X (Si/Al = 1.41(4)) with composition |Na80|[Si112Al80O384]-FAU per unit cell was determined by X-ray diffraction methods in the cubic space group $$ Fd \bar{3} m; $$ a = 24.9434(6) A at 294 K. The structure was refined by using all intensities to the final error indices (using only the 771 reflections for which F o > 4σ(F o)), R 1 = 0.048 (based on F) and R 2 = 0.188 (based on F 2). In the crystallographic studies, the Si/Al ratio of the synthetic FAU-type zeolite is 1.41(4) which is quite consistent with the SEM–EDS analysis.

Single crystals of zeolite Y, [Na-75][Si117Al75O384]-FAU, with diameters up to 0.30 mm were grown from gels; Si/Al = 1.56. They were ion exchanged and fully dehydrated to generate [(NH4)(67)H5Na3] [Si117Al75O384]-FAU (crystal 1, partially deaminated), [H72Na3][Si117Al75O384]-FAU (crystal 2, fully deaminated at 473 K) and [Tl-75][Si117Al75O384]-FAU (crystal 3). Their structures were determined crystallographically at 294 K using synchrotron X-radiation in the cubic space group Fd (3) over barm. They were refined to the final error indices R-1/wR(2) = 0.037/0.126, 0.055/0.190, and 0.044/0.121 using 884, 723, and 851 reflections with F-o > 4 sigma(F-o) for crystals 1, 2, and 3, respectively. In crystal 1,67 NH4+ and 3 Na+ ions per unit cell are found at four different crystallographic sites. Six NH4+ ions were found at the centers of dou ble 6-rings (site I; N center dot center dot center dot O = 2.888(3) angstrom). Filling site I' are 32 NH4+ ions (N center dot center dot center dot O = 2.774(5) angstrom); each is recessed 1.59 angstrom into the sodalite cavity from the plane of the three oxygens to which it bonds. Filling site II in the supercages are 29 NH4+ and 3 Na+ ions, each of which extends 1.69 angstrom and 1.10 angstrom, respectively, into the supercage from its 3-oxygen plane (N center dot center dot center dot O = 2.818(5) angstrom, Na-O = 2.512(19) angstrom). The remaining 5 of the 72 NH4+ ions originally present per unit cell have apparently been deaminated by vacuum dehydration at 294 K. NH4+ ions simultaneously occupy sites I and I' as K+ ions did in [K-71][Si121Al71O384]-FAU, [K-92][Si100Al92O384]-FAU, and [K-96][Si96Al96O384]-FAU; the internitrogen distance is 3.36 angstrom. In crystal 2, three Na+ ions per unit cell are found at site I' (Na-O = 2.207(13) angstrom); no other cations were found so the deamination of NH4+ is complete at 473 K. In crystal 3, 30, 30, 9, 4, and 2 Tl+ ions were found at sites I', II, and three sites III' per unit cell, respectively. The total, 75, agrees with the results of EDX analysis to establish the framework composition (the Si/Al ratio) of these crystals. (C) 2009 Elsevier Inc. All rights reserved.

The single-crystal structure of |Zn35.5|[Si121Al71O384]-FAU per unit cell, a = 24.794(1), dehydrated at 673 K and 1 × 10−6 Torr, has been determined by single-crystal X-ray diffraction techniques in the space group $$ Fd\bar{3}m $$ at 294(1) K. The structure was refined using all intensities to the final error indices (using the 930 reflections for which F o > 4σ(F o)) R 1 = 0.0448 (based on F) and wR 2 = 0.1545 (based on F 2). About 35.5 Zn2+ ions per unit cell are found at an unusually large number of crystallographic distinct positions, six. The 0.5 Zn2+ ion per unit cell is located at the center of double 6-ring (D6R, site I; Zn(I)-O(3) = 2.642(3) A and O(3)-Zn(I)-O(3) = 81.23(12) and 98.77(12)°). Two different site-I′ positions (in the sodalite cavities opposite D6Rs) are occupied by 14 and 3 Zn2+ ions per unit cell, respectively; these Zn2+ ions are recessed 0.67 A and 1.02 A, respectively, into the sodalite cavities from their 3-oxygens plane (Zn(I′a)-O(3) = 2.094(3) A, Zn(I′b)-O(3) = 2.23(5) A, O(3)-Zn(I′a)-O(3) = 110.32(12)°, and O(3)-Zn(I′b)-O(3) = 100.9(30)°). Site-II′ positions (in the sodalite cavities opposite S6Rs) are occupied by 6 Zn2+ ions, each of which extends 0.63 A into the sodalite cavities from their 3-oxygens plane (Zn(II′)-O(2) = 2.164(3) A and O(2)-Zn(II′)-O(2) = 112.00(12)°). Twelve Zn2+ ions are found at two nonequivalent sites II (in the supercage) with occupancies of 7 and 5 ions, respectively; these Zn2+ ions are recessed 0.52 A and 0.96 A, respectively, into the supercage from their 3-oxygens plane (Zn(IIa)-O(2) = 2.138(12) A, Zn(IIb)-O(2) = 2.28(4) A, O(2)-Zn(IIa)-O(2) = 114.2(10)°, and O(2)-Zn(IIb)-O(2) = 103.7(25)°).

A single crystal of zeolite Y, |Na71|[Si121Al71O384]-FAU, was ion exchanged to generate |(NH4)38Na33|[Si121Al71O384]-FAU. This was then vacuum dehydrated at 673 K, and, without re-exposure to the atmosphere, its structure was determined crystallographically using synchrotron X-radiation in the cubic space group $$ Fd\bar{3} $$ m at 294 K. It was refined to the final error index R 1 = 0.0532 with 522 reflections for which F o > 4σ(F o). The composition (best integers) is determined to be |Na33H26(Al5O4)|[Si126Al66O384]-FAU which means full dehydration, deamination, and dealumination were achieved. The 33 Na+ ions per unit cell were found at two crystallographically distinct positions: nine at site I (in the centers of the D6Rs) and 24 at site II (in supercages opposite S6Rs). The 2.5 sodalite units contained a dimeric tetrahedral aluminate cation (Al–O = 1.40(8) and 1.60(8) A) at its center. Each [Al5O4]7+ cation coordinates to framework oxygen of D6Rs with tetrahedral manner. This work demonstrates that it is possible to obtain large amount of dealuminated species within the H-Y zeolite framework which should enhance the acidity of adjacent sites for higher catalytic activity.

Summary of experimental and crystallographic data.Crystal 1 Crystal 2Crystal cross-section (mm) 0.28 0.28Ion exchange T (K) 348 353Ion exchange for K + (day, mL) 10, 150 20, 300Ion exchange for NH 4+ (day, mL) 15, 225 15, 225Dehydration T (K) 473 573Crystal color pale yellow pale yellowData collection T (K) 294(1) 294(1)Space group Fd 3 m Fd 3 m X-ray sourcePohang Light Source, Beamline 4A MX WWavelength (A) 0.76999 0.76999Unit cell constant, a (A) 24.8610(29) 24.7960(29)2 θ range in data collection (deg) 60.55 60.70Total reflections harvested 89,784 126,418No. of unique reflections, m 908 756No. of reflections with F o > 4σ( F o ) 784 461No. of variables, s 39 38Data/parameter ratio, m / s 23.3 19.9Weighting parameters, a / b 0.075/81.1 0.090/143.4Initial error indices R 1 / wR 2 ( F o > 4σ( F o )) a 0.050/0.161 0.064/0.236Final error indices R 1 / wR 2 ( F o > 4σ( F o )) a 0.048/0.158 0.059/0.229 R 1 / wR 2 (all intensities) b 0.054/0.176 0.094/0.366Goodness-of-fit c 1.19 1.08

The single-crystal structure of |Ca 35.5 |[Si 121 Al 71 O 384 ]-FAU, Ca 35.5 Si 121 Al 71 O 384 per unit cell, a = 24.9020(10) A, dehydrated at 673 K and 2 × 10 -6 Torr, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd 3 m at 294 K. The large single crystals of zeolite Y (Si/Al = 1.70) were synthesized up to diameters of 200 μm and Ca 2+ -exchanged zeolite Y were prepared by ion exchange in a batch method of 0.05 M aqueous Ca(NO 3 ) 2 for 4 hrs at 294 K. The structure was refined using all intensities to the final error indices (using only the 971 reflections for which F o > 4σ(F o )) R 1 = 0.038 (based on F) and R 2 = 0.172 (based on F 2 ). About 35.5 Ca 2 + ions per unit cell are found at an unusually large number of crystallographically distinct positions, four. Nearly filling site I (at the centers of the double 6-rings), 14.5 octahedrally coordinated Ca 2+ ions (Ca-O = 2.4194(24) A and O-Ca-O = 87.00(8) and 93.00(8)°) are found per unit cell. One Ca 2+ ion per unit cell is located at site II' in the sodalite cavity and extends 0.50 A into the sodalite cavity from its 3-oxygen plane (Ca-O = 2.324(13) A and O-Ca-O = 115.5(10)°). The remaining twenty Ca 2+ ions are found at two nonequivalent sites II (in the supercages) with occupancies of 10 and 10 ions, respectively. Each of these Ca 2+ ions coordinates to three framework oxygens, either at 2.283(3) or 2.333(5) A, respectively, and extends either 0.24 or 0.54 A, respectively, into the supercage from the three oxygens to which it is bound. In this crystal, site I is the most populated; sites II' and II are only sparsely occupied. Ca 2+ appears to fit the octahedral site I best. No cations are found at sites III or III', which are clearly less favorable for Ca 2+ ions in dehydrated zeolite Y.

Crystal structure determinations on Cu(II) and Zn(II) complexes of tridentate and quadridentate azetidine derivatives show the ligands to be facultative for square-pyramidal and trigonal bipyramidal coordination geometries. While various contributions to the chirality of the complexes are possible, single diastereoisomeric forms (as enantiomer mixtures) have been isolated in all cases in the solid state. Analysis of lattice interactions indicates that H-bonding and aromatic stacking interactions are generally important.