Although HCN has been explored extensively as a precursor in the prebiotic synthesis of biological molecules, macroscopic system-level phenomena, originating from reactions of HCN, such as autocatalysis, oscillations, pattern formation, and phase separation have attracted less attention. Autocatalysis and phase separation are particularly interesting in the context of the origin of life because they are sources of self-replication and compartmentalization. In this work, we investigate the reaction between HCN and cysteamine in water, which exhibits both sigmoidal reaction kinetics and the formation of a distinct liquid phase. We studied the origin of the sigmoidal kinetics using NMR spectroscopy and other techniques, investigated the chemical composition of the products using single-crystal X-ray diffraction and mass spectrometry, and probed the absorption of inert additives into the second liquid phase. Our studies show that the sigmoidal kinetics arise from an autocatalytic feedback loop driven by both an increase in pH and the catalytic nature of the newly formed phase itself. Product analysis revealed co-oligomers with a backbone derived from HCN and branches from cysteamine. This composition suggests that co-oligomerization with thiols provides a route to tractable oligomers, mitigating the formation of insoluble HCN polymers. Furthermore, this second liquid phase effectively sequesters hydrophobic molecules like benzene, demonstrating its capacity to act as a primitive compartment. The phenomena that we observed may provide some insight into prebiotic chemical networks and early-stage chemical evolution.

The work investigates enantiomers of chiral organo-metallic particles that exhibit a collective memory effect. Under the influence of magnetic field millions of particles in solution form macroscopic shapes and when dispersed again at zero field they return to their original shape. The charge and magnetic behaviors of the particles are strongly dependent on the handedness of the chiral molecule in the hybrid organometallic compound. The microparticles forming the shaped structures are collectively coupled under the influence of long-range van der Waals exchange interactions which govern the collective macroscopic structure. There is striking evidence that the nonlocal quantum exchange interactions between particles persist up to a distance of 10 meters at temperatures above 00C. The forces which govern the collective memory effect and shape the macroscopic structure therefore allow to visualize quantum phenomena which extend the classical causality notion into an expanded nonlocal reality in which the quantum fields of the particles exist simultaneously at separated points in space. We propose that the observations are attributed to chiral electronic states dependent van der Waals interactions coupled to vacuum fluctuations.

1,3,7-Triphenyl-4,8-dihydro-1H-imidazo[4,5-g][1,2,4]benzotriazin-4-yl, a stable radical, forms 1 D π stacks. These stacks consist of dimers with alternating interplanar distances measuring 3.443 Å (short) and 4.169 Å (long). Magnetic susceptibility (χT) reaches its peak at 18 ± 4 K, signifying the presence of a dimer with ferromagnetic interactions, quantified by 2J = 18.1 cm-1. The magneto-structural relationship is corroborated by DFT calculations.

Fragment of Calama 009 L6 ordinary chondrite recovered in the Atacama Desert was chosen for a complex study of the bulk interior and the fusion crust by scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), magnetization measurements, and M & ouml;ssbauer spectroscopy. SEM demonstrated the presence of Fe-Ni-Co grains, troilite and chromite inclusions in both the bulk interior and the fusion crust as well as many veins with ferric compound. EDS showed variations in the Ni concentration within the metal grains and within one metal phase in the grain. XRD revealed some differences in the contents of various phases in the bulk interior and in the fusion crust. XRD indicated the presence of magnesioferrite in the fusion crust as well as the formation of goethite nanoparticles with the mean size of 9 nm in both the bulk interior and the fusion crust. Magnetization measurements demonstrated the ferrimagnetic-paramagnetic phase transition in chromite at 44 K and low values of the saturation magnetization moments (6.46 and 3.26 emu g-1 at 100 K) for the bulk interior and the fusion crust, respectively, due to the lack of Fe-Ni-Co alloy as a result of weathering. The M & ouml;ssbauer spectra of the bulk interior and the fusion crust showed some differences in the number and relative areas of spectral components. The revealing of the M & ouml;ssbauer spectral components related to 57Fe in the M1 and M2 sites in olivine and orthopyroxene as well as determining the Fe2+ occupations of these sites from XRD permitted us to estimate the temperature of equilibrium cation distribution for these silicates which are (i) 662 K (XRD) and 706 K (M & ouml;ssbauer spectroscopy) for olivine and (ii) 893 K (XRD) and 910 K (M & ouml;ssbauer spectroscopy) for orthopyroxene.

Iron-containing pharmaceuticals, namely: (i) PreNatal with ferrous fumarate, (ii) Tardyferon® with ferrous sulfate, (iii) Fenules with water free ferrous sulfate, (iv) Iron Complex with iron glycinate, citrate, (v) Gentle Iron, (vi) Hema-Plex® and (vii) Iron Bisglycinate with iron (ferrous) bisglycinate chelate (iron compounds are given as declared by the manufactures) were studied by 57Fe Mössbauer spectroscopy with X-ray diffraction and magnetization measurements for analysis of the iron state. The obtained results demonstrate that the iron compound announced by the manufacturer in each pharmaceutical is not homogeneous and exists as some modifications of this compound or results of its transformation/oxidation probably due to its instability. The presence of ferrous and ferric compounds is observed, and the relative ferric iron fractions are roughly determined for each pharmaceutical product. This analysis clearly shows the differences between the iron compounds proclaimed by the manufacturers and those obtained by Mössbauer spectroscopy. That justifies as to why this technique should be used for the control and analysis of the iron-containing pharmaceuticals.

3,3',3''-(Benzene-1,3,5-triyl)tris(1-phenyl-1H-benzo[e][1,2,4]triazin-4-yl) (1) is a C3-symmetrical triradi-cal comprised of three Blatter radical units connected at the 1, 3, 5 positions of a central trimethyleneben-zene core. This triradical has an excellent air, moisture, and thermal stability. Single-crystal XRD indicates that triradical 1 adopts a propeller-like geometry with the benzotriazinyl moieties twisted by specialIntscript and packs in 1D chains along the c axis to form an extensive network of weak intermolecular interactions. Frozen solution continuous wave (CW) EPR spectra and variable-temperature field-sweep echo-detected (FSED) spectra revealed an intramolecular ferromagnetic exchange within the spin system, supporting a quartet S = 3/2 ground state. DFT calculations further supported these experimental findings.(c) 2023 Elsevier Inc. All rights reserved.

We demonstrate here how nitrate salts of bivalent copper, nickel, cobalt, and manganese, along with an achiral organic ligand, assemble into various structures such as symmetrical double-decker flowers, smooth elongated hexagonal bipyramids, and hexagonal prisms. Large morphological changes occur in these structures because of different metal cations, although they maintain isomorphous hexagonal crystallographic structures. Metal cations with stronger coordination to ligands (Cu and Ni) tend to form uniform crystals with unusual shapes, whereas weaker coordinating metal cations (Mn and Co) produce crystals with more regular hexagonal morphologies. The unusual flower-like crystals formed with copper nitrate have two pairs of six symmetrical petals with hexagonal convex centers. The texture of the petals indicates dendritic growth. Two different types of morphologies were formed by using different copper nitrate-to-ligand ratios. An excess of the metal salt results in uniform and monodisperse hexagonal crystals, whereas the use of an excess of ligand results in double-decker morphologies. Mechanistically, an intermediate structure was observed with slightly concave facets and a domed center. Such structures most likely play a key role in the formation of double-decker crystals that can be formed by fusion processes. The coordination chemistry results in isostructural chiral frameworks consisting of two types of continuous helical channels. Four pyridine units from four separate ligands are coordinated to the metal center in a plane having a chiral (propeller-type) arrangement. The individual double-decker flower crystals are homochiral and a batch consists of crystals having both handedness.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The correlation of crystal habits with the patterns of supramolecular interactions is identified for the complexes of dihalogens formed via unsymmetrical hypervalent 3c/4e N⋯I⋯X bonding.

1,3-Diphenyl-1,4-dihydrobenzo[e][1,2,4]triazin-4-yl-6,7-dicarbonitrile is an exceptionally stable electron-deficient organic radical with promising potential to be used as a building block in a range of electronic and spintronic materials. The radical has a fully reversible one-electron redox and is highly delocalized, with some spin density reaching as far as the nitrile groups. Two polymorphs, alpha and beta, were identified and characterized by single-crystal X-ray diffractometry. Both polymorphs form one-dimensional (1D) pi stacks. However, while in polymorph alpha radicals are located at evenly interplane distances (3.366 & Aring;), in polymorph beta radicals are located at alternate interplane distances (3.182 and 3.318 & Aring;). Magnetic susceptibility measurements for polymorph alpha indicate strong antiferromagnetic interactions along the 1D regular chain. Magnetic susceptibility data cannot be fully fitted to the Bonner and Fischer model for the 2-300 K temperature range. The steeper rise in paramagnetism above 80 K was rationalized by temperature-dependent antiferromagnetic exchange interactions between radicals within the 1D pi stacks, which is indeed supported by Density Functional Theory (DFT) calculations. A microscopic study of the magnetic topology of polymorph alpha together with the interpretation of its magnetic experimental data was pursued by using a First-Principles Bottom-Up approach. Minuscule changes in crystal packing upon changing the temperature significantly affect the magnetic interaction between spin-containing moieties. Temperature, therefore, is the key player in rationalizing the magnetism in polymorph alpha.

Metal-organic Co(ii)-phenylalanine crystals were studied and were found to possess magnetic properties and long-range spin transport. Magnetic measurements confirmed that in the crystals there are antiferromagnetic interactions between Co(ii) and the lattice. The metal-organic crystals (MOCs) also present the chirality-induced spin selectivity (CISS) effect at room temperature. A long-range spin polarization is observed using a magnetic conductive-probe atomic force microscope. The spin polarization is found to be in the range of 35-45%.

We demonstrate here how nitrate salts of bivalent copper, nickel, cobalt, and manganese, along with an achiral organic ligand, assemble into various structures such as symmetrical double-decker flowers, smooth elongated hexagonal bipyramids, and hexagonal prisms. Large morphological changes occur in these structures because of different metal cations, although they maintain isomorphous hexagonal crystallographic structures. Metal cations with stronger coordination to ligands (Cu and Ni) tend to form uniform crystals with unusual shapes, whereas weaker coordinating metal cations (Mn and Co) produce crystals with more regular hexagonal morphologies. The unusual flower-like crystals formed with copper nitrate have two pairs of six symmetrical petals with hexagonal convex centers. The texture of the petals indicates dendritic growth. Two different types of morphologies were formed by using different copper nitrate-to-ligand ratios. An excess of the metal salt results in uniform and hexagonal crystals having a narrow size distribution, whereas the use of an excess of ligand results in double-decker morphologies. Mechanistically, an intermediate structure was observed with slightly concave facets and a domed center. Such structures most likely play a key role in the formation of double-decker crystals that can be formed by fusion processes. The coordination chemistry results in isostructural chiral frameworks consisting of two types of continuous helical channels. Four pyridine units from four separate ligands are coordinated to the metal center in a plane having a chiral (propeller-type) arrangement. The individual double-decker flower crystals are homochiral and a batch consists of crystals having both handedness.

Numerous bio-organisms employ template-assisted crystallization of molecular solids to yield crystal morphologies with unique optical properties that are difficult to reproduce synthetically. Here, a facile procedure is presented to deposit bio-inspired birefringent crystals of xanthine derivatives on a template of single-crystal quartz. Crystalline sheets that are several millimeters in length, several hundred micrometers in width, and 300-600 nm thick, are obtained. The crystal sheets are characterized with a well-defined orientation both in and out of the substrate plane, giving rise to high optical anisotropy in the plane parallel to the quartz surface, with a refractive index difference Δn ≈ 0.25 and a refractive index along the slow axis of n ≈ 1.7. It is further shown that patterning of the crystalline stripes with a tailored periodic grating leads to a thin organic polarization-dependent diffractive meta-surface, opening the door to the fabrication of various optical devices from a platform of small-molecule based organic dielectric crystals.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

We show that metal-organic frameworks, based on tetrahedral pyridyl ligands, can be used as a morphological and structural template to form a series of isostructural crystals having different metal ions and properties. An iterative crystal-to-crystal conversion has been demonstrated by consecutive cation exchanges. The primary manganese-based crystals are characterized by an uncommon space group (P622). The packing includes chiral channels that can mediate the cation exchange, as indicated by energy-dispersive X-ray spectroscopy on microtome-sectioned crystals. The observed cation exchange is in excellent agreement with the Irving-Williams series (MnZn) associated with the relative stability of the resulting coordination nodes. Furthermore, we demonstrate how the metal cation controls the optical and magnetic properties. The crystals maintain their morphology, allowing a quantitative comparison of their properties at both the ensemble and single-crystal level.

Die Vorhersage von Kristallmorphologien ist aufgrund der vielen Faktoren, die das Kristallwachstum beeinflussen, eine Herausforderung. Dan Oron, Michal Lahav, Milko E. van der Boom et al. zeigen in ihrem Forschungsartikel (e202205238), wie der Austausch von Metallkationen in metallorganischen Gerüsten (MOFs) zu einer Serie von chiralen Kristallen mit ähnlicher Morphologie, Packung und einer seltenen Raumgruppe (P622) führt. Die Tatsache, dass die Kristalle ihre Morphologie beibehalten, erleichtert einen quantitativen Vergleich ihrer optischen und magnetischen Eigenschaften.

The spontaneous gelation of poly(4-vinyl pyridine)/pyridine solution produces materials with conductive properties that are suitable for various energy conversion technologies. The gel is a thermoelectric material with a conductivity of 2.2-5.0 × 10-6 S m-1 and dielectric constant ε = 11.3. On the molecular scale, the gel contains various types of hydrogen bonding, which are formed via self-protonation of the pyridine side chains. Our measurements and calculations revealed that the gelation process produces bias-dependent polymer complexes: quasi-symmetric, strongly hydrogen-bonded species, and weakly bound protonated structures. Under an applied DC bias, the gelled complexes differ in their capacitance/conductive characteristics. In this work, we exploited the bias-responsive characteristics of poly(4-vinyl pyridine) gelled complexes to develop a prototype of a thermal energy harvesting device. The measured device efficiency is S = ΔV/ΔT = 0.18 mV/K within the temperature range of 296-360 K. Investigation of the mechanism underlying the conversion of thermal energy into electric charge showed that the heat-controlled proton diffusion (the Soret effect) produces thermogalvanic redox reactions of hydrogen ions on the anode. The charge can be stored in an external capacitor for heat energy harvesting. These results advance our understanding of the molecular mechanisms underlying thermal energy conversion in the poly(4-vinyl pyridine)/pyridine gel. A device prototype, enabling thermal energy harvesting, successfully demonstrates a simple path toward the development of inexpensive, low-energy thermoelectric generators.

Utilizing the inherent ability of Lindquist-type hexaniobate cluster-anions, [Nb6O19]8-, to serve as oxo-donor ligands in complexes with transition-metal cations, we report the synthesis and characterization of the first all-inorganic "ferric" wheel, Li48[(Nb6O19)8Fe8(OH)8]·88H2O, comprised of eight Fe atoms linked by eight hexaniobate cluster-anion ligands. Bond valence sum analysis of the X-ray structure and the synthesis conditions themselves indicate that the Fe atoms are in the +3 oxidation state. This is confirmed by magnetic susceptibility and electron paramagnetic resonance (EPR) measurements which indicate the presence of high spin (S = 5/2) Fe(III) ions. In addition, magnetic susceptibility measurements reveal long-range superexchange antiferromagnetic interactions between the hexaniobate-ligand separated Fe3+ ions (J = -0.22 cm-1). More generally, the results suggest the use of hexaniobate cluster-anions as linkers in the synthesis of other two- or three-dimensional polyoxometalate framework structures.

The olefin metathesis reaction is among the most widely applicable catalytic reactions for carbon–carbon double bond formation. Currently, Mo– and Ru–carbene catalysts are the most common choices for this reaction. It has been suggested that an iron-based catalyst would be a desirable economical and biocompatible substitute of the Ru catalysts; however, practical solutions in this regard are still lacking. Here, we report the discovery and mechanistic studies of three-coordinate iron(II) catalysts for ring-opening metathesis polymerization of olefins. Remarkably, their reactivity enabled the formation of polynorbornene with stereoregularity and high molecular weight (>10 7 g mol –1 ). The polymerization in the presence of styrene revealed cross metathesis reactivity with iron catalysts. Mechanistic studies suggest the possible role of metal–ligand cooperation in formation of the productive catalyst. This work opens the door to the development of iron complexes that can be economical and biocompatible catalysts for olefin metathesis reactions.