Characterization and Thermal Behavior of the Iron Dietary Supplement Ferrous Glycine Sulfate Pentahydrate

Ferrous glycine sulfate pentahydrate [Fe(glycine)(SO4)·5H2O with glycine = C2H5NO2], contained in the supplement for treating iron deficiency anaemia, commercially known as ferro sanol duodenal®, was characterized by laboratory X‐ray powder diffraction (XRPD), scanning electron microscope (SEM), and infrared spectroscopy (IR). The thermal behavior was investigated by thermal analysis (TGA and DTA) and temperature‐dependent in situ XRPD measurements. Furthermore, the phase transitions to a less hydrated form [Fe(glycine)(SO4)·3H2O] and successively to the anhydrous form were demonstrated to occur in the crystalline solid state. Compared to the crystal structure of the pentahydrate, the trihydrate exhibits a different coordination environment of the iron sites where glycine ligands bridge iron forming a 1D polymeric chain structure. From detailed structural comparison, the mechanism of the phase transitions can be concluded

An Old Story in New Light: X-Ray Powder Diffraction Provides Novel Insights into a Long-Known Organic Solid-State Rearrangement Reaction

The first in situ diffraction study of the long-known solid-state rearrangement of p-bromobenzeneazotribenzoylmethane is reported. This proof-of-principle study demonstrates how modern laboratory X-ray powder diffraction, accompanied by up-to-date processing tools, can be used to monitor and describe mechanisms of organic solid-state reactions while it also underpins its necessity for structural characterisation of in situ formed crystalline phases. (doi: 10.5562/cca2127

Synthesis, Crystal Structures, and Properties of Mn(NCS)2 Coordination Compounds with 4-Picoline as Coligand and Crystal Structure of Mn(NCS)2

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Thermodynamically stable and metastable coordination polymers synthesized from solution and the solid state

Different Fe(ii) and Cd(ii) thiocyanate coordination compounds with unusual topology including isomeric modifications were synthesized with 4-picoline and investigated in regard to their thermodynamic relations

crystal structure and de and rehydration behaviorof two new chloride containing zeolitic imidazolate frameworks

A previously unknown solid phase in the zinc-imidazole system relevant for the synthesis of ZIF-8 was obtained by adding a small excess of methylimidazole (Hmim) to a diluted zinc chloride solution. By chemical and thermal analyses, a composition of Zn3(mim)5ClH2O·xH2O with x = 0.74 was determined and the compound denoted as ZIF-yqt hydrate. The crystal structure was solved from laboratory X-ray powder diffraction (XRPD) data. ZIF-yqt hydrate crystallizes in a C-centered monoclinic unit cell with space group C2/c (15) and lattice parameters of a = 13.1574(3) A, b = 16.4959(3) A, c = 13.6403(3) A, and β = 119.166(2)°. The structure is built up from Zn(mim)4/2 and Zn(mim)3/2(Cl0.5H2O0.5)1/1 units forming a self-penetrating yqt1 type net. IR spectroscopy was employed to confirm the presence of water in the coordination sphere of zinc. In addition, noncoordinated water is situated in the voids of this net. By heating, ZIF-yqt hydrate can be completely dehydrated resulting in the formation of anhydrous Zn3(mim..

Synthesis, Structures, Thermal and Luminescence Properties of Zn and Cd Halide Coordination Polymers with 2‐Cyanopyrazine

Reaction of MX2 (M = Cd, Zn; X = Cl, Br, I) with 2‐cyanopyrazine leads to the formation of compounds with the composition CdX2(2‐cyanopyrazine)2 (X = Cl; CdCl, X = Br; CdBr and X = I; CdI) and ZnX2(2‐cyanopyrazine)2 (X = Cl; ZnCl, X = Br; ZnBr and X = I; ZnI/I). In the crystal structures of the Cd compounds and in ZnCl, the metal cations are octahedrally coordinated and are linked into chains by the halide anions via common edges. In contrast, in the crystal structures of ZnBr and ZnI/I the metal cations are tetrahedrally coordinated into discrete complexes. Further investigations show that a second modification of ZnCl2(2‐cyanopyrazine)2 exists (ZnI/II), which is formed by kinetic control. The thermal properties of the 2‐cyanopyrazine rich compounds were investigated by TG‐DTA and temperature dependent XRPD measurements. Upon heating the Cd compounds, all 2‐cyanopyrazine ligands are removed in a single step with no indication of the formation of a 2‐cyanopyrazine deficient phase. A similar behavior is observed for ZnI, whereas for ZnCl and ZnBr, TG‐DTA measurements suggest the formation of a 2‐cyanopyrazine deficient phase that, in case of ZnBr, cannot be isolated and, for ZnCl, cannot be obtained pure. The emission of these compounds is shifted from the blue to orange depending on the crystal structure and the nature of the halide anion

Total scattering reveals the hidden stacking disorder in a 2D covalent organic framework

Interactions between extended π-systems are often invoked as the main driving force for stacking and crystallization of 2D organic polymers. In covalent organic frameworks (COFs), the stacking strongly influences properties such as the accessibility of functional sites, pore geometry, and surface states, but the exact nature of the interlayer interactions is mostly elusive. The stacking mode is often identified as eclipsed based on observed high symmetry diffraction patterns. However, as pointed out by various studies, the energetics of eclipsed stacking are not favorable and offset stacking is preferred. This work presents lower and higher apparent symmetry modifications of the imine-linked TTI-COF prepared through high- and low-temperature reactions. Through local structure investigation by pair distribution function analysis and simulations of stacking disorder, we observe random local layer offsets in the low temperature modification. We show that while stacking disorder can be easily overlooked due to the apparent crystallographic symmetry of these materials, total scattering methods can help clarify this information and suggest that defective local structures could be much more prevalent in COFs than previously thought. A detailed analysis of the local structure helps to improve the search for and design of highly porous tailor-made materials