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Item CRYSTAL STRUCTURE OF MONOPROTONATED NI(II) NITRILOTRIACETATE TETRAHYDRATE(2004) Petrenko, Peter A.; Gdaniec, Maria; Simonov, Iurie; Stăvilă, Vitalie; Gulea, AurelianA Ni(II) complex of the composition Ni(HNta)·4H 2O (I) was synthesized. Its structure was found to consist of neutral mononuclear [Ni(HNta)(H 2O) 3] complexes and crystallization water molecules. The Ni atom has octahedral surrounding and is coordinated to tridentate-chelate HNta 2- ligand through the N atom and O atoms of two deprotonated acetate groups and through the O atoms of three water molecules. The structure of I was compared with those of the Zn(HNta)·4H 2O and Co(HNta)·4H 2O complexes isostructural to I. Thermogravimetric method showed that the decomposition of compound I occurs through several successive stages of dehydration, deaquation, decarboxylation, and the formation of inorganic residue.Item SYNTHESIS AND STRUCTURE OF DI(M-OPHENOXY )-BIS{NITRATO-2-[2- (HYDROXYETHYLIMINO)-METHYL]-PHENOLOIMIDAZOLECOPPER}(2004) Ciumacov, Iurie; Antoșciac, Boris; Țapcov, Victor; Bocelli, Gabrielle; Gulea, AurelianThe crystal structure of di(μ-O phenoxy)-bisnitrato-2-[2- (hydroxyethylimino)-methyl]-phenoloimid-azolecopper was determined. The crystals are monoclinic: a = 10.222(2) , b = 13.810(3) , c = 10.620(2) , β =103.67(3)°, space group P2 1/n, Z = 2, R = 0.050. The copper atom coordinates the singly deprotonated 2-[2-(hydroxyethylimino)-methyl]-phenol molecule, imidazole, and nitrate ion. The coordination polyhedron of the central atom is an extended tetragonal bipyramid with imine and imidazole nitrogen atoms and phenol and alcohol oxygen atoms lying in its base. One axial vertex of the bipyramid is occupied by the oxygen atom of the nitrato group and the other vertex, by phenol oxygen atom of the neighboring complex joined with the initial complex by the symmetry center. Two bridging phenol oxygen atoms unite the complexes into a centrosymmetrical dimer.Item LANTHANIDE COMPLEXES WITH N , N '-BIS(2- HYDROXYBENZYLIDENE)-2-HYDROXYPHENYLMETHANEDIAMINE(2004) Samusi, Nina; Strelcov, Eugeniu; Țapcov, Victor; Gulea, AurelianComplexes of lanthanides with N,N′-bis(2-hydroxybenzylidene)-2- hydroxyphenylmethanediamine (H3L) were synthesized and investigated by the elemental, IR, magnetochemical, and thermogravimetric methods. Using the data obtained, they were found to have compositions Ln2L 2·nH2O and La2L2· MCl2·4H2O (Ln = La3+, Pr3+, Nd3+, Dy3+, Er3+; M = Cu2+, Co 2+, Ni2+; n = 4, 6). Suggestions on their structures were made. In the interval of 20-140°C, these complexes were shown to be high-resistance semiconductors.Item SYNTHESIS, STRUCTURE AND PROPERTIES OF SOME 3D-ELEMENT COMPLEXES WITH 2-[2-(HYDROXYBENZYLIDENE)-AMINO]-2-HYDOXYMETHYLPROPANE-1,3-DIOL(2004) Țapcov, Victor; Ciumacov, Iurie; Antoșciac, Boris; Bocelli, Gabrielle; Samusi, Nina; Gulea, Aurelian2-[2-(Hydroxybenzylidene)-amino]-2-hydoxymethylpropane-1,3-diol (HL) reacts with cobalt, nickel, copper and zinc chlorides, bromides and acetates in water-ethanol solutions and gives MLX·nH2O and ML 2·nH2O complexes (M = Co, Ni, Cu, Zn; X = Cl, Br; n = 0-5). Single crystals of CuLBr were grown, and its crystal structure was determined by X-ray diffraction analysis. The crystals are tetragonal, a = 17.024(2), c = 8.720(2) Å, space group P421c, Z = 8, R 1 = 0.0349. In the structure of this complex, the copper atom coordinates the deprotonated HL molecule. The coordination polyhedron of the central atom is an elongated tetragonal pyramid. Its base is built of the imine nitrogen atom, phenolic and alcoholic oxygen atoms, and bromine atom. The apex of the pyramid is occupied by the bromine atom of the adjacent complex connected with the initial complex by the plane of sliding reflection. Thus, the crystal contains infinite chains of complexes running along the c axis, the complexes being united by both bridging bromine atoms and O-H⋯O hydrogen bonds. The conclusions on the compositions and structures of the remaining compounds were made on the basis of elemental and combined thermal analyses, IR spectroscopy, and magnetic chemistry data. The copper halide complexes were found to have dimeric, and the other metal complexes monomeric, structures. In the synthesized complexes, the azomethine HL can function as a bidentate or tridentate ligand. The thermolysis of the coordination compounds proceeds through the stages of elimination of crystal water molecules (75-90°C) or inner-sphere water molecules (145-155°C) and complete thermal destruction (485-550°C).Item SYNTHESIS AND STUDY OF HETEROMETALLIC CO–BI COMPOUNDS BASED ON ETHYLENEDIAMINETETRAACETIC ACID. CRYSTAL AND MOLECULAR STRUCTURES OF [CO(DH)2(O -NH2C6H4CH3)2]2[BI2(M-EDTA)2(H2O)2] • 10H2O (DH2 IS DIMETHYLGLYOXIME)(2002) Stăvilă, Vitalie; Gulea, Aurelian; Șova, Sergiu; Gdanec, M.; Simonov, IurieCompounds of the [Co(DH)2A2](BiEdta)·6H 2O type (where DH is the monodeprotonated dimethylglyoxime -ON=C(CH3)-(CH3)C=NOH; A is the o-, m-, or p-toluidine; and Edta is the ethylenediaminetetraacetate(4-) ion) were synthesized and studied. The composition and structures of the complexes were determined from their UV and 1H NMR spectra and from X-ray diffraction data. The isomer [Co(DH)2(o-NH2C 6H4CH3)2]2[Bi 2(μ-Edta)2(H2O)2]·10H 2O was structurally characterized using X-ray diffraction analysis. The crystals are triclinic: a = 12.153(2) Å, b = 12.824(3) Å, c = 16.215(3) Å, α = 67.73(3)°, β = 86.18(3)°, γ = 66.96(3)°, space group P1̄ , ρ(calcd) = 1.719 g/cm3, Z = 4. The structure is composed of complex binuclear [Bi2(μ-Edta) 2(H2O)2]2- anions, [Co(DH) 2(o-NH2C6H4CH3) 2]+ cations, and molecules of crystallization water. The Edta4- anion chelates with the Bi atom in a hexadentate manner (N2O4); the fifth O atom functions as a bridging ligand. The bismuth coordination polyhedron can be regarded as a strongly distorted antiprism. In the octahedral cation, the Co(III) atom coordinates four N atoms of two DH ligands (average Co-N 1.897 Å) and two N atoms of two o-toluidine molecules (Co-N 2.023 Å). Thermolysis of the complexes studied was found to proceed in several successive steps, namely, the deaquation, deamination, and pyrolysis of the ligands.Item SYNTHESIS AND STRUCTURE OF {M-OXALATO-BIS[ETHYLENEDIAMINETETRAACETATO- BISMUTHATO(III)]}PENTAAMMINETHIOCYANATOCOBALT(III) DODECAHYDRATE, [CO(NH3)5NCS]2[(EDTA)BI(M-C2O4)BI(EDTA)] • 12H2O(2000) Stăvilă, Vitalie; Gdanec, M.; Șova, Sergiu; Simonov, Iurie; Gulea, Aurelian; Vignacourt, Jean-PierreA heterometallic complex of cobalt(III) and bismuth(III), [Co(NH3)5NCS]2[(Edta)Bi(μ-C2O4)Bi(Edta)] · 12H2O, was synthesized and studied by X-ray diffraction analysis. The crystals are monoclinic, a = 12.792(3) Å, b = 9.792(2) Å, c = 22.945(5) Å, β = 92.92(3)°, P(calcd) = 1.970 g/cm3, space group P21/c, Z = 4. The complex has an isle structure composed of [(Edta)Bi(μ-C2O4)Bi(Edta)]4- and [Co(NH3)5NCS]2+ complex ions and molecules of crystallization water. The Edta4- ligand functions as a hexadentate chelating (2N + 40) agent, while the oxalate ion acts as a bridging ligand. The thiocyanate ion is coordinated to cobalt(III) through the N atom, while the cation interacts with the anion via the Bi-S contact (3.571 Å). Hence, the coordination polyhedron of Bi can be regarded as a tricapped trigonal prism. It was shown that thermolysis of the complex proceeds in several stages, viz., the deaquation, deamination, and pyrolysis of its ligands.Item SINTEZA ȘI CERCETAREA PROPRIETĂȚILOR FARMACOFORE ALE UNOR N-(DIMETILFENIL) HIDRAZINCARBOTIOAMIDE(2023) Erhan, Tatiana; Garbuz, Olga; Ungur, Nicon; Gulea, AurelianThe present study was focused on the synthesis of some N-(dimethylphenyl)hydrazine carbothioamides 1-4, that contain the following N-substituents: 2,4-dimethylphenyl; 2,5-dimethylphenyl; 2,6-dimethylphenyl; 3,4-dimethylphenyl, to increase lipophilicity and N-(dimethylphenyl)-2-(pyridin-2-ylmethylidene)hydrazinecarbothioamides 5-8, analogous of Triapine. The structural formula of the compounds was characterized by means of spectroscopy: FT-IR, 1H-, and 13CRMN, and the molecular structure, for the first time, by means of X-ray diffraction. The study of antioxidant activity has shown that all compounds 1-8 are powerful antioxidants. N-(dimethylphenyl)-2-(pyridin2-ylmethylidene)hydrazinecarbothioamides 5-8 were tested as inhibitors of MCF-7 (breast cancer) cell proliferation. It was found that all the compounds exhibit activity comparable to that of Doxorubicin, among them the compound N-(2,5-dimethylphenyl)-2-(pyridin-2-ylmethylidene)hydrazinecarbothioamide 6, with IC50=0.8 μM/L, demonstrated the highest activity.Item SINTEZA COMBINAȚIILOR COORDINATIVE NOI ALE UNOR METALE 3D ÎN BAZA N(4)-(ACETAT DE ETIL) TIOSEMICARBAZONELOR 2-FORMIL ȘI 2-ACETIL PIRIDINEI. PROPRIETĂȚI ANTIOXIDANTE(2022) Rusnac, Anna; Garbuz, Olga; Șova, Sergiu; Gulea, AurelianThe given work includes the description of methods for the synthesis of new coordinative combinations of Cu(II), Mn(II), Fe(III) Co(III), Ni(II) and Zn(II) with N(4)-(ethyl acetate) thiosemicarbazones of 2-formylpyridine and 2-acetylpyridine. The characterization of the newly synthesized compounds was carried out using 1H NMR, 13C NMR, FTIR spectroscopy, conductivity, and elemental analysis. In addition, the structures of N(4)-(ethyl acetate) thiosemicarbazide and N(4)-(ethyl acetate) thiosemicarbazone 2-acetylpyridine (HL2) were determined using single crystal X-ray diffraction. The antioxidant activity of coordinative combinations was studied and compared with that of free ligands. The most pronounced antioxidant properties are possessed by [Ni(L2)Cl], whose value of IC50=15,05 μM is three times higher than the IC50=46,76 μM of the non-coordinating ligand and about 2,5 times higher than the reference substances Rutin and Trolox.Item STUDY OF THE SYNTHESIS METHODS OF 1,3-ARYL(HETERYL)PROPENONE(CEP USM, 2022) Popușoi, AnaIn this work, we refer to the study of recent specialized literature, where some syntheses methods of chalcone deri- vatives are described. These substances show a very pronounced anticancer activity, having a protective action in the cellular system. They present interest due to their biological properties, such as anti-inflammatory, antioxidant, cytotoxic and antihistamine properties, etc. These important biological properties are the basis of the current research intended to obtain them synthetically. The bibliographic data refers to the synthesis of 1,3-aryl (heteryl) propenones, which are described in several reviews. The main focus is on the synthesis methods of chalcones, which allow us to obtain pure reaction products, short reaction time and high yields. Also, synthesis methods with the use of solid-based heterogeneous catalysts are described, which, in turn, are very active, durable and more economical and can be used for three synthesis cycles, without significant loss of catalytic activity. The synthesis methods studied were: aldol and crotonic condensation, Claisen-Schmidt reaction, Suzuki reaction, coupling of alkynes with aldehydes, microwave irradiation, etcItem STUDY OF THE SYNTHESIS METHODS OF 1,3-ARYL(HETERYL)PROPENONE(CEP USM, 2022) Popushoi, AnaIn this work, we refer to the study of recent specialized literature, where some syntheses methods of chalcone derivatives are described. These substances show a very pronounced anticancer activity, having a protective action in the cellular system. They present interest due to their biological properties, such as anti-inflammatory, antioxidant, cytotoxic and antihistamine properties, etc. These important biological properties are the basis of the current research intended to obtain them synthetically. The bibliographic data refers to the synthesis of 1,3-aryl (heteryl) propenones, which are described in several reviews. The main focus is on the synthesis methods of chalcones, which allow us to obtain pure reaction products, short reaction time and high yields. Also, synthesis methods with the use of solid-based heterogeneous catalysts are described, which, in turn, are very active, durable and more economical and can be used for three synthesis cycles, without significant loss of catalytic activity. The synthesis methods studied were: aldol and crotonic condensation, Claisen-Schmidt reaction, Suzuki reaction, coupling of alkynes with aldehydes, microwave irradiation, etc.