Search

The globally widespread perfluorooctanoic acid (PFOA) is a concerning environmental contaminant, with a possible toxic long-term effects on the environment and human health The development of sensible, rapid, and low-cost detection systems is a current change in modern environmental chemistry. In this context, two triamine-based chemosensors, L1 and L2, containing a fluorescent pyrene unit, and their Zn(II) complexes are proposed as fluorescent probes for the detection of PFOA in aqueous media. Binding studies carried out by means of fluorescence and NMR titrations highlight that protonated forms of the receptors can interact with the carboxylate group of PFOA, thanks to salt bridge formation with the ammonium groups of the aliphatic chain. This interaction induces a decrease in the fluorescence emission of pyrene at neutral and slightly acidic pH values. Similarly, emission quenching has also been observed upon coordination of PFOA by the Zn(II) complexes of the receptors. These results evidence that simple polyamine-based molecular receptors can be employed for the optical recognition of harmful pollutant molecules, such as PFOA, in aqueous media.

Triamine-based receptors containing 2 anthracene units are able to signal ketoprofen in H2O/EtOH solution via fluorescence emission enhancement, exploiting a proton transfer process upon substrate coordination.

Binding ability of Zn(ii) complexes of [9]aneN3-based receptors for selective recognition of glyphosate in aqueous media.

N‐formyl peptide receptors (FPR1, FPR2, and FPR3) play key roles in the regulation of inflammatory processes, and recently, it was demonstrated that FPR1 and FPR2 have a dual role in the progression/suppression of some cancers. Therefore, FPRs represent an important therapeutic target for the treatment of both cancer and inflammatory diseases. Previously, we identified selective or mixed FPR agonists with pyridazinone or pyridinone scaffolds showing a common 4‐(bromophenyl)acetamide fragment, which was essential for activity. We report here new pyrazole and pyrazolone derivatives as restricted analogues of the above 6‐membered compounds, all exhibiting the same 4‐bromophenylacetamide side chain. Most new products had low or absent FPR agonist activity, suggesting that the pyrazole nucleus was not appropriate for FPR agonists. This hypothesis was confirmed by molecular modeling studies, which highlighted that the five‐membered scaffold was responsible for a worse arrangement of the molecules in the receptor binding site., N‐formyl peptide receptors (FPRs) play key roles in inflammation and cancer. The present paper reports a new series of pyrazole and pyrazolone derivatives as potential FPRs agonists, containing the 4‐(bromophenyl)acetamide fragment that was essential for activity in all our previous synthesized compounds. Molecular modeling studies, performed using the first FPR2 co‐crystallized protein, highlighted that the five‐member nucleous is responsible for a worse arrangement of the key fragment (4‐bromophenyl‐2‐acetamide chain) in the receptor binding site.

The synthesis of three new polyamine receptors based on a common 1,4,8,11-tetraazacyclododecane (cyclen) platform with appended, via a methylene linker, heteroaromatic fluorophores, a single quinoline (Q) or an 8-hydroxy-quinoline (8-OH-Q) moiety (L1 and HL2) or a Q and an 8-OH-Q unit (HL3), is reported. The proton binding features of these receptors, together with those of two similar receptors containing two equal Q moieties (L4) and two Q and two acetate groups (H2L5), have been studied by means of potentiometric, 1H NMR, UV-vis absorption and fluorescence emission measurements in aqueous solution at different pH values. While cyclen is a commonly used binding unit, Q and 8-OH-Q represent classical examples of signalling units in conjugated fluorescent chemosensors and their protonation features can strongly influence their ability in metal cations, and anion coordination and sensing. This study reveals that the structural features of these receptors are controlled by a subtle balance between hydrogen bonding and electrostatic repulsions occurring in their protonated species. At the same time, their emission properties are tuned by photoinduced electron and/or proton transfer processes taking place in the excited state.

The synthesis, solution studies, photochemical properties and the X-ray structure of a chromone based fluorescent PdII complex are reported. The ligand contains two chromone units linked as side arms to an ethylenediamine moiety; in the PdII complex the metal ion preorganizes the two hydroxychromone units forming a rigid structure with a negatively charged pocket formed by four oxygen atoms that is able to interact with hard metal cations, such as ions, giving rise to stable bimetallic complexes. Upon interaction with LaIII and GdIII, in particular, the emission intensity at 423 nm increases by a factor of 2 and 8, respectively, while the other rare earth ions quench the fluorescence. Spectrofluorimetric studies on real matrices showed the possibility to use this system as a selective fluorescence probe to detect and trace the presence of Gadolinium in environmental water acting as an OFF–ON chemosensor, with a LOD of 0.4 ppm and a LOQ of 1.2 ppm.

One-dimensional (1D) coordination polymers (CPs) featuring three different topologies, comprising zig-zag, ribbon-like and poly-[n]-catenane structures, were obtained by reaction of Hg(II) ions with a novel bispidine ligand L3, and structurally characterized by SC- and P-XRD methods. The CPs obtained in the form of microcrystalline powders were tested for their ability to undergo solvent adsorption and exchange by P-XRD and

The synthesis and characterization of the two new open-chain ligands 1,15-bis-[6-(2,2'-bipyridyl)]-2,5,8,11,14-pentaaza-octadecane (L1) and 1,15-bis-[2-(1,10-phenanthroline)-9-methyl]-2,5,8,11,14-pentaazaoctadecane (L2), both featuring a tetraethylenpentaamine chain linking via methylene bridges the 6 and 2 positions of two identical 2,2'-bipyridyl (bpy) and 9-methyl-1,10-phenanthroline (9-methyl-phen) moieties respectively, are reported. Their protonation and binding ability for Cu2+ , Zn2+ , Cd2+ and Pb2+ have been studied by coupling potentiometric titrations with UV-vis absorption and fluorescence emission measurements in water. L1 and L2 afford stable mono- and dinuclear complexes, in which the metal ion is bound by a single bpy or 9-methyl-phen unit and the amine groups on the aliphatic chain. However, L1 displays a greater binding ability for Cu2+ and Zn2+ with respect to L2, the stability constants of the [ML1]2+ complexes being 21.8 (Cu2+ ) and 19.4 (Zn2+ ) log units vs 20.34 and 16.8 log. units for the corresponding L2 species. Among all the metal ions tested, only the Zn2+ complex with L2 features an enhanced fluorescence emission at neutral pH, thanks to the simultaneous binding of one Zn2+ ion and H+ ion(s), that inhibits any possible photoinduced electron transfer (PET) process from the amine donors to the excited phen moiety. Binding of a second metal switches off the emission again.

A ligand comprised of a macrocyclic pyridinophane core having a pendant arm containing a secondary amine group linked through a methylene spacer to a pyridyl–oxadiazole–phenyl (PyPD) fluorescent system has been prepared (L). The crystal structures of [ZnL](ClO4)2 and [CuL](ClO4)2 show that M2+ is coordinated to all the nitrogen atoms of the macrocyclic core, the secondary amine of the pendant arm and the nitrogen atom of the pyridine group of the fluorescent moiety, the latter bond being clearly weaker than the one with the pyridine of the macrocycle. Solution studies showed the formation of a highly stable Cu2+ complex with 1 : 1 stoichiometry, whereas with Zn2+ least stable complexes were formed and, given the right conditions, a [Zn3L2]6+ species was also detected, but it was not possible to isolate this species in the solid state. Following Zn2+ coordination, a strong chelation-induced enhancement of fluorescence was observed, a behaviour that was not observed with any of the other metal cations tested.

International audience; Novel adducts of lithium hexafluoroacetylacetonato {Li(hfa)} with polyethers (monoglyme = {CH3OCH2CH2OCH3}, diglyme = {CH3O(CH2CH2O)2CH3}, triglyme = {CH3O(CH2CH2O)3CH3} and tetraglyme {CH3O(CH2CH2O)4CH3} have been synthesized through a single step reaction and characterized by FT-IR spectroscopy, 1H, and 13C NMR, single crystal X-ray diffraction studies along with thermal analysis.

The three different solid forms of dexktoprofen trometamol (DK-T_A, DK-T_B, and DK-T_2H2O) have been studied by using X-ray diffraction and calorimetric methods. In the molecular and crystal structure of DK-T_A, the thermodynamically stable form used in the tablets production process, all the potential H-bond donors and acceptors of each trometamol cation are involved in strong H-bonds which hold together the cations as well as the dexketoprofen/trometamol ionic pairs. The dihydrate species is quickly formed starting from DK-T_A apparently without the formation of an amorphous phase, and the process is fully reversible. In addition, the two solids have comparable crystal density (cell parameters and space group of the resulting hydrate were determined by X-ray powder diffraction). We speculate that the anhydrous and hydrate crystal architectures did not suffer upon the hydration/dehydration process and that the hydrate form belongs to the class of the channel hydrates and most probably is a planar hydrate. Finally, the unit cell parameters and space group were determined also for the metastable DK-T_B solid form.

The synthesis, solution studies, photochemical properties and the X-ray structure of a chromone based fluorescent Pd

The metoprolol free base has been characterized in the solid state by X-ray diffaction (both single-crystal and variable-temperature powder diffraction) and differential scanning calorimetry. These studies are supplemented by mol­ecular modelling and Hirshfeld surface analysis. Structural relationships with the strictly related betaxolol are discussed., Metoprolol {systematic name: (RS)-1-iso­propyl­amino-3-[4-(2-meth­oxy­eth­yl)phen­oxy]propan-2-ol}, C15H25NO3, is a cardioselective β1-adrenergic blocking agent that shares part of its mol­ecular skeleton with a large number of other β-blockers. Results from its solid-state characterization by single-crystal and variable-temperature powder X-ray diffraction and differential scanning calorimetry are presented. Its mol­ecular and crystal arrangements have been further investigated by mol­ecular modelling, by a Cambridge Structural Database (CSD) survey and by Hirshfeld surface analysis. In the crystal, the side arm bearing the isopropyl group, which is common to other β-blockers, adopts an all-trans conformation, which is the most stable arrangement from modelling data. The crystal packing of metoprolol is dominated by an O—H⋯N/N⋯H—O pair of hydrogen bonds (as also confirmed by a Hirshfeld surface analysis), which gives rise to chains containing alternating R and S metoprolol mol­ecules extending along the b axis, supplemented by a weaker O⋯H—N/N—H⋯O pair of inter­actions. In addition, within the same stack of mol­ecules, a C—H⋯O contact, partially oriented along the b and c axes, links homochiral mol­ecules. Amongst the solid-state structures of mol­ecules structurally related to metoprolol deposited in the CSD, the β-blocker drug betaxolol shows the closest analogy in terms of three-dimensional arrangement and inter­actions. Notwithstanding their close similarity, the crystal lattices of the two drugs respond differently on increasing temperature: metoprolol expands anisotropically, while for betaxolol, an isotropic thermal expansion is observed.

The solid-state investigation of the diastereomeric salts (S)-ibuprofen (S-Ibu), (S)-naproxen, (S-Nap), and (S)-ketoprofen (S-Ket) with (R)-(+)- and (S)-(-)-1-phenylethylamine, R-PEA, and S-PEA respectively, has been carried out by using a combination of experimental and in-silico tools. The focus was on their crystal packing and on the stability/transformation of their solid forms under different experimental conditions with the final aim of extracting useful information on the forces/features which could be exploited for the chiral separation of the corresponding racemic compounds. All the salts are 21-column crystals, each column consisting of API and 1-phenylethylamine ions assembled via the 1-phenylethylammonium-carboxylate supramolecular heterosynthon which originates a R43 (10) pattern, the intercolumns contacts being definitely weaker. In spite of an overall similarity in the crystal packing forces and motifs of the anhydrous salts, the temperature stability range suggests that the homochiral species are the most stable. The fact that the homochiral salt of S-Ket (S-Ket_S-PEA) is stable toward the hydration, at variance with the heterochiral one (S-Ket_R-PEA), further confirms this hypothesis. On the other hand, preliminary sorption tests show that S-Ket and S-Ibu preferentially capture the homochiral PEA (S-Nap is not selective). This behavior has been correlated to the almost planar boundary surfaces which characterize and differentiate the 21 sheets in S-Ket_S-PEA and S-Ibu_S-PEA salts with respect to the corresponding heterochiral ones.

Two new maltol-based ligands are presented, L1 (N,N′-bis((3-hydroxy-6-methyl-4-pyron-2-yl)methyl)-N,N′-dimethylethylenediamine) and L2 (N,N′-bis((3-hydroxy-6-hydroxymethyl-4-pyron-2-yl)methyl)-N,N′-dimethylethylenediamine). They were strategically designed by inserting a methyl or hydroxymethyl function at C6, to study the previously hypothesized involvement of that ring position in the anticancer properties and the peculiar metal coordination ability in aqueous solution already shown by this family of ligands. Solid state and solution studies revealed differences neither in the molecular conformation or crystal packing nor in the acid–base behavior compared with the precursor Malten. The introduced substituent groups seem to affect instead both the degradation time (ca. 4–5 h for L1 and L2vs. 10 h for Malten) and the binding properties towards Cu(II), Zn(II) and Co(II), log K values being the highest for L1 within the series of the diamino-bis-maltol ligands. The introduction of –CH2OH at C6 is sufficient to impair the biological activity of the compound and is coherent with the hypothesized mechanism of action.

The synthesis, photochemical properties, biological effects and the X-ray crystal structure of a fluorescent polyamine macrocycle L are reported. L is a polyamine cyclophane macrocycle in which 2,6-bis(5-(2-methylphenyl)-1,3,4-oxadiazol-2-yl)pyridine (POXAPy) acts as a fluorescent sensor and the polyamine as a metal ion binding unit. L performs as a PET-mediated chemosensor, with a maximum emission wavelength close to 360 nm. This gives rise to a signal that is visible to the naked eye in the blue visible range. L is able to detect the Zn(ii) and Cd(ii) metal ions in an aqueous solution at pH = 7, with the coordination of the ions switching the emission ON through a CHEF effect. In contrast, paramagnetic metal ions like Cu(ii) and Ni(ii) completely quench the already low emission of L at this pH value. L affects the cell survival of a leukemic cellular model (U937) at micromolar concentrations with cell death starting after only 24 h of exposure; starting from a final concentration of 5 μM, L almost completely abrogates the survival of the leukemic cells over 72 h, with a mechanism that is compatible with a genomic DNA interaction.

The hetero-tetranuclear Cu

A ligand comprised of a macrocyclic pyridinophane core having a pendant arm containing a secondary amine group linked through a methylene spacer to a pyridyl-oxadiazole-phenyl (PyPD) fluorescent system has been prepared (L). The crystal structures of [ZnL](ClO

Dexketoprofen trometamol is the tromethamine salt of dexketoprofen [(2S)-2-(3-benzoylphenyl)propanoic acid-2-amino-2-(hydroxymethyl)propane-1,3-diol], a nonsteroidal anti-inflammatory drug (NSAID) used for the treatment of moderate- to strong-intensity acute pain. The crystal structure of the hitherto sole known hydrate phase of dexketoprofen trometamol (DK-T_2H2O), as determined by single-crystal X-ray diffraction, is presented. The water molecules are arranged in dimers included in isolated sites and sandwiched between piles of trometamol cations. The molecular and crystal structures of DK-T_2H2O are analyzed and compared to those of the parent anhydrous crystal form DK-T_A. In both the crystal structures, all the potential H-bond donors and acceptor of the dexketoprofen and trometamol ions are engaged, and both the species crystallize in the P21 space group. However, during the DK-T_A&agrave, DK-T_2H2O hydration process, the unique symmetry axis is not conserved, i.e., the ions are arranged in a different way with respect to the screw axis, even if the two crystal structures maintain structural blocks of DK anions and T cations. Quantum mechanical solid-state calculations provide some hints for the possible intermediate structure during the crystalline&ndash, crystalline hydration/dehydration process.

Anisotropic lattice expansion could be a source of misunderstanding in powder pattern recognitions, especially in the case of organic crystals where for the interpretation of room temperature patterns single crystal data at low temperature are usually used. Trying to rationalize the thermal lattice expansion, we studied two close related &beta, blocker molecules with similar packing in the solid state but with different thermal behavior. Solid state calculations, using the fast and accurate HF-3c method and the quasi harmonic approximation for the simulation of the lattice expansion, were able to reproduce the experimental trends with good accuracy. The complete analysis of the calculated thermal expansion of the two structures, as well as of other structures with similar packing found in a database survey, revealed the primary role of the hydrogen bonds. Secondary non-covalent interactions in the plane perpendicular to the hydrogen bond system could also play a role.

The hetero-tetranuclear Cu2+ /Ca2+ /Ca2+ /Cu2+ complex obtained with the N,N'-bis((3-hydroxy-4-pyron-2-yl)methyl)-N,N'-dimethylethylendiamine (Malten) ligand has been studied in solid and solution states as scaffold to bind anions. Three crystal structures showing the same metal ions sequence have been examined; they display a tetracharged complex cation neutralized by four monocharged anions. The anions play two different roles: as coordinated (two ClO4 - , Cl- or NO3 - ) or ancillary (two ClO4 - ) guests. The tetranuclear scaffold hosts two anions also in aqueous and ethanol solutions. Spectrophotometric studies in ethanol allowed to determine the addition constant values for Cl- and Br- (Log K1-2 =4.43(4), 4.39(3) for Cl- , 3.80(3), 3.54(2) for Br- ) while the others, although bound, showed lower affinity for the scaffold. Both the crystals and the solutions change their color depending on the added anion, namely pink, dark green or blue in the presence of ClO4 - , Cl- or NO3 - , respectively, thus the presence of the different anions is visible to the naked eye. The hetero-tetranuclear Cu2+ /Ca2+ /Ca2+ /Cu2+ complex is a versatile architecture to be used as scaffold for anion binding.

The metoprolol fumarate (MF) salt has been characterized by a combined use of powder X-ray diffraction (PXRD), variable temperature PXRD (VT-PXRD), and differential scanning calorimetry. Its molecular and crystal structure, as determined from PXRD data, has been thoroughly compared to those of the analogous tartrate (MT-o) and succinate (MS-m) salts. Moreover, Hirshfeld surface analysis and graph sets analysis have been performed to achieve insights into the intermolecular interactions. Despite their evident similarities at the molecular level, the three salts behave differently upon temperature variation: MF expands/contracts anisotropically (as MS-m), but the melt takes 3 days to recover the starting crystalline phase (as MT-o). A rationale for this behavior is provided based on their crystal arrangements.

The title compound is a new heterotrinuclear CoII–CaII–CoII dimer of L1. L1 undergoes a cobalt-driven preorganization, leading to the formation of an electron-rich area able to host a hard metal ion such as CaII. In the dimer, two neutral [Co(H–2 L1)] moieties, held together by the CaII ion, are rotated by 90°. The trinuclear complexes form layers perpendicular to the c axis; the perchlorate anions are located between the layers and inter­act with the complexes, as well as the lattice water mol­ecules., The title compound, [CaCo2(C22H30N4O6)2](ClO4)2·1.36H2O or {Ca[Co(H–2 L1)]2}·2ClO4·1.36H2O {where L1 is 4,10-bis­[(3-hy­droxy-4-pyron-2-yl)meth­yl]-1,7-dimethyl-1,4,7,10-tetra­aza­cyclo­dodecane}, is a trinuclear complex whose asymmetric unit comprises a quarter of the {Ca[Co(H–2 L1)]2}2+ trinuclear complex, half of a perchlorate ion and 0.34-water mol­ecules. In the neutral [Co(H–2 L1)] moiety, the cobalt ion is hexa­coordinated in a trigonal–prismatic fashion by the surrounding N4O2 donor set. A Ca2+ cation holds together two neutral [Co(H–2 L1)] moieties and is octa­coordinated in a distorted trigonal–dodeca­hedral fashion by the surrounding O atoms belonging to the deprotonated oxide and carbonyl groups of two [Co(H–2 L1)] units. The coordination of the CoII cation preorganizes L1 and an electron-rich area forms, which is able to host hard metal ions. The comparison between the present structure and the previously published ones suggests a high versatility of this ligand; indeed, hard metal ions with different nature and dimensions lead to complexes having different stoichiometry (mono- and dinuclear monomers and trinuclear dimers) or even a polymeric structure. The heterotrinuclear CoII–CaII–CoII complexes are connected in three dimensions via weak C—H⋯O hydrogen bonds, which are also responsible for the inter­actions with the perchlorate anions and the lattice water mol­ecules. The perchlorate anion is disordered about a twofold rotation axis and was refined giving the two positions a fixed occupancy factor of 0.5. The crystal studied was refined as a two-component inversion twin [BASF parameter = 0.14 (4)].

The title compound, {[Ba{Co(H-2L1)}(ClO4)(H2O)]ClO4}n,L1 =4,10-bis[(3-hydroxy-4-pyron-2-yl)methyl]-1,7-dimethyl-1,4,7,10-tetraazacyclododecane, is a one-dimensional coordination polymer. The asymmetric unit consists of a {Ba[Co(H–2L1)](ClO4)(H2O)}+cationic fragment and a non-coordinating ClO4−anion. In the neutral [Co(H–2L1)] moiety, the cobalt ion is hexacoordinated in a trigonal–prismatic fashion by the surrounding N4O2donor set. The Ba2+ion is nine-coordinated and exhibits a distorted [BaO9] monocapped square-antiprismatic geometry, the six oxygen atoms coming from three distinct [Co(H–2L1)] moieties, while the remaining three vertices are occupied by the oxygen atoms of a bidentate perchlorate anion and a water molecule. A barium–μ2-oxygen motif develops along theaaxis, connecting symmetry-related dinuclear BaII–CoIIcationic fragments in a wave-like chain, forming a one-dimensional metal coordination polymer. Non-coordinating ClO4−anions are located in the space between the chains. Weak C—H...O hydrogen bonds involving both coordinating and non-coordinating perchlorate anions build the whole crystal architecture. To our knowledge, this is the first example of a macrocyclic ligand forming a BaII-based one-dimensional coordination polymer, containing CoIIions surrounded by a N4O2donor set.

The ibuprofen alkaline-earth compounds Ibuprofen-Mg and Ibuprofen-Ca were investigated by using combined solid state and solution studies. The molecular and crystal structures of the calcium (Ca_Ibu_Hy, a 1D-coordination polymer based on ibuprofen) and magnesium (Mg_Ibu_Hy_RT and Mg_Ibu_Hy_LT) ibuprofen dihydrate salts have been analyzed in depth by using X-ray diffraction (both single crystal and powder) and in-silico tools. Differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), variable temperature X-ray diffraction experiments were carried out to study the stability of the solid forms under different temperature conditions. The Mg_Ibu_Hy_LT → Mg_Ibu_Hy_RT transition, which occurs between 250 and 300 K, is fully reversible and consists of a mild rearrangement of the crystal structure. Upon raising the temperature, dehydration of the Mg_Ibu_Hy_RT phase occurs, which leads to a completely amorphous phase at T > 340 K. As a consequence, the RT phase of the MgII compound is stable in a quite narrow temperature range. The calcium salt, in turn, gives a partially crystalline anhydrous phase with rising temperature. The coordination behavior of ibuprofen towards MgII, CaII and SrII in a water–ethanol mixture has been studied by means of potentiometric titrations. Based on the almost identical formation constants for CaII- and MgII-Ibuprofen complexes and on the well-known great affinity of MgII-for water molecules, we speculated the formation of solvent-shared ion pairs in the latter case, where the MgII-carboxylate interaction is of the outer-sphere type.

A new tetraglyme adduct of sodium hexafluoroacetylacetonate [Na(hfa)·tetraglyme] has been synthesized and successfully used, together with the RE(hfa)3·diglyme (RE = Y, Yb, Er) complexes, in the synthesis of hexagonal phase NaYF4:Yb3+,Er3+ upconverting films through a facile sol–gel method.

Dexketoprofen [(2S)-2-(3-benzoylphenyl)propanoic acid], C16H14O3, is the S-enantiomer of ketoprofen, a nonsteroidal anti-inflammatory drug (NSAID) that has analgesic, antipyretic and anti-inflammatory properties, and finds applications for the short-term treatment of mild to moderate pain. A new crystalline phase of dexketoprofen is reported. Its solid-state structure was determined by single-crystal X-ray diffraction (SCXRD). The molecular structure of the two independent molecules found in the asymmetric unit of this new phase (DXKP-β) were compared to those of the already known crystal form of dexketoprofen (DXKP-α) and with the S-enantiomer of the racemic compound. The three different conformers of dexketoprofen found in DXKP-α and DXKP-β were then investigated by computational methods. The optimized structures are very close to the corresponding starting geometries and do not differ significantly in energy. The crystal packing of DXKP-β was studied by means of Hirshfeld surface (HS) analysis; interaction energies were also calculated. A comparison with DXKP-α shows close similarities between the two crystal forms, i.e. in both cases, molecules assemble through the catemer O—H...O synthon of the carboxylic acid stabilized by additional C—H...O contacts and, accordingly, the interaction energies, as well as the contributions to the HS area, are very similar. Finally, the thermal behaviour of the two polymorphs of dexketoprofen was assessed by means of XRD (both from single crystal and microcrystalline powder) and differential scanning calorimetry (DSC); both crystal forms are stable under the experimental conditions adopted (air, 300–350 K for DXKP-α and 300–340 K DXKP-β) and no solid–solid phase transition occurs between the two crystal forms in the investigated temperature range (from 100 K up to ca 350 K).

Different variation of one crystallographic axis respect the other ones leds to the so called anisotropic lattice expansion. It could be visualized as a significant shift of a family of peaks during a temperature dependent X-Ray Powder Diffraction experiment. Wrong conclusions on the purity and/or composition of a crystalline phase could be drawn looking to the diffractogram without considering the effect of anisotropic expansion. We first observed anisotropic lattice expansion in metoprolol succinate salt ( metoprolol = (±)-1-isopropylamino-3-[4-(2-methoxy-ethyl)-phenoxy]-propan-2-ol) salt. It is interesting to note that in the case of the related and structural close, metoprolol tartrate salt no such behavior was found. [1] Also the metoprolol free base is subject to anisotropic expansion while the betaxolol expands isotropically beside few structural differences and close solid state arrangement. [2] At the moment we have no easy rationalization for the phenomena. [1, 2] With the aim to shed some light on this phenomenon and to rationalize the factors responsible for it, we started an investigation using semiempirical HF-3c method. [3] We were able to reproduce the experimental observations at a reasonable computational cost within the standard error in reproducing crystal structures. [4] The method was tested against the DFT B3LYP with dispersion correction. [5] The anisotropic expansion was predicted to be active for the solid structure of other molecules with the metoprolol core.

The anisotropic lattice expansion is a different variation of one crystallographic axis respect the other ones. In a temperature dependent X-Ray Powder Diffraction experiment, the anisotropic lattice expansion can be visualized as a significant shift of a set of peaks while others practically did not move. As a consequence, the anisotropic expansion could lead wrong conclusions on the purity and/or composition of a crystalline phase. We observed anisotropic lattice expansion for metoprolol succinate salt ( metoprolol = (±)-1-isopropylamino-3-[4- (2-methoxy-ethyl)-phenoxy]-propan-2-ol) salt. For the related and structural close, metoprolol tartrate salt no such behavior was found. [1] Moreover also the metoprolol free base is subject to anisotropic expansion while the related betaxolol, with similar solid state arrangement and very small structural difference, expands isotropically. [2] In this work, we show that semiempirical HF-3c method [3] is able to reproduce the experimental observations at a reasonable computational cost within the standard error in reproducing crystal structures. [4] Our protocol could help to shed some light on the anisotropic lattice expansion in organic crystals and to rationalize the factor responsible for the phenomenon. [1] P. Paoli, P. Rossi, E. Macedi, A. Ienco, L. Chelazzi, G. L. Bartolucci, B. Bruni Cryst. Growth Des. 2016, 16, 789. [2] P. Rossi, P. Paoli, L. Chelazzi, L. Conti, A. Bencini Acta Cryst. 2019, C75, 87. [3] R. Sure, S. Grimme J. Comput. Chem. 2013, 34, 1672. [4] M. Cutini, B. Civalleri, M. Corno, R. Orlando, J. G. Brandenburg, L. Maschio, P. Ugliengo J. Chem. Theory Comput. 2016, 12, 3340.

We report the synthesis of novel heterobimetallic precursors of the formula [RE(hfa)

A new organic-inorganic hybrid compound of formula: (H2L) (HgBr4)·2H2O [L = 3,3′-diaminobiphenylsulfone] has been obtained by slow evaporation. Its crystal structure determined by X–ray single crystal analysis reveals that this compound crystallizes in the monoclinic system with P21/c space group. The crystal packing is dominated by strong interactions between (H2L)2+ cations and the crystallization water molecules as provided as also evidenced by the Hirshfeld Surface analysis (HS), which highlight that the H⋯O/O⋯H contacts are by far the most important ones. The crystal packing was further investigated by using infrared and Raman spectroscopy, as well as computational techniques which allow to calculate the vibrational frequencies of the species. In addition, TGA, DTA and DSC analyses were carried out to study the thermal behavior. The UV–visible behavior was also investigated to determine the optical properties.

MEN11282 (1) is a precursor of nepadutant (MEN11420), a potent and selective antagonist at the human tachykinin NK-2 receptor (hNK-2), that has been evaluated in clinical trials for different therapeutic indications. Three crystalline forms of 1 were identified and characterized by both single crystal and powder X-ray diffraction (SCXRD and XRPD): a monohydrate (1·H2O, SCXRD) and two different anhydrous forms, namely, 1_α and 1_β (XRPD). Because of the relevance that the solid form of a substance of pharmaceutical interest plays during the manufacturing process, variable temperature powder X-ray diffraction (VT-XRPD) in conjunction with differential scanning calorimetry were used to investigate the behavior of the different solid forms of 1. The rationale for the dehydration and hydration process involving 1·H2O and 1_α and the stability of 1_β toward water uptake is provided based on their crystal packings.