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Radioactive iodine from nuclear waste poses a major threat to public safety due to its toxicity and long half-life. The capture and storage of radioactive iodine remains a major challenge. The incorporation of electron-rich heterocycles into the adsorbents could increase the adsorption capacity for iodine due to their strong interaction. In this study, three novel spiro-thioketal-based porous organic polymers, POPSP-1–3, were synthesized in excellent yields by a thiol-aldehyde polycondensation reaction. The polymers of POPSPs were thoroughly characterized using FT-IR, 13C-NMR, BET, and PXRD techniques. These analyses revealed that the polymers are amorphous in nature and have a low surface area. The iodine uptake capacities of POPSP-1, POPSP-2, and POPSP-3 were measured to be 4.13, 5.25, and 5.65 g g−1, respectively, at a temperature of 75 °C due to the increased density of the adsorption sites. Furthermore, the POPSPs exhibit exceptional adsorption performance in iodine/n-hexane solution and their effectiveness in removing iodine is excellent. This work provides a novel approach for the development of sulfur-rich porous organic polymers (POPs) as effective adsorbents for iodine capture. [ABSTRACT FROM AUTHOR]

Cocrystal modification strategy has been applied to 3,5-dichlorosalicylic acid (DCA) through the addition of various liquid pyrazine derivatives: 2,3-dimethylpyrazine (2,3-DMP); 2,5-dimethylpyrazine (2,5-DMP); and 2,3,5-trimethylpyrazine (TMP). Three new cocrystals (2,3-DMP-DCA = 1:2 for 1; 2,5-DMP-DCA = 1:2 for 2; and TMP-DCA = 1:1 for 3) have been obtained, all of which were characterized by X-ray diffraction analysis, infrared spectroscopy, thermogravimetric analyses and UV–Vis spectroscopy. The Hirshfeld surface analysis has been performed to illustrate the intermolecular interactions. The results revealed that hydrogen bonding and other weaker interactions such as halogen bonding contacts and π···π stacking participated in a cooperative way to stabilize the supramolecular structures and different methyl substitutions changed the bonding mode and intermolecular force of pyrazine derivative cocrystals. Thermodynamic results showed that the stability of liquid pyrazine spices can be improved and the decomposition temperature for cocrystal 3 is higher than the other cocrystals. This work provides an approach to solidification of liquid pyrazine spices for more applications. [ABSTRACT FROM AUTHOR]

Precise revealing the mechanisms of excited‐state intermolecular proton transfer (ESPT) and the corresponding geometrical relaxation upon photoexcitation and photoionization remains a formidable challenge. In this work, the compound (E)‐4‐(((4H‐1,2,4‐triazol‐4‐yl)imino)methyl)‐2,6‐dimethoxyphenol (TIMDP) adopting a D‐π‐A molecular architecture featuring a significant intramolecular charge transfer (ICT) effect has been designed. With the presence of perchloric acid (35 %), TIMDP can be dissolved through the formation of a HClO4–H2O–OH(TIMDP)–N(TIMDP) hydrogen‐bonding bridge. At the ground state, the ICT effect is dominant, giving birth to crystals of TIMDP. Upon external stimuli (e.g. UV light irradiation, electro field), the excited state is achieved, which weakens the ICT effect, and significantly promotes the ESPT effect along the hydrogen‐bonding bridge, resulting in crystals of [HTIMDP]+⋅[H2O]⋅[ClO4]−. As a consequence, the mechanisms of the ESPT can be investigated, which distorted the D‐π‐A molecular architecture, tuned the emission color with the largest Stokes shift of 242 nm, and finally, high photoluminescence quantum yields (12 %) and long fluorescence lifetimes (8.6 μs) have achieved. These results not only provide new insight into ESPT mechanisms, but also open a new avenue for the design of efficient ESPT emitters. [ABSTRACT FROM AUTHOR]

Combining the advantages of ultrathin two-dimensional (2D) nanosheets featuring stimuli-responsive properties with lanthanide-doped upconverting nanoparticles (UCNPs) represents a challenging goal in near infrared (NIR) light-triggered molecular switching under ambient conditions. Here, we present the fabrication of a 2D@UCNPs hybrid system comprising the integration of distinct features of atomically thin 2D spin-crossover nanosheets ({[Fe(1,3-bpp)2(SCN)2]2}n) and ytterbium ion (Yb3+)-sensitized hexagonal phase UCNPs [sodium yttrium fluoride (NaYF4): 20 mol% Yb3+, 1 mol% erbium ions (Er3+)]. The UCNPs are hybridized with 2D nanosheets involving bare thiocyanate (SCN−) ligands on both sides of the basal surfaces of the nanosheets, and as a consequence, effective synergistic effects between the up-conversion luminescence (UCL) and spin-state interconversion were established. Upon NIR (980 nm) irradiation, the UCL weakened the metal-to-ligand charge-transfer (MLCT) and triggered high-spin (HS) to low-spin (LS) state transition. Upon subsequent heating (40 °C), the MLCT strengthened and the LS to HS state transition was achieved, suggesting a reversible molecular-switching had occurred which was triggered by altering NIR and thermal stimuli. In addition, the corresponding aqueous colloidal suspension is highly stable, nontoxic, environmentally and human friendly in nature, making it suitable for practical applications in photo-switching devices and fabrication of next-generation user-friendly and wearable, fashionable optoelectronic devices. [ABSTRACT FROM AUTHOR]

The co-delivery of two or more anti-tumor agents using nanocarriers has shown great promise in cancer therapy, but more work is needed to selectively target drugs to specific subcellular organelles. To this end, our research has reported on “smart” polymeric nanoparticles that can encapsulate two different site-oriented pro-drug molecules, allowing them to reach their targeted subcellular organelles based on NIR-mediated controlled release, allowing for targeted modifications in the nucleus or the mitochondria. Specially, an all-trans retinoic acid (RA) conjugated cisplatin derivative (RA–Pt) can be delivered with high affinity to the nucleus of target cells, facilitating the binding of cisplatin to double-stranded DNA. Similarly, a synthesized derivative generated by conjugation of triphenylphosphine (TPP) and celastrol (TPP–Cet) may facilitate mitochondrial targeted drug delivery in tumor cells, inducing ROS accumulation and thereby leading to apoptosis. Relative to nanoparticles loaded with a single therapeutic agent, dual antitumor agent-loaded nanocarriers showed promising synergy, exhibiting significant tumor inhibition in vivo (81.5%), and less systemic toxicity than the free therapeutic agents alone or the drug-loaded nanoparticles without targeted ligands. These results indicated that site-oriented payloads can effectively enhance antitumor therapeutic efficiency and these studies offer a novel “multistage targeted-delivery” strategy in synergistic therapy for cancer treatment. [ABSTRACT FROM AUTHOR]

In this work, two new single crystals of copper-tetraphenylporphine (Cu-TPP) (crystals 2 and 3), which were induced by external magnetic fields with strengths of 0.5 and 0.8 T, respectively, have been prepared and characterized by single-crystal X-ray diffraction and Hirshfeld surface analysis. Compared with the original Cu-TPP (crystal 1), crystals 2 and 3 exhibit significant differences in their unit cell parameters, crystalline stacking styles and intermolecular interactions, resulting in a “compressed” crystal packing. Here, the number of closer interactions (H…H, C…H/H…C) increased with the magnetic field strength, accompanied by a decrease in the number of π…π (C…C) interactions as a sacrifice. On considering the results of our previous work, the results here suggest that a magnetic field has a different influence on the crystallization process of mono-component and multi-component materials, which will certainly provide some suggestions for the design of crystallization strategies for other materials with the presence of an external magnetic field. [ABSTRACT FROM AUTHOR]

Rivaroxaban is an oral direct Factor Xa inhibitor to treat thrombus. The aim of this study is to investigate the drug-excipient compatibility between rivaroxaban tablet and pharmaceutical excipients by a combination of thermal and spectroscopic methods. Differential scanning calorimetry (DSC) is the most important technique to evaluate the compatibility. In addition, X-ray powder diffraction (XRPD) is a complementary technique to explain the DSC result and exclude relevant interaction. On the basis of DSC curves about rivaroxaban and excipient and mixture (1:1, w/w), the rivaroxaban was considered to be compatible with the most excipients (microcrystalline cellulose, lactose, hydroxyl propyl methyl cellulose, magnesium stearate). Meanwhile, the XRPD studies also showed the compatibility of rivaroxaban and pharmaceutical excipients, especially for the sodium lauryl sulfate. Overall, the compatibility of the excipients with rivaroxaban was assessed successfully by DSC and XRPD, and the formulations developed using the compatible excipient were found to be stable. [ABSTRACT FROM AUTHOR]

In order to determine the effect of halogen bonding on supramolecular assemblies and photophysical properties of diaryl oxalates, diaryl oxalate itself and its derivatives with fluorine, chlorine, bromine, and iodine substituents in the p-position of phenyl rings were studied and compared. Their single-crystal structures were studied by geometrical analysis and theoretical calculation. The study reveals that different halogen bonds are formed with respect to different halogen atoms, such as C...F and X...X (bromine and iodine atoms) interactions, and molecular stacking modes would be affected by halogen bonds directly. Comparative studies of photophysical properties in dilute solution and solid state indicate that halogen substitutions would not affect the emission processes of diaryl oxalates in dilute solution; this is not the case for their solid state. This work has demonstrated that halogen bonds play an important role in regulating structures and photophysical properties of diaryl oxalates. [ABSTRACT FROM AUTHOR]

An investigation into the effect of switching methoxy and hydroxyl groups on molecular salts is presented in this study. The salts HL1+·NO3− (1), L1·HL1+·ClO4− (2), L1·HL1+·H2PO4−·H2O (3), HL2+·NO3− (4), HL2+·ClO4− (5) and HL2+·H2PO4− (6) were synthesized and structurally characterized. The study was carried out by analyzing the crystal structure, properties and intermolecular interactions within each of the salts using IR and fluorescence spectra, TGA, Hirshfeld surface analyses and π…π stacking motifs. Salt 1 has a layered structure, while 4 has a distorted 3-D structure. Salt 2 possesses an edge-to-face type plane interaction, while 5 is formed with a twisted structure. It is important to note that water molecules play a key role in the 1-D chain structure of salt 3. The π…π stacking motif of salts 1–3 have a herringbone structure, while salts 3–6 exhibit a γ-structure. In addition, the competitive crystallization of the synthetic salts was investigated and found to be consistent with the measured solubility. [ABSTRACT FROM AUTHOR]

Abstract: Fabricating of melamine (MM)‐based multi‐component functional self‐assemblies have been investigated intensively. However, studies on protonated MM still in its infancy. Hence in this work, we studied the self‐assembly of protonated MM in different forms (1⋅ClO4− [MMH+⋅ClO4−⋅H2O], 2⋅Br− [MMH2+⋅2Br−⋅H2O], and 3⋅Cl− [MMH2+⋅2Cl−⋅H2O]) with various oxoanions (SO42−, NO3− and PO43−). Results revealed that the original anions ClO4‐, Br‐, and Cl‐, though not included in these self‐assemblies, are mainly responsible for the spectacular morphologies, from cuboids (1.SO42−) to prismoids (2.SO42−), sheets (3.SO42−), fibers (1.NO3−), rods (2.NO3−, 3.NO3−) and ribbons (1.PO43−, 2.PO43−, 3.PO43−). The crystalline phase and compositions of these self‐assemblies were found to be independent from the original protonated MM and the degree of protonation, while depend on the specific oxoanions. Therefore, the self‐assembly mechanism can be proposed. These results may provide an effective strategy for morphological control, especially for further development in protonated MM‐based functional materials. [ABSTRACT FROM AUTHOR]

By using the ligands 4-(4-bromobenzylideneamino)-4H-1,2,4-triazole (L1) and 4-(4-iodobenzylideneamino)-4H-1,2,4-triazole (L2), four different organic salts HL1+·Cl− (1), L1·HL1+·ClO4− (2), HL2+·Cl− (3), and L2·HL2+·ClO4− (4) have been synthesized and structurally characterized through single-crystal X-ray diffraction (L1, L2, 2 and 3) and PXRD (1 and 4) measurements. The results revealed that ligands L1 and L2 themselves exhibit a polymeric 1-D chain in a zigzag structure connected by C–Br…N and C–I…N halogen-bonding contacts, respectively. L1 in salt 2 was connected into a 3-D structure through N–H…O hydrogen-bonding contacts, while the interleaved 3-D network of L2 in salt 3 was mainly connected by C–I…Cl halogen-bonding contacts. As a result, the fluorescence properties of ligands L1 and L2 were reserved in halogen-bonding connected salts 1 and 3, while there was a reduction in hydrogen-bonding connected salts 2 and 4. Thus, the relationship between emission properties and halogen-bonding contacts can be proposed. [ABSTRACT FROM AUTHOR]

In this study, the potential of oxoanion separation with the ligands N-4-methylbenzyl-4-amino-1,2,4-triazole (L1), N-4-fluorobenzyl-4-amino-1,2,4-triazole (L2), N-4-hydroxy benzyl-4-amino-1,2,4-triazole (L3), and N-3-methoxy-4-hydroxybenzyl-4-amino-1,2,4-triazole (L4) was explored. The salts of sulphate, nitrate, and perchlorate were crystallized in the form of [HL1]+[HSO4]−·H2O, [HL2]+[HSO4]−·H2O, 2[HL3]+[SO4]2−·2(H2O), and 2[HL4]+[SO4]2−·H2O, [HL3]+[NO3]−·H2O and [HL4]+[NO3]−, and [HL3]+[ClO4]− and [HL4]+[ClO4]−, respectively. Competitive crystallization and competitive sulphate-binding experiments demonstrated special recognition of the sulphate–water clusters (in the forms of [HSO4−·H2O]n or [SO42−·H2O]n) via the parallel packed 3-D architectures of HL1+, HL2+, and HL4+ cations, which were far more effective and selective than the non-3-D structure of HL3+ cation. The observed selectivity for sulphate, nitrate, and perchlorate was found to be anti-Hofmeister. In addition, the selective separation of sulphate anions in seawater was investigated, which demonstrated the real-world application of the present strategy. [ABSTRACT FROM AUTHOR]

Because of the differences in the position and degree of fluorine substitution, four fluorinated DSA (9,10-distyrylanthracene) derivatives, namely 9,10-bis(4-fluorostyryl)anthracene (4-BFSA), 9,10-bis(3-fluorostyryl)anthracene (3-BFSA), 9,10-bis(3,5-difluorostyryl)anthracene (BDFSA) and 9,10-bis(3,4,5-trifluorostyryl)anthracene (BTFSA), display different crystal packing and photophysical properties in the solid state. Furthermore, the photophysical properties in solution have been investigated. The results show that all the four compounds exhibit tunable aggregation-induced enhanced emission (AIEE) properties. Notably, DSA, 4-BFSA, 3-BFSA and BDFSA display solvatochromic properties. The relationship between their structures and photophysical properties was further discussed. This work has demonstrated that depending on the amount and position, fluorine substitution can tune the structures and photophysical properties of DSA effectively. [ABSTRACT FROM AUTHOR]

Two complexes 1 [Cu(L1)2(H2O)2]·2H2O and 2 [Co(L2)2 (H2O)4]·4H2O formed by hetero N- and O-donor ligands 1-methyl-3-imidazole-4-carboxylic acid (L1H) and 2-methyl-5-pyridine carboxylic acid (L2H) have been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. These two complexes consist of a 2:1 ratio of ligand to metal ion. The analysis of Hirshfeld surfaces and crystal structures reveal that O‒H···O hydrogen bond interactions and C‒H···π intermolecular interactions support the three-dimensional supramolecular structures of complexes 1 and 2. Meanwhile, the coordinated water molecules and lattice water molecules play a key role in the construction of their crystal structures. [ABSTRACT FROM AUTHOR]

Three diaryl oxalate derivatives, bis(4-chlorophenyl)oxalate, bis(2, 6-dichlorophenyl)oxalate and bis(2, 4, 6-trichlorophenyl)oxalate, have been synthesized and characterized via X-ray single crystal diffraction, differential scanning calorimetry, thermogravimetric analysis and infrared spectra, for the purpose of studying the influence of chlorine substitution on the crystal structures of diaryl oxalate. This work has demonstrated that, depending on the position and number, chlorine substitution will influence the molecular geometries and stacking modes of diaryl oxalate by tuning the types and numbers of intermolecular interactions. [ABSTRACT FROM AUTHOR]

The co-crystallization of a benzimidazole derivative ( 1, CHNO, 3-[[[2-[[(4-Cyanophenyl) amino]methyl]-1-methyl-1H-benzimidazol-5-yl]carbonyl]pyridin-2-ylamino]propionic acid ethyl ester), with fumaric acid (FA) and maleic acid (MA), has been performed. The FA and MA molecules, both are connected with two molecules of CHNO, giving birth to a three-components compound ( 1·0.5FA, CHNO) and a four-components compound ( 1·MA, CHNO). Single-crystal X-ray diffractions show that the three different planar moieties (4-cyanophenyl, benzimidazol, and pyridin-2-yl) in compound CHNO display ' cis-form' conformation ( a) in the crystal of 1, while exhibiting 'intermediate-state' conformation ( b) and ' trans-form' conformation ( c) in compounds 1·0.5FA and 1·MA, respectively. Hirshfeld surfaces analysis, DFT calculations, DSC measurements, IR and Raman spectroscopy were performed, which revealed that the thermal stability of the three conformations follows the order c > b > a. [ABSTRACT FROM AUTHOR]

Two new mononuclear iron (II) coordination complexes: Fe(L1)2(SCN)2(1, L1:5-dimethylether-4-(4-methylphenyl)-3-(2-pyridinyl)-1,2,4-triazole) and Fe(L2)3(ClO4)2(2, L2:1-ethyl acetate-2-(2-pyridinyl)-imidazole), for the exploration of spin-crossover compounds have been synthesized and characterized. Structural analysis revealed that the framework of complex1is featured with 1-D chain structure connected by weak π···π interactions between the adjacent L1ligands, while complex2featured with various kinds of weak intermolecular hydrogen bonding interactions between Fe(L2)32+cation and ClO4−anion, which lead to a close crystal packing. The intermolecular interactions have shown a significant influence on the physical properties, and magnetic measurements of complexes1and2in the solid state at the room temperature revealed that the weak intermolecular interactions in1resulted in HS (high-spin) state, while the strong interactions in2lead to LS (low-spin) state over the whole temperature range. [ABSTRACT FROM PUBLISHER]

Nano-scale materials are acquiring a leading role in the fabrication of new generation devices, especially for the practical application of molecular bi-stability. However, the preparation of purely bi-stable nano-objects without the use of surfactants/polymers remains a challenging task. Here, we present a new approach to prepare spin-crossover (SCO) vesicular nano-spheres with single-external diameters of approximately 100 nm using a CHCl3–H2O mixture. The nano-spheres are based on a series SCO complexes, [Fe(H2Bpz2)2(dialkyl-bipy)] (H2Bpz2 = dihydrobis(1-pyrazolyl)borate, dialkyl-bipy = N4,N4′-dialkyl-(2,2′-bipyridine)-4,4′-dicarbo-xamide, alkyl = propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and cetyl), and are prepared through a self-assembly process that is similar to liposomal assembly, with the dialkyl-bipy moiety acting as the hydrophobic tail and the Fe(H2Bpz2) moiety acting as the hydrophilic head. This study reveals that the alkyl chain length plays a key role in the formation of these nano-spheres and the determination of their spin transition temperatures. The spin transition temperatures for the bulk materials are centered at around 160 K, and show a positive correlation with the alkyl chain length. Meanwhile, for the vesicular nano-spheres in the solid state, their transition temperatures are above room-temperature, and the correlation with the alkyl chain length is negative. These results provide an effective strategy for the design of new metal–organic materials for nano-technological applications. [ABSTRACT FROM AUTHOR]

The compound {[Zn(μ-dicyanamide)(pyrazinamide)](pyrazinamide)} has been synthesized and further characterized by elemental analysis, single-crystal X-ray diffraction, and thermogravimetric analysis. Structural analysis revealed that the dicyanamide anion acted as bridging ligand in a μ-1,5 mode, resulting a polymeric 1-D chain structure. The pairwise N3-H3B···N1 and N9-H9B···N7, N3-H3A···O2 and N9-H9A···O1, N3-H3B···N7 and N9-H9B···N1 multiple hydrogen bonding interactions, impart enhanced stability to supramolecular structures. Hirshfeld surfaces and fingerprint plots were applied to arrive at the same conclusion, which is stabilised mainly by H-H, N-H, O-H interactions. DNA binding studies showed that the compound had interacted with DNA. [ABSTRACT FROM AUTHOR]

A series of Fe(II) complexes with (ClO4)−(SeCN)−, (ClO4)−(SCN)−, (Fe2OCl6)2−, and 2(BF4)−counter-anions for complexes1–4, derived from dmbpy (4,4′-dimethyl-2,2′-bipyridine), were prepared. The single-crystal studies and the Hirshfeld surfaces analysis revealed that the (Fe2OCl6)2−anion results more distortional octahedral geometry of the cation than other anions. In particular, the (ClO4)−(SCN)−and (Fe2OCl6)2−anions lead to complexes2and3stabilized via C-H···π interactions and π···π interactions, which were not found in the other two complexes. However, the double-chain structure of complex4was formed by C-H···F and C-H···C hydrogen bonds interactions. Due to the influence of different anions, magnetic susceptibility measurements showed that complex1was in high-spin (HS) state and complex2was in low-spin (LS) state. [ABSTRACT FROM PUBLISHER]

Four novel lanthanide compounds based on the 4-(4-carboxyphenyl)-1,2,4-triazole ligand (Hcpt), {[Pr2(cpt)4(H2O)10]·10H2O·2ClO4} (1), {[Ln(cpt)2(H2O)2(OH)]·4H2O}n (Ln = Er(2), Lu(3)), and {[Sm(cpt)2(CH3CH2OH)(H2O)3]·ClO4}n (4), have been obtained under hydrothermal conditions and further characterized by elemental analysis, single-crystal X-ray diffraction and thermogravimetric analysis. Compound 1 exhibits a discrete dinuclear structure constructed by one cpt− ligand coordinated to two Pr3+ ions and another cpt− ligand coordinated to more than one Pr3+ ion. Compounds 2 and 3 are isomorphous and every cpt− ligand coordinates to two Ln3+ ions, resulting in a polymeric 1-D chain structure. Different from the above compounds, the nitrogen atoms of triazole are also involved in the coordination of compound 4. One cpt− ligand coordinates to two Sm3+ ions and another cpt− ligand coordinates to more than one Sm3+ ion, meanwhile, the nitrogen atoms of triazole coordinate to the third Sm3+ ion, resulting in a 2-D polymeric network structure. The luminescence properties of compound 4 were characterized, and the results revealed that it exhibited characteristic Sm3+ emission in the yellow region. [ABSTRACT FROM AUTHOR]

Single crystals of compound L (CHN): 4-(2-benzimidazole)-1,2,4-triazole and its hydrate were obtained via slow evaporation. The structures of the crystals were characterized by IR, TGA/DSC and X-ray diffraction analysis. Molecules in crystal 1 are linked by a combination of N-H···N and C-H···N hydrogen bonds into 2D layers, and further stacked into a 3D structure by π··· π stacking interactions. Compared to crystal 1, the water molecules play a key role in the construction of the crystal structure of hydrate 2. The 2D layers were formed via O-H···N, O-H···O, N-H···N hydrogen bonds, and further stacked by O-H···O hydrogen bonds and π··· π stacking interactions in crystal 2. A detailed analysis of the intermolecular interactions and crystal packing via Hirshfeld surface analysis and fingerprint plots reveals that the structures are stabilized mainly by N···H/H···N, C···H/H···C hydrogen bonds, H···H weak interactions and π··· π stacking interactions. [ABSTRACT FROM AUTHOR]

2,3-Dimethylpyrazine and 1,2-bis(4-pyridyl)ethane are both N-containing aromatic heterocyclics with two N atoms approximately in the para position. We here report two compounds derived from these heterocyclics (compounds 1 and 2). Compounds 1 and 2 both form a 1:1 2,3-dimethylpyrazine:perchloric acid (PA) and 1,2-bis(4-pyridyl)ethane:PA cocrystal, respectively. Their crystal structures were characterized by single-crystal X-ray diffraction, which revealed that the C-H⋯O and N-H⋯O hydrogen bonding interactions were found to stabilize the crystal structure in compounds 1 and 2. However, PA plays a necessary role for the one-dimensional structure in 1 and the three-dimensional structure in 2. Hirshfeld surfaces and fingerprint plots were applied to get the same conclusion. [ABSTRACT FROM AUTHOR]

Four DSA (9,10-distyrylanthracene) derivatives, namely 9,10-bis(4-fluorostyryl)anthracene (BFSA), 9,10-bis(4-chlorostyryl)anthracene (BCSA), 9,10-bis(4-bromostyryl)anthracene (BBSA) and 9,10-bis(4-iodostyryl)anthracene (BISA) have been synthesized and characterized via single crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry, photoluminescence spectroscopy, ultraviolet-visible absorption spectroscopy, solid fluorescence quantum yield measurement and other techniques, for the purpose of studying the influence of halogen atoms on the structures and photophysical properties of 9,10-distyrylanthracene. The results indicate that the introduction of halogen atoms into DSA significantly influences the molecular geometries and stacking modes in the crystals. The photophysical properties in solution and in the crystalline state of the five compounds were comparatively investigated, and the relationship between the crystalline state emissions and crystal structures was further discussed. This work has demonstrated that the introduction of halogen atoms into DSA could influence the molecular packing and molecular geometries in the crystals and endow them with different photophysical properties. [ABSTRACT FROM AUTHOR]

The quantitative visualizations and comparisons between the four pyrazinamide (PZA) polymorphs (α, β, γ and δ) have been investigated by graphical tools based on three-dimensional Hirshfeld surfaces and two-dimensional fingerprint plots. The comparisons were performed in terms of crystal structure, d, Shape index, Curvedness and d surfaces, and fingerprint plots. The results revealed that the α and γ forms featured with 1D chains and the π···π stacking motifs belong to γ-motif, rich in π···π interactions and form infinite face-to-face stacks, β and δ forms featured with dimer unit and the π···π stacking motifs belong to γ- and herringbone-motif, respectively, the herringbone motif of δ form rich in C-H···π and edge-to-face interactions. We also correlated the phase transformation points of α, β, and δ PZA forms with the ratio of the percentage surface coverage of the N-H···O hydrogen bonds over that of the N-H···N hydrogen bonds, and found a negative correlation. [ABSTRACT FROM AUTHOR]

DNA polyhedron-caged gold nanoparticles (AuNP) were self-assembled using four-point-star DNAs, with three strands hybridizing to each other and the fourth strand attaching to the AuNPs. The DNA-caged AuNPs can work as nanocarriers for doxorubicin, and controlled release behaviour can be triggered by both a DNA enzyme and by the pH value. [ABSTRACT FROM AUTHOR]

A new organic salt of dyclonine (DYC) with p-toluenesulfonic acid ( p-TSA) has been synthesized and characterized by elemental analysis, single-crystal X-ray diffraction, IR spectra, UV spectra, and hot stage microscopy. The structure determination shows that the asymmetric unit of the salt consisting of two entire ions of DYC and p-TSA, and that they are not symmetric. The salt is primarily stabilized by a strong N-H···O hydrogen bonding interaction between DYC and p-TSA. In addition, the luminescent properties and biological activities are discussed. [ABSTRACT FROM AUTHOR]

We here reported a series of co-crystal structure of pyrazinamide (PZA) with m-hydroxybenzoic acid (MHBA), p-hydroxybenzoic acid (PHBA) and 3,4-dihydroxy benzolic acid (3,4-DHBA) and obtained three co-crystals (co-crystal 1- 3, respectively) under the same conditions. These crystal structures were characterized by single-crystal X-ray diffraction, IR spectra, thermogravimetric analyses, differential scanning calorimetry, and Raman spectrum analysis. The images of single crystal diffraction revealed that 1 was a 1:1 (PZA:MHBA) co-crystal, 2 was a 1:1 (PZA:PHBA) co-crystal, and 3 was a 1:1 (PZA:3,4-DHBA). The strong O-H···O, N-H···O hydrogen bonding interactions between PZA and hydroxyl-substituted benzoic acid primarily made the structure of co-crystals stabilized. Hirshfeld surface and fingerprint plots of the three co-crystals showed that the structures were stabilized by H···H, O-H···O, N-H···O C-H···π, and π···π intermolecular interactions. [ABSTRACT FROM AUTHOR]

Estradiol (E) is the main drug used in menopause therapy. This study aimed to evaluate the drug-excipient compatibility of binary mixtures (BMs) (1:1 BMs, w/w), initially by differential scanning calorimetry (DSC), and subsequently, by complementary techniques such as X-ray powder diffraction (XRPD) and high performance liquid chromatography (HPLC) if there was any evidence of interaction. The samples were stored under accelerated stability conditions (40 °C at 75 % relative humidity). The DSC curves of estradiol and the BMs with excipients (corn starch, lactose, xanthan gum, microcrystalline cellulose, magnesium stearate, dibasic calcium phosphate, and talc) were obtained. The results show that estradiol was compatible with all the selected excipients. XRPD and HPLC analysis were instrumental in interpreting the DSC results and excluding relevant pharmaceutical incompatibilities in all cases. Overall, the compatibility of the selected excipients with estradiol was successfully evaluated using a combination of thermal and spectroscopic methods, and the formulations developed using the compatible excipients were found to be stable. [ABSTRACT FROM AUTHOR]

Studies of active drug-excipient compatibility represent an important phase in the preformulation stage of the development of all dosage forms. For the development of conjugation estrogens and medroxyprogesterone acetate (MPA) double-layer tablets, techniques of thermal, isothermal stress testing (IST), and molecular vibrational spectroscopy analysis were performed to access the compatibility. Differential scanning calorimetry (DSC) studies were used as an important and complementary tool during preformulation to determine drug-excipient compatibility. On the basis of DSC results, MPA was found to be compatible with polyethylene glycol 6000. However, the results of Raman and IST studies showed that all the excipients defined in the prototype formula were found to be compatible with MPA. Overall, the compatibility of selected excipients with MPA was successfully evaluated using a combination of thermal and IST methods, and the formulations developed using the compatible excipients were found to be stable. [ABSTRACT FROM AUTHOR]

For the development of dispersible tablets of itraconazole (ITR), techniques of thermal, Raman spectroscopy, and isothermal stress testing (IST) were used to assess the compatibility of ITR with selected excipients. Initially, differential scanning calorimeter (DSC) was used to evaluate the compatibility. Raman spectrum of drug-excipient mixture was also compared with that of pure drug and excipient. Compatibility of excipients defined in the prototype formula was tested using IST. Based on the DSC results alone, PEG-4000 was found to exhibit interaction with ITR. However, the results of Raman and IST studies showed that all the excipients used in the formula were compatible with ITR. Overall, compatibility of excipients with ITR was successfully evaluated using the combination of DSC, Raman spectroscopy, and IST techniques. [ABSTRACT FROM AUTHOR]

Four rotator–stator assembly complexes: benzoic-4-methylammonium-tetrafluoroborate-15-crown-5 ([C8H10NO2-(15-crown-5)]+[BF4]−, 1); benzoic-4-methylammonium-perchlorate-15-crown-5 ([C8H10NO2-(15-crown-5)]+[ClO4]−, 2); benzoic-4-methylammonium-tetrafluoroborate-18-crown-6 ([C8H10NO2-(18-crown-6)]+[BF4]−, 3); benzoic-m-ammonium-tetrafluoroborate-18-crown-6 ([C7H8NO2-(18-crown-6)]+[BF4]−, 4), for the investigation of the supramolecular assembly and host–guest interaction of crown ethers, have been synthesized and characterized. The results revealed that the variation of crown ethers, the substituent position of carboxyl group, as well as the different kinds of inorganic anions all can lead to quite another geometry and directionality of both the anilinium rotors and crown ether stators, which lead to entirely different supramolecular architectures. It is interesting that the optimal distances from the mean O-plane where found for the 18-crown-6 macrocycle with the ammonium cation, and the conformation of the macrocycle was badly affected in complexes with shorter or longer distances. We also studied the Raman spectroscopy of the five complexes, which give further inspection of the intermolecular interactions. [ABSTRACT FROM AUTHOR]

The crystals of two organic salts of tris(hydroxymethyl)aminomethane (THAM) with p-hydroxybenzoic acid (PHBA) and salicylic acid (SA) were obtained. Their crystal structures were characterized by single-crystal X-ray diffraction, IR spectra, differential scanning calorimetry, thermogravimetric analyses and hot stage microscopy. Wherein, 1 forms a 1:1 (THAM:PHBA) salt, and 2 forms a 2:2:1 (THAM:SA:HO) salt. The structure determination shows that the two salts are all primarily stabilized by strong O···H hydrogen bonds interaction between THAM and the two acids. The Hirshfeld surfaces and fingerprint plots of the reported salts were prepared and analyzed and reveal that the structures are stabilized by O···H, H···H, C···H, O···O and O···C intermolecular interactions. Graphical Abstract: The paper is about synthesis, crystal structure, thermal and Hirshfeld surfaces analysis of two THAM salts.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

An investigation into the substituent effect of halogen atoms (F, Cl, Br) on the crystal structure of indole-3-carboxylic acid (ICA) was prepared in this work. The investigation was done through the aspect of crystal structure, intermolecular interactions and π…π stacking motifs with the assistance of infrared spectra, elemental analyses, NMR spectra, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA) and hot stage microscopy (HSM) measurements. The results revealed that the different kinds of halogen atoms and the different substituted positions have a significant effect on the crystal structures, molecular π…π stacking motifs and the kinds of intermolecular interactions. We further correlated the melting points of the ICAs with the H–H, O–H and X–H (X = F, Cl, Br) interactions, and found a positive correlation between them. [ABSTRACT FROM AUTHOR]

In-situ Attenuated total reflectance Fourier transform infrared (ATR-FTIR), focused beam reflectance measurement (FBRM) and particle video microscope (PVM) have been used simultaneously in this work to monitor the concentration, supersaturation, chord length distribution, and crystal habit, respectively, during a cooling crystallization process of Methyprednisolone Hemisuccinate (MPHS) from ethanol system. We developed a new calibration method based on peak ratios for the assessment of the concentration, solubility, and supersaturation in the 20–60°C temperature range. The crystallizations were conducted at two concentrations (7.5 and 9.5% w/w) with three different cooling rates (0.3, 0.5, and 0.7 K/min). The lower concentration was chosen within the constructed calibration range while the higher one was outside the calibration range and it was used to examine the extrapolating and predicting ability of the constructed calibration curves. The metastable zone widths (MSZW), supersaturation at nucleation, and the number of fine particle chord length of MPHS were all increased with the cooling rate, while the number of the larger chord length decreased with the increasing of the cooling rate. [ABSTRACT FROM AUTHOR]

The complex [Cu2(μ-L)2]. DMF (L = 2, 2'-[1-(2, 4, 6-trichlorophenyl)-1H-1, 2, 4-triazole-3, 5-diyl] diphenolate) has been prepared and its structure determined. The two CuII ions are four-coordinated in a planar structure, with the DMF molecule wrapped in the 'wings' of ligand L. Hirshfeld surface and fingerprint plots reveal that the complex structure is stabilised mainly by H···H, C-H ... Cl, C-H···π,π···π and lone-pair···π (C-Cl) intermolecular interactions. [ABSTRACT FROM AUTHOR]

The complex [N(CH3)4]3[Mn3Zn2(3,5-dibromosalox)3O(N3)6Cl2] has been synthesised and characterised. It crystallises as two independent molecules and exhibits a planar [MnIII3-(μ3-oxo)] core as well as μ2-η1:η1-azide bridging geometry. DNA binding studies show that the complex binds with DNA through intercalation. [ABSTRACT FROM AUTHOR]

Two new 1-D coordination polymers [ M (3-Bzpy)(N(CN))] ( M = Cd ( 1), Cu ( 2), 3-Bzpy = 3-benzoylpyridine) have been synthesized and structurally characterized by single-crystal X-ray diffraction and IR. Single-crystal X-ray diffraction reveals that the complexes 1 and 2 are isostructural and all crystallize in monoclinic P2/ c space group with cell dimensions: a = 6.3889(16) Å, b = 7.6496(12) Å, c = 26.767(6) Å, β = 99.131(19)°, V = 1291.6(5) Å, Z = 2 for 1 and a = 6.4483(9) Å, b = 7.5449(10) Å, c = 25.965(4) Å, β = 98.559(10)°, V = 1249.2(3) Å, Z = 2 for 2. Structure analysis manifest that 1 and 2 are all 1-D chains structures which parallel to the crystallographic b axis through end-to-end coordination by bidentate bridging dicyanamide ligands. Magnetic property of complex 2 was further investigated. Graphical Abstract: The paper is about synthesis, crystal structure and magnetic property of two new 1-D coordination polymers. Perspective view down the a-axis of complex 1 with thermal ellipsoids drawn at the 50% probability level [Figure not available: see fulltext.]. [ABSTRACT FROM AUTHOR]

Two polymorphs of 5-[4'-(bromomethyl)biphenyl-2-yl]-2-trityl-2H-tetrazole can be characterised by single-crystal X-ray diffraction and Hirschfeld surface analysis. Both polymorphs crystallise in the monoclinic space group P21/c, but their cell parameters are different. The interatomic distances of phase A and B are different, and the arrangements of the dipolymers in phase A and B are remarkably different for the molecular orientation and interatomic distances according to their different π...π stacking interactions. Additionally, the size and shape of a Hirschfeld surface also reflects the interplay between different atoms and intermolecular contacts in a crystal. From the Hirschfeld surfaces of phase A and B, we can interpret the different proportions of interaction. [ABSTRACT FROM AUTHOR]

The title compound, [Cu(C2N3)2(C12H8N2)] n, has a sheet-like structure, built by [Cu(phen)(dca)2] n (phen is 1,10-phenanthroline and dca is dicyan­amide) chains which are interconnected by secondary long Cu-N bonds between the chains. The Cu2+ ion is in a distorted tetragonal bipyramidal (5 + 1) coordination environment. The sheets stack into the three-dimensional crystal structure through aromatic interactions between the coordinated phen ligands of adjacent sheets. [ABSTRACT FROM AUTHOR]

Owing to the critical roles it plays for both structure and functionality, hydrogen bonding has high hopes for the orientated applications in hydrogen‐bonded organic frameworks (HOFs). Here in this work, a hydrogen‐bonding strategy is performed for adjusting the structure and functionality of a heme‐like ligand meso‐tetra(carboxy‐phenyl)‐porphyrin (TCPP) with co‐former 1,3‐di(4‐pyridyl) propane (1,3‐DPP). A 3D dynamic HOF TCPP‐1,3–DPP, with permanent porosity is obtained. For this HOF, the two components form novel robust 1D porous stripes, with the 1,3‐DPP molecules acting as the lining for the pores that are confined within the region between adjacent carboxyphenyl moieties of TCPP. This confinement has tuned the affinities of TCPP from hydrophobic into hydrophilic. Interestingly, the 1D stripes are further stacked by weak π...π interactions into a 3D framework, the latter is highly dynamic with 1D stripes sliding back and forth, upon pressurized and water adsorption in the solid‐state under ambient conditions, respectively. The activated TCPP‐1,3–DPP has a Brunauer–Emmett–Teller surface area of 258 m2 g−1, and shows a maximum adsorption capacity about 9.8% for water during the adsorption–desorption cycles, demonstrating a promising candidate for the real‐world application in effective dehydration of industrial gases under ambient conditions. A 3D dynamic hydrogen‐bonded organic framework TCPP‐1,3–DPP, which is composed of 1D porous stripes, shows permanent porosity and highly affinity to water. The activated species exhibit a maximum adsorption capacity about 9.8% for water during the adsorption–desorption cycles, demonstrating a promise for the real‐world application in effective dehydration of industrial gas under ambient condition. [ABSTRACT FROM AUTHOR]