Crystal structure of trans-diaqua-bis(methyl methylcarbamohydrazonothioato-κ2 N,N′) nickel(II) iodide semihydrate, C6H22N6O2NiS2I2·0.5H2O

C6H23I2N6NiO2.50S2, monoclinic, C2/c (no. 15), a = 8.2282(4) Å, b = 21.9200(7) Å, c = 11.4906(4) Å, β = 109.451(4)°, V = 1954.19(14) Å3, Z = 4, Rgt (F) = 0.0322, wRref (F 2) = 0.1113, T = 295.

Mannich bases of 1,2,4-triazole-3-thione containing adamantane moiety: Synthesis, preliminary anticancer evaluation, and molecular modeling studies

A series of 18 novel N-Mannich bases derived from 5-adamantyl-1,2,4-triazole-3-thione was synthesized and characterized using NMR spectroscopy and X-ray diffraction technique. All derivatives were evaluated for their anticancer potential against four human cancer cell lines. Several tested compounds exerted good cytotoxic activities on K562 and HL-60 cell lines, along with pronounced selectivity, showing lower cytotoxicity against normal fibroblasts MRC-5 compared to cancer cells. The effects of compounds 5b, 5e, and 5j on the cell cycle were investigated by flow cytometric analysis. It was found that these compounds cause the accumulation of cells in the subG1 and G1 phases of the cell cycle and induce caspase-dependent apoptosis, while the anti-angiogenic effects of 5b, 5e, and 5j have been confirmed in EA.hy926 cells using a tube formation assay. Further, the interaction of Bax protein with compound 5b was investigated by means of molecular modeling, applying the combined molecular docking/molecular dynamics approach.

(E)-4-[(2-Carbamoylhydrazinylidene)methyl]-3-hydroxy-5-hydroxymethyl-2-methylpyridin-1-ium nitrate

The title compound, C9H13N4O3+·NO3−, is the first structurally characterized Schiff base derived from semicarbazide and pyridoxal. Unusually for an unsubstituted semicarbazone, the compound adopts asynconformation, in which the carbonyl O atom is in acisdisposition relative to the azomethine N atom. This arrangement is supported by a pair of hydrogen bonds between the organic cation and the nitrate anion. The cation is essentially planar, with only a hydroxymethyl O atom deviating significantly from the mean plane of the remaining atoms (r.m.s. deviation of the remaining non-H atoms = 0.01 Å). The molecules are linked into flat layers by N—H...O and C—H...O hydrogen bonds. O—H...O hydrogen bonds involving the hydroxymethyl group as a donor interconnect the layers into a three-dimensional structure.

Synthesis, characterization and antitumor activity of polymeric copper(II) complexes with thiosemicarbazones of 3-methyl-5-oxo-1-phenyl-3-pyrazolin-4-carboxaldehyde and 5-oxo-3-phenyl-3-pyrazolin-4-carboxaldehyde

New polymeric copper(II) complexes with two tridentate ONS thiosemicarbazone ligands containing substituted pyrazolone moiety were synthesized and characterized by means of spectroscopic, electrochemical and crystallographic techniques. While both ligands exist as different tautomers in the solid state and DMSO-d(6) solution, Cu(II) ion coordinates the ligands from the same tautomeric form with square-pyramidal geometry around each Cu atom. In the crystal structures, the copper(II) complex cation forms polymeric chains {[Cu(L)Cl](+)}(n) with a bridging chlorine atom. One of the complexes was found to have a significantly higher cytotoxic potential in comparison with cisplatin in inhibition of several cell lines (HL60, REH, C6, L929 and B16). The results obtained on the basis of flow cytometry indicated that apoptosis could be possible mechanism of cell death.

Synthesis, Structural, DFT, and Cytotoxicity Studies of CuII and NiII Complexes with 3-Aminopyrazole Derivatives

Template synthesis of N,N′-bis(4-acetyl-5-methylpyrazole-3-yl)formamidine (ampf) was performed starting from 4-acetyl-3-amino-5-methylpyrazole (aamp) and CH(OC2H5)3 in methanol in the presence of CuCl2, Cu(NO3)2, or Ni(NO3)2. The ligand was isolated in coordinated form as [Cu(ampf)Cl2], [Cu(ampf)(MeOH)(NO3)2]MeOH, and [Ni(ampf)(MeOH)2(NO3)]NO3 correspondingly. The compounds were characterized by elemental analysis, Fourier-transform IR and electronic spectroscopy, thermal analysis, single-crystal X-ray diffraction, and quantum chemical (density functional theory) calculations. The density functional theory calculations provided information on the metal–ligand interactions in the complexes and assisted the assignment of the FT-IR spectra. The antiproliferative activity of the complexes and the ligand precursor, aamp, was tested against human myelogenous leukaemia K562, colon adenocarcinoma HT29, and cervix carcinoma HeLa.

{4-[(Carbamimidoylhydrazono)methyl-kappa2N1,N4]-5-hydroxymethyl-2-methylpyridinium-3-olate-kappaO}(methanol-kappaO)copper(II) dinitrate

The title compound, [Cu(C(9)H(13)N(5)O(2))(CH(4)O)](NO(3))(2), consists of square-planar cationic complex units where the Cu(II) centre is coordinated by an N,N',O-tridentate pyridoxal-aminoguanidine Schiff base adduct and a methanol molecule. The tridentate ligand is a zwitterion exhibiting an almost planar conformation. The dihedral angles between the mean planes of the pyridoxal ring and the six- and five-membered chelate rings are all less than 2.0 degrees. The charge on the complex cation is neutralized by two nitrate counter-ions. Extensive N-H...O and C-H...O hydrogen bonding connects these ionic species and leads to the formation of layers. The pyridoxal hydroxy groups are the only fragments that deviate significantly from the flat layer structure; these groups are involved in O-H...O hydrogen bonding, connecting the layers into a three-dimensional crystal structure.

FT-IR and theoretical study of 3,5-dimethyl-1H-pyrazole-1-carboxamidine (L) and the complexes CoL2(H2O)2(NO3)2, NiL2(H2O)2(NO3)2

In the paper a joint experimental and theoretical study of 3,5-dimethyl-1H-pyrazole-1-carboxamidine (L) as well as its complexes CoL2(H2O)2(NO3)2 and NiL2(H2O)2(NO3)2 is reported. On the basis of FT-IR experiments and a DFT-derived scaled quantum mechanical force field the normal coordinate analysis of L was carried out. The FT-IR spectra of the two complexes were interpreted using the present assignment of L and computed vibrational data of the complexes. The ionic and charge transfer interactions in the complexes were assessed by means of natural bond orbital (NBO) analysis.

Synthesis, spectroscopic and X-ray characterization of a copper(II) complex with the Schiff base derived from pyridoxal and aminoguanidine: NMR spectral studies of the ligand

A copper(II) complex with the pyridoxal-aminoguanidine (PL-AG) Schiff base adduct, as an organic compound of the very potent biological activity and promising pharmacological importance in the treatment of diabetic complications, has been prepared and characterized. The X-ray structural analysis of the [CuCl2(PL-AG)] complex showed that it has a distorted pseudo-square-pyramidal (4+1) structure with the tridentate ONN Schiff base in the equatorial plane, with the Cu-O(1), Cu-N(1) and Cu-N(3) bond lengths of 1.917(2)A, 1.930(2)A and 1.984(2)A, respectively. The bond length of the equatorial Cu-Cl(1) is 2.279(1)A, while that of the apical Cu-Cl(2) is 2.792(1)A. Pyridoxal fragment is coordinated in its zwitterionic form. In addition to the X-ray structural analysis, the complex was characterized by IR spectrometric, conductometric and magnetic techniques, and the ligand itself by IR, 1H and 13C NMR spectra.

Copper(II) Complexes with Reduced Schiff Base: Synthesis, Spectroscopic, Thermal, X-Ray, and Cytotoxic Studies of Novel Copper(II) Complexes with an Arylpyrazole Ligand

The synthesis of a novel arylpyrazole-derived ligand, 1,2-bis[(1,3-diphenylpyrazol-4-yl)methyl]diaminoethane (Ph4Pz2mde), and its complexes prepared with CuCl2 [Cu(Ph4Pz2mde)Cl2(MeOH)] 1, CuBr2 [Cu(Ph4Pz2mde)Br2(MeOH)] 2, from MeOH, and [Cu(Ph4Pz2mde)Cl2(DMF)] 3, from a mixture of MeOH and DMF, are described. The complexes are characterized by elemental and thermal analysis and FT-IR spectroscopy, while the 1H and 13C NMR assignments are given for the ligand. The crystal and molecular structure of [Cu(Ph4Pz2mde)Cl2(DMF)] was determined by single-crystal X-ray diffraction. In-vitro cytotoxicity of the Ph4Pz2mde ligand and two copper(ii) complexes was obtained using sulforhodamine B (SRB) treatment against three human tumour cell lines: HeLa (epitheloid carcinoma of cervix), MCF-7 (breast adenocarcinoma), and MRC-5 (lung fetal fibroblasts).

Transition metal complexes with thiosemicarbazide-based ligands. LIII. [4-(2-Diphenylphosphino-α-ethoxybenzyl-κP)-S-methyl-1-(4-oxidopent-3-en-4-ylidene-κO)thiosemicarbazido-κ2N1,N4]nickel(II)

The title compound, [Ni(C(28)H(30)N(3)O(2)PS)], crystallizes with two independent molecules in the asymmetric unit. The Ni(II) atoms are in significantly deformed square-planar environments formed by an ONNP donor set from a thiosemicarbazide-based tetradentate ligand. The Ni(II) atom and the ONN donor atoms are nearly coplanar, while the P atom deviates from their mean planes by 0.278 (4) and 0.202 (4) Angstrom for the two independent molecules. The P-containing chelate rings are remarkably non-planar, adopting a boat conformation, which is unusual for chelate rings in transition metal complexes with thiosemicarbazide-based tetradentate ligands. The orientation of the ethoxy group bonded to this chelate ring is caused by an intramolecular C-H...pi interaction with the opposing phenyl ring. There are no hydrogen bonds; instead, numerous intermolecular C-H...pi interactions dominate in the crystal packing.

Transition metal complexes with pyrazole-based ligands. XXII. Di-μ-thiocyanato-bis[(3,5-dimethyl-1H-pyrazole-1-carboxamidine-κ2N,N′)(thiocyanato-κN)copper(II)] and a redetermination of bis(3,5-dimethyl-1H-pyrazole-1-carboxamidine-κ2N,N′)bis(nitrato-κO)copper(II)

The title Cu(II) complex, [Cu2(NCS)4(C6H10N4)2], represents the first crystal structure of a polynuclear transition metal complex with the 3,5-dimethyl-1H-pyrazole-1-carboxamidine ligand (HL). It is compared with previously reported crystal structures of metal complexes with the same HL ligand. The molecule contains an eight-membered binuclear Cu2(NCS)2 ring, which is centrosymmetric and in a chair conformation. The Cu atom has a distorted square-pyramidal geometry with a very elongated Cu-S bond of 2.993 (2) A. The crystal structure redetermination of the bis(3,5-dimethyl-1H-pyrazole-1-carboxamidine-kappa(2)N,N')bis(nitrato-kappaO)copper(II)complex, [Cu(NO3)2(C6H10N4)2], and analysis of its hydrogen bonds confirm the significance of the NO3 groups in the formation of a three-dimensional hydrogen-bonding network. Both complexes are centrosymmetric, the inversion centre being located at the mid-point of the Cu...Cu line in (I) and the Cu atom being located at the inversion centre in (II).