Impact of nickel substitution on structural, dielectric, magnetic, and electrochemical properties of copper ferrite nanostructures for energy storage devices

Nickel-substituted copper ferrite nanoparticles (NP) (Cu1-xNixFe2O4) were prepared using a cost-effective hydrothermal method. X-ray diffraction (XRD) pattern revealed a single-phase cubic spinel structure. The increase in lattice parameters and decrease in crystallite size are associated with the replacement of Cu ions by Ni ions in the host lattice of copper ferrite. The optimized Cu0.95Ni0.05Fe2O4 composition was subsequently annealed at 750 °C and 850 °C for further studies. Fourier transform infrared (FT-IR) analysis shows the existence of two promising fundamental adsorption peaks at 465 and 582 cm-1, related to the metal ion stretching vibrations at the tetrahedral (A) and octahedral (B) sites, respectively. The local disorder at both the A and B sublattices upon the incorporation of Ni was observed from the Raman analysis. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) images shows the formation of agglomerates composed of nano-sized spherical particles. A high Barrett-Joyner-Halenda (BJH) surface area was achieved 17.25 m2/g with a particle stability of -11.1 mV obtained by the zeta potential. Both the dielectric loss and dielectric constant are decreased, whereas the AC conductivity gets increased with increasing frequency. The magnetization-field hysteresis curves exhibited ferromagnetic behavior with a pseudo-single domain, and the cyclic voltammetry study revealed a pseudocapacitive trend. This study highlights the importance of Ni substitution to control the physicochemical properties of spinel-phase CuFe2O4 for diverse applications, such as energy storage and lithium-ion batteries.

Preparation of Cu₂ZnSnS₄ Thin Films by Successive Ionic Layer Adsorption and Reaction (SILAR) Method for Supercapacitor Applications

The Cu₂ZnSnS₄ (CZTS) thin films have been prepared at different deposition cycles, deposited on a glass substrate by successive ionic layer adsorption and reaction (SILAR) method followed by the annealing process at elevated temperature. The investigations on the films have been carried out to understand and confirm its structure, functional group present, crystalline morphology, optical and electrochemical behavior. The powder X-ray diffraction patterns recorded indicate that the deposited films are formed in the tetragonal structure. Other parameters like grain size, dislocation density, and microstrain are also calculated. The uniform surface of the films with spherical shaped morphology has been observed by Scanning Electron Microscopy, and the elemental compositions have been confirmed by EDAX. Electrochemical behavior such as cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge analysis have been carried out by electrochemical workstation. The modified electrode exhibits maximum specific capacitance value as 416 F/g for a pure sample. Optical studies have shown that the band gaps are estimated between 1.40 eV and 1.57 eV.

Crystal structure and Hirshfeld surface analysis of 2-amino-pyridinium hydrogen phthalate

New proton-transfer single crystals of 2-amino­pyridinium phthalate were obtained with the aim of synthesizing a new non-linear optical (NLO) material, which is achieved with the help of extensive hydrogen-bonding inter­actions between the ions.

Amino­pyridine and phthalic acid are well known synthons for supra­molecular architectures for the synthesis of new materials for optical applications. The 2-amino­pyridinium hydrogen phthalate title salt, C₅H₇N₂⁺·C₈H₅O₄⁻, crystallizes in the non-centrosymmetric space group P2₁. The nitro­gen atom of the –NH₂ group in the cation deviates from the fitted pyridine plane by 0.035 (7) Å. The plane of the pyridinium ring and phenyl ring of the anion are oriented at an angle of 80.5 (3)° to each other in the asymmetric unit. The anion features a strong intra­molecular O—H⋯O hydrogen bond, forming a self-associated S(7) ring motif. The crystal packing is dominated by inter­molecular N—H⋯O hydrogen bonds leading to the formation of 2₁ helices, with a C(11) chain motif. They propagate along the b axis and enclose R₂²(8) ring motifs. The helices are linked by C—H⋯O hydrogen bonds, forming layers parallel to the ab plane. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to investigate and qu­antify the inter­molecular inter­actions in the crystal.

Molecular structure, spectroscopic and quantum chemical studies on benzoic acid and succinic acid co-crystals of 2-aminopyrimidine

Organic nonlinear optical co-crystals 2-aminopyrimidine benzoic acid (2APB) and 2-aminopyrimidine succinic acid (2APS) have been successfully grown by slow solvent evaporation method at room temperature. The structural characterization of the grown crystals was carried out by single crystal X-ray diffraction. Fourier transform infrared spectroscopy (FT-IR) and FT-Raman spectra of the grown crystals are recorded and the observed vibrational frequencies are assigned. The hybrid computational calculations are carried out by Hartree–Fock (HF) and density functional theory (DFT) (3-parameter, Lee-Yang-Parr (B3LYP)) methods with 6-311[Formula: see text]G(d,p) basis sets and the corresponding results are tabulated. The geometrical parameters of the molecules also have been analyzed. The computed vibrational spectra were compared with experimental result which shows appreciable agreement. The chemical hardness, electronegativity, chemical potential and electrophilicity index were determined by highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) plot. The grown crystals were subjected to population analysis, thermal, linear and nonlinear optical studies of materials. The calculated second-order hyperpolarizability values of these materials are nearly two to four times that of urea.

Structural, Spectroscopic Investigation and Computational Study on Nitrate and Hydrogen Oxalate Salts of 2-Aminopyrimidine

The proton transfer salts of 2-aminopyrimidine with nitric acid (2APNO) and oxalic acid (2APOX) were synthesized and crystallized successfully by solvent evaporation solution growth technique. The crystal packing is stabilized through intricate three dimensional hydrogen bonded network. Both, the molecular structures were optimized with Density Functional Theory (DFT) using B3LYP function and Hartree-Fock method with a 6-311++G(d,p) basis set. Optimized molecular parameters between the methods were compared for the cation showing appreciable agreement. The computed vibrational spectra are compared with experimental result which clearly demonstrates the strong N-H··· O vibrational behaviour. Thermal stability of the crystals were analyzed with TGA/DTA and the melting points of the salts, viz. 2APNO and 2APOX, were identified at 189.5 and 210.9 °C, respectively. The chemical hardness, electronegativity, chemical potential and electrophilicity index of the two crystals were determined by HOMO-LUMO plot. The lower band gap value obtained from the Frontier Molecular Orbital (FMO) analysis favours the possible pharmaceutical/biological activity of the salts.

Investigation of Electrochemical Studies of Magnesium Ion Conducting Poly(vinyl alcohol)-Poly(vinyl pyrrolidone) Based Blend Polymers

Polymer blend electrolytes based on magnesium ion conducting PVA-PVP-MgCl2 polymer were prepared at different compositions by solution casting techniques. The prepared films were characterised by various techniques such as XRD and FTIR. Amorphous nature and structural coordination of polymer electrolyte were confirmed by X-ray diffraction and Fourier transform infrared spectroscopy studies. The ionic conductivity of the prepared polymer electrolytes were analysed through ac impedance spectroscopy. The highest conductivity was found to be in the order of ~10-6 Scm-1 at an ambient temperature for the composition of 50PVA:50PVP:5 wt% MgCl2. Conductivity versus temperature plot was found to follow an Arrhenius nature. The dielectric behaviour and ionic transport properties of the polymer electrolytes were also analyzed.

Plant pathogenic fungus F. solani mediated biosynthesis of nanoceria: antibacterial and antibiofilm activity

The present study reports the synthesis of CeO₂ nanoparticles using Fusarium solani. The biosynthesized CeO₂ nanoparticles were subjected to different characterization techniques and also showed potential antibacterial and antibiofilm activities.

Ethyl 3-(4-chloro-benzo-yl)-1-(4-chloro-benz-yl)-4-(4-chloro-phen-yl)-2,2-dioxo-3,4,6,7,8,8a-hexa-hydro-1H-pyrrolo-[2,1-c][1,4]thia-zine-1-carboxyl-ate

In the title compound, C30H28Cl3NO5S, the pyrrolidine ring adopts an envelope conformation (with the N atom as the flap) and the thia-zine ring is in a distorted chair conformation. The mol-ecular structure shows three intra-molecular C-H⋯O inter-actions leading to self-associated ring S(6) and two S(7) motifs. In the crystal, the molecules are linked by C-H⋯O and C-H⋯Cl inter-actions. Two R 2 (2)(10) and one R 2 (2)(16) centrosymmetrically related ring motifs are observed in the unit cell and they are connected through C(6) and C(11) chain motifs extending along the b and c axes, respectively.

(E)-3-(4-Meth-oxy-phen-yl)-3-[3-(4-meth-oxy-phen-yl)-1H-pyrazol-1-yl]prop-2-enal

In the title mol-ecule, C20H18N2O3, the pyrazole ring forms a dihedral angle of 2.2 (1)° with its meth-oxy-phenyl substituent and a dihedral angle of 67.2 (1)° with the benzene substituent on the propenal unit. In the crystal, mol-ecules are connected by weak C-H⋯O hydrogen bonds, forming R 2 (2)(26) and R 2 (2)(28) cyclic dimers that lie about crystallographic inversion centres. These dimers are further linked through C-H⋯O and C-H⋯N hydrogen bonds, forming C(8), C(9), C(10) and C(16) chain motifs. These primary motifs are further linked to form secondary C 2 (2)(15) chains and R 2 (2)(18) rings.

1-(2,4-Dinitro-phen-yl)-3-phenyl-4-phenyl-sulfanyl-1H-pyrazole

In the title mol­ecule, C₂₁H₁₄N₄O₄S, the pyrazole ring forms dihedral angles of 45.6 (1), 87.7 (1) and 27.4 (1)° with the phenyl, sulfur-substituted benzene and nitro-substituted benzene rings, respectively. In the crystal, mol­ecules are connected by weak C—H⋯O and C—H⋯N hydrogen bonds into layers parallel to (010).

Creatininium 2-chloro-acetate

In the title compound (systematic name: 2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium 2-chloro­acetate), C₄H₈N₃O⁺·C₂H₂ClO₂⁻, the mol­ecular aggregations are stabil­ized through classical (N—H⋯O) and non-classical (C—H⋯O and C—H⋯N) hydrogen-bonding inter­actions. The cations are linked to the anions, forming ion pairs through two N—H⋯O bonds that produce characteristic R₂²(8) ring motifs. These cation–anion pairs are connected through another N—H⋯O hydrogen bond, leading to an R₄²(8) ring motif. Further weak C—H⋯N inter­actions link the mol­ecules along the a axis, while other C—H⋯O inter­actions generate zigzag chains extending along b.

4-Chloro-anilinium 3-carb-oxy-prop-2-enoate

In the title compound, C(6)H(7)ClN(+)·C(4)H(3)O(4) (-), the cations and anions lie on mirror planes and hence only half of the mol-ecules are present in the asymmeric unit. The 4-chloro-anilinium cation and hydrogen maleate anion in the asymmetric unit are each planar and are oriented at an angle of 15.6 (1)° to one another and perpendicular to the b axis. A characterestic intra-molecular O-H⋯O hydrogen bond, forming an S(7) motif, is observed in the maleate anion. In the crystal, the cations and anions are linked by N-H⋯O hydrogen bonds, forming layers in the ab plane. The aromatic rings of the cations are sandwiched between hydrogen-bonded chains and rings formed through the amine group of the cation and maleate anions, leading to alternate hydro-phobic (z = 0 or 1) and hydro-philic layers (z = 1/2) along the c axis.

Creatinium hydrogen oxalate

The crystal structure of the title compound, C(4)H(10)N(3)O(2) (+)·C(2)HO(4) (-), is stabilized by N-H⋯O and O-H⋯O hydrogen bonds. The anions are connected by an O-H⋯O hydrogen bond, leading to C(5) chain extending along c axis. The cations are dimerized around the corners of the unit cell, leading to an R(2) (2)(14) ring motif. This leads to a cationic mol-ecular aggregation at x = 0 or 1 and an anionic mol-ecular aggregation at x = 1/2.

Creatininium hydrogen maleate

In the title compound, C₄H₈N₃O⁺·C₄H₃O₄⁻, the cations and anions are linked through N—H⋯O hydrogen bonds making a ionic pair with an R₂²(8) ring motif. These ionic pairs are further connected through another N—H⋯O hydrogen bond, leading to an R₆⁶(16) ring motif around the inversion centres of the unit cell. These approximately planar aggregates are further connected through weak van der Waals inter­actions in the unit cell. The anions have a characteristic intra­molecular O—H⋯O hydrogen bond with a self-associated ring S(7) motif.

2-Nitro-anilinium bromide

The title compound, C₆H₇N₂O₂⁺·Br⁻, is isomorphous with 2-nitro­anilinium chloride and contains an characteristic intra­molecular N—H⋯O hydrogen bond, forming an S(6) motif. Inter­molecular N—H⋯Br hydrogen bonds occur in the crystal structure. Two zigzag chains of C₂¹(4) motifs extend along the b-axis direction. These primary chain motifs inter­sect like a double helix structure, leading to R₆³(12) ring motifs, which are arranged in tandem along the b axis. Hence, hydro­philic layers are generated at z = 1/4 and 3/4, which are sandwiched between alternate hydro­phobic layers across z = 0 and 1/2.

Diethyl 1-benzyl-2,2-dioxo-4-phenyl-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[2,1-c][1,4]thiazine-1,3-dicarboxylate

In the title compound, C₂₆H₃₁NO₆S, the five-membered pyrrolidine ring adopts an envelope conformation and the six-membered thia­zine ring is in a distorted chair conformation. The crystal packing is stabilized through an inter­molecular C—H⋯O inter­action, generating inversion-related R₂²(10) ring motifs.

A triclinic polymorph of 3-nitro-anilinium chloride

The asymmetric unit of the title compound, C₆H₇N₂O₂⁺·Cl⁻, contains two independent ion pairs. A monoclinic form of the title compound with only one ion pair in the asymmetric unit has been reported previously [Ploug-Sørensen & Andersen (1986). Acta Cryst. C42, 1813–1815]. In the crystal of the title compound, the components are linked into layers parallel to (001) by inter­molecular N—H⋯Cl hydrogen bonds, with alternating hydro­philic and hydro­phobic regions.

2,6-Bis(2-chloro-phen-yl)-4-oxo-3,5-diphenyl-heptane-1,1,7,7-tetra-carbo-nitrile

In the title compound, C(35)H(24)Cl(2)N(4)O, the phenyl rings are oriented almost parallel to each other, making a dihedral angle of 0.6 (2)°, whereas the chloro-phenyl rings are oriented at a dihedral angle of 28.3 (1)°. The crystal structure is stabilized through an extensive series of C-H⋯N, C-H⋯O and C-H⋯Cl inter-actions. One of the C-H⋯N inter-actions generates an R(2) (2)(12) ring motif around a crystallographic inversion centre. C(5), C(10) and C(12) chain motifs are observed in the unit cell through C-H⋯N and C-H⋯Cl inter-actions. During the structure analysis, it was observed that the unit cell contains large accessible voids, which host disordered solvent mol-ecules. This affects the diffraction pattern, mostly at low scattering angles and was corrected with the SQUEEZE program [Spek, A. L. (2009 ▶). Acta Cryst. D65, 148-155].

Creatininium cinnamate

The crystal structure of the title compound (systematic name: 2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium 3-phenyl­prop-2-enoate), C₄H₈N₃O⁺·C₉H₇O₂⁻, is stabilized by N—H⋯O hydrogen bonding. Cations are linked to anions to form ion pairs with an R₂²(8) ring motif. These ion pairs are connected through a C₂²(6) chain motif extending along the c axis of the unit cell. This crystal packing is characterized by hydro­phobic layers at x ∼ 1/2 packed between hydro­philic layers at x ∼ 0.

(E)-3-(4-Chloro-phen-yl)-3-[3-(4-chloro-phen-yl)-1H-pyrazol-1-yl]prop-2-enal

In the title compound, C₁₈H₁₂Cl₂N₂O, the pyrazole ring is almost planar [r.m.s. deviation = 0.002 Å] while the two chloro­phenyl rings are twisted out from the plane of the pyrazole ring, making dihedral angles of 5.3 (1) and 65.34 (4)°. In the crystal, centrosymmetric R₂²(24) dimers are formed about crystallographic inversion centres through a pair of C—H⋯Cl inter­actions. These dimers are further linked through a C—H⋯O hydrogen bond, forming a C(8) chain extending along the a axis. C—H⋯π inter­actions are also observed.

2-Amino-6-(2,4-dichloro-phen-yl)-4-oxo-3,5-diphenyl-cyclo-hex-2-enecarbonitrile

In the title compound, C₂₅H₁₈Cl₂N₂O, the cyclo­hexene ring has a sofa conformation. All the substituents in the cyclo­hexene ring, except the cyano group (which is axial) occupy equatorial positions. The crystal structure is stabilized through N—H⋯O hydrogen bonds, forming a chain extending along the b axis and through C—H⋯N and C—H⋯Cl inter­actions. It is remarkable that only one of the amino H atoms is involved in hydrogen bonding.

(E)-3-Phenyl-3-(3-phenyl-1H-1-pyrazolyl)-2-propenal

In the title compound C₁₈H₁₄N₂O, the pendant rings make dihedral angles of 66.1 (1)° and 13.9 (1) with the central ring. In the crystal, two mol­ecules form a cyclic centrosymmetric R₂²(22) dimer through pairs of C—H⋯O bonds. These dimers are further connected into zigzag chains extending along the b axis through C—H⋯π and C—H⋯O inter­actions.

2-Carboxyanilinium bromide monohydrate

The title compound, C₇H₈NO₂⁺·Br⁻·H₂O, is isomorphous with 2-carboxy­anilinium chloride monohydrate and contains an intra­molecular N—H⋯O hydrogen bond, forming an S(6) motif. The main inter­molecular inter­actions are of the N—H⋯O/Br and O—H⋯O/Br types. Hydrogen-bonding dimers are formed via the carboxyl groups and the uncoordinated water mol­ecule, with centrosymmetric R₄⁴(12) ring motifs, in tandem with centrosymmetric R₈⁴(16) ring motifs formed by the cations and bromide anions. The hydrogen-bonded ring motifs inter­sect, forming chains with graph-set motif C₄³(10) extending along the a axis. These form a two-dimensional hydrogen-bonded network in (101) which is extended along [010] through N—H⋯Br hydrogen bonds. Hydro­philic layers are generated at z = 0 and 1/2 which are sandwiched between alternate hydro­phobic layers across z = 1/4 and 3/4.

1,5-Dimethyl-3-oxo-2-phenyl-2,3-di-hy-dro-1H-pyrazol-4-aminium 2-hydroxy-benzoate

In the title salt, C(11)H(14)N(3)O(+)·C(7)H(5)O(3) (-), the phenyl ring of the cation is oriented at an angle of 67.0 (1)° with respect to the five-membered pyrazolone ring. The carboxyl-ate plane of the anion is twisted out from the plane of the aromatic ring at an angle of 13.7 (3)°. In the crystal, the cations form hydrogen-bonded dimers with an R(2) (2)(10) ring motif. The salicylate anion has an intra-molecular O-H⋯O hydrogen bond.

1'-Methyl-4'-(1-naphth-yl)-3''-(1-naphthyl-methyl-ene)acenaphthene-1-spiro-2'-pyrrolidine-3'-spiro-1''-cyclo-hexane-2,2''-dione

In the title compound, C(42)H(33)NO(2), the six-membered cyclo-hexa-none ring adopts a slightly distorted chair conformation and the five-membered pyrrolidine ring is in an envelope conformation. The mol-ecular structure features four intra-molecular C-H⋯O inter-actions and an intra-molecular C-H⋯π inter-action. Furthermore, the crystal packing is stabilized by an inter-molecular C-H⋯O and three inter-molecular C-H⋯π inter-actions.