Three- and four-coordinated silver(I) ions in the coordination polymers [Ag(Me<Subscript>4</Subscript>Pyz)<Subscript>2</Subscript>]PF<Subscript>6</Subscript> and [Ag(2,3-Et<Subscript>2</Subscript>Pyz)<Subscript>2</Subscript>]PF<Subscript>6</Subscript>

The coordination polymers [AgPF₆(Me₄Pyz)₂] (I) and [AgPF₆(2,3-Et₂Pyz)₂] (II) were synthesized, and their structures were determined. Crystals of I are monoclinic, space group C2/c, a = 10.213(2) Å, b = 16.267(3) Å, c = 12.663(3) Å, β = 92.90(3)°, V = 2102.1(7) ų, ρ_calcd = 1.660 g/cm³, Z = 4. The structure of I is built of polymeric zigzag [Ag(C₈H₁₂N₂)] _∞ ⁺ chains and octahedral [PF₆] anions. The coordination polyhedron of the Ag⁺ ion is a flat triangle. Crystals of II are tetragonal, space group P \(\bar 4\)2(1)/c,a = b = 10.641(1) Å, c = 18.942(1) Å, V = 2144.6(2) ų, ρ_calcd = 1.627 g/cm³, Z = 4. In the structure of II, 2D cationic layers of fused square rings exist; the rings consist of four Ag⁺ cations linked by four bridging ligands of diethylpyrazine Et₂Pyz. The coordination polyhedron of the Ag⁺ ion is an irregular four-vertex polyhedron.     

Synthesis and structure of coordination polymer compounds of AgReO<Subscript>4</Subscript> and AgPF<Subscript>6</Subscript> with piperazine

Coordination polymers [Ag(C₄H₁₀N₂)]ReO₄ (I) and [Ag(C₄H₁₀N₂)]PF₆ (II) (C₄H₁₀N₂ is piperazine, Ppz) were synthesized and their structures were determined. Crystals of compound I are monoclinic, space group P2₁/c, a = 6.207(1) Å, b = 12.533(1) Å, c = 11.386(1) Å, β = 93.41(1)°, V = 884.2(2) ų, ρ_calc = 3.337 g/cm³, Z = 4. Crystals of II are monoclinic, space group C2/m, a = 8.723(1) Å, b = 9.083(1) Å, c = 5.797(1) Å, β = 95.07(1)°, V = 457.5(1) ų, ρ_calc = 2.548 g/cm³, Z = 2. Structure I contains polymer chains [Ag(Ppz)] _∞ ⁺ . The silver atom is linked with two nitrogen atoms of the adjacent Ppz ligands to form a nearly linear fragment; the Ag-N_av distance is 2.173 Å, and the NAgN angle is 169.4(3)°. The chains are linked with each other by weak interactions Ag…O(ReO₄) (2.643(8) Å) and N-H…O hydrogen bonds. The structure of compound II also contains cationic polymer chains [Ag(Ppz)] _∞ ⁺ . The Ag⁺ ion is located in the inversion center and has a linear coordination (Ag-N distance is 2.171(9) Å). The central P atom of the octahedral fluorophos-phate ion is also located in the inversion center; the anion is slightly distorted and has no contacts with silver ions at a distance <3.4 Å.     

Vapor pressure and heat capacities of perfluoro-<Emphasis Type="Italic">N</Emphasis>-(4-methylcyclohexyl)piperidine

Heat capacities of perfluoro-N-(4-methylcyclohexyl)piperidine (PMCP) have been measured by low-temperature adiabatic calorimetry. The purity of the compound, its triple-point temperature, and its enthalpy and entropy of fusion have been determined. The saturated vapor pressure was determined by comparative ebulliometry as a function of temperature in the 6.2–101.6 kPa pressure range and 374.2–460.9 K temperature range. The calorimetric enthalpy of vaporization at T = 298.15 K has been measured. The following thermodynamic properties were calculated for PMCP: normal boiling temperature, enthalpy of vaporization Δ_vap H _m ⁰ (T) as a function of temperature, and critical parameters. The enthalpies of vaporization at 298.15 K obtained experimentally and by calculation methods match within their error limits, which validates their adequacy and the adequacy of the Δ_vap H _m ⁰ = f(T) equation as an extrapolation.     

Microbial Transformation of Curcumin to Its Derivatives with a Novel <Emphasis Type="Italic">Pichia kudriavzevii</Emphasis> ZJPH0802 Strain

Curcumin, a polyphenolic compound, has shown a wide range of pharmacological activities and has been widely used as a food additive. However, the clinical use of curcumin is limited to some extent because of its poor water solubility and low bioavailability. To overcome these problems, many approaches have been attempted and structural modification of curcumin by microbial transformation has been proven to be an alternative. In this study, we isolated a novel yeast strain Pichia kudriavzevii ZJPH0802 from a soil sample, which is capable of converting curcumin to its derivatives. The transformed products by this strain were evaluated by HPLC, (+) electrospray ionization (ESI)-MSⁿ, and ¹H nuclear magnetic resonance methods. Compared with controls, two new peaks of the transformed broth appeared at retention times of 26 min (I) and 62 min (II) by HPLC analysis. The two transformed products were then further identified by (+) ESI-MSⁿ. The spectrum showed that compound I had an accurate [M+H+NH₃]⁺ ion at m/z 392, [M+H]⁺ ion at m/z 375, [M+H–H₂O]⁺ ion at m/z 357, and (+) ESI-MS³ spectrum showed that ion at m/z 357 could further form fragment ions at m/z 339, 177, and 163; compound II had an accurate [M+H]⁺ ion at m/z 373, [M+H–H₂O]⁺ ion at m/z 355, and (+) ESI-MS³ spectrum showed that ion at m/z 355 could further form fragment ions at m/z 219, 179, 177, 163, and 137. These two transformed products thereby were confirmed as hexahydrocurcumin (I) and tetrahydrocurcumin (II).     

Structural characterization of a mixed-ligand complex of copper(II) with 1,10-phenanthroline and the <Emphasis Type="Italic">m</Emphasis>-aminobenzoate ion

A new copper(II) complex of 1,10-phenanthroline (C1₂H₈N₂) and the meta-aminobenzoate ion (m-amb; C₇H₆NO ₂ ^? ), having the formula Cu(C₁₂H₈N₂)(C₇H₆NO₂)Cl?0.5H₂O, is prepared and characterized by elemental analysis, IR spectroscopy, and single crystal X-ray diffraction. The structure is built up from monomeric units in which the coordination environment around the metal ion is a square plane arising from a bidentate 1,10-phenanthroline molecule, a monodentate m-amb anion, and a chloride ion. A very long (Cu–N = 2.856(5) Å) bond to the nitrogen atom of an adjacent m-amb ion generates [101] polymeric chains in the crystal. The crystal structure is consolidated by N–H???O and O–H???O hydrogen bonds and C–H???O, C–H???Cl, and aromatic π–π stacking interactions. Crystal data: C₁₉H₁₅ClCuN₃O_2.5, M _r = 424.33, monoclinic, P2₁/n (No. 14), a = 9.8200(5) Å, b = 10.9291(7) Å, c = 16.3803(9) Å, β = 105.293(3)°, V = 1695.74(17) ų, Z = 4, R(F) = 0.043, wR(F ²) = 0.122.     

Mononuclear and heterodinuclear phenanthrolinedione complexes of <Emphasis Type="Italic">d</Emphasis>- and <Emphasis Type="Italic">f</Emphasis>-block elements

1,10-Phenanthroline-5,6-dione (Phd) complexes of group 3 and lanthanide elements having formulae Ln(hfac)₃(Phd) (Ln = Y, Eu, Yb; hfac = hexafluoroacetylacetonate) were synthesised and characterised. Complexes of d-block elements of the type [MCl(Phd)(p-cymene)]⁺ (M = Ru, Os) were also prepared. In all these species, coordination of the polydentate ligand occurs by the N-donor moieties, as indicated by DFT calculations. The novel compounds were tested, together with fac-ReBr(Phd)(CO)₃, as precursors for the preparation of heterobimetallic d/f derivatives. The reaction of the rhenium complex with yttrium or lanthanide anhydrous triflate salts led to the formation of the complexes ReBr(CO)₃(N,N′-Phd-O,O′)Ln(OTf)₃(THF) (Ln = Y, Eu, Yb), where the trivalent ions interacted with the quinonoid moiety. The redox properties of the rhenium centre were strongly affected by the coordination of Ln(OTf)₃, as observed by comparing the cyclic voltammetry measurements carried out on fac-ReBr(Phd)(CO)₃ and on ReBr(CO)₃(N,N′-Phd-O,O′)Y(OTf)₃.     

Thermodynamic characteristics of complexation between Ho<Superscript>3+</Superscript> and ethylenediamine-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>'-disuccinic acid in aqueous solutions at 298.15 K

The thermodynamic characteristics of complexation between ethylenediamine-N,N'-disuccinic acid (H₄Y; EDDA) and Ho³⁺ ion were determined calorimetrically and potentiometrically at 298.15 K and ionic strengths of 0.1, 0.5, 1.0, and 1.5 (KNO₃). The logK, Δ_rG, Δ_rH, and Δ_rS values for the formation of HoY^– and HOHY complexes were calculated at the studied and zero ionic strength values. The changes in thermodynamic parameters of the reactions are discussed.     

Crystal and molecular structures and luminescence properties of [Eu(Cin)<Subscript>3</Subscript>]<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> complex

The crystal structure of europium cinnamate of the composition [Eu(Cin)₃] _n (Cin is cinnamic acid anion C₉H₇O ₂ ^? ) was determined by X-ray crystallography (a = 22.626(1) Å, c = 7.7330(7) Å, space group R3/c, Z = 3, ρ_calc = 1.448 g/cm³). The coordination polyhedron of Eu atoms is a distorted trigonal prism with three centered square faces. The structure is built of infinite polymeric chains [Eu(Cin)₃] _n running along the c axis and linked by van der Waals and π stacking interactions. Luminescent characteristics of the compound were determined.     

Reaction of transsilylation of <Emphasis Type="Italic">N</Emphasis>-methyl-<Emphasis Type="Italic">N</Emphasis>-trimethylsilylacetamide with silanes ClCH<Subscript>2</Subscript>SiR<Superscript>1</Superscript>R<Superscript>2</Superscript>Cl

The reaction of N-methyl-N-trimethylsilylacetamide with silanes ClCH₂SiR¹R²Cl (R¹, R² = H, Me; H, Ph; Ph₂) leads to the formation of (O→Si) chelate compounds with pentacoordinate silicon: N-[chloro(methyl)-silyl]methyl-, N-[chloro(phenyl)silyl]methyl-, and N-[chloro(diphenyl)silyl]methyl-N-methylacetamides. From the data of multinuclear NMR spectroscopy, the intermediates of the reaction of N-methyl-N-trimethylsilylacetamide with ClCH₂SiPhHCl and ClCH₂SiPh²Cl are stable in CDCl₃ solution at room temperature during several days and slowly rearrange to the final (O–Si) chelate compounds.     

Electronic Structure and Relative Stabilities of 10- and 12-Vertex. <Emphasis Type="Italic">Closo</Emphasis>and <Emphasis Type="Italic">Nido</Emphasis>-Heteroborane Clusters of Ga,Ge, and As Elements

A DFT method with the B3LYP functional and the 6-311++G(d,p) diffuse basis set is used to predict geometries, relative stabilities, electronic structures, and the bonding of closo- and nido-Ga_mB_n–mH _n ^2? , Ge_mB_n–mH _n ^m?2 , and As_mB_n–mH _n ^{2 m?2} (n = 10, 12 and m = 1, 2) Clusters are obtained by replacing BH with isolobal GaH, GeH⁺, and AsH²⁺ fragments, keeping the same skeleton electron pairs (SEP). Based on the polyhedral skeletal electron pairs theory (PSEPT), closo and nido structures are predicted and can be of significant interest for experimentalists working in the field of heteroboranes. Different cluster stabilities are studied according to Gimarc′s and Williams′ rules, where our calculations show that the monosubstituted clusters deviate from these rules, giving rise to open structures. As₂B₈H _n ²⁺ as 10-vertex structures lead to nido-type clusters, however, Ge_mB_n–mH _n ^m?2 (n = 10, 12 and m = 1, 2) give rise to closo isomers with close energies. All optimized structures exhibit large HOMO–LUMO gaps suggesting a good kinetic stability, thus predicting their isolation and characterization.     

Nickel(II) complexes of new polydentate carboxyamide: spectroscopic,kinetics of thermal decomposition and X-ray powder diffraction studies

Complexes of Ni^II with new ligands N′,N′′-bis(3-carboxy-1-oxoprop-2-enyl), 2-Amino-N-arylbenzamidine (C₂₁H₁₇N₃O₆), N′,N′′-bis(3-carboxy-1-oxopropanyl) 2-Amino-N-arylbenzamidine (C₂₁H₂₁N₃O₆) and N′,N′′-bis(3-carboxy-1- oxophenelenyl) 2-Amino-N-arylbenzamidine (C₂₉H₂₁N₃O₆) have been synthesized and characterized by elemental analyses, vibrational spectra, electronic spectra, TOF-mass spectra, magnetic susceptibility measurements, thermal studies and X-ray powder diffraction studies. Vibrational spectra indicate coordination of amide and carboxylate oxygen of the ligands along with two water molecules giving a MO₆ weak field octahedral chromophore. Electronic spectra and magnetic susceptibility measurements reveal octahedral geometry for Ni^II complexes. The elemental analyses and mass spectral data have justified the ML complexes. Kinetic and thermodynamic parameters were computed from the thermal data using Coats and Redfern method, which confirm first order kinetics. The crystal data: C₂₁H₁₉N₃O₈ Ni is orthorhombic, space group P_mmm, a = b = 9.015360(Å), c = 10.554430(Å), V = 572.11A³; C₂₁H₂₃N₃O₈Ni is monoclinic, space group P_2/m, a = 15.08206(Å), b = 5.358276(Å), c = 9.898351(Å), V = 671.58A³; C₂₉H₂₃N₃O₈Ni is tetragonal, space group P_4/m, a = b = 6.328104(Å), c = 9.82213(Å), V = 393.33A³. Molecular structures of the complexes have been optimized by MM2 calculations and supported octahedral arrangements around Nickel(II) ions.     

Synthesis and membrane-protective activity of 2,6-diisobornylphenol derivatives with <Emphasis Type="Italic">N</Emphasis>- and <Emphasis Type="Italic">O</Emphasis>-containing fragments at position 4

Two series of new amide derivatives containing 2,6-diisobornylphenol moiety were synthesized based on 3,5-diisobornyl-4-hydroxybenzoic acid and 4-butylaminomethyl-2,6-diisobornylphenol. Toxicity, membrane-protective (MP) and antioxidant (AO) activity of the obtained compounds were evaluated using red blood cells of laboratory mice as the test object. The tests demonstrated the absence of hemolytic activity for all the synthesized derivatives and the presence of high MP and AO activity under conditions of acute H₂O₂-induced oxidative stress for (3,5-diisobornyl-4-hydroxyphenyl)(morpholino)methanone and N-n-butyl-N-(3,5-diisobornyl-4-hydroxybenzyl)acetamide. A comparison of the data of the newly obtained compounds and those of described earlier 2,6-diisobornylphenol derivatives with N- and O-containing fragments at position 4 (alkoxymethyl, carboxy, and aminomethyl derivatives) led to a conclusion that the most promising for further studies of pharmacological activity are compounds containing methoxycarbonyl, methoxymethyl, ethoxymethyl, morpholinomethyl, di-n-butylaminomethyl, (azepan-1-yl)methyl, or N-acetyl-N-alkylaminomethyl function, which provide low toxicity and high MP and AO activity.     

Spin crossover in homo- and heteroligand iron(II) complexes with tris(pyrazol-1-yl)methane derivatives

The studies concerning coordination compounds of various salts of iron(II) with tris(pyrazol-1-yl)methane derivatives (HC(pz)₃) are discussed. The results of a number of studies on the synthesis and investigation of the homo- and heteroligand iron(II) complexes with tris(3,5- dimethylpyrazol-1-yl)methane (HC(3,5-Me₂pz)₃) are considered. The study of the temperature dependence μ_eff (T) showed that the spin crossover (SCO) ¹A₁?⁵T₂ observed in a series of the compounds discussed is accompanied by thermochromism (color change pink (purple) ? colorless). Specific features of the SCO and their dependence on the outer-sphere anion in the iron(II) complexes are discussed. The data of the recently published work devoted to the synthesis of the iron(II) complexes with three N-substituted HC(pz)₃ derivatives (general formula ^xL, where x = H, CH₂C₆H₅ (Bn) and p-SO₃C₆H₄CH₃ (Ts)) are considered.     

Mononuclear cobalt (III) complexes with <Emphasis Type="Italic">N</Emphasis>-salicylidene-2-hydroxy-5-bromobenzylamine and <Emphasis Type="Italic">N</Emphasis>-salicylidene-2-hydroxy-5-chlorobenzylamine

Cobalt (III) complexes with N-salicylidene-2-hydroxy-5-bromobenzylamine (H₂sbba) and N-salicylidene-2-hydroxy-5-chlorobenzylamine (H₂scba), [n-(C₄H₉)₄N][Co(sbba)₂] (I) and [n-(C₄H₉)₄N][Co(scba)₂] (II), were synthesized. The crystal structure of II was determined by the single-crystal X-ray diffraction method at 90 K confirming its crystallization in the monoclinic space group P2₁/n with a = 11.729(2) Å, b = 16.901(3) Å, c = 21.483(4) Å, β = 98.840(4)°, V = 4208.2(14) ų, D_x = 1.295 g cm^?3, and Z = 4. The R1 [I > 2σ(I)] and wR2 (all data) values of 0.0664 and 0.1920, respectively, for all 9521 independent reflections. The compound is composed of a tetra(n-butyl)ammonium cation and an octahedral cobalt(III) complex anion with two scba^2? ligands in a meridional fashion. The electronic spectral features of I and II are consistent with the octahedral cobalt(III) ion with an N₂O₄ donor set.     

Binuclear copper(II) complexes with acyldihydrazones of <Emphasis Type="Italic">N</Emphasis>-benzenesulfonyl-<Emphasis Type="Italic">L</Emphasis>-aspartic acid

The structure and the EPR spectra of copper(II) coordination compounds with acyldihydrazones of N-benzenesulfonyl-L-aspartic acid and salicylaldehyde (2-hydroxyacetophenone) were described. The compounds were studied by chemical and thermal analyses, IR spectroscopy, and EPR. The molecular and crystal structures of copper(II) complexes with N-benzenesulfonyl-L-aspartic acid bis(salicylidene)hydrazone (H₄L¹) [Cu₂L¹ · 2Py] · 1.5 H₂O was determined by X-ray diffraction. The crystals are triclinic: a = 10.4714(4) Å, b = 12.9702(5) Å, c = 14.6187(9) Å, α = 104.763(2)°, β = 93.082(2)°, γ = 111.4240(10)°, space group P \(\bar 1\), Z = 2. The binuclear complexes containing copper cations whose coordination polyhedra are connected by an aliphatic spacer (Cu...Cu, 8.669 Å) are additionally linked by phenoxy bridges (Cu...Cu, 3.398 Å). The EPR spectra of these compounds in solutions exhibit an isotropic signal of seven HFS lines due to two equivalent copper ions with the spin Hamiltonian parameters g = 2.115?2.120, a _Cu = (35.5?38.0) × 10^?4 cm^?1, which is indicative of weak exchange interactions between the paramagnetic sites.     

Synthesis,crystal structure,and antibacterial activity of oxovanadium(V) complexes derived from <Emphasis Type="Italic">N</Emphasis>'-[1-(5-fluoro-2-hydroxyphenyl)methylidene]nicotinohydrazide and <Emphasis Type="Italic">N</Emphasis>'-(5-fluoro-2-hydroxybenzylidene)-2-hydroxynaphthylhydrazide

Two new oxovanadium(V) complexes, [VOL¹(OCH₃)(CH₃OH)] (I) and [VOL²(OCH₃)] (II), where L¹ and L² are the di-anionic form of N'-[1-(5-fluoro-2-hydroxyphenyl)methylidene]nicotinohydrazide and N'-(5-fluoro-2-hydroxybenzylidene)-2-hydroxynaphthylhydrazide, respectively, have been synthesized and characterized by elemental analysis, FT-IR spectra, and single crystal X-ray determination (CIF files CCDC nos. 891852 (I), 891853 (II)). The crystal of I is monoclinic: space group P2₁/c, a = 8.061(1), b = 15.293(2), c = 13.471(2) Å, ß = 92.595(2)°, V = 1658.8(4) ų, Z = 4. The crystal of II is monoclinic: space group P2₁/n, a = 7.4454(9), b = 8.0833(9), c = 28.906(2) Å, ß = 92.644(2)°, V = 1737.8(3) ų, Z = 4. The V atom in I is in an octahedral coordination, and that in II is in a square-pyramidal coordination. The antibacterial activity of the compounds against various bacteria was assayed.     

Solution Thermodynamics of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis><Superscript>/</Superscript>-Ethylenebis-(salicylideneiminato)-diaquochromium(III) Chloride in Aqueous Dimethylsulphoxide

The densities, viscosities and refractive indices of N,N ^/-ethylene-bis(salicylideneiminato)-diaquochromium(III) chloride, [Cr(salen)(H₂O)₂]Cl, in aqueous dimethylsulfoxide (DMSO) with different mass fractions (w ₂ = 0.20, 0.40, 0.60, 0.80 and 1.00) of DMSO were determined at 298.15, 308.15 and 318.15 K under atmospheric pressure. From measured densities, viscosities and refractive indices the apparent molar volumes (V _φ ), standard partial molar volume (V _φ ⁰ ), the slope (S _V ^* ), standard isobaric partial molar expansibility (φ _E ⁰ ) and its temperature dependence (?φ _E ⁰ /?T) _p , the viscosity B-coefficient, its temperature dependence (?B/?T), solvation number (S _n ) and apparent molar refractivity (R _D ^φ ), etc., were calculated and discussed on the basis of ion–ion and ion–solvent interactions. These results revealed that the solutions are characterized by ion–solvent interactions rather than by ion–ion interactions and the complex behaves as a long range structure maker. Thermodynamics of viscous flow was discussed in terms of transition state theory.     

Crystal and molecular structure of the potassium salt of 2,4-di-<Emphasis Type="Italic">iso</Emphasis>-propoxy-6-dinitromethyl-1,3,5-triazine

An X-ray diffraction study of the potassium salt of 2,4-di-iso-propoxy-6-dinitromethyl-1,3,5-triazine was performed. Monoclinic crystals, C₁₀H₁₄N₅O ₆ ^? ·K⁺; M = 339.36; a = 9.645(2) Å, b = 8.803(2) Å, c = 17.686(3) Å; β = 92.50(2)°; V = 1500.2(5) Å ³, d _c = 1.50 g/cm³, Z = 4, space group P2₁/a. The 2,4-di-iso-propoxy-6-dinitromethyl-1,3,5-triazine anion is nonplanar. The 1,3,5-triazine heterocycle is planar; the angle between the ring and the dinitromethyl fragment is 87.9(5)°. The potassium cation is in the general position; its coordination number is 7. The cation is bonded to four 2,4-di-iso-propoxy-6-dinitromethyl-1,3,5-triazine molecules. Infinite layers are formed due to the coordination bonds in crystal.     

Synthesis of <Emphasis Type="Italic">ortho</Emphasis>-carboranyl derivatives of (<Emphasis Type="Italic">S</Emphasis>)-asparagine and (<Emphasis Type="Italic">S</Emphasis>)-glutamine

(S)-Asparagine and (S)-glutamine ortho-carboranyl derivatives with free amino and carboxy groups in the α-position were synthesized. By an example of N ^γ-(1,2-dicarba-closo-dodecarboran-3-yl)-(S)-glutamine it was demonstrated that the developed synthetic approach carboranyl derivatives of amino acids allowed the preparation of optically pure isomers.     

Synthesis of new <Emphasis Type="Italic">N</Emphasis>-(pyridin-3-ylmethyl)-2-aminothiazoline derivatives possessing anticholinesterase and antiradical activity as potential multifunctional agents for the treatment of neurodegenerative diseases

New N-(pyridin-3-ylmethyl)-2-aminothiazolines containing various substituents at the 5 position of the thiazoline ring and the 4-tert-butylbenzyl, 4-isopropylbenzyl, or 4-fluorobenzyl moiety at the nitrogen atom of the amino group were synthesized. The inhibitory activity of the synthesized compounds against human erythrocyte acetylcholinesterase (AChE, EC 3.1.1.7), equine serum butyrylcholinesterase (BChE, EC 3.1.1.8), and porcine liver carboxylesterase (CaE, EC 3.1.1.1) was evaluated and their antioxidant properties were studied by ABTS assay. N-(Pyridin-3-ylmethyl)-2-aminothiazolines proveded to be very weak AChE inhibitors, while their inhibitory activity against BChE and CaE was structure-dependent. 2-Aminothiazolines containing the 4-tert-butylbenzyl moiety are more efficient BChE inhibitors compared to the derivatives containing the 4-isopropylbenzyl or 4-fluorobenzyl substituent. An analysis of the dependence of the esterase profile of N-(pyridin-3-ylmethyl)-2-aminothiazolines on the structure of the substituent at the 5 position of the thiazoline ring of these compounds demonstrated that the derivatives containing the iodomethyl substituent possess the highest anti-BChE activity, the compounds with R² = H and R³ = CH₂I have the optimal esterase profile. Regardless of the structure of the substituents in the benzyl moiety, all N-(pyridin-3-ylmethyl)-2-aminothiazolines containing the iodomethyl substituent at the 5 position of the thiazoline ring exhibited high radical scavenging activity comparable with that of the standard antioxidant Trolox. N-(Pyridin-3-ylmethyl)-2-aminothiazolines were shown to be a new promising class of compounds for the design of multifunctional agents for the treatment of neurodegenerative diseases.