Structural improvement of ZnO electrodes through solution-processed routes for enhancing open-circuit voltage in dye-sensitized solar cells

We report herein one of our recent studies on nanostructured ZnO electrodes for application in dye-sensitized solar cells, focusing on achieving a higher open-circuit voltage (V_OC). ZnO films were obtained through solution-processed routes including pyrolytic conversion of layered hydroxide zinc acetate (LHZA) films deposited on a fluorine-doped tin oxide-coated conducting glass substrate by a chemical bath deposition method. The morphology of the initial LHZA and the converted ZnO films was tuned from a thick (approximately 12 μm) flower bed-/lawn-like bilayer structure to a thin (1.2 μm) lawn-like quasi-monolayer structure by decreasing the Zn source concentration in the chemical bath. V_OC was found to be enhanced with this morphological change from 0.692 (the bilayer structure) to 0.735 V (the quasi-monolayer structure). Fine tuning of the quasi-monolayer structure by introducing the grain growth effect led to V_OC of the cell as high as 0.807 V, although a short-circuit photocurrent density (J_SC) remained low. Further attempts were then made to increase J_SC while maintaining the high V_OC. When the thickness of the lawn-like monolayer film was increased up to approximately 5 μm, the resultant cell showed V_OC?=?0.750 V, J_SC?=?6.20 mA cm^?2 and a conversion efficiency (η) of 2.83%. The film with a modified flower bed-/lawn-like bilayer structure approximately 11 μm in thickness finally yielded V_OC?=?0.741 V, J_SC?=?13.6 mA cm^?2, and η?=?5.44%.     

Investigation of the Expansion of an Oxygen Microwave Remote Plasma for the Growth of Functional Oxide Thin Films

The expansion of an oxygen low-pressure microwave plasma was investigated in order to determine the optimal plasma parameters for the growth of functional oxide semiconductors. Langmuir probe measurements show that the electron density (n _e ) increases with the injected power up to a saturation value of 3.0 × 10⁹ cm^?3 determined at 10 mTorr while electron temperature (T _e ) remains constant at a value of 1.5 eV. When pressure is varied, n _e shows a maximum value at a range from 12 to 20 mTorr while T _e decreases monotonously with increasing pressure. In addition, both n _e and T _e decrease with the axial distance from the plasma source. These effects were discussed through the loss mechanisms in the remote plasma. For a pressure of 13 mTorr and at a substrate temperature of 500 °C, plasma enhanced oxidation of pure metallic Ti thin films lead to the formation of a pure TiO₂ anatase phase compared to a mixed phase of TiO₂ and TiO in the absence of plasma activation. For Mn thin films, the exposure to oxygen remote plasma led to the formation of MnO₂ as opposed to obtaining Mn₃O₄ when oxidation is performed in the oxygen gas ambient. Remote plasma processing was thus found to provide selective pathways to control oxidation states, stoichiometry and phase composition of technologically attractive oxide thin films.     

Structural modification and band gap tailoring of zinc oxide thin films using copper impurities

The doping effects of Cu on structural, morphological and optical properties of ZnO thin films and their PEC properties have been investigated via chemical bath deposition (CBD) technique at 353 K bath temperature and a pH of 11.5 with post-deposition annealing at 673 K. The concentration of Cu in ZnO varied between 1 and 5 at.%. X-ray diffraction analysis revealed that the synthesized Cu-doped ZnO (CZO) thin films were highly crystalline with hexagonal wurtzite structure, showing strong preferential growth along the c-axis for 3 at.% Cu concentration. A shift in angular peak position of 0.545^o in 2θ towards higher angle was observed for CZO films which is an indication of effective substitution of Cu atoms on Zn lattice. Crystallite sizes were enhanced from 28 to 32 nm in the (002) crystal plane. Optical analysis indicates a red shift in the absorption band edge up to 450 nm upon Cu doping. Transmittance characteristics increased slightly from 80 to 90% in the visible range at optimum Cu concentration of 3 at.%. Optical energy band gap was found to decrease from 3.03 eV for undoped ZnO to 2.7 eV upon Cu doping. The morphological structures of the CZO thin films were strongly influenced by Cu impurities and its concentration. The water contact angles showed strong dependence on Cu impurities in ZnO and decreased considerably from 71.3 to 15.2°. The synthesized CZO films showed enhanced photoelectrochemical properties, giving a short circuit current (I _sc) of 0.098 mAcm^?2 and open circuit voltage (V _oc) of 796 mV for an optimum Cu concentration of 3 at.% with photoconversion efficiency of 0.062% and fill factor of 63%.

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Thermal analysis of heat-treated silver fir wood and larval frass

Glasses having composition 5Li₂O–5ZnO– xBi₂O₃ –(90 ? x) P₂O₅ (x = 5, 10, 15, 20 and 25 mol%) were prepared by the normal melt quenching technique. Nanocomposite glass containing bismuth phosphate BiPO₄ nanocrystals was obtained, which can be attributed to homogeneous nucleation process. The formation of BiPO₄ nanocrystals was confirmed and characterized by X-ray diffraction patterns (XRD), transmission electron microscopy (TEM), differential scanning calorimetry, optical absorption (UV–Vis) and micro-hardness studies. The morphological analysis by XRD and TEM microscopy showed the formation of hexagonal BiPO₄ nanocrystals, and its estimated nanocrystalline sizes were found to be varying from 5.35 to 11.53 nm depending on the Bi₂O₃ concentrations. The density (ρ) and molar volume (V _m) were also determined and found to be in compositional dependence. Glass transition temperature (T _g) and glass crystallization temperature (T _c) were obtained and found to be increased (from 240.0 to 337.2 °C) with increasing Bi₂O₃ up to 20 mol% and then decreased (from 337.2 to 331.8 °C) due to the structural changes in the glass network. Effect of BiPO₄ content on the optical properties had been investigated. From the UV–Vis spectra, it was observed that the fundamental absorption edge shifts toward lower wavelengths, i.e., blueshifts with increasing Bi₂O₃ mol% up to 20 mol%, and then shifts toward higher wavelengths, i.e., redshifts beyond 20 mol%. It was also observed that the obtained E _opt (for indirect and direct transitions) increases with gradual increase in Bi₂O₃ content up to 20 mol% and then decreases beyond 20 mol%. This may be due to the introduction of Bi cations into the glass network as a network former up to 20 mol% causing a decrease in ΔE values, beyond 20 mol%, the introduction of Bi ions into the glass network interstitially leads to increase the values of ΔE. The optical properties of the present nanocrystallized glasses showed a quantum size dependence, in which the optical band gap energy (E _opt) was changed as a function of BiPO₄ nanocrystalline sizes.     

Synthesis and characterization of new metal-free and metallophthalocyanines fused α-methylferrocenylmethoxy units

Synthesis of metal-free and metallophthalocyanines bearing α-methylferrocenylmethoxy units was described. Precursor 3 required for the preparation of phthalocyanines 4–9, was synthsized by the nucleophilic aromatic substitution reaction between α-methylferrocenylmethanol and 4-nitrophthalonitrile in dry DMF. The metal-free phthalocyanine 4 was prepared from 4-(α-methylferrocenylmethoxy)phthalonitrile 3 in 1-pentanol with a catalytic amount of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Metallophthalocyanines (M = Zn, Cu, Co, Ni and Pb) were prepared by cyclotetramerization reaction of phthalonitrile with appropriate materials. The phthalonitrile, metal-free and metallophthalocyanines were characterized by ¹H and ¹³C NMR, FT-IR UV–Vis and mass spectral data, as well as elemental analyses, which were consistent with the proposed structures.     

Enhanced lithium-ion intercalation and conduction of transparent tantalum oxide films by lithium addition with an atmospheric pressure plasma jet

An investigation is conducted on enhancing lithium-ion intercalation and conduction performance of transparent organo tantalum oxide (TaO _y C _z ) films, by addition of lithium via a fast co-synthesis onto 40 Ω/□ flexible polyethylene terephthalate/indium tin oxide substrates at the short exposed durations of 33–34 s, using an atmospheric pressure plasma jet (APPJ) at various mixed concentrations of tantalum ethoxide [Ta(OC₂H₅)₅] and lithium tert-butoxide [(CH₃)₃COLi] precursors. Transparent organo-lithiated tantalum oxide (Li _x TaO _y C _z ) films expose noteworthy Li⁺ ion intercalation and conduction performance for 200 cycles of reversible Li⁺ ion intercalation and deintercalation in a 1 M LiClO₄-propylene carbonate electrolyte, by switching measurements with a potential sweep from ?1.25 to 1.25 V at a scan rate of 50 mV/s and a potential step at ?1.25 and 1.25 V, even after being bent 360° around a 2.5-cm diameter rod for 1000 cycles. The Li⁺ ionic diffusion coefficient and conductivity of 6.2?×?10^?10 cm²/s and 6.0?×?10^?11 S/cm for TaO _y C _z films are greatly progressed of up to 9.6?×?10^?10 cm²/s and 7.8?×?10^?9 S/cm for Li _x TaO _y C _z films by co-synthesis with an APPJ.     

Efficient electrochromic performance of anatase TiO2 thin films prepared by nebulized spray deposition method

Anatase TiO₂ thin films with high optical modulation, better reversibility, fast switching time, and enhanced coloration efficiency were prepared by nebulized spray pyrolysis technique. X-ray diffraction study confirmed the formation of anatase phase TiO₂ in the present work. This inference was substantiated from the Raman active modes of A_1g, 2 B_1g, and 3 E_g corresponding to O–Ti–O bond in TiO₂. The PL emission peak observed at 400 nm is corresponds to the indirect transition (X_1b?→?Γ₃) from the conduction band to the valence band. The average reflectance of TiO₂ thin films was varied from 31 to 20%. The electrochemical study revealed the excellent performance of TiO₂ films with high optical modulation (ΔT?=?61%), fast switching kinetics (t _b ?=?1.6 s, t _c ?=?2.4 s), good coloration efficiency (100 cm² C^?1), and better reversibility (86%). The efficient electrochromic behavior of films may be due to the smooth microstructure nature, which provides an easy pathway for the diffusion and charge transfer process of Li⁺ ions in TiO₂ film matrix. The fast transfer of Li⁺ ion was realized from the electrochemical impedance spectroscopic measurement.     

Polyaniline/montmorillonite nanocomposite thin layers deposited on different substrates

Preparation method of polyaniline/montmorillonite (PANI/MMT) nanocomposite in the form of thin layer deposited on various substrates is optimized in this work to obtain high electrical conductivity. Simple method (i.e. polymerization of anilinium sulfate in the presence of MMT) has been used for the preparation and following four conditions were varied: preparation temperature (T = 10 or 20 °C), preparation time (t = 4 or 6 h), size fraction of MMT (p < 1 or 5 µm), and type of substrate (microscope glass slides, silica glass slides, polyester foils). Therefore, 24 samples were prepared, characterized and their electrical conductivity was compared. Raman spectroscopy and scanning electron microscopy were used for the characterization of the structure of samples. Thickness of layers was measured using atomic force microscopy. Based on the comparison of samples and with respect to the aim of obtaining high electrical conductivity, it was found that the most suitable substrate is polyester foil and preparation conditions are T = 20 °C, t = 6 h, p < 5 µm. To obtain highly conductive layers on glass substrates (although less conductive than layers on foil), preparation time have to be shortened to 4 h.     

Synthesis,characterization, antimicrobial activity and ultrastructure of the affected bacteria of new quinoline compounds

The reaction on 8-hydroxy quinoline-7-aldehyde azo compounds (HL _n ) (where n = 1–5) with 4-amino-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one to obtain HL _n (where n = 6–10) have been characterized by means of TLC, melting point and spectral data, such as IR, ¹H NMR, mass spectra and thermal studies. The X-ray diffraction patterns of two starting materials 8-hydroxy quinoline-7-aldehyde (start 1), 4-amino-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one (start 2) and the ligands (HL_5,10) are investigated in powder form. All the ligands have been screened for their antimicrobial activity against four local bacterial species, two Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) as well as against four local fungi; Aspergillus niger, Alternaria alternata, Penicillium italicum and Fusarium oxysporium. The results show that the azo ligands (HL _n ) (where n = 1–5) have no antimicrobial activity against bacteria and fungi while most azomethine ligands (HL _n ) (where n = 6–10) are good antibacterial agents against E. coli and K. pneumoniae as well as antifungal agents against P. italicum and A. alternata. The results were compared to standard substances (start 1) and (start 2). Among the azomethine ligands, HL₁₀ was the most effective against the most microorganisms tested. The size of clear zone was ordered as p-(OCH₃ < CH₃ < H < Cl < NO₂) as expected from Hammett’s constant (σ ^R ). Also, the ultrastructure study of the affected bacteria confirmed that HL₈ is good antibacterial agent against E. coli and S. aureus.     

Exact treatment of generalized modifications of finite-dimensional systems by the LRM approach

LRM (Low Rank Modification) is a mathematical method that produces eigenvalues and eigenstates of generalized eigenvalue equations. It is similar to the perturbation expansion in that it assumes the knowledge of the eigenvalues and eigenstates of some related (unperturbed) system. However, unlike perturbation expansion, LRM produces correct results however large the modification of the original system. LRM of finite-dimensional systems is here generalized to the combined (external and internal) modifications. Parent n-dimensional system A _n containing n eigenvalues λ _i and n eigenstates \({| {\Phi_i}\rangle}\) is described by the generalized n × n eigenvalue equation. In an external modification system A _n interacts with another ρ-dimensional system B _ρ which is situated outside the system A _n . In an internal modification relatively small σ-dimensional subsystem of the parent system A _n is modified. Modified system C _n+ρ that contains external as well as internal modifications is described by the generalized (n + ρ) × (n + ρ) eigenvalue equation. This system has (n + ρ) eigenvalues \({\varepsilon_s}\) and (n + ρ) corresponding eigenstates \({| {\Psi_s}\rangle}\) . In LRM this generalized (ρ + n) × (ρ + n) eigenvalue equation is replaced with a (nonlinear) (ρ + σ) × (ρ + σ) equation which produces all eigenvalues \({\varepsilon_s \notin \left\{ {\lambda_i}\right\}}\) and all the corresponding eigenstates \({| {\Psi_s}\rangle }\) of C _{n + ρ}. Another equation produces remaining solutions (if any) that satisfy \({\varepsilon_s \in \left\{ {\lambda_i}\right\}}\) . Those two equations produce exact solution of the modified system C _{n + ρ}. If (ρ + σ) is small with respect to n, this approach is numerically much more efficient than a standard diagonalization of the original generalized eigenvalue equation. Unlike perturbation expansion, LRM produces exact results, however large modification of the parent system A _n .     

Electro-deposition under a modulated electrical field as an enhanced method for the preparation of an efficient photoanode of dye-sensitized solar cells

This paper describes an application of a new electro-deposition method in a modulated electrical field in order to have an efficient semiconductor coating on a conductive substrate. The prepared film was used as a photoanode of dye-sensitized solar cells (DSSCs). Electro-deposition of nanoparticles usually was performed by applying a DC electrical field in a suspension. In the DC field, a homogeneous layer could not be performed because of unwanted electrochemical reactions that might occur on the substrate surface. Modulated electrical fields based on pulsed AC and a sweeping voltage profile were used. The photovoltaic performance of the assembled solar cells showed a significant difference between the films produced in different electrical field conditions. Under the illumination of simulated AM 1.5 sunlight (100 mW cm^?2) with an aperture black mask, the energy conversion efficiency of 2.45% (V _OC = 768 mV, J _SC = 4.74 mA cm^?2, FF = 67%) was obtained with a thin layer of TiO₂ nanoparticles deposited in a pulsed waveform voltage. A crack-free and uniform porous layer produced in this condition showed an enhancement of about seven times over the photoanode prepared using conventional DC electrical field with the same voltage amplitude. The solar cell efficiency was increased to 4.22% (V _OC = 735 mV, J _SC = 7.92 mA cm^?2, FF = 72%) by just increasing the TiO₂ film thickness and using a blocking layer beneath the semiconductor layer. Moreover, a higher electron recombination lifetime presented better electron transport and collection efficiency of the film deposited in the pulsed electrical field conditions.     

Dip-coating deposition of resistive BiVO<Subscript>4</Subscript> thin film and evaluation of their photoelectrochemical parameters under distinct sources illumination

Resistive monoclinic bismuth vanadate (BiVO₄) nanocrystals in the form of thin films were obtained by the solution combustion synthesis coupled with the dip-coating deposition process. The structure, morphology, and optical properties of BiVO₄ nanocrystals were characterized by means of x-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectroscopy. The photoelectrochemical properties were obtained by cyclic voltammetry and chronoamperometry techniques in potassium chloride (KCl) electrolyte solution under distinct visible light sources irradiation condition. Under blue InGaN light emitting diode (LED) irradiation, the electrode has a better efficiency, faster response time (260 ms), and faster decay time (65 ms), when compared with the irradiation by dichroic lamp. Besides, the photocurrent density (j _ph) is approximately 39 times higher than j _ph obtained under dichroic lamp. The performance analysis based on the methylene blue degradation reaction has shown that the BiVO₄ material has higher electroactivity under InGaN LED irradiation condition, with estimated k _obs value of 200 × 10^?4 min^?1, which is a little higher than the value obtained with dichroic lamp illumination. In the dark condition, the BiVO₄ presented much lower photocatalytic activity.     

Synthesis,spectroscopic characterization,crystal structures,and theoretical studies of (<Emphasis Type="Italic">E</Emphasis>)-2-(2,4-dimethoxybenzylidene)thiosemicarbazone and (<Emphasis Type="Italic">E</Emphasis>)-2-(2,5-dimethoxybenzylidene)thiosemicarbazone

Two thiosemicarbazones, (E)-2-(2,4-dimethoxybenzylidene)thiosemicarbazone (24-MBTSC (1)) and (E)-2-(2,5-dimethoxybenzylidene)thiosemicarbazone (25-MBTSC (2)), derived from 2,4-dimethoxybenzaldehyde and 2,5-dimethoxybenzaldehyde, respectively, with thiosemicarbazide have been synthesized and their structures were characterized by elemental analyses, FT-IR, ¹H NMR spectroscopy, and X-ray single-crystal diffraction analysis. Molecular orbital calculations have been carried out for 1 and 2 by using an ab initio method (HF) and also density functional method (B3LYP) at 6-31G basis set. Compound 1 crystallizes in the monoclinic system, space group P2₁/c, with a = 8.1342(5) Å, b = 18.1406(10) Å, c = 8.2847(6) Å, β = 109.7258(17)°, V = 1150.75(12) Å³, and Z = 4, whereas compound 2 crystallizes in the orthorhombic system, space group Pbca, with a = 11.0868(6) Å, b = 13.1332(6) Å, c = 15.9006(8) Å, V = 2315.2(2) Å³, and Z = 8. The compounds 1 and 2 displays a trans-configuration about the C=N double bond.     

A family of four-step trigonometrically-fitted methods and its application to the schrödinger equation

In this article we present a singularly almost P-stable exponentially-fitted four-step method for the approximate solution of the one-dimensional Schrödinger equation. More specifically we present a method that is singularly almost P-stable (a concept later introduced in this article) and also integrates exactly any linear combination of the functions {1, x, exp ( ±I v x) , x exp ( ±I v x) , x ² exp ( ±I v x)}. The numerical experimentation showed that our method is considerably more efficient compared to well known methods used for the approximate solution of resonance problem of the radial Schrödinger equation.     

Use of the ionic liquid trioctylmethyl ammonium dodecanedioate as a corrosion inhibitor of steel in production water

The properties of trioctylmethyl ammonium dodecanedioate (TAD) as a corrosion inhibitor (CI) of API 5L X52 steel in production water (PW) were evaluated in steady state using weight loss and polarization techniques within a Reynolds number (N _Re ) interval ranging from 500 to 40,000. The highest obtained IE was 87 % at 100 ppm with N _Re  = 2500, whereas the lowest IE was 15 % at 10 ppm with N _Re  = 4000. TAD was classified as a mixed-type CI of API 5L X52 steel in PW. The \(\Delta G_{\text{ads}}^{^\circ }\) data established a relationship between the N _Re and the adsorption process, confirming the occurrence of physical adsorption phenomena.     

The response electron–electron repulsion energy and energy component analysis in CC/MBPT methods

Molecular properties are computed as responses to perturbations (energy derivatives) in coupled-cluster (CC)/many-body perturbation theory (MBPT) models. Here, the CC/MBPT energy derivative with respect to a general two-electron (2-e) perturbation is assembled from gradient theory for 2-e property evaluation, including the electron repulsion energy. The correlation energy (?E) is shown to be the sum of response kinetic (?T), electron–nuclear attraction (?V), and electron repulsion (?V _ee ) energies. Thus, evaluation of total V _ee for energy component analysis is simple: For total energy (E), total 1-e responses T and V, and nuclear–nuclear repulsion energy (V _NN ), V _ee  = E ? V _NN  ? T ? V is the true 2-e response value. Component energy analysis is illustrated in an assessment of steric repulsion in ethane’s rotational barrier. Earlier SCF-based results (Bader et al. in J Am Chem Soc 112:6530, 1990) are corroborated: The higher-energy eclipsed geometry is favored versus staggered in the two repulsion energies (V _NN and V _ee ), while decisively disfavored in electron–nuclear attraction energy (V). Our best quality calculations (CCSD/cc-pVQZ) attain practical Virial Theorem compliance (i.e., agreement among the kinetic energy, potential energy, and total energy representations) in assigning 2.70 ± 0.06 to the barrier height; ?195.80 kcal/mol is assigned to the drop in “steric” repulsion upon going to the eclipsed geometry. Steric repulsion is not responsible for any fraction of the ~3 kcal/mol barrier.     

Study of the growth of <Emphasis Type="Italic">Enterococcus faecalis</Emphasis>, <Emphasis Type="Italic">Escherichia coli</Emphasis> and their mixtures by microcalorimetry

In a majority of environments, microbes live as interacting communities. Microbial communities are composed of a mix of microbes with often unknown functions. Polymicrobial diseases represent the clinical and pathological manifestations induced by the presence of multiple infectious agents. These diseases are difficult to diagnose and treat and usually are more severe than monomicrobial infections. The interaction relationship between Enterococcus faecalis and Escherichia coli was researched using a Calvet calorimeter. Three mixtures of both bacteria were prepared in the following proportions: 20 + 80 % (0.2 mL E. faecalis + 0.8 mL E. coli), 50 + 50 % (0.5 mL E. faecalis + 0.5 mL E. coli) and 80 + 20 % (0.8 mL E. faecalis + 0.2 mL E. coli). Experiments were carried out at concentration of 10⁶ CFU mL^?1 and a constant temperature of 309.65 K. The differences in shape of graph of E. faecalis, E. coli and their mixtures were compared. Also, the thermokinetic parameters such as detection time (t _d), growth constant (k), generation time (G) and the amount of heat released (Q) were calculated.     

A novel angle-dependent potential and its exact solution

The quantum mechanics of a diatomic molecule in a noncentral potential of the type V (r) = V _θ (θ)/r ² + V _r (r) are investigated analytically. The θ-dependent part of the relevant potential is suggested for the first time as a novel angle-dependent (NAD) potential \({V_{\theta}(\theta)=\frac{\hbar^2}{2\mu}\left(\frac{\gamma +\beta \sin^2\theta +\alpha \sin^4 \theta}{\sin^2\theta \cos^2\theta}\right)}\) and the radial part is selected as the Coulomb potential or the harmonic oscillator potential, i.e., V _r (r) =  ? H/r or V _r (r) = Kr ², respectively. Exact solutions are obtained in the Schrödinger picture by means of a mathematical method named the Nikiforov–Uvarov (NU). The effect of the angle-dependent part on the solution of the radial part is discussed in several values of the NAD potential’s parameters as well as different values of usual quantum numbers.     

Synthesis,structural phase transition,and characterization of potassium hydrogen bis-dichloroacetate

Potassium hydrogen bis-dichloroacetate (1) was synthesized and separated as crystals. Differential scanning calorimetry (DSC) measurement reveals that this compound undergoes a reversible phase transition at about 259 K with a heat hysteresis of 23.5 K. Dielectric anomaly observed at 260 K in the heating process further confirms the phase transition. The room temperature X-ray single-crystal structure determination indicates that 1 crystallizes in the monoclinic crystal system with a centrosymmetric space group P2₁/c, and cell parameters are a =?6.240(1), b =?23.177(4), c =?7.335(1) Å, β =?106.938(1)°, V =?1014.8(3) ų, and Z =?4. In the low temperature phase, 1 also crystallizes in monolinic with space group P2₁/c, and cell parameters are a =?6.180(1), b =?22.988(2), c =?7.200(1) Å, β =?108.098(1)°, V =?972.4(1) ų, and Z =?4. The structural phase transition is dominating caused by the torsion of bond angles.