Crystal structure and cytotoxic activities of a bis(pyrrolyl-imine) gold(III) complex

A gold(III) complex with N,N′-ethylenebis(pyrrol-2-yl-methyleneamine) (H₂pyren) was synthesized and characterized by physicochemical and spectroscopic measurements. Density functional theory (DFT) studies and cytotoxic assays were performed. Infrared, mass spectrometry, and ¹H, ¹³C, and {¹⁵N,¹H} nuclear magnetic resonance analyses indicate that pyren is deprotonated and gold(III) is four coordinate in a square planar environment, with the pyrrole and imine nitrogens as donors. The structure was confirmed by powder X-ray diffraction and confirmed as a minimum of the potential energy surface by DFT. Cytotoxic activity of [Au(pyren)]⁺ was active against three tumorigenic cell lines with IC₅₀ values of 35 μM. Interaction studies with CT-DNA by fluorescence and competition with ethidium bromide (EB) showed a quenching of the emission band of DNA with a Stern–Volmer quenching constant value of (3.0 ± 0.1) × 10⁴ M^?1 and a decrease in fluorescence quenching of EB-DNA system, respectively, confirming that DNA is a possible target for the complex via an intercalative binding, which was confirmed by DNA conformational changes observed with circular dichroism spectroscopy.     

Crystal structure of a La(III) complex with macrocyclic cavitand cucurbit[6]uril

Slow evaporation in air of a lanthanum nitrate solution containing macrocyclic cavitand cucurbit[6]uril yields a complex of the composition of [La(H₂O)₆(X@C₃₆H₃₆N₂₄O₁₂)(NO₃)](NO₃)₂· 6.96H₂O (X = 0.5C₅H₅N + 0.5H₂O). The complex is structurally characterized using single crystal X-ray diffraction. Lanthanum atoms are coordinated with oxygen atoms of carbonyl groups of cucurbit[6]uril portals. The compound crystallizes in the orthorhombic crystal system, space group Pnn2, unit cell parameters (150 K): a = 11.997(2) Å, b = 17.093(3) Å, c = 14.133(3) Å, V = 2899.3(10) ų, Z = 2. Lanthanum atoms are disordered, alternative positions being related by the two-fold axis. The complex has an island structure. A pyridine molecule occupies an internal cavity of one half of cucurbit[6]uril molecules, while a water molecule occupies the other.     

Crystal and molecular structure of bis(di-n-propyldithiocarbamato) copper(III) penta-iodide Cu[S2CN(C3H7)2]2I5

Institute of Inorganic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 4, pp. 184–187, July–August, 1989.     

Crystal structure and DNA interaction of the facial-type rac-tris[2-(aminomethyl)benzimidazole]cobalt(III) complex

rac-[Co(ambi)3]Cl3.3H2O corresponds to a tris-chelate complex bearing 2-(aminomethyl)benzimidazole (ambi) ligands bound to the Co(III) ion in a facial-type fashion. The high metal q/r ratio and electronic delocalization between coordination heterocyclic functionalities can provide powerful tools to minimize DNA condensation, which arises from the neutralization of the negatively charged sugar phosphate backbone in the presence of multivalent [Co(ambi)3]3+.     

Crystal structure of [2,6-bis(3,5-dimethyl-N-pyrazolyl)pyridine]-(azido)(chloro)copper(II).

In the title compound, the coordination around the Cu atom is a distorted square-pyramid involving three N atoms from the ligand and one N atom from the azido group at the basal plane. The Cl atom is located at the apical position. The Cu atom is 0.32(5)A above the basal plane. There are three intramolecular and four weak intermolecular hydrogen bonds in the structure. IR spectra confirm the asymmetric N3 stretching vibrations of the terminal azide group.     

Crystal structure of ammonium pentachloroaquaruthenate(III) (NH4)2[Ru(H2O)Cl5]

The structure of ammonium pentachloroaquaruthenate was established by X-ray diffraction analysis. The structure was built of the [Ru(H₂O)Cl₅]^2? complex anions and NH ₄ ⁺ cations. The compound was obtained in the form of dark red fine crystals, which are stable on storage in air.     

Crystal structure of the N,N′,N″-triphenyl-guanidinium-bis-[η5-π-(3)-dicarbollide]Ni(III) complex

Single crystals of a new compound containing triphenylguanidinium and bis(dicarbollide)nickel(III) [C(NHC₆H₅)₃][Ni(B₉C₂H₁₁)₂] are obtained and analyzed by LOW-TEMPERATURE. Crystallographic data are: C₂₃H₄₀B₁₈N₃Ni, M = 611.87, monoclinic system, space group P2₁/c, unit cell parameters: a = 21.9085(5) Å, b = 19.9294(4) Å, c = 14.8721(4) Å, β = 91.4033(9)°, V = 6491,5(4) ų, Z = 8, d _x = 1.252 g/cm³, T = 100 K, F(000) = 2536, μ = 0.621 mm^?1. The structure was solved by direct and Fourier methods and refined by the full matrix least squares technique in the anisotropic/isotropic (for H atoms) approximation up to the final factor R ₁ = 0.053 for 10429 I _hkl ≥ 2σ _I (Bruker X8 APEX diffractometer, {ie547-1} radiation). It contains two independent [C(NHC₆H₅)₃]⁺ cations with different conformations and two [Ni(B₉C₂H₁₁)₂]^? anions with the same transoid conformation. Three types of weak intermolecular interactions are found: {ie547-2}; C-H…π between the H(C) atoms of cluster anions and delocalized π systems of Ph rings of cations; π…π interactions of Ph rings of cation 2 with each other.     

Metal derivatives of thiosemicarbazones: crystal structure of [chloro bis(triphenylphosphino) (thiophene-2-carbaldehyde thiosemicarbazone) copper(I)] complex

Reactions of copper(I) halides (X = Cl, Br, I) with thiophene-2-carbaldehyde thiosemicarbazone and triphenylphosphine in 1 : 1 : 2 molar ratio yield tetrahedral mononuclear complexes, [CuX(η¹-S-Httsc)(Ph₃P)₂] (X = Cl, 1; Br, 2; I, 3), characterized by elemental analysis, IR, NMR (¹H, ¹³C, ³¹P), and single crystal X-ray crystallography (1). The unit cell of 1 has two independent distorted tetrahedral molecules (1a and 1b) with different bond parameters. One acetonitrile is entrapped between them. Crystal data: C₈₆H₇₇Cl₂Cu₂N₇P₄S₄ 1: triclinic, P-1, a = 12.8810(9), b = 18.5049(13), c = 18.7430(13) Å, α = 63.7130(10), β = 89.0960(10), γ = 85.5010(10)°, V = 3992.4(5) ų, Z = 2, R _(int) = 0.0314. Bond parameters: 1a, Cu(1A)–Cl(1A), 2.3803(5); Cu(1A)–S(1A), 2.3822(5); Cu(1A)–P(1A), 2.2498(5) Å; P(1A)–Cu(1A)–P(2A), 124.294(19)°; 1b, Cu(1B)–Cl(1B), 2.3975(5); Cu(1B)–S(1B), 2.3756(5); Cu(1B)–P(1B), 2.2777(5) Å; P(1B)–Cu(1B)–P(2B), 127.156(19)°.     

Crystal structure of indium(III) Schiff base complex

The title compound [In(C₂₂H₃₀N₄O₄)]Cl (I) bis[(N-salicylidene-N′-(2-hydroxyethyl)ethyleneediamine) indium(III) chloride is prepared, and its crystal structure is determined by single crystal X-ray diffraction at room temperature. The complex crystallizes in the monoclinic space group P2₁/n, a = 9.9704(6) ?, b = 24.9554(15) ?, c = 10.5707(6) ?, β = 116.46(2)°, V = 2354.6(2), Z = 4. The X-ray analysis reveals that the In^III ion is surrounded by four nitrogen and two oxygen atoms from two ligands leading to a distorted octahedral geometry. The molecule has the form of tongs at a junction point with the metal. Five membered rings adopt envelope conformation. In the crystal structure, the molecules are linked via N-H...Cl, O-H...O, O-H...Cl, and C-H...Cl intermolecular interactions. The structure is further stabilized by C-H...π (arene) interactions.     

Asymmetric synthesis of glutamic acid from sodium bis[N-salicylideneglycinato]cobaltate(III) and sodium bis[N-3-methylsalicylideneglycinato]cobaltate(III)

Conclusions The reaction of potassium -bis[N-salicylideneglycinato]cobaltate (III) and potassium -bis[N-3-methylsalicylideneglycinato]cobaltate (III) with methyl acrylate in water at pH 11.4 gives a mixture of diastereomeric complexes, and electrochemical reduction of which gives S-glutamic acid in asymmetric yields ranging from 10 to 46%, and a chemical yield that is close to 100% when based on reacted glycine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 428–430, February, 1977.     

Kinetics of substitution at tris-(5-bromo-1,10-phenanthroline)-iron(II) and -iron(III)

Summary Rate constants are reported for several substitutions of the tris-5-bromo-1,10-phenanthroline (5-Brphen) complexes of iron(II) and of iron(III). These reactions include aquation in aqueous solution [iron(II) and iron(III)] and in several series of binary aqueous mixtures [iron(II) only], and reaction with hydroxide and with cyanide [iron(II) only]. Reactivities are compared with those established fot analogous reactions of related complexes, and with thermodynamic parameters of the ligands and complexes.Reprints of this article are not available.     

A quantum chemical study of gallium(III) (μ-oxo)bis[phthalocyaninate] and gallium(III) (μ-oxo)bis[perfluorophthalocyaninate] molecules

By the DFT (U)PBE0 method the structural parameters of molecules, cations, dications, and anions of gallium(III) (μ-oxo)bis[phthalocyaninate], gallium(III) (μ-oxo)bis[perfluorophthalocyaninate], and heteroleptic bis-phthalocyaninate ^FPcGaOGaPc are determined. The ∠GaOGa bond angle and the Ga?Ga internuclear distance depend non-monotonically on the charge. The ionization potential of the (PcGa)₂O molecule of 5.71 eV, the second electron detachment energy of 7.94 eV, and the electron affinity of 2.14 eV increase to 6.14 eV, 8.37 eV, and 2.72 eV after the perfluorination of one Pc moiety and to 6.60 eV, 8.70 eV, and 3.13 eV respectively after complete fluorination.