A Germanosilicate Structure with 11×11×12‐Ring Channels Solved by Electron Crystallography

Zeolites have been widely used in industry owing to their ordered micropores and stable frameworks. The pore sizes and shapes are the key parameters that affect the selectivity and efficiency in their applications in catalysis, sorption, and separation. Zeolites with pores defined by 10 and 12 TO₄ tetrahedra are often used for various catalytic processes. To optimize the performance of zeolites, it is extremely desirable to fine‐tune the pore sizes/shapes. The first germanosilicate zeolite with a three‐dimensional 11×11×12‐ring channel system, PKU‐16 (PKU, Peking University) is presented. Nanosized PKU‐16 was structurally characterized by the new three‐dimensional rotation electron diffraction (RED) technique. PKU‐16 is structurally related to the zeolite β polymorph C (BEC, 12×12×12‐ring channels) by rotating half of the four‐rings in double mtw units.     

High‐Silica Zeolite SSZ‐61 with Dumbbell‐Shaped Extra‐Large‐Pore Channels

The synthesis of the high‐silica zeolite SSZ‐61 using a particularly bulky polycyclic structure‐directing agent and the subsequent elucidation of its unusual framework structure with extra‐large dumbbell‐shaped pore openings are described. By using information derived from a variety of X‐ray powder diffraction and electron microscopy techniques, the complex framework structure, with 20 Si atoms in the asymmetric unit, could be determined and the full structure refined. The Si atoms at the waist of the dumbbell are only three‐connected and are bonded to terminal O atoms pointing into the channel. Unlike the six previously reported extra‐large‐pore zeolites, SSZ‐61 contains no heteroatoms in the framework and can be calcined easily. This, coupled with the possibility of inserting a catalytically active center in the channel between the terminal O atoms in place of H⁺, afford SSZ‐61 intriguing potential for catalytic applications.     

Photomagnetic Switching of the Complex [Nd(dmf)4(H2O)3(μ‐CN)Fe(CN)5]⋅H2O Analyzed by Single‐Crystal X‐Ray Diffraction

X‐ray vision : Single‐crystal XRD experiments (see picture) reveal the excited‐state structure of the photomagnetic heterobimetallic title complex. The system shows a decrease in all the iron–ligand bond lengths, suggesting that photoexcitation involves a ligand‐to‐metal charge transfer or a change in the superexchange coupling between the metal centers.

     

Photomagnetic Switching of Heterometallic Complexes [M(dmf)4(H2O)3(μ‐CN)Fe(CN)5]⋅H2O (M=Nd,La, Gd,Y) Analyzed by Single‐Crystal X‐ray Diffraction and Ab Initio Theory

Single‐crystal X‐ray diffraction measurements have been carried out on [Nd(dmf)₄(H₂O)₃(μ‐CN)Fe(CN)₅]?H₂O ( 1 ; dmf=dimethylformamide), [Nd(dmf)₄(H₂O)₃(μ‐CN)Co(CN)₅]?H₂O ( 2 ), [La(dmf)₄(H₂O)₃(μ‐CN)Fe(CN)₅]?H₂O ( 3 ), [Gd(dmf)₄(H₂O)₃(μ‐CN)Fe(CN)₅]?H₂O ( 4 ), and [Y(dmf)₄(H₂O)₃(μ‐CN)Fe(CN)₅]?H₂O ( 5 ), at 15(2) K with and without UV illumination of the crystals. Significant changes in unit‐cell parameters were observed for all the iron‐containing complexes, whereas 2 showed no response to UV illumination. Photoexcited crystal structures have been determined for 1 , 3 , and 4 based on refinements of two‐conformer models, and excited‐state occupancies of 78.6(1), 84(6), and 86.6(7) % were reached, respectively. Significant bond‐length changes were observed for the Fe–ligand bonds (up to 0.19 Å), the cyano bonds (up to 0.09 Å), and the lanthanide–ligand bonds (up to 0.10 Å). Ab initio theoretical calculations were carried out for the experimental ground‐state geometry of 1 to understand the electronic structure changes upon UV illumination. The calculations suggest that UV illumination gives a charge transfer from the cyano groups on the iron atom to the lanthanide ion moiety, {Nd(dmf)₄(H₂O)₃}, with a distance of approximately 6 Å from the iron atom. The charge transfer is accompanied by a reorganization of the spin state on the {Fe(CN)₆} complex, and a change in geometry that produces a metastable charge‐transfer state with an increased number of unpaired electrons, thus accounting for the observed photomagnetic effect.     

New Structure Type among Octahydrated Rare‐Earth Sulfates, β‐Ce2(SO4)3·8H2O,and a new Ce2(SO4)3·4H2O Polymorph

Syntheses, crystal structures and thermal behavior of two new hydrated cerium(III) sulfates are reported, Ce₂(SO₄)₃·4H₂O ( I ) and β‐Ce₂(SO₄)₃·8H₂O ( II ), both forming three‐dimensional networks. Compound I crystallizes in the space group P2₁/n. There are two non‐equivalent cerium atoms in the structure of I , one nine‐ and one ten‐fold coordinated to oxygen atoms. The cerium polyhedra are edge sharing, forming helically propagating chains, held together by sulfate groups. The structure is compact, all the sulfate groups are edge‐sharing with cerium polyhedra and one third of the oxygen atoms, belonging to sulfate groups, are in the S–Oμ₃–Ce₂ bonding mode. Compound II constitutes a new structure type among the octahydrated rare‐earth sulfates which belongs to the space group Pn. Each cerium atom is in contact with nine oxygen atoms, these belong to four water molecules, three corner sharing and one edge sharing sulfate groups. The crystal structure is built up by layers of [Ce(H₂O)₄(SO₄)]_nⁿ⁺ held together by doubly edge sharing sulfate groups. The dehydration of II is a three step process, forming Ce₂(SO₄)₃·5H₂O, Ce₂(SO₄)₃·4H₂O and Ce₂(SO₄)₃, respectively. During the oxidative decomposition of the anhydrous form, Ce₂(SO₄)₃, into the final product CeO₂, small amount of CeO(SO₄) as an intermediate species was detected.     

Azocinoindole Synthesis by a Gold(I)‐Catalyzed Ring Expansion of 2‐Propargyl‐β‐Tetrahydrocarboline

A new methodology taking advantage of gold(I)‐catalyzed ring expansion has been developed to assemble tricyclic 1H‐azocino[5,4‐b]indoles from 2‐propargyl‐β‐tetrahydrocarbolines. The azocinoindoles were obtained in moderate to excellent yields; the structure of which was established by X‐ray crystallographic analysis. A mechanism involving regioselective intramolecular hydroarylation, [1,2]‐alkenyl migration and carbon–carbon bond‐fragmentation was proposed.     

Kristallstrukturen der iso‐Thiocyanatoberyllate (Ph4P)2[Be(NCS)4] und (Ph4P)4[{Be2(NCS)4(μ‐NCS)2}{Be2(NCS)6(μ‐H2N2C2S2)}]

Bis(tetraphenylphosphonium) hexachloridodiberyllate, (Ph₄P)₂[Be₂Cl₆], reacts with excess trimethylsilyl‐iso‐thiocyanate to give a mixture of colourless single crystals of (Ph₄P)₂[Be(NCS)₄] ( 1 ) and (Ph₄P)₄[{Be₂(NCS)₄(μ‐NCS)₂}{Be₂(NCS)₆(μ‐H₂N₂C₂S₂)}] ( 2 ), which can be separated by selection. Both complexes were characterized by X‐ray diffraction. Compound 1 can be prepared without by‐products by treatment of (Ph₄P)₂[BeCl₄] with excess Me₃SiNCS in dichloromethane solution. 1 : Space group I4₁/a, Z = 4, lattice dimensions at 100(2) K: a = b = 1091.2(1), c = 3937.1(3) pm, R₁ = 0.0474. The [Be(NCS)₄]^2– ion of 1 forms tetragonally distorted tetrahedral anions with Be–N distances of 168.4(2) pm and weak intermolecular S ··· S contacts along [100] and [010]. 2 ·4CH₂Cl₂: Space group P , Z = 1, lattice dimensions at 100(2) K: a = 919.5(1), b = 1248.3(1), c = 2707.0(2) pm, α = 101.61(1) °, β = 95.08(1) °, γ = 94.52(1) °, R₁ = 0.103. Compound 2 contains two different anionic complexes in the ratio 1:1. In {Be₂(NCS)₄(μ‐NCS)₂}^2–, the beryllium atoms are connected by (NCS)^– bridging groups forming centrosymmetric eight‐membered Be₂(NCS)₂ rings with distances Be–N of 168(1) pm and Be–S of 235.2(9) pm. The second anion {Be₂(NCS)₆(μ‐H₂N₂C₂S₂)}^2– consists of two {Be(NCS)₃}^– units, which are linked by the nitrogen atoms of the unique dimeric cyclo‐addition product of HNCS with Be–N distances of 179(1) pm.     

Environmentally Friendly γ‐MnO2 Hexagon‐Based Nanoarchitectures: Structural Understanding and Their Energy‐Saving Applications

Although about 200,000 metric tons of γ‐MnO₂ are used annually worldwide for industrial applications, the γ‐MnO₂ structure is still known to possess a highly ambiguous crystal lattice. To better understand the γ‐MnO₂ atomic structure, hexagon‐based nanoarchitectures were successfully synthesized and used to elucidate its internal structure for the present work. The structural analysis results, obtained from the hexagon‐based nanoarchitectures, clearly show the coexistence of akhtenskite (ε‐MnO₂), pyrolusite (β‐MnO₂), and ramsdellite in the so‐called γ‐MnO₂ phase and verified the heterogeneous phase assembly of the γ‐MnO₂ state, which violates the well‐known “De Wolff” model and derivative models, but partially accords with Heuer's results. Furthermore, heterogeneous γ‐MnO₂ assembly was found to be a metastable structure under hydrothermal conditions, and the individual components of the heterogeneous γ‐MnO₂ system have structural similarities and a high lattice matches with pyrolusite (β‐MnO₂). The as‐obtained γ‐MnO₂ nanoarchitectures are nontoxic and environmentally friendly, and the application of such nanoarchitectures as support matrices successfully mitigates the common problems for phase‐change materials of inorganic salts, such as phase separation and supercooling‐effects, thereby showing prospect in energy‐saving applications in future “smart‐house” systems.     

The Sodium (Iso)Cyanurates Nax[H3–xC3N3O3]·yH2O (x = 1–3, y = 0, 1): A Key‐Series for Understanding the Crystal Chemistry of Metal (Iso)Cyanurates

The (iso)cyanurates Na[H₂C₃N₃O₃] · H₂O, Na₂[HC₃N₃O₃] · H₂O, Na₂[HC₃N₃O₃], and Na₃[C₃N₃O₃] were synthesized phase pure from Na₂CO₃ · 10H₂O, NaOH, and cyanuric acid, respectively, in aqueous solution by carefully adjusting the crystallization conditions. The crystal structures of all compounds were determined by single‐crystal X‐ray diffraction {Na₂[HC₃N₃O₃] · H₂O: P1 , a = 3.51660(10) Å, b = 7.8300(3) Å, c = 11.3966(4) Å, α = 86.4400(10)°, β = 85.5350(10)°, γ = 85.0720(10)°, Z = 2, R₁ = 0.030, wR₂ = 0.078; Na₂[HC₃N₃O₃]: Pnma, a = 6.3409(6) Å, b = 12.2382(13) Å, c = 6.5919(7) Å, Z = 4, R₁ = 0.045, wR₂ = 0.079; Na₃[C₃N₃O₃]: R3 c, a = 11.7459(3) Å, c = 6.5286(3) Å, Z = 3, R₁ = 0.039, wR₂ = 0.066}. The structures show ribbons (Na[H₂C₃N₃O₃] · H₂O), dimers (Na₂[HC₃N₃O₃] · H₂O), chains (Na₂[HC₃N₃O₃]), or columns (Na₃[C₃N₃O₃]) of hydrogen‐bonded and parallel stacked (iso)cyanurate anions. These motifs are shown to be characteristic for certain degrees of protonation and hydration, and all (iso)cyanurate crystal structures found so far were classified accordingly. X‐ray powder patterns, thermogravimetry curves, IR and UV/Vis spectra were measured for all compounds.     

Synthesis and Investigation of 1,3‐Bis(5‐nitraminotetrazol‐1‐yl)propan‐2‐ol and its Salts

1,3‐Bis(5‐nitraminotetrazol‐1‐yl)propan‐2‐ol ( 5 ) was prepared by the reaction of 5‐aminotetrazole and 1,3‐dichloroisopropanol under basic conditions. Obtained 1,3‐bis(5‐aminotetrazol‐1‐yl)propan‐2‐ol ( 3 ) was nitrated with 100 % nitric acid. In this context in situ hydrolysis of the nitrate ester was studied. Metal and nitrogen‐rich salts of the neutral compound 5 were prepared and analyzed. Crystal structures of three salts and the sensitivities toward impact, friction and electrostatic discharge were determined as well. The performance values of the compounds were calculated using the EXPLO5 program. A detailed comparison of the different salts is also enclosed.     

A New Energetic Complex [Co(2,4,3‐tpt)2(H2O)2]·2NO3: Synthesis,Structure, and Catalytic Thermal Decomposition for Ammonium Perchlorate

The energetic complex, [Co(2,4,3‐tpt)₂(H₂O)₂] · 2NO₃ ( 1 ) [2,4,3‐tpt = 3‐(2‐pyridyl)‐ 4‐(4'‐pyridyl)‐5‐(3′‐pyridyl)‐1H‐1,2,4‐triazole], was synthesized and characterized by single‐crystal X‐ray diffraction, thermogravimetric analyses, elemental analysis, X‐ray powder diffraction, and IR spectroscopy. The title complex is a 0D motif with a unit of [Co(2,4,3‐tpt)₂(H₂O)₂]²⁺, whereas NO₃^– ions not only act as counter anions to balance the charge of the Co^II cations, but also provide hydrogen bond interactions, which make the 0D motif into a 1D chain. Furthermore, the thermal decomposition of ammonium perchlorate (AP) with complex 1 was explored by differential scanning calorimetry (DSC) over the temperature range from 50–500 °C. AP is completely decomposed in a shorter time in the presence of complex 1 , and the decomposition heat of the mixture is 2.143 kJ g^–1, significantly higher than pure AP. By Kissinger's method, the ratio of E_a/ln(A) is 11.87 for the mixture, which indicates that complex 1 shows good catalytic activity toward AP decomposition.     

A Crystalline Mesoporous Germanate with 48‐Ring Channels for CO2 Separation

One of the challenges in materials science has been to prepare crystalline inorganic compounds with mesopores. Although several design strategies have been developed to address the challenge, expansion of pore sizes in inorganic materials is more difficult compared to that for metal–organic frameworks. Herein, we designed a novel mesoporous germanate PKU‐17 with 3D 48×16×16‐ring channels by introducing two large building units (Ge₁₀ and Ge₇ clusters) into the same framework. The key for this design strategy is the selection of 2‐propanolamine (MIPA), which serves as the terminal species to promote the crystallization of Ge₇ clusters. Moreover, it is responsible for the coexistence of Ge₁₀ and Ge₇ clusters. To our knowledge, the discovery of PKU‐17 sets a new record in pore sizes among germanates. It is also the first germanate that exhibits a good selectivity toward CO₂ over N₂ and CH₄.     

High‐Pressure Synthesis and Structural Investigation of H3P8O8N9: A New Phosphorus(V) Oxonitride Imide with an Interrupted Framework Structure

The first crystalline phosphorus oxonitride imide H₃P₈O₈N₉ (=P₈O₈N₆(NH)₃) has been synthesized under high‐pressure and high‐temperature conditions. To this end, a new, highly reactive phosphorus oxonitride imide precursor compound was prepared and treated at 12 GPa and 750 °C by using a multianvil assembly. H₃P₈O₈N₉ was obtained as a colorless, microcrystalline solid. The crystal structure of H₃P₈O₈N₉ was solved ab initio by powder X‐ray diffraction analysis, applying the charge‐flipping algorithm, and refined by the Rietveld method (C2/c (no. 15), a=1352.11(7), b=479.83(3), c=1820.42(9) pm, β=96.955(4)°, Z=4). H₃P₈O₈N₉ exhibits a highly condensed (κ=0.47), 3D, but interrupted network that is composed of all‐side vertex‐sharing (Q⁴) and only threefold‐linking (Q³) P(O,N)₄ tetrahedra in a Q⁴/Q³ ratio of 3:1. The structure, which includes 4‐ring assemblies as the smallest ring size, can be subdivided into alternating open‐branched zweier double layers {oB,${2{{2\hfill \atop \infty \hfill}}}$ }[²P₃(O,N)₇] and layers containing pairwise‐linked Q³ tetrahedra parallel (001). Information on the hydrogen atoms in H₃P₈O₈N₉ was obtained by 1D ¹H MAS, 2D homo‐ and heteronuclear (together with ³¹P) correlation NMR spectroscopy, and a ¹H spin‐diffusion experiment with a hard‐pulse sequence designed for selective excitation of a single peak. Two hydrogen sites with a multiplicity ratio of 2:1 were identified and thus the formula of H₃P₈O₈N₉ was unambiguously determined. The protons were assigned to Wyckoff positions 8f and 4e, the latter located within the Q³ tetrahedra layers.     

[Be3(μ3‐O)3(MeCN)6{Be(MeCN)3}3](I)6 – ein Berylliumkomplex mit Cyclo‐(Be3O3)‐Kern und sein Hydrolyseprodukt [Be(H2O)4](I)2·2MeCN

Single crystals of [Be₃(μ₃‐O)₃(MeCN)₆{Be(MeCN)₃}₃](I)₆·4CH₃CN ( 1 ·4CH₃CN) were obtained in low yield by the reaction of beryllium powder with iodine in acetonitrile suspension, which probably result from traces of beryllium oxide containing the applied beryllium metal. The compound 1 ·4CH₃CN forms moisture sensitive, colourless crystal needles, which were characterized by IR spectroscopy and X‐ray diffraction (Space group Pnma, Z = 4, lattice dimensions at 100(2) K: a = 2317.4(1), b = 2491.4(1), c = 1190.6(1) pm, R₁ = 0.0315). The hexaiodide complex cation 1 ⁶⁺consists of a cyclo‐Be₃O₃ core with slightly distorted chair conformation, stabilized by coordination of two acetonitrile ligands at each of the beryllium atoms and by a {Be(CH₃CN)₃}²⁺ cation at each of the oxygen atoms. This unique coordination behaviour results in coplanar OBe₃ units with short Be–O distances of 155.0 pm and 153.6 pm on average of bond lengths within the cyclo‐Be₃O₃ unit and of the peripheric BeO bonds, respectively. Exposure of compound 1 ·4CH₃CN to moist air leads to small orange crystal plates of [Be(H₂O)₄]I₂·2CH₃CN ( 3 ·2CH₃CN). According to the crystal structure determination (Space group C2/c, Z = 4, lattice dimensions at 100(2) K: a = 1220.7(1), b = 735.0(1), c = 1608.5(1) pm, β = 97.97(1)°, R₁ = 0.0394), all hydrogen atoms of the dication [Be(H₂O)₄]²⁺ are involved to form O–H ··· N and O–H ··· I hydrogen bonds with the acetonitrile molecules and the iodide ions, respectively. Quantum chemical calculations (B3LYP/6‐311+G**) at the model [Be₃(μ₃‐O)₃(HCN)₆{Be(HCN)₃}₃]⁶⁺ show that chair and boat conformation are stable and that the distorted chair conformation is stabilized by packing effects.     

A Dynamic Crystal‐to‐Amorphous Transformation Microporous ZnII Mixed Neutral‐ligand Metal‐organic Polymer {[Zn(bpp)2(μ‐4,4′‐bipy)(H2O)2](ClO4)2·H2O}n

A new rarely reported Zn^II mixed‐polypyridine coordination polymer with both rigid and flexible spacers, {[Zn(bpp)₂(μ‐4,4′‐bipy)(H₂O)₂](ClO₄)₂ · H₂O}_n ( 1 ), has been synthesized and characterized by elemental analysis, IR‐, ¹H NMR‐, ¹³C NMR spectroscopy and single‐crystal X‐ray diffraction. The thermal stability of compound 1 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The single‐crystal X‐ray structure of 1 shows that the complex has been formed from a 1D polymer as a result of bridging by the 4,4′‐bipy ligands. Solution and solid‐state luminescent spectra of the compound 1 indicate intense fluorescent emissions at ca. 353.6 and 468.8 nm, respectively. Removal of the interstitial water guest molecules results in a loss of crystallinity, but exposure to water vapor reestablishes the original structure, thus constituting 1 as a third‐generation porous framework.     

A New Chair‐shaped Conformation Containing HgHgOHgHgO: Synthesis and Structure of Hg4(L2)2(NO3)4 (L2 = morpholin‐4‐ylpyridin‐2‐ylmethyleneamine)

. The complex Hg₄(L²)₂(NO₃)₄ ( 1 ) (L² = morpholin‐4‐ylpyridin‐2‐ylmethyleneamine) has been synthesized and characterized by CHN analysis, IR, and UV/Vis spectroscopy. The crystal structure of 1 was determined using single‐crystal X‐ray diffraction. The crystal structure of 1 contains four mercury atoms, four nitrate anions (two terminal and two bridge ones) and two L² ligand molecules. A chair shape, six‐membered ring is formed with the sequence OHgHgOHgHg built from Hg–Hg dumbbells and oxygen atoms from the nitrate co‐ligands. In the crystal structure, the asymmetric unit of the compound is built up by one‐half of the molecule. It contains the Hg₂²⁺ moiety with a mercury–mercury bonded core, in which one diimine ligand is coordinated to one of the mercury atoms. The nitrate anions act as anisobidentate and bidentate ligands.     

A New Family of Two‐Dimensional Zeolites Prepared from the Intermediate Layered Precursor IPC‐3P Obtained during the Synthesis of TUN Zeolite

The crystallization of zeolite TUN with 1,4‐bis(N‐methylpyrrolidinium)butane as template proceeds through an intermediate, designated IPC‐3P, following the Ostwald rule of successive transformations. This apparently layered transient product has been thoroughly investigated and found to consist of MWW monolayers stacked without alignment in register, that is, disordered compared with MCM‐22P. The structure was confirmed based on X‐ray diffraction and high‐resolution (HR)TEM analysis. The layered zeolite precursor IPC‐3P can be swollen and pillared affording a combined micro‐ and mesoporous material with enhanced Brunauer–Emmett–Teller (BET) surface area (685 m²g^?1) and greater accessibility of Brønsted acid sites for bulky molecules. This mesoporous material was probed with 2,6‐di‐tert‐butylpyridine (DTBP). IPC‐3P and its modification create a new layered zeolite sub‐family belonging to the MWW family. FTIR data indicate that (Al)MWW materials MCM‐22 and IPC‐3 with Si/Al ratios greater than 20 exhibit a lower relative ratio of Brønsted to Lewis acid sites than MCM‐22 (with Si/Al ratios of around 13), that is, less than 2 versus more than 3, respectively. This is maintained even upon pillaring and warrants further exploration of materials like IPC‐3P with a higher Al content. The unique XRD features of IPC‐3P indicating misaligned stacking of layers and distinct from MCM‐22P, are also seen in other MWW materials such as EMM‐10P, hexamethonium‐templated (HM)‐MCM‐22, ITQ‐30, and UZM‐8 suggesting the need for more detailed study of their identity and properties.