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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].

Abstract Synthesis of morphologically well-defined crystals of metalloporphyrin by direct crystallization based on conventional anti-solvent crystallization method without using any additives has been rarely reported. Herein, we demonstrate an unconventional and additive-free synthetic method named reverse anti-solvent crystallization method to achieve well-defined zinc-porphyrin cube crystals by reversing the order of the addition of solvents. The extended first solvation shell effect mechanism is therefore suggested to support the synthetic process by providing a novel kinetic route for reaching the local supersaturation environment depending on the order of addition of solvents, which turned out to be critical to achieve clean cube morphology of the crystal. We believe that our work not only extends fundamental knowledge about the kinetic process in binary solvent systems, but also enables great opportunities for shape-directing crystallization of various organic and organometallic compounds.

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]. [ABSTRACT FROM AUTHOR]

A spatially ordered quantum dot array of cationic indium nanoclusters was synthesized in a single crystal of zeolite X. X-ray photoelectron spectroscopy experiments confirmed the existence of both atomic and cationic indiums inside the single crystal.

Fully indium-exchanged zeolite X is prepared by solvent-free redox ion-exchange of fully dehydrated fully T1(super +)-exchanged zeolite with In metal at 50 degree Celsius. Electron-probe microanalysis and single-crystal X-ray diffraction showed the product to be an indium aluminosilicate free of thallium.

Urea intercalated in montmorillonite (MMT) leads to considerable improvement of N efficiency in soils; however, there are no systematic approaches to elucidate the properties of urea intercalates within the interlayer space of swelling clays. This study focused on both the optimization of massive urea intercalation into MMT and the systematic characterization of urea-intercalated MMT (UCM). Anhydrous metal salts, which could allow optimal urea intercalation, were used for the first time to synthesize metal-urea complexes in a solid state. Massive intercalation of metal-urea complex into MMT was performed by simply mixing dehydrated MMT with a molten metal-urea complex containing excess urea at 105 ± 5°C. Successful complexation was confirmed by both the unique infrared spectra absorbance bands and the thermal behaviors of the coordinated urea molecules. The intercalation of metal-urea complexes into MMT was clearly demonstrated by a significant expansion of d001 spacing from 1.52 to 1.74 nm in Ca-UCM, as revealed by x-ray diffraction patterns. Infrared spectra also revealed that the intercalation of urea in the interlayer led to a distinct red shift in stretching vibration energy of the structural hydroxyl group of MMT from 3446 to 3483 cm-1 and from 3360 to 3400 cm-1. Experimental urea loading capacity was estimated to be 33.7% urea. All the intercalated urea molecules were found to be quickly and completely released by water molecules through ligand exchange, maintaining their effectiveness as a N source for crop cultivation. [ABSTRACT FROM AUTHOR]

Large colorless single crystals of FAU-type zeolites were synthesized from gels with the composition xSiO : 2.0NaAlO : 7.5NaOH : 454HO : 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 |Na|[SiAlO]-FAU per unit cell was determined by X-ray diffraction methods in the cubic space group $$ Fd \bar{3} m; $$ a = 24.9434(6) Å at 294 K. The structure was refined by using all intensities to the final error indices (using only the 771 reflections for which F > 4σ( F)), R = 0.048 (based on F) and R = 0.188 (based on F). 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. [ABSTRACT FROM AUTHOR]

The single-crystal structure of |Zn|[SiAlO]-FAU per unit cell, a = 24.794(1), dehydrated at 673 K and 1 × 10 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 > 4σ( F)) R = 0.0448 (based on F) and wR = 0.1545 (based on F). About 35.5 Zn ions per unit cell are found at an unusually large number of crystallographic distinct positions, six. The 0.5 Zn ion per unit cell is located at the center of double 6-ring (D6R, site I; Zn(I)-O(3) = 2.642(3) Å 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 Zn ions per unit cell, respectively; these Zn ions are recessed 0.67 Å and 1.02 Å, respectively, into the sodalite cavities from their 3-oxygens plane (Zn(I′a)-O(3) = 2.094(3) Å, Zn(I′b)-O(3) = 2.23(5) Å, 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 Zn ions, each of which extends 0.63 Å into the sodalite cavities from their 3-oxygens plane (Zn(II′)-O(2) = 2.164(3) Å and O(2)-Zn(II′)-O(2) = 112.00(12)°). Twelve Zn ions are found at two nonequivalent sites II (in the supercage) with occupancies of 7 and 5 ions, respectively; these Zn ions are recessed 0.52 Å and 0.96 Å, respectively, into the supercage from their 3-oxygens plane (Zn(IIa)-O(2) = 2.138(12) Å, Zn(IIb)-O(2) = 2.28(4) Å, O(2)-Zn(IIa)-O(2) = 114.2(10)°, and O(2)-Zn(IIb)-O(2) = 103.7(25)°). [ABSTRACT FROM AUTHOR]

The lifetime of H2O2 is an important factor in the feasibility of Fenton's reaction for soil and groundwater remediation. The lifetime of H2O2 was evaluated in Fenton's reaction and Fenton-like reactions with haematite and magnetite. H2O2 was more stable in the Fenton-like reaction than in the Fenton's reaction. The lifetime of H2O2 was also highly affected by the solution pH, and a pH buffered acidic condition was preferred. Fenton's reaction and Fenton-like reaction were tested for phenanthrene adsorbed on sand. Fenton-like reaction and acidic condition showed better degradation rates in comparing with those of Fenton's reaction and unbuffered systems. The dissolved iron species were measured in the Fenton's reaction, and Fenton-like reaction with haematite as a function of pH. In the presence of H2O2, ferric iron was the major dissolved iron species and the pH buffered to acidic condition maintained relatively high levels of dissolved iron in the aqueous solution. The higher iron concentration in the solution contributed to effective production of hydroxyl radical and degradation of organic contaminants. [ABSTRACT FROM AUTHOR]

Selective functionalisation of the tridentate ligand 1-(2-aminoethyl)-3-methyl-3-(2-pyridyl)azetidine at its terminal amino-nitrogen atom can be readily achieved by both reductive alkylation and simple alkylation reactions to give tri-, quadri-, quinque- and sexi-dentate derivatives. Simple alkylation by 2-picolinyl chloride provides the only example of a second reaction pathway where the azetidine ring of the reactant has undergone activation towards ring opening. Structural characterisation of the Cu(ii) complexes of these ligands has revealed several remarkable aspects of their solid-state coordination chemistry, including the formation of infinite helical aggregates through π-stacking and tetramerisation through carboxylate bridging, as well as further examples of the crystallisation of mixed species found to be rather common with complexes of the parent ligand. [ABSTRACT FROM AUTHOR]

A relatively simple azetidine derivative with 2-aminoethyl and 2-pyridyl substituents functions as a tridentate ligand towards Cu(ii), giving species in which the CuN3unit is essentially planar and that, in the solid state, show a subtle balance between mononuclear and binuclear forms, allowing both to be simultaneously present in some lattices. Displacement of the ligand from Cu(ii) by the use of cyanide results in the formation of cyanogen, which appears to slowly react with the free amine to give an oxamidine characterised in its doubly-deprotonated form as its binuclear Ni(ii) complex. [ABSTRACT FROM AUTHOR]

In the title compound, [Cr(ONO)2(cyclam)]NO2 (cyclam is 1,4,8,11-tetraazacyclotetradecane, C10H24N2), the complex cation is located on a twofold symmetry axis. The central Cr atom has a distorted octahedral coordination, involving two Cr-O bonds, with the monodentate nitrite O atoms adopting a cis configuration, and four Cr-N bonds. The mean Cr-N and Cr-O distances are 2.0895 (14) and 1.9698 (14) Å. [ABSTRACT FROM AUTHOR]