Adsorption of acid and basic dyes on NiO-SiO2 composites

A series of composites containing 2.5–21.0% NiO on a surface of macroporous silica is synthesized. The specific surface area of the composites measured by the thermal desorption of nitrogen decreases with an increase in the NiO content from 24 for the original silica carrier to 16 m²/g the for composite containing 21.0% NiO. The basic dye, methylene blue (MB), is only adsorbed on SiO₂ in water solutions, while acid blue anthraquinone (ABA) is only adsorbed on the NiO. The effective specific surface area Seff and effective diameters D _eff of NiO nanoparticles are calculated from the adsorption isotherms of ABA on NiO composites and on NiO synthesized without a carrier. S _eff of NiO nanoparticles decreases from 76 to 42 m²/g and D _eff increases from 8 to 14 nm with rising NiO content in the composites. The NiO nanoparticles synthesized without a carrier are characterized by the lowest S _eff (30 m²/g) and the largest D _eff (20 nm).     

Reduction reactions of bovine serum albumin and lysozyme by CO- .2 radical in polyvinyl alcohol solution: a pulse radiolysis study

Pulse radiolytic reduction of bovine serum albumin (BSA) and lysozyme by CO^⨪₂ radical in presence of polyvinyl alcohol (PVA) has been studied. At pH 6.8 in presence of 2% (w/v) PVA, reduction of BSA and lysozyme (both at 1×10⁻⁴ mol dm⁻³) give an additional transient peak at 390 nm along with the usual 420 nm peak. The bimolecular rate constants for the reaction of CO^⨪₂ radical at pH 6.8±0.2 with BSA are 2.7×10⁸ and 7.13×10⁸ dm³ mol⁻¹ s⁻¹ at 420 nm and 390 nm respectively. The same for lysozyme are 3.2×10⁸ and 5.6×10⁸ dm³ mol⁻¹ s⁻¹ at 420 nm and 390 nm, respectively. Dimethyl disulfide also gives 390 nm and 420 nm peaks in this system upon reduction with CO^⨪₂ radical. The 390 nm peak is ascribed to the sulfenium radical (RSS(H)R). Studies on the variation of pH suggests the protonation of RSSR^⨪ radical (420 nm) to form RSS(H)R radical (390 nm) in this viscous media. The decay of RSS(H)R radical occurs via formation of RS radical and RS(H)S(H)R, the final product being RSH in both cases.     

4-Ferrocenylphenol as an electron transfer mediator in PQQ-dependent alcohol and glucose dehydrogenase-catalyzed reactions

Enzyme electrodes containing pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase (ADH) and glucose dehydrogenase (GDH) as a biological component in combination with 4-ferrocenylphenol (1) as an electron transfer mediator between PQQ and a carbon electrode were constructed and used for measurements of ethanol and d-glucose. Analysis of the current response of the carbon electrodes modified with 1 at different pH and potentials demonstrated that 1 participates in the bioelectrocatalytic oxidation of d-glucose or ethanol. The biosensors showed the highest response at pH 5.5 and the working potentials of 0.3 and 0.4 V (versus Ag|AgCl) for ADH and GDH, respectively. The electrocatalytic processes under such conditions at these electrodes are characterized by the apparent values of the Michaelis constants K_M^app of 7.1 and 13 mM and the maximal current density j_max 40 and 26 μA cm⁻² for ethanol and d-glucose, respectively. No electrocatalysis was found when glucose oxidase from Aspergillus niger was used instead of GDH.     

Influence of dipalmitoylphosphatidylcholine (or dioleoylphosphatidylcholine) and phospholipase A2 enzyme on the properties of emulsions

The properties of n-tetradecane emulsions with dipalmitoylphosphatidylcholine (DPPC) or dioleoylphosphatidylcholine (DOPC) in 1M ethanol were investigated at 20 and 37°C. The zwitterionic phospholipids having the same headgroup bound to the apolar tail composed of two saturated or unsaturated chains were used as stabilizing agents. Both phospholipids may self-organize into aggregates, which possess different sizes and surface affinities. Electrokinetic properties of the systems at natural pH or pH 8 were investigated taking into account the effective diameter of the droplets as well as the zeta potentials using the dynamic light scattering technique. The effect of both phospholipids decreases the initially negative zeta potential of the n-tetradecane emulsion and is more evident in the case of DPPC especially at a physiological temperature near its main temperature transition. The change of zeta potential by DOPC is visible at both temperatures probably as an effect of a loose packing of this phospholipid on n-tetradecane droplets, because of the presence of double bonds in its molecule. Also, the role of ethanol dipoles on the stability of oil/phospholipid emulsions is obvious. The other aim of paper was the characterization of the phospholipase A(2) influence on DOPC hydrolysis in the emulsion environment in order to emphasize the importance of such methodology. The present work is the first study that explores the effects of both electrolyte ions and ethanol molecules on DOPC hydrolysis by phospholipase. The effect of enzyme on the n-tetradecane/DOPC emulsions was investigated at pH 8 with Na(+) or Ca(2+) ions, which occur in the physiological fluids. The effective diameters do not always correlate with the zeta potentials. A possible reason of such behavior might a mechanism different from the electrostatic stabilization. The particular role of Ca(2+) ions in the emulsions with phospholipids was confirmed. Those investigations provide insight into the properties of the PLA(2) hydrolysis process enhanced by added ethanol. It is believed that the enzyme effect on the phospholipid aggregation behavior at the oil-water interface will be helpful for understanding other biological phenomena.     

Remark on the ground state potentials and dissociation energies of the alkali hydrides

The ground state Rydberg—Klein—Rees (RKR) potentials and the corresponding molecular constants of the alkali hydrides, recommended in a recent article by Stwalley et al. (J. Phys. Chem. Ref. Data, to be published [1]) are critically evaluated in the framework of the reduced potential curve (RPC) scheme. A comparison with the older RPC analysis of the ground states of the alkali hydrides is briefly discussed. The efficiency of the RPC method for the detection of errors in the RKR potential (spectroscopic constants) and for the estimation of the dissociation energy is emphasized. Although the RKR potentials of NaH and RbH are known only up to 54 and 57% of D_e, respectively, the RPC method permitted here at least a substantial reduction of the uncertainty in the lower limit of D_e(NaH) (by 70 cm⁻¹) and in the lower and upper limits of D_e(RbH) (by 250 and 500 cm⁻¹, respectively) which are now estimated as 15 870, 14 230 and 14 680 cm⁻¹, respectively. The RPC picture even suggests that the values 14 380 and 14 580 cm⁻¹ may possibly be taken as reasonable limits for D_e(RbH). Accurate extensions of the inner wings of the potentials of NaH, RbH and CsH were calculated using the generalized reduced potential curve (GRPC) method. The limit of error of these extensions should be smaller than 0.002 Å if the potentials are correct.     

Estimation of the standard reduction potentials of some 1-arylethyl radicals in acetonitrile

The redox properties of some arylethyl radicals, which are involved in the electrochemical synthesis of important anti-inflammatory agents, have been investigated in CH₃CN by an indirect electrochemical method based on the catalytic reduction of the corresponding arylethyl halides (RX) by electrogenerated aromatic or heteroaromatic anion radicals (D⁻). The reaction between RX and D⁻ leads to a radical R, which can react with D⁻ either by radical coupling (k₃) or by electron transfer (k₄). Examination of the competition between these reactions, which can be expressed by a dimensionless parameter q=k₄/(k₃+k₄), as a function of E⁰_D/D⁻ allows estimation of the reduction potentials of the arylethyl radicals. The standard reduction potentials obtained for the radicals 1-(4-isobutylphenyl)ethyl, 1-(6-methoxy-2-naphthyl)ethyl, and 1-(4-biphenyl)ethyl are −1.64, −1.62, and −1.15 V vs. SCE, respectively.     

Photo-induced degradation of some flavins in aqueous solution

The blue-light induced photo-degradation of FMN, FAD, riboflavin, lumiflavin, and lumichrome in aqueous solution at pH 8 is studied by measurement of absorption coefficient spectral changes due to continuous excitation at 428 nm. The quantum yields of photo-degradation determined are ϕ_D(riboflavin, pH 8) ≈ 7.8 × 10⁻³, ϕ_D(FMN, pH 5.6) ≈ 7.3 × 10⁻³, ϕ_D(FMN, pH 8) ≈ 4.6 × 10⁻³, ϕ_D(FAD, pH 8) ≈ 3.7 × 10⁻⁴, ϕ_D(lumichrome, pH 8) ≈ 1.8 × 10⁻⁴, and ϕ_D(lumiflavin, pH 8) ⩽ 1.1 × 10⁻⁵. In a mass-spectroscopic analysis, the photo-products of FMN dissolved in water (solution pH is 5.6) were identified to be lumichrome and the lumiflavin derivatives dihydroxymethyllumiflavin, formyllumiflavin, and lumiflavin-hydroxy-acetaldehyde. An absorption and emission spectroscopic characterisation of the primary photoproducts of FMN at pH 8 is carried out.     

Solid-state Electrochemical Sensor Based on a Cross-linked Copper(II)-doped Copolymer and Carbon Nanotube Material for Selective and Sensitive Detection of Monohydrogen Phosphate

A novel solid-state electrochemical sensor based on a newly synthesized cross-linked copper(II) doped-copolymer and carbon nanotube material was developed for the direct determination of monohydrogen phosphate ions (HPO₄²⁻). The synthesized copolymers were characterized by FTIR, XPS, TG/DTG-DTA and SEM techniques. The sensor had a Nernstian slope:-30.7±0.4 mV/decade, linear concentrations range: 1.0×10⁻⁶ - 1.0×10⁻¹ M, detection limit: 6.5×10⁻⁷ M, response time: 4 s and life time: 17 weeks. The sensor displayed constant potentials in the pH range 7.0-9.5. The sensor was successfully used as an indicator electrode in potentiometric titration and the direct determination of HPO₄ ²⁻ in water samples.     

Simultaneous Determination of Procaspase Activating Compound 1 and Permeability Markers in Intestinal Perfusion Samples and Application to a Rat Intestinal Absorption Study

A sensitive and simple HPLC method for simultaneous determination of PAC-1 (first procaspase-activating compound), phenol red, and permeability markers (carbamazepine and furosemide) in perfusion samples was developed and validated to assess intestinal absorption of PAC-1 using single-pass intestinal perfusion technique (SPIP) in rats. The chromatographic separation was carried out on a Kromasil C₁₈ column (150 mm × 4.6 mm, 5 μm) with acetonitrile–methanol–30 mmol L⁻¹ phosphate buffer (pH 3.0, 25:10:65, v/v/v) as mobile phase at a flow rate of 1.0 mL min⁻¹, and the wavelength of the UV detector was set at 281 nm. The calibration curves were linear in the ranges of 2.40–48.0 μg mL⁻¹ for PAC-1; 3.60–72.0 μg mL⁻¹ for carbamazepine; 3.20–64.0 μg mL⁻¹ for furosemide, and 4.80–96.0 μg mL⁻¹ for phenol red (r > 0.999). Both the intra- and inter-day precisions (RSD%) of all analytes were less than 6.8 % at three concentration levels, while accuracy ranged from 95.4 to 104.5 %. Data obtained in all method validation studies indicated that the method was suitable for the intended purpose. The effective permeability values (P _eff) considering water flux with the help of non-permeable marker phenol red was calculated to be 0.42 × 10⁻⁴, 0.62 × 10⁻⁴, 0.32 × 10⁻⁴ cm s⁻¹ for PAC-1; 0.72 × 10⁻⁴, 0.77 × 10⁻⁴, 0.52 × 10⁻⁴ cm s⁻¹ for carbamazepine; 0.20 × 10⁻⁴, 0.16 × 10⁻⁴, 0.12 × 10⁻⁴ cm s⁻¹ for furosemide in duodenum, jejunum and ileum, respectively. The P _eff value can be increased by co-perfusion with verapamil, indicating that absorption of PAC-1 is efficiently transported by P-glycoprotein (P-gp) in the gut wall.

     

Selective colorimetric assay of cyanide ions using a thioamide-based probe containing phenol and pyridyl groups

The selective assay of cyanide ions with a thioamide compound (HNPTU) containing phenol and pyridine as a chemosensor is reported using absorbance changes in a buffered aqueous solution (50 mM HEPES, pH 7.4) containing ethanol. Upon treatment with cyanide ions, the colorless solution of HNPTU turned yellow. No significant changes were observed with other comparable anions, such as F⁻, Cl⁻, Br⁻, I⁻, and CH₃COO⁻. The color change of HNPTU upon treatment with CN⁻ was maintained even in the presence of the comparable monovalent anions. The complex stability constant (K_a = 2.6 × 10³) for the stoichiometric 1:1 complexation of HNPTU with cyanide ions was obtained based on absorbance titrations. The interaction of HNPTU with cyanide ions was proposed to be deprotonation, as shown by NMR and Cu(II) treatment experiments.     

An electrochemical method for determination of the standard Gibbs energy of anion transfer between water and n-octanol

The transfer of the ions Cl⁻, Br⁻, I⁻, ClO₄⁻, SCN⁻, NO₃⁻, BF₄⁻, and (C₆H₅)₄B⁻ across the water|n-octanol (W|OC) liquid interface was studied and the standard Gibbs energies of ion transfer were determined. The ion transfer was achieved by oxidation of decamethylferrocene dissolved in a droplet of n-octanol that was attached to a graphite electrode immersed in the aqueous solutions of the respective alkali salts of the anions. The electrode reaction can be described by the equation: dmfc_(OC)+X_(W)⁻⇄dmfc⁺_(OC)+X⁻_(OC)+e⁻, where X⁻ is the transferred anion. Square-wave voltammetry at this three-phase arrangement was utilised to determine the formal potential of the decamethylferrocene/decamethylferrocenium (dmfc/dmfc⁺) couple under the condition of ion transfer across the water|n-octanol interface. For calibration the standard Gibbs energies of ion transfer have been extrapolated to octanol from the series of known data for methanol, ethanol, n-propanol, and n-butanol. All these data are consistent and the experimental dependence of the formal potentials on the standard Gibbs energies is as predicted by theory. The validity of data is further supported by calculations of Gibbs energies of ion transfer using the Born theory. Until now it was not possible to perform electrochemical measurements at the water|n-octanol interface because in the conventional four-electrode cells this interface cannot be polarised. With the new method it is now for the first time possible to determine the Gibbs energies of transfer of ions across the water|n-octanol interface. These values are of very wide use for assessing the lipophilicity of compounds in chemistry, medicine, and pharmacology.     

Electrochemical capacitors with KCl electrolyte

Potassium manganese dioxide K_xMnO_{2 + δ}·nH₂O and amorphous MnO₂ in a mild 2 M KCl aqueous electrolyte prove to be excellent electrodes for faradaic electrochemical capacitors. The K_xMnO_{2 + δ}·nH₂O materials were prepared by direct thermal decomposition of KMnO₄ and contained a large amorphous/crystalline ratio. A sample decomposed at 550 °C gave a specific cyclic capacitance between −0.2 and +1.0 V/SCE of 240 F·g⁻¹, which corresponds to nearly one-third of the Mn(IV) ions participating in the faradaic reaction. Excellent cyclability at 12 mA·cm⁻² was found for 100 cycles. On short-circuit, K_0,31MnO_2,12·0,63 H₂O in 2 M KCl and pH 10.6 aqueous solution gave an initial current density of 0.58 A·cm⁻² and a total released charge of 4.6 C·cm⁻² compared with 0.32 A·cm⁻² and 11.1 C·cm⁻² for RuOOH·nH₂O in 5.3 M H₂SO₄. Similar results obtained with amorphous MnO₂ demonstrate that alkali ions can be used as the working ion in a faradaic supercapacitor, which frees the search for new materials from the constraint of working in a strong-acid aqueous medium.     

Rhodamine-linked pyridyl thiourea as a receptor for selective recognition of F–, Al3+ and Ag+ under different conditions

A new rhodamine-labelled pyridyl thiourea-based compound 1 has been designed and synthesised. While the receptor selectively recognises F^– and Al³⁺ ions in CH₃CN, Al³⁺ and Ag⁺ ions are selectively screened from other cations in CH₃CN/water (4/1, v/v; 10 μM Tris–HCl buffer, pH 6.8) by observing different emission characteristics and colour changes. While Ag⁺ is sensed through an increase in emission at 416 nm, Al³⁺ is detected by a ratiometric change in emission of 1 with a band at 585 nm. The receptor shows in vitro detection of both the ions in human cervical cancer (HeLa) cells.     

Ice/Water Interface: Zeta Potential, Point of Zero Charge, and Hydrophobicity

The ice/water interface is a common and important part of many biological, environmental, and technological systems. In contrast to its importance, the system has not been extensively studied and is not well understood. Therefore, in this paper the properties of the H₂O ice/water and D₂O ice/water interfaces were investigated. Although the zeta potential vs pH data points were significantly scattered, it was determined that the isoelectric point (iep) of D₂O ice particles in water at 3.5°C containing 10⁻³ M NaCl occurs at about pH 3.0. The negative values of the zeta potential, calculated from the electrophoretic mobility, seem to decrease with decreasing content of NaCl, while the iep shifts to a higher pH. The point of zero charge (pzc) of D₂O ice and H₂O ice, determined by changes in pH of 10⁻⁴ M NaCl aqueous solution at 0.5°C after the ice particle addition, was found to be very different from the iep and equal to pH 7.0 ± 0.5. The shift of the iep with NaCl concentration and the difference in the positions of the iep and pzc on the pH scale point to complex specific adsorption of ions at the interface. Interestingly, similar values of iep and pzc were found for very different systems, such as hydrophilic ice and highly hydrophobic hexadecane droplets in water. A comparison of the zeta potential vs pH curves for hydrophilic ice and hydrophobic materials that do not possess dissociative functional groups at the interface (diamond, air bubbles, bacteria, and hexadecane) indicated that all of them have an iep near pH 3.5. These results indicate that the zeta potential and surface charge data alone cannot be used to delineate the electrochemical properties of a given water/moiety interface because similar electrical properties do not necessary mean a similar structure of the interfacial region. A good example is the aliphatic hydrocarbon/water interface in comparison to the ice/water interface. Although the experiments were carried out with care, both the zeta potential, measured with a precise ZetaPlus meter, and ΔpH values (a measure of surface charge) vs pH were significantly scattered, and the origin of dissemination of the data points was not established. Differently charged ice particles and not fully equilibrium conditions at the ice/water interface may have been responsible for the dissemination of the data.     

Structural and electrical characteristics of ALD-HfO2/n-Si gate stack with SiON interfacial layer for advanced CMOS technology

We report the fabrication of an ultra-thin silicon oxynitride (SiON) as an interfacial layer (IL) for n-Si/ALD-HfO₂ gate stack with reduced leakage current. The XRD, AFM, FTIR, FESEM and EDAX characterizations have been performed for structural and morphological studies. Electrical parameters such as dielectric constant (K), interface trap density (D_it), leakage current density (J), effective oxide charge (Q_eff), barrier height (Φ_bo), ideality factor (ƞ), breakdown-voltage (V_br) and series resistance (R_s) were extracted through C-V, G-V and I-V measurements. The determined values of K, D_it, J, Q_eff, Φ_bo, ƞ, V_br and R_s are 14.4, 0.5 × 10 ¹¹ eV⁻¹ cm⁻², 2.2 × 10⁻⁹ A/cm², 0.3 × 10¹³ cm⁻², 0.42, 2.1, −0.33 and 14.5 MΩ respectively. SiON growth prior to HfO₂ deposition has curtailed the problem of high leakage current density and interfacial traps due to sufficient amount of N₂ incorporated at the interface.     

Gas phase reactions of Cl2O with X−(D2O)n=0–4 (X = O,OD, O2, DO2, and O3)

The reactions of Cl₂O with the cluster ions X⁻(D₂O)_n=0–4 (X = O, OD, O₂, DO₂, and O₃) were studied in a He buffer gas at temperatures within the range 171–298 K and pressures of 0.27–0.51 Torr, using a flow-tube apparatus. All ions were found to react with Cl₂O at rates slower than predicted by the collision rate and the charge center was transferred from X⁻ to Cl⁻ or ClO⁻. The primary product ions Cl⁻(DOCl) and ClO⁻(DOCl) were observed to react further to produce the ions Cl₃O⁻ and Cl₃O₂⁻. The rate constants for the observed reactions are reported and the role that thermodynamics plays in determining possible reaction channels is discussed.     

Cationic grafting of olefins from PVC: The effect of reaction conditions

The cationic grafting of isobutylene, styrene, α-methylstyrene, and β-pinene from a poly(vinyl chloride) (PVC) backbone was investigated. Grafting-from was induced by Et₂AlCl in 1,2-dichloroethane and methylene dichloride solutions from 20 to −70 °C. The effects of temperature and proton trap [2,6-di-tert-butylpyridine (DtBP)] on grafting-from efficiency (G_eff), extent of grafting, branch length (molecular weight), and number of branches per PVC molecule were determined. Reducing the temperature invariably increased the G_eff and the molecular weight of polyisobutylene, polystyrene, poly(α-methylstyrene), and poly(β-pinene) branches attached to PVC. The magnitude of the effects was different with the various olefins and depended on the reaction conditions. The effect of DtBP was examined in the 5 × 10⁻⁴–4 × 10⁻³ mol/L range. By increasing the DtBP concentration the G_eff increased; however, the number-average molecular weight of the grafted branches decreased. The lengths of the grafted branches can be controlled, and G_eff's close to 100% were obtained. The fact that the proton trap reduced the molecular weights of grafted branches suggests that besides proton scavenging, DtBP may also abstract protons from the growing carbenium ion site. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1675–1680, 2001     

Analysis of hen egg white lysozyme adsorption on Si(Ti)O2 ∣ aqueous solution interfaces at low ionic strength: a biphasic reaction related to solution self-association

Adsorption kinetics of hen-egg white lysozyme at concentrations of 10⁻⁷, 10⁻⁶, 10⁻⁴ M and at pH 8.0 have been measured on Si_0.8Ti_0.2O₂ surfaces by means of optical waveguide lightmode spectroscopy and were found to proceed in two distinct kinetic régimes: a fast and quasi linear increase of the surface concentration followed by slower kinetics that could be described qualitatively by the theory of random sequential adsorption. The transition between these two kinetic régimes was correlated with abrupt changes in the values of the mean refractive index and of the thickness of the adsorbed layer as well as in the desorption kinetics performed either before or after the transition from the first régime to the second. Experiments carried out at the same ionic strength but at different pH values showed that the adsorption behaviour of lysozyme is related to its self-association properties in highly concentrated solutions.     

Potentiodynamic hydrogen permeation on Palladium-Kelvin probe compared to 3D printed microelectrochemical cell

A specially designed flow cell, fabricated via rapid prototyping (3D printing), was used to perform in-situ electrochemical hydrogen loading and cyclic voltammetry on a Pd foil in alkaline solution during scanning Kelvin probe (SKP) measurements. SKP was successfully employed for hydrogen detection on the exit side of the sample, including determination of hydrogen diffusion coefficient in Pd to 3.32 ⋅ 10^− 7 cm²⋅ s^− 1 at 23 °C. Convection of electrolyte allowed hydrogen charging even under H₂-forming conditions without surface blockage by evolving gas bubbles at very negative potentials. Comparison with electrochemical hydrogen detection under the same conditions, allowed a more comprehensive interpretation of SKP results including determination of trapping effects on measurement of diffusion coefficient. In this manner, the potentiodynamic hydrogen loading technique combined with SKP-H-detection was utilized to determine the effective hydrogen diffusion coefficient (D_eff).     

Regulating the slow magnetic relaxation behavior of two different shapes Dy4 clusters with in situ formed penta- and heptadentate Schiff base ligands

The design and synthesis of clusters possessing the same number of cores but different connection methods and properties have always been difficult. Herein, we used 2-pyridinaldehyde, 1,3-diamino-2-propanol, and Dy (ClO₄)₃·6H₂O at room temperature (RT) to obtain the cluster [Dy₄(L¹)₄(μ₂-OH)₄]·4ClO₄⁻ ( 1 , HL¹ = 2-pyridinecarboxaldehyde-1,3-diamino-2-propanol) with square Dy₄O₈ cluster cores. Cluster 1 consisted of four Schiff base ligands (L¹)⁻, four Dy(III) ions, four bridged (μ₂-OH)⁻, and four free ClO₄⁻. The ligand HL¹ was formed by in situ Schiff base reaction with 2-pyridinecarbaldehyde and 1,3-diamino-2-propanol in the presence of Dy(III) ions. 2-Aldehyde-8-hydroxyquinoline, 1,3-diamino-2-propanol, and Dy (NO₃)₃·6H₂O reacted at RT to yield a tetranuclear Dy(III) cluster [Dy₄(L²)₂(μ₃-OH)₂(NO₃)₄(EtOH)₂]·2CH₃CN ( 2 , H₃L² = 2-aldehyde-8-hydroxyquinoline-1,3-diamino-2-propanol) with butterfly-shaped Dy₄O₆ cluster core. Cluster 2 consisted of two ligands (L²)³⁻, four Dy(III) ions, two bridged μ₃-OH, two end-group-coordinated ethanol molecules, and four bidentate-chelated NO₃⁻. The in situ reaction of 2-aldehyde-8-hydroxyquinoline and 1,3-diamino-2-propanol under Dy(III) ion-assisted catalytic conditions provided the ligand H₃L². It is worth noting that the magnetic test showed that 1 is a typical single-molecule magnet (SMM), whereas 2 only showed a significant frequency dependence behavior. We considered Orbach and Raman processes (τ⁻¹ = τ₀⁻¹ exp(−U_eff/k_BT) + CTⁿ) to fit 1 and 2 in the high-temperature range and obtained U_eff = 7.01 and 5.43 K and τ₀ = 1.18 × 10⁻⁴ and 4.14 × 10⁻⁵ s, respectively.