Existence Of Intermolecular Interactions Research Articles

Green blend nanocomposites developed from waste sericin, polyvinyl alcohol and boehmite for flexible electronic devices

The present research article demonstrates the dispersion of boehmite (BHM) nanoparticles into sericin (SER) from silk industry waste with polyvinyl alcohol (PVA) to enhance the optical, mechanical, thermal and electrical characteristics of PVA/SER blend nanocomposites prepared by a simple green synthesis. Techniques such as Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV visible spectroscopy, field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were carried out for the characterization of the prepared composites. XRD revealed the increased crystallinity of the polymer blend by the reinforcement of BHM. The existence of intermolecular interactions in the blend composite was confirmed by FTIR and UV spectroscopy. The optical bandgap energy of the biopolymer blend decreases with the inclusion of BHM. The SEM and HR-TEM confirmed the homogeneous dispersion of BHM in the blend at 5 wt% loading. The glass transition temperature and thermal stability of the blend nanocomposites were significantly improved by the inclusion of BHM was deduced from DSC and TGA. The dielectric constant and AC conductivity were remarkably increased with the reinforcement of nanoparticles. The activation energy obtained from AC conductivity decreased with temperature. The mechanical properties of the blend nanocomposites (hardness, tensile strength and Young's modulus) were greatly increased in presence of BHM. The 5 wt% sample has the highest tensile strength, Young's modulus, dielectric constant, AC conductivity and optical properties, allowing it to be used to make optoelectronic devices with better charge-storing capacity and flexible-type electrochemical gadgets.

Development of biopolymer composite films based on chicory extract reinforced polyvinyl alcohol/chitosan blend via green approach for flexible optoelectrical devices

AbstractBiopolymer blend composite films based on polyvinyl alcohol (PVA) and chitosan (CS) incorporated with varying amounts of chicory extract (CE) have been developed by the green solution casting technique. The impact of CE content on structural, thermal, mechanical and electrical properties was thoroughly examined. The existence of intermolecular interactions in the blend composite was confirmed by Fourier‐transform infrared and ultraviolet spectroscopy. The x‐ray diffraction pattern proved the successful preparation of PVA/CS/CE composite film. The scanning electron microscopy images of the composites showed shape and grain size for the different bio‐filler contents. The thermal transition temperature of the blend composites was significantly improved by the addition of CE extract deduced from differential scanning calorimetry. The dielectric study showed that the permittivity remarkably increases with decreasing frequency and maximum dielectric constant was observed for 15 wt% loading. The activation energy obtained from the AC conductivity decreased as the temperature increased. The addition of CE extract improved the hardness and tensile strength of the PVA/CS blend composite in comparison with a pristine pure blend. The controllable mechanical, thermal, optical, and electrical characteristics of the PVA/CS blend composite suggest that it might be an attractive optical material for the advancement of futuristic flexible‐type optoelectronic and energy storage systems.

Concentration-dependence of specific rotation of optically active glycerol analogues and structurally related compounds: The significance of intermolecular hydrogen bonding

Specific rotation of optically active glycerol analogues, (S)-3-(benzyloxy)propane-1,2-diol [(S)-1], (S)-3-methoxypropane-1,2-diol [(S)-6] and (S)-3-phenoxypropane-1,2-diol [(S)-13], changed its sign from (+) to (–) with increasing concentration in CHCl3, whereas no significant concentration-dependent change was observed in MeOH. The 1H NMR spectrum of (S)-1 showed concentration-dependent changes of the chemical shift in CDCl3. Intermolecular interaction by OH⋯OH hydrogen bonds was suggested by single crystal X-ray crystallography of (S)-13. The concentration-dependent changes of specific rotation of (S)-1, (S)-6, and (S)-13 in CHCl3 can therefore be presumed to be due to self-assembly of these compounds via intermolecular hydrogen bonding at high concentration. The remarkable concentration-dependent changes in specific rotation were also observed to occur in the compounds with related chemical structures, such as (S)-3-hydroxy-4-methoxy-4-oxobutanoic acid [(S)-10], (S)-1-[(2-methylpropan-2-yl)oxycarbonyl]pyrrolidine-2-carboxylic acid [Boc-L-Pro-OH, (S)-14], (R)-3-hydroxy-4,4-dimethylhydrofran-2(3H)-one [(R)-15], (R)-tetrahydrofuran-2-carboxylic acid [(R)-16], (S)-3-methyl-2-[(2-methylpropan-2-yl)oxycarbonylamino]butanoic acid [Boc-L-Val-OH, (S)-17], (R)-oxiran-2-ylmethanol [(R)-18], and (4S)-4-isopropyloxazolidin-2-one [(S)-19]. The existence of intermolecular interaction by C=O⋯HO hydrogen bonds was suggested by single crystal X-ray crystallography of (S)-10, (S)-13, and (S)-14. Thus, this series of chiral compounds have multiple functional groups in appropriate positions that serve as hydrogen-bond donors and/or acceptors, resulting in significant concentration-dependent changes of specific rotation.

Acoustical Studies on Binary Mixtures of Methyl Acrylate with Benzene and Mono-Substituted Benzenes at 313.15 K

Ultrasonic velocities and Densities of binary mixtures of Methyl Acrylate (MA) with Benzene and mono-substituted Benzenes like Benzene (B), Methyl benzene (MB), and Ethyl benzene (EB) have been measured at 313.15 K, by using these data, various acoustical parameters like Isentropic compressibility (KS), Intermolecular free length (Lf), acoustic impedance (Z) and relative association (RA) were calculated, further by using these acoustical parameters, excess properties like excess ultrasonic velocities (uE), excess acoustic impedance (ZE), excess isentropic compressibility (KSE) and excess inter-molecular free-length (LfE) were calculated and fitted to Redlich-Kister equation. The existence of inter-molecular interactions between the components in the liquid mixtures was discussed.

Optimization and Enhancement of the Peroxidase-like Activity of Hemin in Aqueous Solutions of Sodium Dodecylsulfate.

Iron porphyrins play several important roles in present-day living systems and probably already existed in very early life forms. Hemin (= ferric protoporphyrin IX = ferric heme b), for example, is the prosthetic group at the active site of heme peroxidases, catalyzing the oxidation of a number of different types of reducing substrates after hemin is first oxidized by hydrogen peroxide as the oxidizing substrate of the enzyme. The active site of heme peroxidases consists of a hydrophobic pocket in which hemin is embedded noncovalently and kept in place through coordination of the iron atom to a proximal histidine side chain of the protein. It is this partially hydrophobic local environment of the enzyme which determines the efficiency with which the sequential reactions of the oxidizing and reducing substrates proceed at the active site. Free hemin, which has been separated from the protein moiety of heme peroxidases, is known to aggregate in an aqueous solution and exhibits low catalytic activity. Based on previous reports on the use of surfactant micelles to solubilize free hemin in a nonaggregated state, the peroxidase-like activity of hemin in the presence of sodium dodecyl sulfate (SDS) at concentrations below and above the critical concentration for SDS micelle formation (critical micellization concentration (cmc)) was systematically investigated. In most experiments, 3,3',5,5'-tetramethylbenzidine (TMB) was applied as a reducing substrate at pH = 7.2. The presence of SDS clearly had a positive effect on the reaction in terms of initial reaction rate and reaction yield, even at concentrations below the cmc. The highest activity correlated with the cmc value, as demonstrated for reactions at three different HEPES concentrations. The 4-(2-hydroxyethyl)-1-piperazineethanesulfonate salt (HEPES) served as a pH buffer substance and also had an accelerating effect on the reaction. At the cmc, the addition of l-histidine (l-His) resulted in a further concentration-dependent increase in the peroxidase-like activity of hemin until a maximal effect was reached at an optimal l-His concentration, probably corresponding to an ideal mono-l-His ligation to hemin. Some of the results obtained can be understood on the basis of molecular dynamics simulations, which indicated the existence of intermolecular interactions between hemin and HEPES and between hemin and SDS. Preliminary experiments with SDS/dodecanol vesicles at pH = 7.2 showed that in the presence of the vesicles, hemin exhibited similar peroxidase-like activity as in the case of SDS micelles. This supports the hypothesis that micelle- or vesicle-associated ferric or ferrous iron porphyrins may have played a role as primitive catalysts in membranous prebiotic compartment systems before cellular life emerged.

A new avibactam Gemini quaternary ammonium salt: synthesis, self-assembly, vibrational spectra, crystal structures and DFT calculations

Avibactam ([AV]), a non-β-lactam β-lactamase inhibitor, contains a sulfonic acid group, which making separation and purification extremely difficult. The ability of the gemini quaternary ammonium salt N,N,N,N’,N’,N’-hexabutylbutanediammonium dibromide [444][Br]2 to precipitate [AV] from aqueous solutions resulted in the successful synthesis of a new avibactam gemini quaternary ammonium salt [444][AV]2. To understand the self-assembly, the transmission electron microscope (TEM) and spectra of [444] cations and [AV] anions in aqueous solution were investigated. By using a slow evaporation technique, the [444][AV]2 complex single crystal was produced from a water solvent. The title crystal structure conformation was done by single crystal X-ray diffraction (SCXRD) technique, and its belongs to the P-1 space group with the triclinic system. The thermal stability of [444][AV]2 has been investigated by TG/DSC studies, and its experimental vibrational bands (FT-IR and Raman) have been studied and assigned. The stability test indicated that [444][AV]2 exhibits outstanding physical stability under long-term and accelerated conditions. According to DFT calculations, electrostatic potential and Mulliken charges showed that [444] cations were readily adsorbed on the negatively charged [AV] anions surface sites through electrostatic attraction, and the existence of inter-molecular interactions was assessed by Hirshfeld surface of [444][AV]2 single crystal.

Exploring the Solubility and Bioavailability of Sodium Salt and Its Free Acid Solid Dispersions of Dolutegravir.

Amorphous salt solid dispersion (ASSD) of Dolutegravir amorphous salt (DSSD) was generated using quench cooling and compared to its Dolutegravir free acid solid dispersion (DFSD) to improve the solubility and bioavailability. Soluplus (SLP) was used as a polymeric carrier in both solid dispersions. The prepared DSSD and DFSD, physical mixtures, and individual compounds were characterized by employing DSC, XRPD, and FTIR to assess the formation of the single homogenous amorphous phase and the existence of intermolecular interactions. Partial crystallinity was observed for DSSD, unlike DFSD, which is completely amorphous. No intermolecular interactions were observed between the Dolutegravir sodium (DS)/Dolutegravir free acid (DF) and SLP from the FTIR spectra of DSSD and DFSD. Both DSSD and DFSD improved the solubility of Dolutegravir (DTG) to 5.7 and 4.54 folds compared to the pure forms. Similarly, drug release from DSSD and DFSD was 2 and 1.5 folds higher than that in the pure form, owing to the rapid dissolution of the drug from the formulations. The permeability of DSSD and DFSD was estimated using the dialysis membrane, which enhanced the DTG permeability. The improvement in in vitro studies was translated into in vivo pharmacokinetic profiles of DSSD and DFSD, where 4.0 and 5.6 folds, respectively, improved the Cmax of DTG.

Effect of palm wax on the mechanical, thermal, and moisture absorption properties of thermoplastic cassava starch composites

Thermoplastic starch is a potentially sustainable and biodegradable material. However, it possesses some limitations in terms of mechanical performance and high moisture sensitivity. In this current work, the characteristics of thermoplastic cassava starch (TPCS) containing palm wax at various loading were evaluated. TPCS was prepared via hot pressing by varying the ratios of palm wax (2.5, 5, 10, and 15 wt%). Next, characterization via scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), mechanical, water solubility, thickness swelling and moisture absorption tests, were conducted on the samples. The findings showed that incorporating starch-based thermoplastics with palm wax has remarkably improved mechanical characteristics of the thermoplastic blends. Besides, the morphology of the samples demonstrated irregular and rougher cleavage fracture after palm wax addition. FT-IR indicated the existence of intermolecular interaction between TPCS and palm wax with the intermolecular hydrogen bonds that existed between them. The thermal stability of TPCS has improved with rising palm wax content. The incorporation of 15 wt% palm wax resulted in the lowest moisture absorption value among the samples. Overall, the developed TPCS/palm wax with improved mechanical and moisture resistance characteristics has the potential to be used as biodegradable materials.

Structural characterization, theoretical and antibacterial study of a V-shaped, cyclohexane bridged ONNO Schiff base

A tetradentate ONNO Schiff base bearing two chloro substituents, namely 6,6′-((1E,1′E)-(cyclohexane-1,2-diylbis(azanylylidene))bis(methanylylidene))bis(2-chlorophenol) (AD2C), was obtained through condensation of 3-chlorosalicyladehyde with 1,2-cyclohexanediamine. Structure elucidation was performed through physicochemical and spectroscopic analyses viz. melting point, elemental analysis, FTIR, 1H and 13C NMR, UV-Visible and single crystal X-ray diffraction. The ν(C=N) was observed at 1626 cm−1 while the azomethine proton and carbon chemical shifts appeared at 8.27 ppm and 157.56 ppm, respectively. The n‒π*(C=N) absorption band was observed at 324 nm. The crystal structure was stabilized by intramolecular hydrogen bond O˗H···N and intermolecular hydrogen bonds C˗H···O, C˗H···Cl, C˗H···π as well as π···π interactions. The existence of intermolecular interactions was confirmed through Hirshfeld analysis, showing high contribution of H⋯H contact. The B3LYP method was used to calculate the optimized structure of the molecule through density functional theory (DFT) using the 6–311++G(d, p) basis set and was found to be consistent with the X-ray diffraction value. The frontier molecular orbitals and molecular electrostatic potential of the compound investigated through DFT calculations revealed a significantly large energy gap of 4.615 eV and nucleophilic regions located at the hydroxyl groups. The compound showed no antibacterial activity against five bacterial strains namely Bacillus subtilis (ATCC 6633), Proteus vulgaris (ATCC 6380), Pseudomonas aeruginosa, Staphylococcus aureus subsp. aureus Rosenbach (ATCC 6538) and Streptococcus mutans Clarke (ATCC 700,610).

The structure-property studies and mechanism of optical limiting action of methyl 4-((4-aminophenyl)ethynyl)benzoate crystal under continuous wave laser excitation

This study focuses on the design of the new dye of donor-π-acceptor (D−π−A) system of methyl 4-((4-aminophenyl)ethynyl)benzoate (MAPEB) to highlight its structural-property relation through a combined experimental and quantum chemical calculation approaches for optical limiting applications. MAPEB was synthesized via aerobic condition palladium-catalysed Sonogashira cross-coupling reaction with good yield. This molecular structure was confirmed by single crystal X-ray crystallographic analysis and the crystal exhibits monoclinic non-centrosymmetric space group of Pc. The existence of intermolecular interactions was confirmed by Hirshfeld analysis, showing high contribution of C⋯H contact which suggested the high nonlinear optical response of the compound. The experimental spectroscopic data including Fourier Transform Infrared (FT-IR), 1H and 13C Nuclear Magnetic Resonance, electronic absorption spectra, HOMO-LUMO energy gap were compared with Density Functional Theory (DFT) at 6–311++G (d,p) basis set. The experimental results complement the theoretical findings in supporting anticipated electronic properties of the molecule. Additionally, the z-scan analysis unveils an excellent value of χ3 of MAPEB in the order of 10−6 esu which indicate good nonlinear optical material under 532 nm continuous wave laser. Low optical limiting action was measured at 110 kW/cm2 which is suitable for various continuous wave laser applications. These findings prove that MAPEB has the potential to be employed as NLO materials for photonic applications.

μ-phenoxide bridged mixed ligand Cu(II) complex: Synthesis, 3D supramolecular architecture, DFT, energy frameworks and antimicrobial studies

As an essential class of heterocyclic derivatives, 8-hydroxyquinoline(HQ) and 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (TFTB) have a broad range of pharmaceutical applications and they are found to be excellent precursors for metal complexes and crystal engineering. The novel mixed ligand Cu(II) complex [Cu2(C8H4O2SF3)2(C9H6NO)2] has been synthesized using a metal salt and the above ligands in a 1:1:1 M ratio and characterized by FT-IR, UV–visible, SEM and EDAX techniques. Single crystal X-ray structure analysis reveals a centrosymmetric dinuclear form of the Cu(II) complex, linked by the obtuse phenolate oxygen atom, and the central Cu(II) ion adopts a distorted square pyramidal coordination geometry. The Cu(II) complex exhibits various intermolecular interactions, leading to the construction of R22(16), R22(10) and R22(20) supramolecular synthons. The existence of intermolecular interactions is supported by Hirshfeld surface analysis and quantified by 2D fingerprint plots. In addition, the 3D topology of the molecular packing is visualized through energy frameworks, which reveal the predominance of dispersion energy over other interaction energies. DFT calculations have been performed for the mixed ligand Cu(II) complex to study the optimal geometry, related reactive parameters and the HOMO-LUMO energy gap (0.8232 eV). Further, the Cu(II) complex was evaluated against MRSA and showed an MIC value of 15 μg/mL. A time-killing assay for the Cu(II) complex was performed to study the antimicrobial effect with respect to time. A molecular docking study revealed the binding affinity of the Cu(II) complex to penicillin-binding protein 2, with an excellent binding score of −8.0 kcal/mol.

Structural and dynamics study of polar liquid mixtures by dielectric and FTIR spectroscopic characterizations

Dielectric Permittivity Spectra of the binary mixture of Acetonitrile (ACN) with Benzaldehyde (BENZ) have been studied at 11 different concentrations in the frequency range of 10MHz–50GHz for four different temperatures (10°C, 15°C, 20°C and 25°C) using TDR technique. The binary system of ACN-BENZ has been selected to understand the effect of nitrile and aldehyde group on the dielectric parameters and intermolecular interaction. Static Dielectric Constant (ε0), Relaxation Time (τ) are obtained for above mentioned temperatures using nonlinear least squares fit method. Density (ρ) and Refractive Index (nD) are also obtained for 30°C temperature. These parameters are used to calculate the Excess Static Dielectric Constant (ε0E), Excess Inverse Relaxation Time (1/τ)E and Excess Molar Volume (VmE) and are fitted to Redlich-Kister equation. The departure in the excess parameters expresses the strength of the molecular connectivities and the existence of intermolecular interaction between unlike molecules. Kirkwood correlation factor, Bruggeman factor and thermodynamic parameters are studied to understand the information about the molecular interactions and orientation behaviour of dipoles after intermolecular interaction. The study of Fourier Transform Infrared Spectroscopy has been carried out to support the dielectric characterization and confirms the intermolecular association between ACN-BENZ binary system.

Preparation of pH-sensitive and antioxidant packaging films based on κ-carrageenan and mulberry polyphenolic extract

In this study, antioxidant and pH-sensitive κ-carrageenan based films were developed by incorporating different amounts of mulberry polyphenolic extract (MPE). Due to abundant anthocyanin content, MPE showed pH-sensitive property with solution color changed from red to purple and final gray when pH value increased from 2 to 13. When MPE was incorporated into κ-carrageenan film, the composite films presented blue color. Notably, the incorporation of 2 and 4 wt% of MPE could significantly increase the thickness, tensile strength, thermal stability, antioxidant activity and pH-sensitive property of κ-carrageenan film. However, the moisture content, water vapor permeability, UV–vis light transmittance and elongation at break were greatly reduced when 2 and 4 wt% of MPE were incorporated. In addition, κ-carrageenan-MPE films exhibited heterogeneous and rougher surfaces as compared with κ-carrageenan film. The existence of intermolecular interactions between MPE and κ-carrageenan matrix was confirmed by infrared spectroscopy and X-ray diffraction. When applied to monitor the freshness of milk, κ-carrageenan-MPE films showed evident color changes as milk deteriorated after storage at 40 °C for 8 h. Our results suggested that κ-carrageenan-MPE films could be used as novel active and intelligent food packaging materials.

Experimental and quantum chemical investigation on imidazolium trifluoroacetate single crystal for optoelectronic applications

The nonlinear optical single crystal of imidazolium trifluoroacetate (ITF) was grown by the solvent evaporation technique. The crystal is subjected to various experimental characterizations such as X-ray diffraction, vibrational, optical, thermal and NLO analysis. In parallel, the molecular functional properties are explored by density functional theory. The inter and intramolecular charge transfer interactions stabilization energies are assessed from the NBO analysis. The material has more than 60% transmission in the entire visible region, and the melting point of the crystal is 143 °C. The HOMO–LUMO energy gaps and the molecular charge transfer properties are investigated by frontier molecular orbital analysis. The existence of intermolecular interactions in the crystal was quantitatively interpreted from the Hirshfeld surface analysis. The ITF crystal possesses 1.67 higher second harmonic generation efficiency compared to typical KDP material.

DORI Reveals the Influence of Noncovalent Interactions on Covalent Bonding Patterns in Molecular Crystals Under Pressure.

The study of organic molecular crystals under high pressure provides fundamental insight into crystal packing distortions and reveals mechanisms of phase transitions and the crystallization of polymorphs. These solid-state transformations can be monitored directly by analyzing electron charge densities that are experimentally obtained at high pressure. However, restricting the analysis to the featureless electron density does not reveal the chemical bonding nature and the existence of intermolecular interactions. This shortcoming can be resolved by the use of the DORI (density overlap region indicator) descriptor, which is capable of simultaneously detecting both covalent patterns and noncovalent interactions from electron density and its derivatives. Using the biscarbonyl[14]annulene crystal under pressure as an example, we demonstrate how DORI can be exploited on experimental electron densities to reveal and monitor changes in electronic structure patterns resulting from molecular compression. A novel approach based on a flood-fill-type algorithm is proposed for analyzing the topology of the DORI isosurface. This approach avoids the arbitrary selection of DORI isovalues and provides an intuitive way to assess how compression packing affects covalent bonding in organic solids.

Development of antioxidant and intelligent pH-sensing packaging films by incorporating purple-fleshed sweet potato extract into chitosan matrix

Antioxidant and intelligent pH-sensing films were prepared by incorporating anthocyanin-rich purple-fleshed sweet potato extract (PSPE) into chitosan matrix. Effect of PSPE incorporation on physical, structural, antioxidant and pH-sensing properties of chitosan-PSPE films was determined. Eight principal compounds in PSPE were identified as anthocyanins based on mass spectroscopic analysis. Due to abundant anthocyanin content, PSPE could change its colors with changing pH. The incorporation of PSPE could significantly increase the thickness, water solubility, UV–vis light barrier property and thermal stability of chitosan film. However, the incorporation of PSPE could decrease the moisture content, elongation at break and crystalline character of chitosan film. Water vapor barrier property and tensile strength of chitosan film were almost unchanged by PSPE incorporation. Microstructure observation showed a homogeneous state of chitosan-PSPE films. The existence of intermolecular interactions between PSPE and chitosan matrix was confirmed by infrared spectroscopy. Antioxidant assays showed chitosan-PSPE films could scavenge free radicals in dose- and time-dependent manners. Moreover, chitosan-PSPE films exhibited visible color changes along with the pH change. Therefore, chitosan-PSPE films can be used as antioxidant and intelligent pH-sensing films to extend the shelf-life and monitor the quality of food products.

Qualitative and quantitative analysis of intermolecular interactions in xanthenedione derivatives.

The existence of intermolecular interactions and the conformational geometry adopted by molecules are related to biological activity. Xanthenedione molecules are promising and emerging antioxidants and acetylcholinesterase inhibitors. To examine the role of different functional groups involved in the intermolecular interactions and conformational geometries adopted in xanthenediones, a series of three substituted xanthenediones have been crystallized [9-(3-hydroxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione, C23H26O4, 9-(5-bromo-2-methoxyphenyl)-3,3,6,6-tetramethyl-3,4,6,7-tetrahydro-2H-xanthene-1,8(5H,9H)-dione, C24H27BrO4, and 3,3,6,6-tetramethyl-9-(pyridin-2-yl)-3,4,6,7-tetrahydro-2H-xanthene-1,8(5H,9H)-dione, C22H25NO3] and their intermolecular interactions analyzed via Hirshfeld analysis. The results show that all the derivatives adopt the same structural conformation, where the central ring has a shallow boat conformation and the outer rings have a twisted boat conformation. The intermolecular interactions in the molecules are predominantly O-H...O, C-H...O and π-π interactions. The optimized structures of the derivatives from theoretical B3LYP/6-311G** calculations show a good correlation with the experimental structures. The lattice energy involved in the intermolecular interactions has been explored using PIXELC.

Elaboration, Structural, Vibrational, DSC Investigations and Hirshfeld Surface Analysis of New Organic–Inorganic Hybrid Compound: [H2mela]Cu2Br6

The present paper accounts for the synthesis, crystal structure, differential scanning calorimetry and vibrational spectroscopy of a new compound (1,3,5-triazinidium-2,4,6-triamine) hexabromidodicuprate (II) grown at room temperature by slow evaporation of aqueous solution. From X-ray diffraction data collected at room temperature, it is concluded that it crystallizes in the monoclinic system (P21/c space group). The anion and the cation are linked by N–H···Br hydrogen bonds. Furthermore, the room temperature IR and Raman spectra of the title compound were recorded and analyzed. The differential scanning calorimetric has also been investigated. Hirshfeld surfaces were used to confirm the existence of inter-molecular interactions in the compound.

The miscibility of collagen/hyaluronic acid/chitosan blends investigated in dilute solutions and solids

In the present study, the results from viscometric measurements, tensile tests and Fourier transform infrared spectroscopy (FTIR) of polymer blends containing collagen (Coll) and hyaluronic acid (HA) with and without chitosan (Ch) are presented.The viscosity interaction parameter of each polymer in 0.1mol·dm−3 CH3COOH/0.3mol·dm−3 NaCl solution for the collagen and 0.3mol·dm−3 NaCl or 0.1mol·dm−3 HCl solution for the hyaluronic acid and 0.1mol·dm−3 CH3COOH/0.3mol·dm−3 NaCl solution for the chitosan as well as the two-component blend systems and the ternary blend systems have been determined. These studies indicated that collagen/hyaluronic acid blends were miscible at any composition (Coll/HA: 80/20, 50/50, 20/80) in 0.1mol·dm−3 CH3COOH/0.3mol·dm−3 NaCl and 0.1mol·dm−3 HCl at 25°C. In the case of Coll/HA/Ch ternary blends, the polymeric components were partially miscible. The mechanical properties of films such as tensile strength and Young's modulus depend on the blend composition. Coll/HA blends possessed a tensile strength and Young's modulus of 16.3–57.6MPa and 1.0–1.9GPa, respectively. The addition of chitosan to the blend led to an increase in tensile strength by approximately 50%. The results of FTIR analysis suggested that there was the existence of intermolecular interactions between functional groups of polymers.

A simplified concentration series to produce a pair of 2D asynchronous spectra based on the DAOSD approach

We propose a substantially simplified approach to construct a pair of 2D asynchronous spectra based on the DAOSD approach proposed in our previous papers. By using a new concentration series, only three 1D spectra are used to generate a pair of 2D correlation spectra together with two reference spectra. By using this method, the previous problem of labor intensive traditional DAOSD approach has been successfully addressed. We apply the new approach to characterize intermolecular interaction between acetonitrile and butanone dissolved in carbon tetrachloride. The existence of intermolecular interaction between the two solutes can be confirmed by the presence of a cross peak in the resultant 2D IR spectra. In addition, the absence of cross peak around (2254, 2292) in Ψbutanone provides another experimental evidence to reveal the intrinsic relationship between the CN stretching band and an overtone band (δCH3+νC–C).