Yellow Crystals Research Articles

Stoichiometric effect on the defect states and optical properties of LiInSe2 single crystals

LiInSe2 crystals are promising semiconductor materials for neutron detectors due to the large neutron capture cross-sectional area of the specific isotopes (6Li) and high charge transport properties. However, the optoelectronic performance fails to reach the expected level due to the difficulty of controlling the crystal defects. Herein, we modulate the stoichiometric ratio to control the type of defects in single LiInSe2 crystals grown by the vertical Bridgman method. The UV‒vis–NIR transmission results indicate that the band gap of the yellow colored Li1.01In1Se2 sample is close to ~ 2.83 eV at room temperature, and this value is consistent with the theoretical band gap of LiInSe2 (~ 2.86 eV). Photoluminescence (PL) spectroscopy was used to analyze the defect concentration. The results indicate that the defect types in the yellow Li1.01In1Se2 single crystal are VSe+ and LiIn2−; these result from the introduction of excess Li and the suppression of the adverse defects in InLi2+ and VLi−. These results demonstrate a feasible route for obtaining high-quality yellow 6LiInSe2 crystals and promote the application of 6LiInSe2 neutron detectors.

Structural design and characterization of a new type of organic nonlinear optical flavanone crystal

Two new crystals were designed and obtained: the chalcone derivative HMMP (1-(2‑hydroxy-4-methoxyphenyl)-3-(4-(methylthio)phenyl)prop‑2-en-1-one) and the flavanone derivative 7M4MC (7‑methoxy-2-(4-(methylthio)phenyl)chroman-4-one). Yellow bulk 7M4MC single crystal with dimensions of 3 × 2 × 1 mm3 and orange-yellow needle-like HMMP single crystal were grown by solution evaporation. 7M4MC crystal belongs to the P21 space group of the monoclinic structure, which has a non-centrosymmetric structure. HMMP crystal monoclinic, belongs to the P21/m space group with a centrosymmetric structure. In the 7M4MC molecule, the methoxy and methylthio groups act as electron donors (D) and the carbonyl group acts as an electron acceptor (A), forming a d-π-A-π-D structure with an electron gradient. 7M4MC exhibits a high degree of second-harmonic generation intensity (11 × KDP), a broad transmission range (600–1600 nm, >88 %), an elevated optical energy bandgap (Eg = 2.57 eV), high thermal stability (Tm = 105 °C) and excellent dielectric properties (εr ≈ 2.1). This work not only provides two new crystals but also offers a viable molecular design option by changing the degree of intramolecular distortion by altering the backbone structure.

An Improved and Efficient Practical Process for the Synthesis of Enantiomerically Pure Solifenacin Succinate as an Antimuscarinic Agent

Background: Solifenacin succinate is an active pharmaceutical drug molecule that is extremely effective in treating overactive bladder symptoms, such as urine incontinence, urgency, and frequent urination. The free base is yellow oil, and the salt solifenacin succinate forms yellowish crystals that are extremely stable and effective. Solifenacin is a very active antagonist due to its potent muscarinic M3 receptor antagonist characteristics. Furthermore, solifenacin is effective in the treatment of bowel syndrome (IBS) by blocking M3 receptors and a broad spectrum of bowel dysfunction. Objective: The objective of this study was to develop a practical and highly efficient scalable synthesis of enantiomerically pure solifenacin as an antimuscarinic agent. Methods: In this work, the Zn(OTf)2 catalyst was used to develop a novel, environmentally benign, high-yielding, and robust protocol for the synthesis of enantiomerically pure solifenacin succinate. Results: The synthesis of enantiomerically pure solifenacin succinate was achieved in seven steps using commercially available phenylethylamine and benzoyl chloride as the starting materials. We carried out the reaction optimization by treatment of (S)-1-phenyl-3,4-dihydroisoquinoline-2(1H)- carbonyl chloride and (R)-(-)-3-Quinuclidinolin in the presence of Zn(OTf)2 catalyst. Furthermore, the solifenacin-free base was treated with succinic acid to afford its corresponding salt. The highlight of this protocol is the use of 20 mol% Zn(OTf)2 catalyst for the first time. The readily available starting materials, robustness, easy operation, high yield, and low cost make the approach more attractive and highly applicable. Conclusion: In summary, we developed a novel Zn(OTf)2-catalysed environmentally benign, highyielding, and robust protocol for the synthesis of enantiomerically pure solifenacin succinate. The proposed strategy is highly cost-effective and avoids the use of hazardous and unsafe sensitive, strong bases as well as tedious work-up procedures. Effective synthesis was achieved using readily available starting materials and reagents. Thus, the protocol is highly efficient, compatible, and commercially viable for the synthesis of important solifenacin products.

Multicolor Emission in o-Carborane Derivatives Induced by Conformation Diversity through C-C Double Bond Substitution.

Rationally designed molecules with versatile conformations are ideal candidates for creating challenging single component-based multicolor emissive materials. Herein, a new strategy is presented by introducing a C-C double bond in an o-carborane derivative. Compared to a linear connection using a C-C triple bond (CbPyY), a C-C double bond connection (CbPyE) exhibited a zigzag structure and unique fluorescence behavior. Yellow, yellowish orange, and red crystals or films of CbPyE can be obtained, while only orange ones of CbPyY were achieved under the same condition. Single crystal XRD and theoretical calculation studies revealed the zigzag structure brings asymmetry to one arm of CbPyE, which causes conformation diversity and leads to the multicolor emission. Interestingly, different emissions showed different responses to acetone vapor; the yellow one showed much higher sensitivity and faster response than the other two. It is believed that the prepared materials and the proposed strategy would contribute to future advances in single-fluorophore-based multicolor emissive materials.

Structure Modification of Cinnamic Acid to (E)-1-(3,4-dihydroisoquinoline-2(1H)-yl)-3-phenylprop-2-en-1-one and Antioxidant Activity Test by DPPH Method

Antioxidants can protect cells from free radical damage by stabilizing them. One of the compounds that has antioxidant activity is cinnamic acid. Cinnamic acid and its derivatives have several activities: antibacterial, anticancer, and antioxidant. However, the ability of cinnamic acid to capture free radicals is still relatively low. One of the efforts that can be made to increase the antioxidant activity of cinnamic acid is to modify its structure. Structure modification is an effort to improve the pharmacological activity of a compound through chemical synthesis reactions. The cinnamic acid structure can be modified by changing the carboxylic -OH group into an amine group through an N-atom acylation reaction. This study was conducted by reacting cinnamoyl chloride (1a), which is a cinnamic acid derivative with 1,2,3,4-tetrahydroisoquinoline (2b) which is a compound of isoquinoline group to produce (E)-1-(3,4-dihydroisoquinoline-2(1H)-yl)-3-phenylprop-2-en-1-one (3b) and then tested for antioxidant activity using DPPH method. The resulting product compound was yellow crystals with a yield of 81.56%. The antioxidant activity produced by the product is more significant than that of cinnamic acid compounds at the same concentration.

Di-chloridotetra-kis-(3-meth-oxy-aniline)nickel(II).

The reaction of nickel(II) chloride with 3-meth-oxy-aniline yielded di-chlorido-tetra-kis-(3-meth-oxy-aniline)nickel(II), [NiCl2(C7H9NO)4], as yellow crystals. The NiII ion is pseudo-octa-hedral with the chloride ions trans to each other. The four 3-meth-oxy-aniline ligands differ primarily due to different conformations about the Ni-N bond, which also affect the hydrogen bonding. Inter-molecular N-H⋯ Cl hydrogen bonds and short Cl⋯Cl contacts between mol-ecules link them into chains parallel to the b axis.

Cytotoxic of Usnic Acid Isolated from Ramalina sp.

Ramalina sp. (Ramalinaceae) is a type of lichen known to contain many active secondary metabolite compounds that have the potential to be used as medicine or medicinal raw materials. One of the biological activities possessed by Ramalina sp. lichen is its anticancer activity. This research aims to isolate and identify active secondary metabolite compounds from the methanol extract of the Ramalina sp. lichen and to find out the cytotoxic activity of the isolated compound against MCF7 breast cancer cells. Compound 1 (usnic acid) was successfully isolated from fraction A. The isolation and purification process was carried out starting with a maceration process using acetone solvent, followed by silica gel column chromatography using a gradient solvent system consisting of n-hexane, n-hexane: EtOAc, EtOAc, EtOAc: MeOH, and MeOH with 5% increment of polarity to obtain 17 fractions (F-1 to F-17). From the 17 fractions obtained, fraction 3 (F-3) and fraction 4 (F-4) (eluted with n-hexane: EtOAc 30%), which had the same TLC profile, were combined and named as fraction A. Compound 1 (50 mg) is a yellow needle crystal that was formed in a bottle of fraction A, which was obtained after the process of combining fractions F-3 and F-4 and solvent evaporation process. The crystals were then separated and purified with CHCl3 and MeOH. Compound 1 was then characterized based on spectroscopic data. Various spectroscopic analysis data, including FTIR, 1D- and 2D-NMR, and LC-ESI-MS, show that Compound 1 is a dibenzofuran derivative compound with 18 carbons (3 from carbonyl groups (C=O) and 3 from methyl groups) and 2 hydroxyls (-OH). Cytotoxicity assay showed that at a low concentration of 18.75 ug/mL, Com-pound 1 caused a 67.06% decrease in MCF7 viability.

Silica Gel Chromatographic Methods for Identification, Isolation and Purification of Gossypol Acetic Acid.

Several cottonseed varieties are cultivated in different countries. Each variety produces a different amount of gossypol as a natural toxic compound. The rising interest in cottonseed products (oil and feed) increases the demand for establishing simple methods for gossypol detection. Silica gel-based methods are ideal for its isolation, purification, and characterization. Silica gel-based methods are variants and can be used as simple methods for tracking plants' compounds. In this study, gossypol was isolated, characterized, and purified as gossypol acetic acid in the form of yellow crystals. Methods used for its characterization were TLC, preparative TLC, silica gel column, UV/IR spectrophotometer, and HPLC (robust spherical silica gel). A comparative study between its amount in both the Egyptian and Chinese varieties was performed. Under the experimental conditions, the Egyptian's cottonseed contains 8.705 gm/kg, while the Chinese's cottonseed contains 5.395 gm/kg. The TLC used in this study proved to be fast, accurate, and inexpensive. It can be used for gossypol acetic acid evaluation and quantification. Additionally, using TLC as a pre-purification step will give a pre-judgment for the sample's purity and quality. This step will protect the expensive HPLC silica gel-based column from any unexpected impurities. During each step, the silica gel itself could be simply removed by paper filtration. Collectively, the different silica gel-based methods as well as the other used methods are recommended for better Gossypol acetic acid isolation, purification, and characterization, as well as for maintaining HPLC columns.

Isolation of Novel 6-methylideneoxecane-3,4,5,7,8,9-hexol from the Leaves of Rauwolfia vomitoria, Apocynaceae

Rauwolfia vomitoria (Wennberg) belongs to the family Apocynaceae, the dried leaves were extracted successively using n-hexane, dichloromethane, and 70% methanol, concentrated in vacuo. Extracts were subjected to antibacterial assay and the butanol fraction was subjected to chromatographic purification to obtain NBF12 which was subjected to spectral analysis. The antibacterial of n-Hexane, dichloromethane, and 70% methanol extracts was inactive against the screened organisms assessed (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa). NBF12 is yellowish crystals (10.5 mg), Rf (0.69), UV, max Abs (248) The carbon 13C-NMR spectrum displayed ten carbon atoms; one methylene, two methylene oxide carbon, 6-carbinolic carbon (Sp3) and a quaternary carbon (SP2). The spectrum showed a tertiary carbon at δ131.09 ppm, due to C-6 and at δ 114.74 ppm due to exocyclic methylidene carbon (Sp2) (C=CH2) linked to the C-6position. Based on the spectral data NBF12 is 6-methylideneoxecane-3,4,5,7,8,9-hexol with a molecular formula C10H18O7, molecular weight 250 g/mol.

Zinc(II) coordination compound with N′-(pyridin-2-ylmethylene)nicotinohydrazide: Synthesis, crystal structure, computational and cytotoxicity studies

In this work, we report on the synthesis of a novel zinc(II) coordination compound [ZnL2] (1), which was readily obtained from the reaction of Zn(OAc)·2H2O and N′-(pyridin-2-ylmethylene)nicotinohydrazide (HL) in methanol. Recrystallization of 1 from dimethylformamide under ambient conditions allowed to produce yellow block-like crystals of 1·H2O. Complex 1·H2O was characterized by FT-IR and 1H NMR spectroscopy, while its optical properties were studied by UV–vis and spectrofluorimetry in methanol. The crystal structure of the title complex was revealed by single crystal X-ray diffraction and further explored in detail by the Hirshfeld surface analysis. Theoretical investigations based on the DFT calculations have also been applied to show the electronic properties of complex 1. The antitumor activities of the parent ligand HL and complex 1 were studied using Dalton's lymphoma malignant cancer model. Both compounds were found to induce concentration-dependent cytotoxicity and apoptotic cell death, leading to a decrease in cell viability, body weight, and tumor volume in mice with the superior activity of complex 1 over HL. Mice treated with complex 1 demonstrated an increase in life span with a survival period of 23 days. Finally, using a molecular docking approach, we have probed complex 1 to inhibit the recombinant mouse tumor-necrosis factor alpha (mTNF).

Synthesis, structure, and catalytic performance of solvent induced zinc clusters in furan synthesis by cycloisomerization reaction

Two Zn(II) clusters were synthesized by the reaction of Zn(OAc)2·2H2O and 1,2‐bis(2‐hydroxy‐3‐methoxybenzylidene)hydrazine as a N2O4‐donor Schiff base ligand in 1:3 molar ratio. The reaction in methanol gave yellow‐brown needle crystals, while block yellow crystals were achieved in a mixture of methanol:water (50:50 v/v). Investigation of the crystals by single crystal X‐ray analysis showed that solvent has considerable effect on the structure and composition of the products. In methanol, two independent pentanuclear Zn(II) clusters with the same general formula of [Zn5(L)2(μ‐OAc)4(OAc)2(CH3OH)2] but different coordination environments around Zn(II) cores, and bridging mode of the acetate ligands are present in the unit cell. In a mixture of methanol:water, a pentanuclear cluster and a 1D coordination polymer with pentanuclear repetitive unit are simultaneously present in the crystal structure. These compounds were further characterized by spectroscopic techniques, and they were used as catalysts for intramolecular cycloisomerization of 1,4‐diphenylbut‐3‐yn‐1‐one. The results indicated that these Zn(II) clusters can efficiently produce 2,5‐diphenylfuran through catalytic cycloisomerization reaction.

Trapping an unprecedented octacoordinated iron(II) complex with neutral bis-tetrazolylpyridyl ligands and solvent molecules.

Iron(II) can show a very rich coordination chemistry with concomitant modulation of its properties as promising functional materials. Metalation of the neutral tridentate nitrogen-donor mer-coordinating ligand 2,6-bis(2-(methyl)-2H-tetrazol-5-yl)pyridine (Me2btp) with Fe(ClO4)2·6H2O through accurate solvent polarity control enables the selective crystallization of [FeHS/LS(Me2btp)2](ClO4)2·MeCN·2.75H2O (2HS/LS·MeCN·2.75H2O) as red rods, where half of the iron(II) centres resides in the low spin (LS, S = 0) state and the other half is in the high spin (HS, S = 2) state. The red rods spontaneously convert into yellow crystals once removed from the mother liquor and exposed to air due to solvent rearrangement within the crystal packing; these new crystals can be assigned to [FeHS(Me2btp)2](ClO4)2·solvent (2HS·solvent) where all the iron(II) centres are now blocked in the HS state, as confirmed by magnetic measurements. The polarity of the crystallization solvent, together with the maintenance of the crystals within the mother liquor, are pivotal for the reactivity and interconversion of different species. Indeed, upon long standing in solution, 2HS/LS·MeCN·2.75H2O converts to another form of red crystals belonging to [FeLS(Me2btp)2][FeHS(Me2btp)(MeCN)2(H2O)](ClO4)4·MeCN (2LS·3HS·MeCN), as confirmed by single crystal X-ray diffraction data. In this co-crystal, the iron(II) in 2 resides in the LS state at all temperatures while the iron(II) in 3 is blocked in the HS state. Well-formed yellow crystals could be also isolated among the red crystals of 2HS/LS·MeCN·2.75H2O, and they could be identified as the unprecedented octacoordinated species [Fe(Me2btp)2(MeCN)(H2O)](ClO4)2·H2O (1·H2O) by single-crystal X-ray diffraction. These yellow crystals are stable in the air, but slowly convert into 2LS·3HS·MeCN if kept in the mother liquor for about one week. 1·H2O can be considered the trapped intermediate in the solid state during the conversion of [FeHS(Me2btp)2]2+ into [FeHS(Me2btp)(MeCN)2(H2O)]2+ in solution, where the two tridentate ligands in the starting species can unfold to accommodate coordinated MeCN and H2O molecules, as confirmed by theoretical calculations, and eventually one of the two Me2btp is completely replaced by the solvent.

ISOLASI DAN UJI AKTIVITAS ANTIBAKTERI SENYAWA METABOLIT SEKUNDER DARI EKSTRAK METANOL DAUN MARPUYAN (Rhodamnia cinerea Jack.)

A study on isolation and antibacterial activity of secondary metabolites from the methanol extract of Marpuyan (Rhodamnia cinerea Jack.) Leaves on Escherichia coli has been carried out. Isolation was carried out by column chromatography methods. Whereas the antibacterial activity test was carried out using agar diffusion method. The results of the isolation produced 17.9 mg of RC-F13 isolate compound in the form of light yellow crystals, with a melting point of 170-172oC and soluble in methanol. The results of identification of RC- F13 isolate compounds through testing with AlCl3 reagents, positive including the flavonoid group, were strengthened by the results of the UV spectrum and FT-IR spectrum. Based on the results of the UV spectrum, it was seen that the RC- F13 isolate compound showed λ max 353.60, 257.00 and 209.20 nm. The FT-IR spectrum shows the presence of several functional groups such as OH, C aliphatic C-H, C = O carbonyl, C = C aromatic and C-O. testing the antibacterial activity of methanol extract with a concentration of 20%; 10%; 1%; 0.1% and 0.01%, fraction 13 at 1% concentration; 0.1% and 0.01% and RC- F13 isolate compound concentration of 0.1%, against Escherichia coli bacteria did not show any antibacterial activity which was marked by the absence of clear areas around the disc.

Tuning emission of luminescent 2-7 disubstituted sila-and germafluorenes with –(trifluoromethyl)phenyl, -(malononitrile)phenyl, and -nitrobenzene substituents

2,7-Disubstitution and DFT-guided design have been used to tune emission wavelengths for three new fluorescent 2,7-alkynyl(aryl)-3,6-dimethoxy-9,9-diphenyl-sila- and germafluorenes. Two germafluorenes with trifluoromethyl phenyl and nitrobenzene substituents were prepared using a Pd-catalyzed Sonogashira coupling reaction to incorporate alkynyl(aryl) groups at the 2,7-positions of the ring. Another new silafluorene was prepared by modifying a benzaldehyde-substituted silafluorene to incorporate a malononitrile group. These compounds were characterized utilizing multinuclear NMR, UV–Vis, and fluorescence spectroscopic techniques. The germafluorene with the trifluoromethyl phenyl substituent was also characterized via elemental analysis and X-ray crystallography. These metallafluorenes (MFs), which are yellow or red-orange crystals in the solid state, showed a wide range of quantum yields and spectroscopic features, with the malononitrile-containing MF exhibiting significantly red-shifted emission relative to other MFs. These data demonstrate the value in applying DFT to MF design and the dramatic impact the 2,7-substituent has on the optical properties of this class of compounds.

Shear-induced flow and dynamics of the nematic phase of Sunset Yellow lyotropic chromonic liquid crystal

ABSTRACT Fundamental understanding of rheological properties of lyotropic chromonic liquid crystals is inadequate compared to their thermotropic counterparts in spite of the growing interest in these materials. Here, we investigate the rheological properties of a lyotropic chromonic nematic liquid crystal (LCLC), prepared by dissolving 32 wt% of Sunset Yellow (SSY) in water. The flow curves (stress-strain rate, σ − γ ˙ ) at different temperatures exhibit three flow regimes R1, R2 and R3, respectively. At room temperature, in R1 ( γ ˙ < γ ˙ cl ) and R3 ( γ ˙ > γ ˙ cu ) the sample exhibits Newtonian flow behaviour ( σ ∝ γ ˙ ), whereas, in R2 ( γ ˙ cl < γ ˙ < γ ˙ cu ), it shows a power-law dependence ( σ ∼ γ ˙ β ). With increasing shear rate the change of stress from R1 to R2 is continuous, whereas the change is discontinuous from R2 to R3. We observe stress fluctuations under steady shear in regime R2 similar to those reported in worm-like micellar systems and in thermotropic twist-bend nematic liquid crystals. The non-monotonic flow behaviour and the stress dynamics are corroborated using in situ rheo-microscopy.

Structural, electrical and optical studies on organic NLO single crystal of N‐benzyl‐2‐methyl‐4‐nitroaniline (BNA)

AbstractThe 2‐methyl‐4‐nitroaniline (NA) was converted into the raw material N‐benzyl‐2‐methyl‐4‐nitroaniline (BNA), and the solubility of BNA in various organic solvents was calculated gravimetrically. BNA's solubility and crystal structure make it an excellent solvent for the low‐temperature solution growth method used to create single crystals of BNA with orthorhombic structure studied through single crystal analysis. Methanol was used to harvest the 3×10 mm3 BNA single crystals, which are big, translucent yellow crystals. BNA, the subject compound, the exothermic and endothermic nature was characterised by TG analyses, differential scanning calorimeter (DSC), functional studies by infrared (IR) spectra, NMR spectral and optical transmission studies. An Nd:YAG laser (1064 nm) was used to observe the second harmonic generation (SHG) of grown crystal leads about 3 times more than KDP crystal. Possible polarization for various temperatures, the crystal's dielectric properties was measured as a function of frequency. Larger surface morphology with high optical to wave conversion efficiency and the results were reviewed. Responding to electric field to leads to liquid crystal display and THz purposes.

Improved Description of Intra- and Intermolecular Interactions through Dispersion-Corrected Second-Order Møller-Plesset Perturbation Theory.

ConspectusThe quantum chemical modeling of organic crystals and other molecular condensed-phase problems requires computationally affordable electronic structure methods which can simultaneously describe intramolecular conformational energies and intermolecular interactions accurately. To achieve this, we have developed a spin-component-scaled, dispersion-corrected second-order Møller-Plesset perturbation theory (SCS-MP2D) model. SCS-MP2D augments canonical MP2 with a dispersion correction which removes the uncoupled Hartree-Fock dispersion energy present in canonical MP2 and replaces it with a more reliable coupled Kohn-Sham treatment, all evaluated within the framework of Grimme's D3 dispersion model. The spin-component scaling is then used to improve the description of the residual (nondispersion) portion of the correlation energy.The SCS-MP2D model improves upon earlier corrected MP2 models in a few ways. Compared to the highly successful dispersion-corrected MP2C model, which is based solely on intermolecular perturbation theory, the SCS-MP2D dispersion correction improves the description of both inter- and intramolecular interactions. The dispersion correction can also be evaluated with trivial computational cost, and nuclear analytic gradients are computed readily to enable geometry optimizations. In contrast to earlier spin-component scaling MP2 models, the optimal spin-component scaling coefficients are only mildly sensitive to the choice of training data, and a single global parametrization of the model can describe both thermochemistry and noncovalent interactions.The resulting dispersion-corrected, spin-component-scaled MP2 (SCS-MP2D) model predicts conformational energies and intermolecular interactions with accuracy comparable to or better than those of many range-separated and double-hybrid density functionals, as is demonstrated on a variety of benchmark tests. Among the functionals considered here, only the revDSD-PBEP86-D3(BJ) functional gives consistently smaller errors in benchmark tests. The results presented also hint that further improvements of SCS-MP2D may be possible through a more robust fitting procedure for the seven empirical parameters.To demonstrate the performance of SCS-MP2D further, several applications to molecular crystal problems are presented. The three chosen examples all represent cases where density-driven delocalization error causes GGA or hybrid density functionals to artificially stabilize crystals exhibiting more extended π-conjugation. Our pragmatic strategy addresses the delocalization error by combining a periodic density functional theory (DFT) treatment of the infinite lattice with intramolecular/conformational energy corrections computed with SCS-MP2D. For the anticancer drug axitinib, applying the SCS-MP2D conformational energy correction produces crystal polymorph stabilities that are consistent with experiment, in contrast to earlier studies. For the crystal structure prediction of the ROY molecule, so named for its colorful red, orange, and yellow crystals, this approach leads to the first plausible crystal energy landscape, and it reveals that the lowest-energy polymorphs have already been found experimentally. Finally, in the context of photomechanical crystals, which transform light into mechanical work, these techniques are used to predict the structural transformations and extract design principles for maximizing the work performed.

Formation, Characterization, and Bonding of cis- and trans-[PtCl2{Te(CH2)6}2], cis-trans-[Pt3Cl6{Te(CH2)6}4], and cis-trans-[Pt4Cl8{Te(CH2)6}4]: Experimental and DFT Study.

[PtCl2{Te(CH2)6}2] (1) was synthesized from the cyclic telluroether Te(CH2)6 and cis-[PtCl2(NCPh)2] in dichloromethane at room temperature under the exclusion of light. The crystal structure determination showed that in the solid state, 1 crystallizes as yellow plate-like crystals of the cis-isomer 1cis and the orange-red interwoven needles of 1trans. The crystals could be separated under the microscope. NMR experiments showed that upon dissolution of the crystals of 1cis in CDCl3, it isomerizes and forms a dynamic equilibrium with the trans-isomer 1trans that becomes the predominant species. Small amounts of cis-trans-[Pt3Cl6{Te(CH2)6}4] (2) and cis-trans-[Pt4Cl8{Te(CH2)6}4] (3) were also formed and structurally characterized. Both compounds show rare bridging telluroether ligands and two different platinum coordination environments, one exhibiting a cis-Cl/cis-Te(CH2)6 arrangement and the other a trans-Cl/trans-Te(CH2)6 arrangement. Complex 2 has an open structure with two terminal and two bridging telluroether ligands, whereas complex 3 has a cyclic structure with four Te(CH2)6 bridging ligands. The bonding and formation of the complexes have been discussed through the use of DFT calculations combined with QTAIM analysis. The recrystallization of the mixture of the 1:1 reaction from d6-DMSO afforded [PtCl2{S(O)(CD3)2}{Te(CH2)6}] (4) that could also be characterized both structurally and spectroscopically.

Synthesis, molecular structure, DFT studies, non-covalent interaction plots, Hirshfeld surface analysis and molecular docking studies of homoleptic Mn(II)(4,4,4-trifluoro-1-phenyl-1,3-butanedione)2

A simple room temperature stirring reaction of MnCl2·4H2O and 4,4,4-trifluoro-1-phenyl-1,3-butanedione (TFPBDH) afforded a yellow crystals of monomeric, square-planar Mn(TFPBD)2 as revealed by single-crystal X-ray diffraction and DFT analysis (B3LYP/6–311+G(d,p)/LanL2DZ). ESI-MS analysis confirms the solution stability of Mn(TFPBD)2 and further supported by FT-IR and UV–Vis analysis. Quantum theory of atoms in molecules (QTAIM) analysis, non-covalent interaction (NCI) plots, Hirshfeld surface (HS) analysis (CE-B3LYP/6–31G(d,p) were carried out to understand the CH···F, CH···π and other intra- and intermolecular interactions prevails within the supramolecular architecture. Further, the molecular stability was assessed in terms of interaction energy (IE) calculations by constructing various energy frameworks through electrostatic, dispersion, polarization, and repulsion energies (total IE = −162.8 kJ mol−1). The in silico molecular docking demonstrates the binding affinity of Mn(TFPBD)2 towards penicillin-binding protein 2, PBP2 (6G9S) and staphylococcal aureus FtsZ (4DXD) with an excellent binding score of −6.36 and −9.84 kcal/mol respectively.

A New Albite Microanalytical Reference Material from Piz Beverin for Na, Al and Si Determination, and the Potential for New K‐Feldspar Reference Materials

Determination of alkali elements is important to Earth scientists, yet suitable and reliable microanalytical reference materials are lacking. This paper proposes a new albite reference material and evaluates the potential for future K‐feldspar reference materials. The proposed Piz Beverin albite reference material from Switzerland yields a homogeneous composition at the centimetre‐ to micrometre‐scale for Si, Al and Na with &lt; 2000 μg g‐1 total trace elements (mostly heterogeneously distributed Ca, K and Sr). EPMA and LA‐ICP‐MS measurements confirm a composition of 99.5(2)% albite component, which is supported further by bulk XRF measurements. A round robin evaluation involving nine independent EPMA laboratories confirms its composition and homogeneity for Si, Al and Na. In addition, a set of five distinct clear K‐feldspar samples was evaluated as possible reference materials. The first two crystals of adular and orthoclase yield unacceptable inhomogeneities with &gt; 2% relative local variations of Na, K and Ba contents. The three other investigated sets of K‐feldspar crystals are yellow sanidine crystals from Itrongay (Madagascar). Despite distinct compositions, EPMA confirms they are each homogeneous at the centimetre to micrometre scale for Si, Al and K and have no apparent inclusions; further investigation to find larger amounts of these materials is therefore justified.