Conformations of sodium poly(styrene-4-sulfonate) macromolecules in solutions with different ionic strengths

Translational friction and viscosity of dilute solutions of sodium poly(styrene-4-sulfonate) with molecular masses of M = (5 × 10⁴)−(85 × 10⁴) are studied at different concentrations of low-molecular-mass salts. Molecular masses of the polymer are determined from the sedimentation-diffusion data. The study of the correlation between molecular masses and hydrodynamic characteristics resulted in ascertainment of the Kuhn-Mark-Houwink-Sakurada relationships for salt-free aqueous solutions of the polymer and solutions of the polymer in 0.2 M NaCl, 4.17 M NaCl, and 1.0 M KCl. It is shown that, as the ionic strengths of solutions are varied from minimum (H₂O) to maximum (4.17 M), macromolecules of the strong polyelectrolyte sodium poly(styrene-4-sulfonate) change their conformations from rigid rods to coils and, then, approach a globular conformation. In terms of the Gray-Bloomfield-Hearst and Yamakawa-Fujii theories and within the framework of the weakly bent cylinder model, the statistical Kuhn segment length and the hydrodynamic diameter of sodium poly(styrene sulfonate) chains are estimated in 0.2 and 4.17 M NaCl, 1.0 M KCl, and salt-free aqueous solutions. The electrostatic component of the equilibrium rigidity is taken into account within the framework of the Odijk-Fixman-Skolnick and Dobrynin theories.     

Ion binding in sulfonate-containing polyelectrolytes

Emf measurements have been used to study the activity and the extent of sodium ion binding to several polyelectrolytes, poly(styrenesulfonate) (PSS), poly(2-acrylamido-2-methylpropanesulfonate) (PAMS), poly(3-methacryloyloxypropane-1-sulfonate) (PMOS), and copoly[(N-t-butylacrylamide)-(2-acrylamido-2-methylpropanesulfonate)] (NB–AMS) (mole ratio 3.8:1). The activity coefficient of sodium ion in Na-PAMS and Na-PMOS without added salt is found to be in the range from 0.1 to 0.3 and is insensitive to changes in polymer concentration. However, it increases with increasing concentration of the added salt. The extent of sodium ion binding at a given sodium ion concentration, as estimated from the activity data for some sodium and tetrabutylammonium (TBA) salts, decreases in the order Na-PAMS ≈? Na-PMOS > TBA–PAMS > TBA–(NB–AMS). This indicates that a significant portion of the binding is attributed to the binding of TBA⁺ ions. Also compared are the results of ion binding in Na-PAMS and Na-PSS as a function of ionic strength. At low ionic strength (<1.0M), the order of binding strength is Na-PAMS > Na-PSS, while the order is reversed at high ionic strength (>1.0M). This finding is in good agreement with data obtained by dilatometry and viscometry.     

pH-metric studies on formation constants of the complexes of substituted pyrazoles with some lanthanide metal ions and the influence of ionic strengths on complex equilibria in a 70% dioxane-water mixture

The pK a values of N-heterocyclic compounds (substituted pyrazoles) in a 70% (v/v) dioxane-water mixture have been determined using pH-metric measurements. The stability constants of the complexes of Dy(III), Nd(III), Sm(III), and Tb(III) with 3-(2-hydroxyphenyl)-5-methylpyrazole, l-phenyl-3-(2-hydimyphenyl)-5-methylpyrazole 3-(2-hydroxy-4-methylphenyl)-5-methylpyrazole, and l-phenyl-3-(2-hydroxy-4-methylphenyl)-5-methylpyrazole have been determined by the pH-metric method at ( 300 ± 0.1) K. The effect of ionic strengths on the complexes of Sm³⁺ and Pr³⁺ ions with pyrazole has been investigated in the internal from 0.02 to 0.1 mol dm⁻³ (sodium perchlorate) in the pH range 2–3.     

Second Dissociation Constant of H<Subscript>2</Subscript>Te and the Absorption Spectra of HTe<Superscript>–</Superscript>, Te<Superscript>2–</Superscript> and Te<Subscript>2</Subscript><Superscript>2–</Superscript> in Aqueous Solution

We have measured the second acid dissociation constant, K _2a , at several ionic strengths for hydrogen telluride (H₂Te) using the Charge Transfer to Solvent (CTTS) uv spectra of its anions HTe⁻ and Te²⁻. Since it is produced in our solutions, we have also determined the spectra of Te₂ ²⁻ both in the uv and in the visible regions. At 25 ^∘C, K _2a = (1.28 ± 0.02) × 10⁻¹² by extrapolation to zero ionic strength. Its value at an ionic strength equal to 0.5 mol.dm^-3 was estimated to be (8.7 ± 0.2) × 10⁻¹². The solution thermodynamics of these species are also discussed and comparisons are made to related acids.     

Thermal Decomposition of Some Chemical Compounds Used As Food Preservatives and Kinetic Parameters of This Process

Thermal decomposition processes of selected chemicals used as food preservatives such as sodium formate, sodium propionate, sodium nitrates(V and III) and sodium sulphate(IV) were examined by the derivatographic method. Based on the curves obtained, the number of decomposition stages and characteristic temperatures of these compounds have been found. Mass decrements calculated from TG curves ranged from 28.9% for sodium formate to 77.8% for sodium nitrate(V), while sodium sulphate showed a mass increment of 5.6%. Kinetic parameters such as activation energy (E _a ), frequency factor (A ) and reaction order (n ) were calculated from TG, DTG and T curves. Sodium formate shows the highest values of E _a and A which amount to 171.7 kJ mol^–1 and 5.8⋅10¹⁴ s^–1 , respectively, while the lowest ones, E _a =28.2 kJ mol^–1 and A =3.65⋅10² s^–1 belong to sodium nitrate(V). This revised version was published online in August 2006 with corrections to the Cover Date.     

Electrochemical impedance of microelectrodes

The influence of the radius (10 <a < 1500 μm) of a Pt disk electrode on the impedance frequency spectrum of the [Fe(CN)₆]^3-/4- reversible system is studied in the frequency range 5 × 10^-3 to 10³ Hz. The impedance is calculated by applying the Fourier transform to potential and current pulses of various lengths obtained when imposing a step potential. For electrodes witha < 100 μm, the spectrum in the complex plane has the form characteristic of microelectrodes, while for electrodes of higher radii, it corresponds to a finite Warburg impedance. The main impedance parameters, such as the charge transfer resistance, the diffusion resistance, and the frequency in the maximum of the imaginary constituent are determined. The latter decreases with an increase ina by the lawf* ∼ 1/a² at lowa and is independent ofa on electrodes witha > 100 μm, which agrees with the impedance theory for microelectrodes     

Oxygen- versus carbon-coordination of the alpha-stabilized phosphorus ylide Ph<Subscript>3</Subscript>P=C(H)R in palladacycles bearing secondary amines

The ortho-metalated complex [Pd(x){κ ² (C,N)-[C₆H₄CH₂NRR′ (Y)}] (2a–4a and 2b–3b) was prepared by refluxing in benzene equimolecular amounts of Pd(OAc)₂ and secondary benzylamine [a, EtNHCH₂Ph; b, t-BuNHCH₂Ph followed by addition of excess NaCl. The reaction of the complexes [Pd(x){κ ² (C,N)-[C₆H₄CH₂NRR′ (Y)}] (2a–4a and 2b–3b) with a stoichiometric amount of Ph₃P=C(H)COC₆H₄-4-Z (Z = Br, Ph) (ZBPPY) (1:1 molar ratio), in THF at low temperature, gives the cationic derivatives [Pd(OC(Z-4-C₆H₄C=CHPPh₃){κ ² (C,N)-[C₆H₄CH₂NRR′(Y)}] (5a–9a, 4b–6b, and 4b′–6b′), in which the ylide ligand is O-coordinated to the Pd(II) center and trans to the ortho-metalated C(6)H(4) group, in an “end-on carbonyl”. Ortho-metallation, ylide O-coordination, and C-coordination in complexes (5a–9a, 4b–6b, and 4b′–6b′) were characterized by elemental analysis as well as various spectroscopic techniques.     

Impedance studies on the 5-V cathode material,LiCoPO<Subscript>4</Subscript>

Olivine-structured LiCoPO₄ is synthesized by a Pechini-type polymer precursor method. The structure and the morphology of the compounds are studied by the Rietveld-refined X-ray diffraction, scanning electron microscopy, Brunauer, Emmett, and Teller surface area technique, infrared spectroscopy, and Raman spectroscopy techniques, respectively. The ionic conductivity (σ ionic), dielectric, and electric modulus properties of LiCoPO₄ are investigated on sintered pellets by impedance spectroscopy in the temperature range, 27–50 °C. The σ (ionic) values at 27 and 50 °C are 8.8 × 10⁻⁸ and 49 × 10⁻⁸ S cm⁻¹, respectively with an energy of activation (E _a) = 0.43 eV. The electric modulus studies suggest the presence of non-Debye type of relaxation. Preliminary charge–discharge cycling data are presented.     

Ionic strength dependence of formation constants, complexation of nitrilotriacetic acid with tungsten(VI) ion

The dependence on ionic strength of protonation of nitrilotriacetic acid and its complexation with W(VI) is reported in sodium perchlorate, sodium nitrate and sodium chloride solutions as background salts. The measurements have been performed at 25°C and various ionic strengths in the range 0.1–1.0 mol dm⁻³, using a combination of potentiometric and spectrophotometric techniques. The overall analysis of the present and the previous data dealing with the determination of stability constants at different ionic strengths allowed us to obtain a general equation, by which a formation constant determined at a fixed ionic strength can be calculated, with a good approximation, at another ionic strength, if 0.1 ≤ ionic strength ≤ 1.0 mol dm⁻³ sodium perchlorate, sodium nitrate or sodium chloride.     

Syntheses and crystal structures of cobalt(II) and zinc(II) complexes with 4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate

Abstract Sodium 4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate (1) is synthesized by the sulfonation of 6-hydroxybiochanin A and its structure is characterized by elemental analysis, ¹H-NMR, and IR spectroscopy. It is assembled with cobalt(II) or zinc(II), hexaquacobalt(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (2) and hexaquazinc(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (3) are obtained and characterized by IR spectroscopy. Simultaneously, their three-dimensional structures are determined by single-crystal X-ray analysis. It turns out that 2 and 3 are isomorphous and crystallize in the triclinic crystal system, space group P-1. Hydrophilic regions are defined by O–H···O hydrogen bonds involving the coordinated water molecules, the included water molecules, and sulfonate groups. Aromatic π...π stacking interactions assemble the isoflavone skeletons into columns and these columns formed hydrophobic regions. The sulfonate group is an important bridge as a structural link between the hydrophilic regions and the hydrophobic regions. Hydrogen bonds, π...π stacking interactions and the electrostatic interactions assemble 2 and 3 into three-dimensional network structures. Graphical abstract Sodium 4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate (1) is synthesized and assembled with cobalt(II) or zinc(II). Hexaquacobalt(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (2) and hexaquazinc(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (3) are obtained and determined by single-crystal X-ray analysis. It turns out that 2 and 3 are isomorphous and assembled into three-dimensional network structures, characterized by hydrophilic regions defined by hydrogen bonds involving the coordinated water molecules, the included water molecules, and the sulfonate groups and by hydrophobic columns, formed by the isoflavone skeletons, interacting through π...π stacking interactions.      

Aggregation number of aqueous sodium cholate micelles from mutual diffusion measurements

With reported values ranging from about 3 to 16, the aggregation number of aqueous sodium cholate micelles is not well established. To provide new information on the aggregation of a bile salt, Taylor dispersion is used to measure the binary mutual diffusion coefficientD of aqueous sodium cholate at concentrations from 0.001 to 0.100 mol-dm^-3 at 25°C. The results are compared with calculatedD values based on the association equilibrium nCholate^- + βnNa⁺ ⇋ (NaβCholate) _n ^(β-1)n wheren is the aggregation number and β is the degree of sodium counterion binding. Fitting the association model to the diffusion data givesn = 3.9±0.6 and β = 0.21 ±0.08. In contrast to the drop inD with increasing concentration of sodium cholate, the diffusion coefficients of sodium dodecylsulfate and other long-chain ionic surfactants increase above the critical micelle region. The ent diffusion behavior of the surfactants is related to changes in the driving forces and mobilities caused by ion association.     

Inclusion complexation of diclofenac with natural and modified cyclodextrins explored through phase solubility, 1H-NMR and molecular modeling studies

Guest–host interactions were examined for neutral diclofenac (Diclo) and Diclofenac sodium (Diclo sodium) with each of the cyclodextrin (CD) derivatives: α-CD, β-CD, γ-CD and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), all in 0.05 M aqueous phosphate buffer solution adjusted to 0.2 M ionic strength with NaCl at 20 °C, and with β-CD at different pHs and temperatures. The pH solubility profiles were measured to obtain the acid–base ionization constants (pK _as) for Diclo in the presence and absence of β-CD. Phase solubility diagrams (PSDs) were also measured and analyzed through rigorous procedures to obtain estimates of the complex formation constants for Diclo/CD and Diclo sodium/CD complexation in aqueous solutions. The results indicate that both Diclo and Diclo sodium form soluble 1:1 complexes with α-, β-, and HP-β-CD. In contrast, Diclo forms soluble 1:1 Diclo/γ-CD complexes, while Diclo sodium forms 1:1 and 2:1 Diclo/γ-CD, but the 1:1 complex saturates at 5.8 mM γ-CD with a solubility product constant (pK _sp = 5.5). Therefore, though overall complex stabilities were found to follow the decreasing order: γ-CD > HP-β-CD > β-CD > α-CD, some complex precipitation problems may be faced with aqueous formulations of Diclo sodium with γ-CD, where the overall concentration of the latter exceeds 5.8 mM γ-CD. Both ¹H-NMR spectroscopic and molecular mechanical modeling (MM⁺) studies of Diclo/β-CD indicate the possible formation of soluble isomeric 1:1 complexes in water.     

Tunable phase transition behaviors of pH-sensitive polyaspartamides having various cationic pendant groups

New pH-sensitive graft copolymers based on poly(2-hydroxyethyl aspartamide) (PHEA) were prepared by attaching various cationic monomers, such as 4-(aminomethyl)pyridine (PY), 1-(3-aminopropyl)imidazole (IM), and N-(3-aminopropyl)dibuthylamine (BU), as pH-sensitive units and octadecylamine (C₁₈) as a hydrophobic segment on poly(succinimide). Phase transition of each copolymer solution occurred at a vicinity of the pK _a value of the cationic groups, and their insoluble pH ranges were broadened as the feed amount of pH-sensitive moieties was increased. Depending on the cationic grafts having different pK _a values, the pH ranges where the copolymer became insoluble could be tuned. Copolymers PHEA-g-C₁₈-PY, PHEA-g-C₁₈-IM, and PHEA-g-C₁₈-BU exhibited phase separations in solutions at pH ranges of 4∼6, 6∼8, and 9∼12, respectively. These polymers have the unique feature of their pH sensitivity profiles being identified to three regimes. Under low pH conditions (below pK _a ), the polymer solution is transparent. At medium pH (around pK _a ), polymer precipitation occurred in solution. At pH > pK _a , the polymer solution is gradually dissolved again.     

Stress-optical behavior of cycloaliphatic polyesters

Stress-strain-birefringence measurements were carried out on elastomeric networks of poly(oxymethylene-1,4-cis-cyclohexylenemethyleneoxysebacoyl) at several temperatures between 5 and 80°C. The dependence of both the birefringence Δn and the true stress f/A on temperature was found to be linear for T > 30°C; for T < 30°C an anomalous increase in the birefringence and a sharp decrease in the stress was observed. This behavior suggests that crystallinity is developed in the strained networks at low temperatures, and the crystallites are oriented in the direction of the elongation. Values of the optical configuration parameter Δa ranged from 9.15 to 8.28 in units of 10²⁴ cm³ in the temperature range studied. The value at 40°C of 10²⁴Δa, obtained from experiments performed on swollen networks, amounted to 7.47 cm³. These results suggest that intermolecular interactions enhance the birefringence of the strained networks. The quantities Δa and d In Δa/dT were calculated by using the valence optical scheme. Although the calculations reproduce the temperature coefficient fairly well, the theoretical values of Δa are smaller than the experimental ones. The agreement between theory and experiment is better assuming that the CH₂CH₂? COOCH₂ segment is freely rotating.     

Highly hydrophobically modified polyelectrolytes: Field variables to control emulsion type

Highly hydrophobically modified (with n-dodecylamide chain) linear poly(acrylic acid)s (HHMPAAH) and poly(sodium acrylate)s (HHMPAANa) with various degrees of grafting (τ) were synthesized and used as emulsifiers of the n-dodecane/water system. The type of emulsion, oil in water (O/W) or water in oil (W/O), was investigated as a function of the polymer chemical structure (τ, salt or acid form of the copolymer) and aqueous phase electrolyte concentration (NaNO₃). Increasing τ and/or salt concentration was found to favor the formation of inverse emulsions. Direct liquid–liquid dispersions are more likely to form with poly(sodium acrylate)s than with poly(acrylic acid)s. Hence, field variables such as τ, pH and ionic strength are relevant parameters to control emulsion type. Moreover, a balanced polyelectrolyte neither soluble in oil nor in water was synthesized for the first time. With this original emulsifier, the dispersion type was found to change from O/W to W/O with polymer salting out. The work provides convenient model system for fundamental studies of polymer conformation at liquid–liquid interfaces. Received: 31 March 1998 Accepted: 30 April 1998     

Dissociation Quotients for Citric Acid in Aqueous Sodium Chloride Media to 150°C

The three molal dissociation quotients for citric acid were measured potentiometrically with a hydrogen-electrode concentration cell from 5 to 150°C in NaCl solutions at ionic strengths of 0.1, 0.3, 0.6, and 1 molal. The molal dissociation quotients and available literature data at infinite dilution were fitted by empirical equations in the all-anionic form involving an extended Debye-Hückel term and up to five adjustable parameters involving functions of temperature and ionic strength. This treatment yielded the following thermodynamic quantitites for the first dissociation equilibrium at 25°C: logK _1a=−3.127±0.002, ΔH _1a ^o =4.1±0.2 kJ-mol⁻¹, ΔS _1a ^o =−46.3±0.7 J-K⁻¹-mol⁻¹, and ΔCp _1a ^o =−162±7 J-K⁻¹-mol⁻¹; for the second acid dissociation equilibrium at 25°C: logK _2a =−4.759±0.001, ΔH _2a ^o =2.2±0.1, ΔS _2a ^o =−83.8±0.4, and ΔCp _2a ^o =−192±15, and for the third dissociation equilibrium at 25°C: logK _3a=−6.397±0.002, ΔH _3a ^o =−3.6±0.2, ΔS _3a ^o =−134.5±0.7, and ΔCp _3a ^o =−231±7.     

Water-soluble phosphate-functionalized polyfluorene as fluorescence biosensors toward cytochrome c

An anionic water-soluble polyfluorene derivative, poly(9,9-bis(6′-phosphatehexyl)fluorene-alt-1,4-phenylene) sodium salt (PFHPNa), was synthesized by Suzuki coupling reaction in DMF/water. Polymer PFHPNa was well soluble in water with a strong blue fluorescence emission. Effect of the side chain length on fluorescence sensory properties was studied by comparing quenching efficiencies toward different quenchers of PFHPNa with a reported polymer poly(9,9-bis(3′-phosphatepropyl)fluorene-alt-1,4-phenylene) sodium salt (PFPPNa), which have different side chains in length. For small molecular quenchers (methylviologen, MV²⁺) and meso-5,10,15,20-tetrakis-(N-methyl-4-pyridyl)porphine (TMPyP4), polymer PFHPNa had lower sensitivity due to the much longer side chain length. The positively charged metalloprotein cytochrome c could quench fluorescence of conjugated polymers via energy transfer and electron transfer. Moreover, polymer PFHPNa showed higher fluorescence quenching toward large biomolecules than PFPPNa. The corresponding Stern-Volmer (K _sv) value of polymer PFHPNa was determined to be 2.1×10⁸ M⁻¹ for cytochrome c. It could be used as a sensitive and selective fluorescence sensor for protein cytochrome c. Supported by the National Natural Science Foundation of China (Grant Nos. 20574067 & 50633040), the Science Fund for Creative Research Groups (Grant No. 20621401), and the 973 Project (Grant No. 2002CB613402)     

The Solvent-Like Nature of Silica Particles in Organic Solvents

 Kamlet-Taft’s α (hydrogen bond donor acidity) and π^* (dipolarity/polarizability) values of various silica batches measured in various solvents are presented. The α and π^* parameters for the various solid acids are analyzed by means of Fe(phen)₂(CN)₂ (cis-dicyano-bis-(1,10)-phenanthroline-iron(II), 1), Michler’s ketone (4,4′-bis-(dimethylamino)-benzophenone, 2), and two hydrophilic derivatives of 2, (4-(dimethylamino)-4′-(di-2-hydroxyethyl)-amino-benzophenone (3a) and 4,4′-bis-(di-(2-hydroxyethyl)-amino)-benzophenone (3b) as well as coumarin 153 (4) as solvatochromic surface polarity indicators. Apparent β (hydrogen bond acceptor basicity) parameters for bare silica have been evaluated by means of an aminobenzodifuranone dye (5) as solvatochromic probe. The chemical interpretation of the α and π^* parameters and the nature of the solvent/surface interaction which they reflect are discussed. It can be shown that an increase of the HBA (hydrogen bond accepting) capacity of the solvent significantly decreases the HBD (hydrogen bond donating) capacity of the surface environment, whereas the dipolarity/polarizability value of the silica/solvent interface is a composite of many effects. The classification of the polarity of silica particles in organic solvents compared to pure liquids is outlined.     

Synthesis and tautomeric transformations of 2-(tert-butyl)-1,2,4-benzotriazine-3(2H)-thiones

Treatment of 2-(tert-butyl)-1,2,3,4-benzotetrazinium tetrafluoroborates with sodium thiocyanate afforded 2-(tert-butylazo)phenyl isothiocyanates 3, which exist in equilibrium with 2-(tert-butyl)-1,2,4-benzotriazine-3(2H)-thiones 3′. The equilibrium depends on the substituents R in the benzene ring: the percentage of the open isomer 3 is about 20% for R = H or Me; for R = Cl or Br, the equilibrium is completely shifted to cyclic isomer 3′. The equilibrium is slow on the time scale of the ¹H and ¹³C NMR experiments. For compounds 3a/3′a (R = H), the spectra at 24 °C show two sets of signals, while those at 0 °C contain only signals for isomer 3′a. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1192–1195, July, 2006.     

Synthesis, crystal structure and photoluminescence of a novel tetra-nuclear calcium complex [(Ca(C15H8O7S)-(H2O)(DMSO))3(Ca(C15H8O7S) (DMSO)2]·4DMSO

The sulfonate derivate of chrysin coordinates with Ca²⁺ to form a novel tetra-nuclear calcium complex [(Ca(C₁₅H₈O₇S)(H₂O)(DMSO)₃(Ca(C₁₅H₈O₇S)(DMSO)₂]·4DMSO. The structure of the complex is characterized by IR,¹H NMR and X-ray single-crystal diffraction analysis. The results show that the complex crystallizes in triclinic, space group PĪ, cell parametera = 1.4725(6) nm,b = 1.6480(7) nm,c = 2.1006(8) nm, α = 83.928(7)°, β= 85.938(7)°, γ= 85.212(7)°,V = 5.041(3) nm³,Dc = 1.476 g/cm³,Z = 2, μ=0.568 nm⁻¹,F(000) = 2324,R = 0.0778,wR = 0.1821. In the complex, four Ca²⁺ which are bridged by four 5-hydroxyanion-7-dihydro-xyfla-vone-6-sulfonate ligands with their carbonyl and 5-hydroxyanion group build an approximate square. The coordination number of Ca²⁺ is 7 and the coordinated atoms are all oxygen from the carbonyl, hydroxyl and suflo-group of 5-hydroxyanion-7-hydroxyflavone-6-sulfonate, H₂O and DMSO. Four ligands locate on two sides of the square. Two of them on the same side are almost paralleled and aromatic п-п stacking exists between them. Ligands on the opposite side are nearly perpendicular to each other. Meanwhile, the solid of title compound has the photoluminescent phenomenon. The title compound emits green fluorescence (λ_em = 520 nm) when it is excited at the wavelength of 410 nm and its photoluminescent mechanism is discussed.