Dušanka D. Radanović

Synthesis, structure and characterization of novel Cd(II) and Zn(II) complexes with the condensation product of 2-formylpyridine and selenosemicarbazide Antiproliferative activity of the synthesized complexes and related selenosemicarbazone complexes.

Two novel Cd(II) and Zn(II) complexes with the condensation product of 2-formylpyridine and selenosemicarbazide were synthesized. The structure of Cd(II) complex was determined by X-ray crystallography. The ligand is coordinated in a neutral form via pyridine and azomethine nitrogen atoms and the selenium donor. The cadmium ion completes its five-coordination by two chloride ligands, forming a square-pyramidal geometry. The structure of Zn(II) complex was established by analysis of spectroscopic data, which indicated coordination of the ligand as a bidentate via the selenium and the azomethine nitrogen atoms. The cytotoxic activity of the newly synthesized complexes, as well as if five structurally related complexes and the ligand evaluated against eight tumor cell lines. The new Cd(II) complex showed the highest activity similar to cisplatin with IC50 less than 10muM for all cell lines. Cell cycle distribution and apoptosis study showed that Cd(II) complex and cisplatin might have some similarity in anticancer activity, which was not the case for cisplatin and other studied complexes. Effects of the complexes on matrix metalloproteinases (MMPs) MMP-9 and MMP-2 was also studied. Cd(II) and Zn(II) complexes and cisplatin increased MMP-2 activity in supernatants of tested cells, while Ni(II) complex with the same ligand decreased the activity, implying a possible activity in preventing tumor invasion and metastasis processes.

Simple synthetic method and structural characteristics of (1,3-propanediaminetetraacetato)cobalt(II) complexes: uniform crystal packing in a series of metal(II) complexes with 1,3-propanediaminetetraacetate ligand

Abstract Starting from Ba[Ba(1,3-pdta)]·2H2O three new hexadentate cobalt(II) complexes [MII(H2O)6][CoII(1,3-pdta)]·2H2O (MII=Ba (1), Co (2) and Mg (3)) (where 1,3-pdta represents the 1,3-propanediaminetetraacetate ion) have been prepared and characterized. Presented in this paper, the crystal structures of the complexes containing CoII and MgII counter cations are isomorphic, as are the other crystal structures of metal(II) complexes with 1,3-pdta ligand, so far reported in the literature. The complexes crystallize in the space group Pnna of the orthorhombic crystal system. The structural unit consists of discrete [CoII(1,3-pdta)]2− and [MII(H2O)6]2+ octahedra, and two water solvent molecules all of which lie on a twofold axis of symmetry. The complex cations and anions alternate in the crystal lattice each being octahedrally surrounded by the counter ions. Electronic absorption spectra of [CoII(1,3-pdta)]2− complexes are presented and discussed in terms of octahedral distortion in edta-type CoII complexes.

Synthesis and X-ray structural study of magnesium (1,3-propanediaminetetraacetato)cuprate(II) octahydrate, Mg[Cu(1,3-pdta)]·8H2O.: Stereochemistry of hexadentate copper(II)–edta-type complexes in relation to the structure of the ligand

Abstract The hexadentate complex Mg[Cu(1,3-pdta)]·8H2O (1) (where 1,3-pdta represents the 1,3-propanediaminetetraacetate ion) has been prepared and isolated and its structure established by X-ray crystallography. The structure converged to R=0.030 for 1537 observed reflections. The Cu(II) ion is surrounded by two nitrogen atoms and four oxygen atoms of the ligand, making a tetragonally elongated octahedron (T=0.868). The Mg cation is bonded octahedrally to six water molecules. Both complex ions utilize a two-fold symmetry axis that is present in the crystal. The conformations of the chelate rings were found to be envelope for the glycinates and skew-boat for the six-membered diamine (T) ring. Comparison of the structures of the hexadentate copper(II)–edta-type complexes shows an expected variation in their stereochemistry, depending on the structure of the ligand. Infrared (carboxylate region) and electronic absorption spectra are also given.

The favored trans(O6) geometry in hexadentate copper(II) complexes of 1,3-propanediamine-N,N′-diacetic-N,N′-di-3-propionic acid. Crystal structure of trans(O6)-Na2[Cu(1,3-pddadp)]·NaNO3·2H2O. Strain analysis and spectral assignments of complexes

The octahedral copper(II) complexes of 1,3-propanediamine- N,N′- diacetic- N,N′- di-3-propionic acid (H 4 1,3-pddadp) prepared in the region of pH 2 to 7 are hexadentates. Only one ( trans ( O 6 )) of the three geometrical isomers was found to dominate. The trans ( O 6 )-Na 2 [Cu(1,3-pddadp)]·NaNO 3 ·2H 2 O complex crystallizes in the space group P 2/ c of the monoclinic crystal system with a =9.231(2), b= 11.736(14), c =10.150(2) A, β =109.33(2)° and Z =2. The conformations of the chelate rings are found to be envelope for the glycinate and skew-boat for the β-alaninate and 1,3-propanediamine rings. The complex is a tetragonally elongated octahedron ( T ∼0.8) with C 2 molecular symmetry. IR (carboxylate region) and electronic absorption spectra are assigned and discussed in relation to the structure of complexes. For hexadentate Cu(II) edta-type complexes of known structures the strain analysis is also discussed.

SQUARE-PYRAMIDAL COPPER(II) COMPLEXES OF LINEAR TETRADENTATE EDDA-TYPE LIGANDS FORMING SIX-MEMBERED RINGS. MOLECULAR STRUCTURES OF CU(1,3-PDDA) (H2O) AND CU(EDDP) (H2O).3.5H2O

Abstract Three square-pyramidal copper(II) complexes containing a linear O-N-N-O-type tetradentate ligand have been prepared and characterized. The ligands used are 1,3-propanediamine-N,N′-diacetate ion (1,3-pdda), ethylenediamine-N,N′-di-3-propionate ion (eddp) and 1,3-propanediamine-N,N′-di-3-propionate ion (1,3-pddp). In the three compounds a water molecule is in the axial position while the four atoms of ligand are in the basal plane. A five-coordinate, square-pyramidal geometry has been established crystallographically for the complexes [Cu(1,3-pdda)(H2O)] (1) (orthorhombic, Pnma, a = 8.937(4), b = 11.770(5), c = 10.269(5) A, V = 1080.2(8) A3, Z = 4 and R = 0.0699) and [Cu(eddp)(H2O)]·3.5H2O (2) (monoclinic, C2/c, a = 24.430(8), b = 12.195(3), c = 10.514(2) A, β = 110.92(2) V = 2926(1) A3, Z = 8 and R = 0.0515). The Cu(II) ions of these structures are lifted out of plane of the four in-plane ligand atoms by distances ϱ = 0.182(5) and 0.154(1) A, respectively. The six-membered diamine ring of complex 1 assumes the stable chair conformation. The other rings of chelates have expected conformations. The structural data correlating the square-pyramidal stereochemistry are discussed in relation to those obtained for similar complexes. The IR and electronic absorption spectra of [Cu(edda-type)(H2O)] complexes are discussed in comparison with those of related complexes of known geometries. The magnetic measurements are also reported for the complexes studied.

Preparation and molecular structure of the trans(O6) isomer of dihydrogen (1,3-propanediamine-N,N′-diacetato-N,N′-di-3-propionato)copper(II) complex. The stereochemistry of copper(II)-edta-type complexes in relation to the structure of the ligand

Abstract The hexadentate complex [Cu(H21,3-pddadp)] · 1.5H20 (1,3-pddadp = 1,3-propanediamine-N,N′-diacetate-N,N′-di-3-propionate ion) has been prepared and isolated and its molecular structure determined by the single crystal X-ray diffraction technique. The complex is a trans(O6) isomer, in which the copper(II) ion is surrounded octahedrally by two nitrogen and four oxygen atoms of 1,3-pddadp with two protonated β-alaninate rings in trans positions. The copper atom environment is a tetragonally elongated octahedron with tetragonality (T) 0.798. A comparison of structures of the copper(II)-edta-type complexes shows an expected variation in their stereochemistry, depending on the structure of the ligand. The 1,3-pddadp ligand encircles the CuII ion more favourably than the edta ligand, which is capable of forming five-membered chelate rings only. Some properties of the complex are also given.

Square-pyramidal copper(II) chelate complexes of edta-type and related ligands forming six-membered rings. Crystal structure of magnesium (ethylenediamine-N,N,N′-tri-3-propionato-N′-3-propionate)copper(II) decahydrate, Mg[Cu(edtp)]·10H2O

Abstract Two square-pyramidal complexes, Mg[Cu(edtp)]·10H2O (1) (edtp=ethylenediamine-N,N,N′,N′-tetra-3-propionate ion, acting as a pentadentate) and Mg[Cu(ed3p)]2·6H2O (2) (ed3p=ethylenediamine-N,N,N′-tri-3-propionate ion) have been prepared and characterized. A square-pyramidal geometry was established crystallographically for the complex Mg[Cu(edtp)]·10H2O (1). The Cu(II) ion in the complex anion is displaced by 0.195 A from the plane of the four in-plane (2N and 2O) ligand atoms towards the apical oxygen atom of the β-alaninate (R) ring (CuOax=2.173 A). The conformations of the chelate rings are those usually expected for these kinds of chelates (a five-membered diamine (E) ring in a twist(λ) conformation, two β-alaninate (G1 and G2) rings in a distorted twist-chair and one β-alaninate (R) ring in a distorted twist-boat conformation). The structural data correlating the square-pyramidal stereochemistry are discussed with reference to those obtained for related complexes. Electronic absorption and reflectance spectra are discussed in comparison with those of related complexes of known structures. IR data (carboxylate region) are also reported.

Synthesis, crystal structures and antimicrobial activity of azido and isocyanato Zn(II) complexes with the condensation product of 2-quinolinecarboxaldehyde and Girard’s T reagent

Abstract Two Zn(II) complexes with the condensation product of 2-quinolinecarboxaldehyde and trimethylammonium acetohydrazide chloride (Girard’s T reagent) (HLCl) and monodentate pseudohalides (azide and cyanate) have been synthesized and characterized by elemental analysis, IR and NMR spectroscopy, and single-crystal X-ray diffraction. In both complexes, the coordination surroundings of the Zn(II) ions consist of a deprotonated hydrazone ligand coordinated through an NNO set of donor atoms and two monodentate pseudohalides (N3– or NCO–) at the remaining coordination sites. The Zn(II) complexes showed low to moderate activity against laboratory control strains of pathogenic bacteria and fungi.

Synthesis, characterization, DFT calculations and antimicrobial activity of pentagonal-bipyramidal Zn(II) and Cd(II) complexes with 2,6-diacetylpyridine-bis(trimethylammoniumacetohydrazone)

Abstract Isothiocyanate complexes of Zn(II) and Cd(II) with the condensation product of 2,6-diacetylpyridine and trimethylammoniumacetohydrazide (Girard’s T reagent) were synthesized, characterized, and their antimicrobial activities were evaluated. The structures of the complexes were determined by elemental analysis, IR, and NMR spectroscopy. The crystal structure of the Zn(II) complex was also determined. Quantum-chemical calculations of the geometry and total energy of isomers of 2,6-diacetylpyridine-bis(trimethylammoniumacetohydrazone) were performed in vacuum and methanol solution, with the aim to explain conformational behavior and E/Z isomerism of this compound. DFT calculations of the molecular structures and the relative stabilities of linkage isomers of the Cd(II) complex showed that the isomer with N–Cd–N coordination of SCN− is the most stable. Complexes of Zn(II) and Cd(II) exhibited low to moderate activity against the tested microbial strains.

Synthesis, characterization and antimicrobial activity of pentagonal-bipyramidal isothiocyanato Co(II) and Ni(II) complexes with 2,6-diacetylpyridine bis(trimethylammoniumacetohydrazone)

Abstract Pentagonal-bipyramidal isothiocyanato Co(II) and Ni(II) complexes with condensation product of 2,6-diacetylpyridine and trimethylammoniumacetohydrazide (Girard’s T reagent) were synthesized and characterized by elemental analyses, IR and UV–vis spectra, molar conductivity, and magnetic susceptibility. Crystal structures of the Co(II) and Ni(II) complexes were also determined. Antimicrobial activities of the ligand and metal complexes were examined.