Application of multivariate curve resolution to non-invasive Raman spectra has been investigated for rapid on-line analysis of crystallisation processes and high-throughput screening. Exploring quantification of mefenamic acid solid forms (form I, form II, and dimethylformamide solvate) from the Raman spectra indicated excellent agreement with off-line X-ray analysis.
View Article and Find Full Text PDFX-ray Diffraction Computed Tomography (XRD-CT) represents a cutting-edge method for non-destructive material analysis, offering the unique capability of providing molecular-level information with spatial resolution. In this study, we have applied XRD-CT to investigate pharmaceutically relevant tablets that have been subjected to a range of compression pressures typical in tablet manufacturing. By employing XRD-CT to pharmaceutical tablets, we reveal material changes without tablet destruction, thereby avoiding potential phase transformations during sample preparation that could lead to errors in the interpretation of the processes that have occurred.
View Article and Find Full Text PDFFront Plant Sci
October 2024
The recent increase in legality of . has led to interest in developing new varieties with unique aromatic or effect-driven traits. Selectively breeding plants for the genetic stability and consistency of their secondary metabolite profiles is one application of phenotyping.
View Article and Find Full Text PDFL. produces a wide variety of volatile secondary metabolites that contribute to its unique aroma. The major volatile constituents include monoterpenes, sesquiterpenes, and their oxygenated derivates.
View Article and Find Full Text PDFWater-to-ice transformation results in a 10% increase in volume, which can have a significant impact on biopharmaceuticals during freeze-thaw cycles due to the mechanical stresses imparted by the growing ice crystals. Whether these stresses would contribute to the destabilization of biopharmaceuticals depends on both the magnitude of the stress and sensitivity of a particular system to pressure and sheer stresses. To address the gap of the "magnitude" question, a phospholipid, 1,2-dipalmitoyl--glycero-3-phosphocholine (DPPC), is evaluated as a probe to detect and quantify the freeze-induced pressure.
View Article and Find Full Text PDFPharmaceutical cocrystals use common robust hydrogen bonding synthons to create novel materials with different physicochemical properties. In this systematic study of a series of cocrystals, we explore the effect of high pressure on one of these commonly used motifs, the acid-pyridine motif, to assess the commonality of behaviour under extreme conditions. We have surveyed five pyridine dicarboxylic acid systems using both synchrotron and neutron diffraction methods to elucidate the changes in structure.
View Article and Find Full Text PDFWe present an extensive exploration of the solid-form landscape of chlorpropamide (CPA) using a combined experimental-computational approach at the frontiers of both fields. We have obtained new conformational polymorphs of CPA, placing them into context with known forms using flexible-molecule crystal structure prediction. We highlight the formation of a new polymorph (ζ-CPA) via spray-drying experiments despite its notable metastability (14 kJ/mol) relative to the thermodynamic α-form, and we identify and resolve the ball-milled η-form isolated in 2019.
View Article and Find Full Text PDFα-FAPbI (FA = CH(NH)) with a cubic perovskite structure is promising for photophysical applications. However, α-FAPbI is metastable at room temperature, and it transforms to the δ-phase at a certain period of time at room temperature. Herein, we report a thiocyanate-stabilized pseudo-cubic perovskite FAPbI with ordered columnar defects (α'-phase).
View Article and Find Full Text PDFPostsynthetic modification of metal-organic frameworks (MOFs) has proven to be a hugely powerful tool to tune physical properties and introduce functionality, by exploiting reactive sites on both the MOF linkers and their inorganic secondary building units (SBUs), and so has facilitated a wide range of applications. Studies into the reactivity of MOF SBUs have focussed solely on removal of neutral coordinating solvents, or direct exchange of linkers such as carboxylates, despite the prevalence of ancillary charge-balancing oxide and hydroxide ligands found in many SBUs. Herein, we show that the μ-OH ligands in the MIL-53 topology Sc MOF, GUF-1, are labile, and can be substituted for μ-OCH units through reaction with pore-bound methanol molecules in a very rare example of pressure-induced postsynthetic modification.
View Article and Find Full Text PDFIntroduction: Cannabidiol (CBD) is a non-intoxicating phytocannabinoid with increasing popularity due to its purported therapeutic efficacy for numerous off-label conditions including anxiety and autism spectrum disorder (ASD). Those with ASD are commonly deficient in endogenous cannabinoid signaling and GABAergic tone. CBD has a complex pharmacodynamic profile that includes enhancing GABA and endocannabinoid signaling.
View Article and Find Full Text PDFActa Crystallogr B Struct Sci Cryst Eng Mater
April 2023
Understanding the solvation and desolvation of pharmaceutical materials is an important part of materials discovery and development. In situ structural data are vital to understand the changes to crystal form that may occur in the system. In this study, the isolation and characterization of seven solvates of the L-type calcium channel antagonist, nifedipine, is described using variable-temperature powder X-ray diffraction so that the structural evolution as a function of temperature can be followed.
View Article and Find Full Text PDFThe emission of white light from a single material is atypical and is of interest for solid-state lighting applications. Broadband light emission has been observed in some layered perovskite derivatives, PbBr ( = -NH), and correlates with static structural distortions corresponding to out-of-plane tilting of the lead bromide octahedra. While materials with different organic cations can yield distinct out-of-plane tilts, the underlying origin of the octahedral tilting remains poorly understood.
View Article and Find Full Text PDFL. produces over 200 known secondary metabolites that contribute to its distinctive aroma. Studies on compounds traditionally associated with the scent of this plant have focused on those within the terpenoid class.
View Article and Find Full Text PDFDynamic organic crystals have come to the fore as potential lightweight alternatives to inorganic actuators providing high weight-to-force ratios. We have observed pressure-induced superelastic behaviour in Form I of isonicotinamide. The reversible single-crystal to single-crystal transformation exhibited by the system is an important component for functioning actuators.
View Article and Find Full Text PDFMannitol, a common pharmaceutical ingredient, exhibits complex polymorphism even in simple binary mannitol/water mixtures, with four crystalline forms observed. In this investigation, time/temperature-resolved synchrotron X-ray diffraction measurements are performed during freezing and thawing of mannitol/water mixtures. Mannitol crystallization depends strongly on the cooling rate and is initiated during cooling, if the cooling rate is lower than the critical cooling rate; otherwise, mannitol remains amorphous during freezing and crystallizes during subsequent heating above -30 °C.
View Article and Find Full Text PDFThe layered perovskite (MA)PbI(SCN) (MA = CHNH) is a member of an emerging series of compounds derived from hybrid organic-inorganic perovskites. Here, we successfully synthesized (MA)PbIBr(SCN) (0 ≤ < 1.6) by using a solid-state reaction.
View Article and Find Full Text PDFUnderstanding polymorphism in chiral systems for drug manufacturing is essential to avoid undesired therapeutic effects. Generally, polymorphism is studied through changes in temperature and solution concentration. A less common approach is the application of pressure.
View Article and Find Full Text PDFRecent reports have linked severe lung injuries and deaths to the use of e-cigarettes and vaping products. Nevertheless, the causal relationship between exposure to vaping emissions and the observed health outcomes remains to be elucidated. Through chemical and toxicological characterization of vaping emission products, this study demonstrates that during vaping processes, changes in chemical composition of several commonly used vape juice diluents (also known as cutting agents) lead to the formation of toxic byproducts, including quinones, carbonyls, esters, and alkyl alcohols.
View Article and Find Full Text PDFControlling the connectivity and topology of solids is a versatile way to target desired physical properties. This is especially relevant in the realm of hybrid halide semiconductors, where the long-range connectivity of the inorganic substructural unit can lead to significant changes in optoelectronic properties such as photoluminescence, charge transport, and absorption. We present a new series of hybrid metal-halide semiconductors, (phenH)BiI·HO, (2,2-bpyH)BiI, (BrbpyH)BiI·HO, (phenH)PbI·2HO, and (2,2-bpyH)PbI where (phenH) = 1,10-phenanthroline-1,10-diium, (2,2-bpyH) = 2,2'-bipyridine-1,1'-diium and (BrbpyH) = 6,6'-dibromo-2,2'-bipyridium.
View Article and Find Full Text PDFOrienting light-emitting molecules relative to the substrate is an effective method to enhance the optical outcoupling of organic light-emitting devices. Platinum(II) phosphorescent complexes enable facile control of the molecular alignment due to their planar structures. Here, the orientation of Pt(II) complexes during the growth of emissive layers is controlled by two different methods: modifying the molecular structure and using structural templating.
View Article and Find Full Text PDFCaprolactam, a precursor to nylon-6 has been investigated as part of our studies into the polymerization of materials at high pressure. Single-crystal X-ray and neutron powder diffraction data have been used to explore the high-pressure phase behavior of caprolactam; two new high pressure solid forms were observed. The transition between each of the forms requires a substantial rearrangement of the molecules and we observe that the kinetic barrier to the conversion can aid retention of phases beyond their region of stability.
View Article and Find Full Text PDFHybrid metal halides yield highly desirable optoelectronic properties and offer significant opportunity due to their solution processability. This contribution reports a new series of hybrid semiconductors, (CH)MX (M = Bi, Sb; X = Cl, Br, I), that are composed of edge-sharing MX chains separated in space by π-stacked tropylium (CH) cations; the inorganic chains resemble the connectivity of BiI. The Bi compounds have blue-shifted optical absorptions relative to the Sb compounds that span the visible and near-IR region.
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