P1 Space Group Research Articles

VCD spectra of chiral naphthalene-1-carboxamides in the solid-state

The VCD spectra of chiral 2,3-dihydro-1H-benzo[de]isoquinolin-1-one (8-substituted naphthalene-1-carboxamide, BIQ) were studied in KBr pellets. The X-ray diffractometry revealed that the Me, Ph, and pClPh BIQs crystalize in the monoclinic P21, while nBu, pMePh, and oMeOPh BIQs in the orthorhombic P212121 space group. Only the Me-BIQ crystal exhibits the presence of cyclic amide dimers, while the others contain chains of the amid group hydrogen bonds. For all BIQs, except pMePh, the most intense IR band in the 1750–1550 cm−1 region is located at ca. 1680 cm−1 and is accompanied by two weak ones at ca. 1618 and 1590 cm−1. For the pMePh derivative, four almost equally intense IR bands at 1662, 1639, 1614, and 1588 cm−1 are observed. This region of the IR spectra of BIQs, but pMePh, is well reproduced by calculations based on BIQ monomers. On the other hand, the complex IR pattern of pMePh is computationally reproduced when larger crystal fragments, like octamers, are considered. Registration of the VCD spectra enabled recognizing the complexity of IR contours at ca. 1680 cm−1 by the corresponding VCD motives. For (i) Me, Ph and pClPh (R)-enantiomers, two (+)(–) bands were distinguished and for (ii) nBu and pMePh ones, one VCD band with right-side asymmetry was found. For (iii) oMeOPh the VCD pattern cannot be unambiguously assigned. Thus, the VCD spectra in the ν(C=O) range diverse the studied compounds. Among the set of molecules, pMePh has exceptional crystal geometry. Therefore, its most intense ν(C=O) band position and shape can be connected with the geometry of the hydrogen bonds, interactions, and crystal packing. Interpretation of the VCD spectra is based on linear and packed BIQ octamers. This cluster model can reproduce the main features of the solid-state VCD of BIQs.

Synthesis, crystal structure, spectroscopic and computational studies of NLO active 2-methylimdazolium 4-nitrobenzoic acid single crystal

In this report, we have presented the theoretical and experimental investigation of 2-Methylimdazolium 4-Nitrobenzoic Acid (2MI4NB) – an organic crystal. The good quality 2MI4NB single crystal was grown by slow evaporation technique. Both single and powder X-ray diffraction (XRD) analysis confirmed that the grown crystal structure is Triclinic with the P1 space group. The vibrational modes present in the chemical were validated through Fourier transform infrared (FT-IR) spectrum investigations. Density functional theory (DFT), a quantum chemical approach, has emerged as a potential or an effective tool for studying molecular structure and NLO properties and is being used frequently in applications involving NLO systems. HOMO-LUMO analysis and reactivity parameters were calculated. Molecular Electrostatic Potential (MEP), Natural Bond Orbital (NBO) analysis and first order hyper polarizability were studied by B3LYP theoretical level with 6-311++G(d,p) basic set. In addition, the Mulliken Atomic Charge was calculated with the same basic set. The thermal properties of the 2MI4NB crystal was analysed by TG-DTA studies. It shows that the two endothermic peaks were observed. The optical absorption spectrum shows that there is no absorption in the region of 430–1200 nm. The Z-scan analysis gives the third order NLO properties like refractive index and third-order NLO susceptibility of 2MI4NB crystals.

Investigating the structural and mechanical behavioral properties of semi-organic nonlinear optical single crystal: L-arginine tetrafluoroborate

A semi-organic nonlinear optical material L-Arginine tetrafluoroborate (LAFB) was synthesized as single crystal using Slow Evaporation Technique. Various properties of this material were analyzed to make it suitable for NLO applications. The structural behavior of the material was determined by single crystal XRD and found that the crystal has orthorhombic structure and was synthesized with P212121 space group. The High-Resolution X-Ray Diffraction (HRXRD) study was conducted to determine the change in the lattice parameters resulting from strain, defects or by other means in LAFB material. The diffraction curve analysis show that the grown crystal consisted of interstitial type point defect. The Shock Damage Threshold (SDT) measures the stability of the compound against shock, the analysis exhibits that under Mach number 2.2 up to 10th shock no significant cracks were observed in the crystal but damage area of the crystal was increased. The mechanical behavior of the sample against highly intense laser was analyzed through Laser Damage Threshold (LDT). The calculated value of LDT was to be 0.75[Formula: see text]GW/cm2 for 1 pulse per second whereas it decreased to 0.57[Formula: see text]GW/cm2 for 10 pulse per second. To explore the mechanical properties of the material, Nano indentation was carried out, by which the values of H[Formula: see text][Formula: see text]MPa and E[Formula: see text][Formula: see text]GPa were obtained.

Synthesis, Characterization and Antibacterial Properties of Complex [Ag(SCN)(2-NH2py)

The reaction of AgSCN with 2-aminopyridine in ammonia solution produces the colorless crystal of catena-poly [Ag(SCN))(C6H5N2)]n. The crystals were characterized by FTIR analysis and single crystal X-Ray diffraction. The silver(I) ion bind to one N atom of 2-aminopyridine, one N atom of thiocyanate and two S atoms of two thiocyanates to form a pseudo-tetrahedral complex. The presence of thiocyanates bridge ligand give an one-dimensional polymer. Complex [Ag(SCN)(2-NH2py)] crystallizes in monoclinic lattice and P21 space group with a=9,122(3) Å, b=4,1506(15) Å, c=11,269(4) Å, α= γ= 90°, β= 109,214(8)°, R= 0,0287. Intermolecular hydrogen bonds between amino group and thiocyanate NH-H…N-CS (2.389 Å) are also found in this structure. In vitro antibacterial screening complex was evaluated against two bacteria (Escherichia coli and Staphylococcus aureus). The results show that complex has higher antibacterial activity than 2-aminopyridine and KSCN. This is due to central ion and the ability of the ligand to interact with membrane proteins.

Mebendazolium mesylate anhydride salt: rational design based on supramolecular assembly, synthesis, and solid-state characterization.

The design mebendazole (MBZ) multicomponent systems is important to obtain new materials that incorporate the API (active pharmaceutical ingredient) with better thermal stability, avoiding the interconversion of desmotropes. Interestingly, the presence of water molecules in the mebendazolium mesylate monohydrate prevents the formation of the R22(8) supramolecular synthon, found in all mebendazolium salts with polyatomic counterions. Here, we designed a new mebendazolium mesylate anhydrous salt based on statistical scrutiny of all mebendazole crystal structures identified in the literature and an exhaustive analysis of the conformational and geometrical requirements for the supramolecular assembly. The synthesis of this new salt and its solid-state characterization through single-crystal X-ray diffraction and complementary techniques are presented. As expected, mebendazole recrystallization in methanol with methanesulfonic acid - a Food and Drug Administration accepted coformer - in the absence of water yields a mesylate anhydrous salt with 1 : 1 stoichiometry. This new salt crystallizes in the P212121 (19) space group. The main intermolecular interactions found in the crystal structure are the hydrogen bonds that form a R22(8) supramolecular motif that assembles the ionic pairs. Additional non-classical H-bond, as well as π⋯π and carbonyl⋯cation interactions, contribute to the final stabilization of the crystal packing. This new salt is stable up to 205 °C when it undergoes the endothermic loss of the ester moiety to yield 2-amino-5-benzoylbenzimidazole. Moreover, preliminary dissolution experiments in aqueous 0.1 mol L-1 HCl suggest an apparent solubility of mebendazolium mesylate anhydride 2.67 times higher than that of the preferred for pharmaceutical formulations MBZ form C.

Advancing nonlinear optics: discovery and characterization of new non-centrosymmetric phenazine-based halides.

Organic-inorganic metal halides (OIMHs) have drawn considerable attention due to their remarkable optoelectronic properties and substantial promise for nonlinear optical applications. In this research, phenazine has been selected as the organic cation because of its π-conjugated feature. Three compounds, (C12H9N2)PbCl3, (C12H9N2)SbCl4, and (C12H9N2)2InBr4·Br, were synthesized. Initial space group assignments were centrosymmetric for (C12H9N2)PbCl3 and (C12H9N2)SbCl4. However, under 1550 nm laser excitation, (C12H9N2)PbCl3 and (C12H9N2)SbCl4 exhibited second harmonic generation intensities ∼1.7 times greater than that of the benchmark KH2PO4. Structural reevaluation ultimately confirmed non-centrosymmetric P1 and P21 space groups for (C12H9N2)PbCl3 and (C12H9N2)SbCl4, respectively. Upon excitation at 335 nm and 470 nm, (C12H9N2)PbCl3, (C12H9N2)SbCl4, and (C12H9N2)2InBr4·Br emit fluorescence at room temperature. (C12H9N2)2InBr4·Br exhibits reversible phase transitions, showing potential for phase change energy storage. Our research underscores the critical role of comprehensive experimental validation in determining the precise crystallographic space groups and reveals the extensive potential of OIMHs as versatile candidates for advanced optoelectronic applications.

KOH selective etching synthesis and electrochemical performance of nano porous Li2FeSiO4/C composite

Nano porous Li2FeSiO4/C composite (LFS-10S) was prepared by KOH selective etching Li2FeSiO4-(SiO2)0.1/C composites. This method allows directly pore-creating on Li2FeSiO4 crystal. Common porous Li2FeSiO4/C (LFS) were also prepared as a control. LFS-10S and LFS were characterized by XRD, SEM, TEM and nitrogen adsorption/desorption test. XRD analysis shows that the LFS-10S material was composed of crystalline particles with a monoclinic crystal system in the P21 space group. SEM and TEM tests indicate that the particle size of LFS-10S is 20 ∼ 30 nm. The nitrogen adsorption/desorption test shows that the specific surface area of LFS-10S is 123.23 m2/g, larger than that of LFS (71.56 m2/g). These features make LFS-10S exhibit better electrochemical performance over LFS. The specific discharge capacity of LFS-10S at 0.1 C is as high as 235.2 mA h g−1, higher than that of LFS (158.4 mA h g−1). Moreover, the rate performance, cycling performance and lithium ion diffusion coefficient of LFS-10S are all better than those of LFS.

Solid state synthesis of zwitterionic cocrystal 5-fluorouracil L-phenylalanine explicated via structural, spectroscopy, quantum chemicals, Hirshfeld and docking analysis

The single crystal 5-Fluorouracil l-phenylalanine (5FUPA) was synthesized using solid state technique and crystallized at room temperature using the slow evaporation method. The crystal with orthorhombic structure and P212121 space group was obtained. Quantum chemical studies were used to compute the structural parameters and various spectroscopic properties for 5FUPA using the B3LYP/6–311++G (d, p). The structural parameters from reported single crystal XRD and calculated from DFT were compared, and they were showing good agreement with each other. The peaks obtained by experimental FTIR and modes calculated by theoretical DFT method have a good degree of consistency. The UV–Visible absorption spectrum of 5FUPA shown to have maximum absorption peak at 266 nm. The NBO analysis was used to calculate the interaction between bonding and anti-bonding orbitals and their stabilization energy in 5FUPA. The most reactive sites of the 5FUPA cocrystal were investigated by Fukui function descriptor and Molecular Electrostatic Potential (MEP) energy surface calculated using Mulliken charges. Inter- and intra-molecular interactions of the 5FUPA were investigated using the Hirshfeld surface and finger print methods. The topological studies ELF, LOL and thermodynamic parameters at different temperatures were performed. The molecular docking outcomes indicate that, cocrystal 5FUPA have better inhibitory effects on breast cancer proteins when compared to 5-fluorouracil and l-phenylalanine. The 5FUPA cocrystal has performed better compared to the other two molecules in terms of docking affinity, having a better binding score range of -8.3 kcal/mol to -9.4 kcal/mol. This demonstrates that 5FUPA cocrystal has unveiled more bioactivity and reactivity when compared with 5-fluorouracil and l-phenylalanine, and can be further considered as a breast cancer medication after clinical trials.

Experimental evidence on the sustainability of crystallographic and chiral symmetry of L-alanine under dynamic shocked conditions

Over the years, crystallographic phase transitions of the polar and non-polar amino acids under static high-pressure-temperature conditions have been well documented, especially after the development of the diamond anvil cell techniques. In contrast, the crystallographic structural science of such primary amino acids under dynamic shocked conditions is still to be explored substantially as it is in a premature stage which requires being loaded with a few possible deep insights whereby exploring the structural kinetics could be a reality. In the present context, we have performed the acoustic shock wave recovery experiment on non-polar amino acid of L-Alanine powder samples such that X-ray diffraction (XRD) and circular dichroism (CD) spectroscopic techniques have been enabled to investigate the structural and chiral stability under shocked conditions. Based on the observed results, it is observed that the crystallographic structure with the P212121 space group and the same chirality is maintained even at the 200-shocked condition with a transient pressure of 2.0 MPa. The observed dynamic shock wave loading structural stability outcome is identified to be well-matched with the previous static high-pressure compression results.

Structural, spectroscopic and second harmonic generation evaluation of 1,2,4-triazolinium tartrate - tartaric acid as a promising nonlinear optical material

Crystallization of 1,2,4-triazole with (2R,3R)-(+)-tartaric acid (l (+)-tartaric acid) in a 1:2 ratio yields the ionic co-crystals of 1,2,4-triazolium tartrate – tartaric acid (1:1), (C2H4N3) (C4H5O6)‧C4H6O6 – (abbreviated as TATT). TATT crystallizes in the tetragonal system with a non-centrosymmetric P41212 space group of eight molecules per unit cell. Apart from ionic interaction by the building ions and N–H‧‧‧O, the 1,2,4-triazolinium cation and the tartrate anion interact through hydrogen bonds and O–H‧‧‧O with tartaric acid to form a supramolecular complex (C2H4N3) (C4H5O6)‧C4H6O6 (TATT). Hydrogen bonds further organise these supramolecular complexes into a three-dimensional network. The interactions between the building blocks of the co-crystal were analyzed using Hirshfeld surface and 2D fingerprint plots. Normal coordinate force field calculations based on density functional theory (DFT) and structure optimizations were utilized to interpret the molecular structure and fundamental vibrational frequencies. The wave numbers' complete vibrational assignments were determined through potential energy distribution (PED). The HOMO and LUMO energy gap calculations explained the charge transfer interactions within the supramolecular unit. For the TATT co-crystal, the efficiency of the second harmonic generation (SHG) process was investigated under 800 nm irradiation using the Kurtz–Perry powder technique. The ionic co-crystal demonstrated a low SHG efficiency on the order of 10−1 compared to that of KDP.

Influence of the ancillary ligand on the crystalline structures and magnetic properties of mesaconato‐bridged Mn coordination polymers

Abstract{[Mn(mes)(dmb)(H2O)] ⋅ H2O}n (1) and [Mn(mes)(bpy)]n (2); (mes=mesaconato; dmb=5,5’‐dimethyl‐2,2’‐bipyridine; bpy=2,2’‐bipyridine), were obtained by self‐assembly solution reaction at ambient conditions, and structurally characterized by single crystal X‐ray diffraction. 1 crystallizes in an orthorhombic system with a Pbca space group and forms a one‐dimensional (1D) coordination polymer; the six‐coordinated Mn(II) centers display a distorted‐trigonal prismatic configuration. 2 crystallizes in an orthorhombic system with a P21212 space group yielding a two‐dimensional (2D) coordination array, their metal centers having a distorted octahedral geometry. Magnetic susceptibility measurements reveal that 1 is paramagnetic, while 2 shows weak antiferromagnetic coupling.

Reddish-orange emitting Eu2−x Gd x Ge2O7 pyrogermanate ceramic phosphors: synthesis and role of Eu3+/Gd3+ substitution on the optical features

In this work, highly luminescent pyrogermanates were successfully synthesized through the solid-state reaction route, and the role of gradual Eu3+ substitution for Gd3+ on the structure and photoluminescent properties of Eu2−x Gd x Ge2O7 pyrogermanates was investigated. Pure Eu2Ge2O7 ceramic is triclinic, belonging to the P1 (#1) space group, and by increasing the x values, the crystal structure changes with the partial substitution of Eu3+ ions by the Gd3+ ions into the chemical lattice. The other phase-pure ceramic, Gd2Ge2O7, belongs to the tetragonal P41212 (#92) space group. Complete solid solubility was attained for x ⩽ 1.6, where Gd3+ replaced Eu3+ in the triclinic structure. It was verified that the band gap energies are dependent on the crystalline structure, increasing as Gd replaced Eu in the Eu2−x Gd x Ge2O7. The lowest band gap value (5.13 eV) was observed for the triclinic Eu2Ge2O7, and the highest one (5.88 eV) for the tetragonal Gd2Ge2O7. Highly intense reddish-orange emission (quantum efficiency up to 91.9%), through excitation at charge transfer band and Ln3+ f–f transitions were evaluated as the Gd substitution rises. Substitution-sensitive phase change at the nanoscale was monitored by Eu3+ emission, validating the presence of Eu3+ in the triclinic and/or tetragonal phase depending on the chemical composition (or the Gd3+/Eu3+ ratio). The chromaticity diagram figured out a reddish-orange emission, making them promising materials for high-entropy and photonic devices as solid-state lighting using excitation by near UV light-emitting devices.

Structural and electrical properties of Gd and W co-doped La2Mo2O9 as electrolyte for IT-SOFCs

In this study, a modified sol-gel method was employed to synthesize Gd and W co-doped La2Mo2O9 (LMX). The impact of Gd and W co-doping on the pristine LMX lattice was examined using X-Ray diffraction, and the local structural parameters were analyzed through Rietveld refinement. The findings indicate that both the pure and co-doped LMX samples possess a cubic structure with a P213 space group. To investigate the electrical performance of the lanthanum molybdate (La2Mo2O9) both in its pure form and when co-doped with Gd and W, electrochemical impedance spectroscopy was conducted. The results demonstrated that co-doping enhances the conductivity of oxy-ions compared to pure LMX. Specifically, La1.7Gd0.3Mo1.7W0.3O9 (LMXG3) exhibited a higher ionic conductivity of approximately 2 x 10−2 Scm−1 at a temperature of 650 °C, surpassing the conductivity of the pure LMX sample and other co-doped LMX samples. This investigation highlights the potential of the Gd and W co-doped LMX system as a solid electrolyte for intermediate-temperature solid oxide fuel cells (IT-SOFCs).

Li4Mo5O17 crystal as possible scintillating material: Growth and luminescence properties

Transparent Li4Mo5O17 crystals with dimensions 60 × 30 × 20 mm were grown by low-thermal-gradient Czochralski technique. Optimal growth parameters were determined. According to SCXRD, Li4Mo5O17 compound crystallizes in the triclinic space group of P1¯ and the unit cell parameters at 150 K are a = 6.7596(2) Å, b = 9.4546(3) Å, c = 10.7909(3) Å, α = 73.1610(10)°, β = 88.8810(10)°, γ = 69.7460(10)°, V = 616.75(3) Å3. Uniformity of obtained crystals was confirmed by XRD analysis. Li4Mo5O17 crystal structure and cell parameters were studied by SCXRD. Li4Mo5O17 melting point at 546 °C was determined by DSC curve in 300–1000 K range. Luminescence was registered with peak maximum 670 nm at 370 nm excitation and 645 nm at 300 nm excitation.

Investigations on growth, XRD, strain, FTIR, UV–Vis NIR, photoluminescence, SHG, and Z-scan analyses of L-cysteine picrate single crystal for NLO and optical limiting applications

Organic single crystal of L-cysteine picrate (LCP), an efficient NLO material for frequency conversion, optoelectronic, and optical limiting applications has been grown within 20 days by Slow Evaporation Solution Technique (SEST). PXRD analysis shows that the LCP is subjected to the noncentrosymmetric space group of P21 with a monoclinic crystal system. The very low strain value depicts that the level and dislocations of the defect in the lattice of LCP crystal are very low. The various functional group assignments were investigated by using Fourier-Transform Infrared (FTIR) spectrum analysis with the range of 4000–400 cm−1. The optical analysis (UV–Visible) confirmed that the crystal has a lower cut-off wavelength of 250 nm and very low absorption in the entire visible region. Photoluminescence (PL) spectrum analysis confirmed that the material exhibits blue emission and is suitable for LED device fabrication. The SHG efficiency for LCP crystal is established to be 1.7 times higher than KDP material. Z-scan measurement determined the LCP exhibits two-photon absorption-induced optical limiting action with a nonlinear absorption coefficient of 0.70 × 10−10 m/W and onset limiting threshold of 2.36 × 1012 W/m2 which indicates that it can be used in making laser protection gadgets.

Crystal structure, bond characterization and lattice energy of B-site 1:3 ordering inverse spinel Li1.25Ga0.25Ti1.5O4 ceramic

In this work, inverse spinel structured Li1.25Ga0.25Ti1.5O4 ceramics with a space group of P4332 were synthesized by a solid-state reaction method. XRD, SAED, HRTEM, and Raman spectra analysis demonstrated that the Li1.25Ga0.25Ti1.5O4 ceramic was formed a A-site 1:3 disordered and B-site 1:3 ordered spinel structured. A high relative density (98.7%) with excellent microwave dielectric properties of εr = 23.8, Q×f = 93,800 GHz, and τf = –21.9 ppm/oC were obtained in 1110 °C for 4 h. Bond valence analysis demonstrated that the average cations of Li1.25Ga0.25Ti1.5O4 were in the rattling state, and the polarizability of Ti4+ was underestimated. The P–V-L chemical bond theory and lattice energy analysis results indicated that B–O bonds were the main factor to affect the εr and Q × f, and the under-bonding Ti4+and Ga3+ has a significant effect on the τf. All the results show that the Li1.25Ga0.25Ti1.5O4 ceramic might be a potential candidate for 5 G communication technology.

Highlighting non-covalent interactions to molecular structure, electronic and vibrational spectra in a new hybrid organic-inorganic cobalt complex: synthesis, experimental and computational study

Abstract In this study, a novel hybrid organic-inorganic compound, 4-(ammoniummethyl)pyridinium tetracholoraobaltate(II) monohydrate, with non-centrosymmetric properties have been synthesized and characterized by several techniques of powder and single-crystal X-ray diffraction, infrared IR and UV–Visible spectroscopies, and calorimetric (DSC) and the thermogravimetric (TG) analysis. The crystallization of this hybrid compound was found in a monoclinic system with a P21 space group. Additionally, the optimized structures of cation, anion and compound by using hybrid B3LYP method with 6-311++G(d,p) and 6-31+G(d) basis sets shown good correlations with the experimental data and the complete vibrational assignments and force constants are reported for three species. The surface morphology and the micrographs were checked by the scanning electron microscopy (SEM). The UV–Visible absorption spectrum has been used to study the optical properties and the energy gap of our compound. Hirshfeld surface (HS) analysis associated matched up with 2D fingerprint plots were used to confirm the existence of intermolecular and non-covalent interactions in the compound and confirmed by several topological approaches: Quantum Theory of Atom-in-Molecules (QTAIM), reduced density gradient (RDG) and molecular electrostatic potential surface (MEP). The frontier molecular orbitals HOMO and LUMO have been investigated for chemical reactivity and kinetic stability.

Syntheses, Crystal Structure, and Second Harmonic Generation Response of Four Novel Noncentrosymmetric Tellurites of Quaternary A/M/Te/O (A = Ba, Sr, Ca; M = V, Nb, Ta) System: BaTa4Te3O17, BaNb4Te3O17, SrTa4Te3O17, and CaV2TeO8.

Four new noncentrosymmetric tellurites of quaternary A/M/Te/O (A = Ba, Sr, Ca; M = V, Nb, Ta) system, namely, BaTa4Te3O17 (1), BaNb4Te3O17 (2), SrTa4Te3O17 (3), and CaV2TeO8 (4), were synthesized and characterized by single-crystal X-ray diffraction, thermal analysis, diffuse reflectance spectroscopy, and powder second harmonic generation (SHG) response measurements. The isostructural compounds 1-3 crystallize in the P212121 space group and have a three-dimensional (Ta4Te3O17)2-/(Nb4Te3O17)2- anionic framework, whereas the layered compound 4 crystallizes in the Ccc2 space group and has a [V2TeO8]2- anionic layer. The phase-matching compounds 1, 2, and 3 and the non-phase-matching compound 4 show powder SHG responses equivalent to ∼27, ∼13, ∼24, and ∼68% of that of LiNbO3, respectively.

Optimizing optical and antimicrobial properties of europium-doped copper sulphate pentahydrate crystal via unidirectional growth and characterization

A Europium-doped Copper Sulphate Pentahydrate crystal was grown using Unidirectional growth method, resulting in a crystal that was 108 mm long. Various characterization methods were employed to investigate its growth, optical, structural, and antimicrobial properties. X-ray Diffraction analysis showed that the crystal belonged to the P1 space group and calculated its corresponding lattice parameters. The band gap of the grown crystal was determined by analysing its response to UV excitation. Fourier transform infrared spectroscopy identified the presence of OH and sulfoxide bond. Surface images of the crystal were taken using the Scanning electron microscope, and EDAX reports confirmed the presence of Europium in the grown crystal. Photoluminescence studies showed the emission peak at 640 nm, and 5D0 to 7FJ (J = 2,3) transition levels were observed in the emission spectrum corresponding to europium ions in the orange-red region using 320 nm of excitation wavelength. Antimicrobial studies were conducted on Eu doped CuSO4·5H2O crystals using two gram-positive, two gram-negative bacteria, and two fungal cultures. The zone of inhibition was measured and found to be 12,12,13.5,14 mm and 16,17 mm for Staphylococcus aureus, Enterococcus Faecalis, Escherichia coli, Klebsiella pneumoniae, and Candida, Aspergillus, respectively. These findings indicate that Eu doped CuSO4·5H2O is a fast-growing crystal that exhibits good quality optical and antimicrobial activity.

Synthesis, crystal structure, thermal properties of a homoleptic Schiff base cobalt complex bis(N-tert-pentyl salicylaldimine)cobalt(II) as precursor for coating Co3O4 thin film by a plasma enhanced MOCVD

A Schiff base complex of cobalt namely, bis(N-tert-pentyl-salicylaldimine)cobalt(II) (2) was synthesized by treating the parent complex, bis(salicylaldehydato)cobalt(II) (1) with n-tert-pentylamine in a methanolic medium. Complex 2 was analysed by dynamic TG/DTA using high purity Ar as purge gas at ambient pressure and was found to be volatile without undergoing decomposition leaving a negligible amount of (1.8 %) residue at 322 °C after melting sharply at 155 °C. The parent complex (1) wherein four oxygen atoms are coordinated to cobalt yielded a residue of 58 % at 400 °C. The dissimilarity in thermal property of 2 (CoN2O2) from that of 1 (CoO2O2) arises from the bonding of nitrogen atoms to cobalt by introducing n-tert-pentylamine which caused replacement of aldehyde O (–CH = O) with azomethine nitrogen (–CH = N). Single crystal XRD analysis of complex 2 revealed it to crystallise in orthorhombic crystal system with a space group of P212121. Further 2 was characterised by FTIR, elemental analysis and mass spectrometry. Transpiration TG technique was employed to evaluate the temperature dependence of saturated vapour pressure (pe) and enthalpy of vaporization (ΔvapH° = 102.3 ± 2.5 kJ mol−1) for 2 in the temperature range of 443–545 K. Complex 2 was transformed in to Co3O4 thin film at 350 °C in an Ar plasma by using a lab made plasma assisted chemical vapour deposition (CVD) process at 1.2 mbar deposition pressure. XRD revealed a preferential growth of cubic Co3O4 in the (311) plane. The SEM images confirmed a dense but scattered growth of cauliflower shaped structures. The particle size was found to be 19.3 nm. Kubelka-Munk function yielded a band gap of 2.01 eV.