Inclusion Crystals Research Articles

Hybrid Hairy Platelets with Tunable Structures by Inclusion Crystallization of Polyferrocene-Containing Block Copolymers and Silicotungstic Acid.

Herein, we report hybrid hairy platelets formed by block copolymers containing a poly(ethylene oxide) (PEO) midblock and polyferrocene end-blocks with silicotungstic acid (STA). As inclusion crystallization of PEO midblocks and STA clusters lead to crystalline lamellae in thin films at room temperature, the polyferrocene end-blocks that are excluded from the lattice will graft on the surface of the lamellae, giving rise to hybrid hairy platelets. The dependence of crystallographic structures and morphologies of platelets on the length of end-blocks is investigated. The presence of relatively long end-blocks induces the formation of an inclusion crystal with a tetragonal cell (termed as β-form), whereas an inclusion crystal with an orthorhombic cell (termed as α-form) can be formed with block copolymers with relatively shorter end-blocks.

Solvent-dependent alignments and halogen-related interactions in inclusion crystals of adamantane-based macrocycle with pyridazine moieties

Six inclusion crystals were formed from crystallization of an adamantane-based macrocycle bearing pyridazine parts in various solvents. In inclusion crystals with cyclic ethers, halogen⋯halogen interactions between the macrocycles were observed.

Selective alkane co-inclusion by methylene- and adamantane-bridged macrocycle with biphenyl units

A methylene- and adamantane-bridged macrocycle with biphenyl units showed selective co-inclusion of n-hexane among the hexane isomers through crystallization. In the use of n-pentane or n-heptane, inclusion crystals with alkanes were not formed.

Dynamic behavior of macrocycle-based organic frameworks in single-crystal to single-crystal guest exchanges

An adamantane-based macrocycle afforded three inclusion crystals with diverse 1D channels. Single-crystal to single-crystal guest exchanges occurred for two crystals, where their frameworks displayed distinctive structural transformations.

Geochemical and tectonic constraints on the genesis of iron formation-hosted magnetite-hematite deposits at the Guanhães Block (Brazil) by contact metasomatism with pegmatite intrusions

The Horto-Baratinha (HBD) and Cuité (CTE) are two high-grade iron ore deposits (>60% wt. Fe) located in the Guanhães Tectonic Block (GB), at the eastern margin of the São Francisco Craton bordering the late Neoproterozoic–Cambrian Araçuaí-West Congo Orogenic belt. The orebodies are hosted by Orosirian to early Statherian metamorphic banded iron formation (IF) associated with quartzite and aluminous schists. The metasedimentary units are time-correlated with the Serra da Serpentina and Serra de São José Groups exposed in the Southern Espinhaço fold-thrust belt. They occur as tectonic slivers inserted in the pre-Rhyacian gneissic rocks and the granitic plutons of the Statherian Borrachudos Suite that comprise the GB. In the GB, the IF was intruded by anatectic pegmatites of Ediacaran to Cambrian crystallization age with the development of massive, granular magnetite-rich high-grade orebodies at the contact zone, contrasting with the hosting schistose quartz-hematite IF. The Fe-mineralization of the IF during the Brasiliano Orogeny developed in three distinct stages. (1) Syn- to late-collisional stage (ca. 580–560 Ma) with partial Fe enrichment along sheared zones, crystallization of oriented platy hematite crystals and development of discontinuous lens-shaped schistose high-grade orebodies. (2) Syn- to late-collisional stage (ca. 560–530 Ma) with the formation of massive magnetite bodies by contact metamorphic-metasomatism with the pegmatite. (3) Late- to post-tectonic stage with the oxidation of magnetite to kenomagnetite, martite and crystallization of granular hematite, probably by increased input of meteoric fluids during gravitational collapse of the Araçuaí-West Congo Orogen (ca. 530–490 Ma). In the HBD deposit, the first mineralization stage was unimportant for the enrichment of the IF that exhibit Fe contents of 32.45 to 43.50 wt%.Whole-rock data indicates that the massive hematite-magnetite high-grade iron ore pods exhibit Fe contents between 50.24 and 69.46 wt%, and increasing content of Al2O3, MgO and CaO and the trace elements Zr, Y, Zn, and Ni near the contact with pegmatite, associated with the presence of interstitial silicates and carbonates in their composition. Lamellar hematite exhibit very low contents of trace elements as in other specularitic IFs and orebodies from the eastern São Francisco Craton. A consistent increase in the content of trace elements, mainly Mg, V, Cr, Mn, Co, Ni, Zn, and Ga, is observed in kenomagnetite. Granular hematite grains are enriched an Al, Ti, Zr, Nb, Mo, Sn, Sb, Hf, Ta, and W. Notably, Mn and Ti may occur in relatively high concentrations in kenomagnetite and hematite with the crystallization of ilmenite inclusions, associated with the contact-metasomatic stages.

Structural elucidation of liquid cyclooctatetraene and cyclooctadienes in inclusion crystals

A disubstituted adamantane derivative having chloropyrimidine units (1) was utilized as a V-shaped host molecule to create inclusion crystals and to elucidate the molecular structures of the guests by X-ray crystallographic analysis. The crystallization of 1 and 1,3,5,7-cyclooctatetraene (a) in chloroform resulted in the formation of co-crystal (1a) with 2:3 host:guest complexation stoichiometry. Host 1 was assembled into a molecular network composed of double layer structures bearing channels where guest molecules (a) were accommodated. Co-crystals (1b, 1c) containing 1,3-cyclooctadiene (b) and 1,5-cyclooctadiene (c) were obtained at identical stoichiometry under similar conditions. The host molecules arrangement in both 1b and 1c was similar to that of 1a. In each case, guest molecules b and c were accommodated in the channels formed between the layers of the host molecules. In all co-crystals, the molecular structures of the guests a‒c, along with the host frameworks, were determined by crystallographic analysis.

Inclusion Crystallization of Silicotungstic Acid and Poly(ethylene oxide) and Its Impact on Proton Conductivities

In the present work, the hybridization of subnanometer-scale metal oxide cluster SiW₁₂O₄₀⁴– (STA) with poly(ethylene oxide) (PEO) and PEO-block-poly(propylene oxide)-block-PEO was investigated. A new crystalline phase was formed in the hybrid nanocomposites, which is attributed to the inclusion of PEO in the lattices of STA, that is, inclusion crystallization. The crystal lattice and dimensions of STA/PEO inclusion crystals are determined to be an orthorhombic unit cell with a = 1.52 nm, b = 2.74 nm, c = 2.52 nm, and α = β = γ = 90°. Remarkably, hybrid nanosheets with large size and high shape asymmetries can be formed by lamellar inclusion crystals. The dependence of proton conductivities of STA nanocomposites on crystalline structures was examined, and it was found that the formation of hybrid nanosheets could enhance proton conductivities of STA nanocomposites. This work provides new insight into the development of cluster-based nanocomposites with controlled morphology and optimized performance.

Inclusion crystals of V-shaped host molecules having trialkoxybenzene moieties with a carborane or benzoquinone derivative

Crystallization of an o-carborane or benzoquinone derivative with adamantane-based molecules possessing pyrogallol derivatives resulted in the formation of inclusion crystals through CH⋯O or lone pair⋯π interactions.

Uniform hybrid nanoribbons from unidirectional inclusion crystallization controlled by size-amphiphilic block copolymers.

Herein, we suggest a unique approach to control the growth of hybrid crystals of silicotungstic acid (STA) by introducing a poly(ethylene oxide) (PEO)-containing block copolymer and a poly(methyl methacrylate)-b-poly(ethylene oxide)-b-poly(methyl methacrylate) block copolymer (MEM BCP). Remarkably, perfectly straight ribbon-like lamellae with a uniform width and a large length/width ratio (>200) can be obtained. The length of hybrid nanoribbons can be tuned by annealing time and temperature, whereas the width is dependent on the molecular weight of the PEO mid-block. The stability of hybrid nanoribbons has been investigated against solvent vapor, high temperatures and the presence of phosphotungstic acid (PTA). The formation of hybrid nanoribbons leads to enhanced mechanical properties and proton conductivities of STA hybrid nanocomposites. This effective approach will provide a representative strategy to the control of crystalline hybrid materials in the solid state.

Co-Inclusion of cyclic ethers and chloroform by a macrocycle with benzophenone-3,3′,4,4′-tetracarboxylic diimide units

Crystallization of a diimide-based macrocycle having adamantane parts and several cyclic ethers in chloroform provided inclusion crystals, where both guests were cooperatively accommodated within inner spaces between the macrocycles.

Volatiles in the martian crust and mantle: Clues from the NWA 6162 shergottite

Martian meteorites of various petrogeneses retain a record of volatiles on Mars: from the hydrosphere, crustal water to the mantle. Sputtering of the martian atmosphere by solar wind after the loss of Mars' magnetic field enriched it in deuterium, which exchanged with martian crustal water. Recent studies show that the hydrogen isotopic composition of the martian crustal water reservoir varies from 3000 to 7000‰ but requires better constraints. Melt inclusion glasses, maskelynite and fusion crust from the depleted olivine-phyric shergotite NWA 6162 were analyzed using NanoSIMS, providing a unique insight into the hydrogen isotopic and volatile elemental content of both the martian crustal water reservoir and the mantle source.The H2O, S, and Cl contents of the melt inclusion glasses are ∼0-3137, 14-239, and 16-967 ppm, respectively. δD values vary from −560 to 6137‰. The water content positively correlates with the δD values in both the melt inclusion glasses and maskelynite in a two end-member mixing trend. One end-member is the magmatic water with a δD value of ∼0‰, and the other end member is the martian crustal water with δD ranging from 5000 to 6000‰. NWA 6162, a depleted olivine-phyric shergottite, originated from a different mantle source to the enriched lherzolitic shergottites. However, both types of shergottites exchanged with martian crustal water with the same δD values, indicating a homogeneous martian crustal water hydrogen isotopic composition (5000-6000‰). Most melt inclusion glasses from NWA 6162 have low water content (0-234 ppm) except for two enriched locations as micron-sized bands and dendrites. The low water content in most melt inclusion glasses, the dendritic shaped water enriched areas in melt inclusions, and the martian crustal water diffusion profile recorded in maskelynite collectively suggest short-lived water-rock interactions in the NWA 6162 parent rock that was probably induced by impact. Furthermore, a great contribution (up to 98%) of surface Cl accompanying D-enriched water was recorded in the melt inclusions supported by the positive correlation between Cl and H2O. The presence of sulfide and S-rich hot spots and low δD end-member of the magmatic water indicate that the degassing during post-entrapment crystallization and ascent of the melt inclusion is negligible. H2O, S, and Cl contents of the martian mantle reservoir are estimated to be 0.1-3, 0.5-15, and 0.5-4 ppm respectively, after the correction of fractional crystallization of the melt inclusions and contribution from the martian surface reservoir. The martian mantle reservoir estimated from NWA 6162 was water-, S-, and Cl-poorer than the Earth's interior.

Inclusion of Alkanes with a Crystal Consisting of Exocavity Complexes of p-tert-Butylthiacalix[4]arene with Diethylamine: Extension of Guest Scope by Changing the Structure of Inclusion Crystals

A crystal of the exocavity complex of p-tert-butylthiacalix[4]arene (2) with diethylamine (2·Et2NH) includes alkanes that cannot be included in a crystal of compound 2 alone and produces two types ...

Formation pathways for MgO·Al2O3 inclusions in iron melt

The crystallization of inclusions plays a decisive role in determining the structure, properties and size distribution of inclusions in steel. MgO·Al2O3 (MA) spinel is one of the most common inclusions having great influence on steel performance. Understanding the crystallization pathways of MA from molten steel is important to control their behaviors. Based on the thermodynamic properties of metastable phases of MA calculated by first principle prior to critical nucleus formation, the present work suggests that there are four possible pathways for MA inclusions nucleation from molten iron. According to the four nucleation pathways, the reaction among [Mg], [Al] and [O] could be the most probable pathway leading to MA inclusion formation, while Al2O3 reacting with MgO is almost impossible pathway for MA inclusion formation. The size of MA inclusions is dominated by the formation pathways, which have a close relationship with the adding ways of deoxidizer.

Assessment of the reliability of elastic geobarometry with quartz inclusions

Elastic geobarometry makes use of the contrast in elastic proprieties between host and inclusion crystals to determine the entrapment conditions of the inclusions from the residual stress and strain measured in the inclusion when its host is at ambient conditions. The theoretical basis has been developed extensively in the past few years, but an experimental validation of the method is still required. We performed two syntheses experiments with quartz inclusions in pure almandine garnet at eclogitic conditions. Experiment labelled Alm-1 with synthesis performed at P = 3.0 GPa and T = 775 °C and Alm-2 at P = 2.5 GPa and T = 800 °C. All the experiments have been carried out in a piston-cylinder press. Isolated, fully-enclosed quartz inclusions in the recovered garnets have been then measured using micro-Raman spectroscopy. All fully-buried inclusions exhibit Raman peaks at higher frequencies and wavenumbers than those obtained from quartz crystals at ambient pressure. If these peak shifts are interpreted as a remnant pressures by use of hydrostatic calibrations of the Raman shifts of quartz with pressure, the remnant pressures show a large spread in values and lead to significant errors in back-calculated entrapment pressures, of up to 1.4 GPa for inclusions synthesised at 3.0 GPa. These results confirm that quartz inclusions trapped inside garnet are not subject to hydrostatic pressure.We therefore used the phonon-mode Grüneisen tensors of quartz to calculate the full strain state of each inclusion, from which the full anisotropic stress state can be calculated by using the elastic properties of quartz. The mean residual remnant stress of the inclusions determined in this way show a much smaller spread in values. Entrapment pressures calculated from this mean stress with the isotropic model for host-inclusion systems differ from the known experimental values by <0.2 GPa, which is of the order of the combined experimental uncertainties. These results show that the most significant effect of the elastic anisotropy of quartz is on the Raman shifts of the inclusion, and not on the subsequent calculation of entrapment conditions.

Inclusion abilities towards hexyne isomers by co-crystallization with extended V-shaped host molecule

Disubstituted adamantane derivative possessing chloropyrazine (1) was synthesized and used as an extended V-shaped host molecule for the preparation of inclusion crystals containing hexyne isomers. The crystallization of 1 with 3-hexyne or 2-hexyne in chloroform provided co-crystals (1a, 1b) with 1:2 host:guest complexation stoichiometry, whereas guest-free crystals (1c) were produced in the case of 1-hexyne. In the co-crystals, the dimers built from 1 through CH···O interaction were arranged into a molecular network through multiple intermolecular interactions, and the guest molecules were accommodated within the cavity built from four molecules of 1. From the crystallization of equimolar binary mixtures of 3-hexyne or 2-hexyne and 1-hexyne in the presence of 1, co-crystals 1a and 1b were supplied, respectively. Competition experiments revealed that the selectivity order of 1 for the hexyne isomers was 3-hexyne and 2-hexyne ≫ 1-hexyne.

Inclusion crystals as vapochromic chemosensors: fabrication of a mini-sensor array for discrimination of small aromatic molecules based on side-chain engineering of naphthalenediimide derivatives

A mini-sensor array based on side-chain engineering of NDI derivatives achieved unique vapochromic/vapofluorochromic behaviors for aromatic vapors.

Cycloalkanes and cycloalkenes in dispersive force oriented inclusion crystals by a functionalized acyclic host molecule

The complexation of alicyclic compounds with a functionalized acyclic host gave inclusion crystals. Guest molecules were enclathrated within the cavity of the cyclic dimer of host molecules.

In situ generation of sustainable PLA-based nanocomposites by shear induced crystallization of nanofibrillar inclusions.

In situ formation of polymer nanofibrils during compounding with a second polymer followed by their immediate solidification due to shear induced crystallization for two pairs of polymers is described. Sustainable green biopolymer–biopolymer nanocomposites of polylactide (PLA) were then fabricated based on two copolyesters forming nanofibrils during shearing: poly(butylene adipate-co-succinate-co-glutarate-co-terephthalate) (PBASGT) and poly(butylene adipate-co-terephthalate) (PBAT). The shear induced crystallization allowed solidification of PBASGT or PBAT nanofibers immediately under applying a high shear rate without subsequent cooling. The melt memory unveiling as a self-nucleation facilitated shear-induced crystallization. Formation of nanofibril-matrix morphology led to an exceptional combination of strength, modulus and ductility. In situ SEM observation of the tensile test revealed crazing as a dominant mechanism for PLA deformation. However, addition of PBASGT or PBAT resulted in intensified crazing followed by shear banding. Increase of PBASGT or PBAT concentration promoted the brittle-to-ductile transition of the PLA matrix. At the same time, PBAT or PBASGT nanofibers span PLA craze surfaces and at large strain, when PLA craze tufts get broken, they bridge the craze gaps resulting in an increase of both strength and plasticity of PLA.

Piezofluorochromism in Charge-Transfer Inclusion Crystals: The Influence of High Pressure versus Mechanical Grinding

The front cover artwork is provided by the group of Prof. Y. Hisaeda at Kyushu University (Japan). The work is in collaboration with the group of Prof. M. Abe and Prof. Y. Akahama at University of Hyogo and Dr. H. Sato at Rigaku Corporation. The image shows multicolor piezofluorochromism in charge-transfer crystals under high-pressure using a diamond anvil cell. Read the full text of the Communication at 10.1002/cptc.201700227.

Enantioseparation of Sulfoxides and Nitriles by Inclusion Crystallization with Chiral Organic Salts Based on l‐Phenylalanine

Enantioselective inclusion of aromatic sulfoxides and nitriles was achieved in a host framework created by organic salts comprising achiral benzoic acids and a chiral primary amine (1a) derived from l‐phenylalanine. Tuning of the combined achiral acid component successfully changed the chiral recognition ability of the organic salts. The guest molecules were hydrogen‐bonded to form three‐component inclusion crystals, and the enantiomers of nitriles and sulfoxides were separated with high selectivity up to 92 and 98 % ee. As far as we know, this is the first example of the enantioseparation of non‐functionalized aromatic nitriles.