Synthesis, crystal structure, and magnetic properties of a nitronyl nitroxide biradical-coordinated copper(II) complex

A coordination compound constructed from a nitronyl nitroxide biradical NITPh(3-NIT) and CuII(hfac)2(H2O)2 building blocks [NITPh(3-NIT) = 1,3-bis(1′-oxyl-3′-oxido-4′,4′, 5′, 5′-tetramethyl-4,5-dihydro-1 H-imidazol-2-y1)-benzene, hfac = hexafluoroacetylacetonato] is successfully synthesized. The crystal structure is determined by X-ray single-crystal diffraction. The asymmetric complex {[(NITPh(3-NIT)]Cu(hfac)2} consists of one Cu(II) ion and two >N–O• groups and adopts a distorted triangular bipyramid with a penta-coordinated central copper(II) atom and three hfac oxygen atoms at the base and a >N–O• oxygen atom and one hfac oxygen atom at the apices. Intramolecular O. . .O bonding and π–π stacking interactions are observed between molecules. A magnetic susceptibility study of the coordination compound shows antiferromagnetic interactions between Cu(II) ions and >N–O• groups and very weak ferromagnetic interactions between Cu(II) ions and the free >N–O• group through O. . .O bonding between the nitroxide group oxygen atom and the oxygen atom of hfac.

Theoretical methods for measuring chemo-physical properties of nucleic acids during the oxidation of DNA and the incidence of cancer

The purpose of this papers is to investigate theoretical methods to measure the chemo-physical properties of nucleic acids during DNA radicalization and cancer incidence. For this purpose, structures consisting of DNA nucleotides were considered and all structures were optimized using DFT at the CAM-B3LYP / 6-31G level and spatial parameters such as bond length, HOMO and LUMO orbitals, and thermodynamic parameters were obtained, as well as NMR spectroscopy. The results showed that the guanine base had better conditions for oxidation compared to other bases. Also in the NMR calculations using the GIAO method we were able to examine the single and double chain structure in different states when it is natural and abnormal. Therefore, in this work, we try to find a normal relationship between chemical displacement and the rate of natural state DNA aberration, by studying the comparison of isotropic and anisotropic parameters with respect to DNA bases such as adenine, guanine, cytosine, thymine. It was concluded that the skewness (η) is between (0.1) and the skewness is between (1-1), which can be correlated with the abnormalities of the DNA base from the normal to abnormal state. It was also found that the phosphate group oxygen atom in the abnormal form showed most of the changes in these parameters compared to the natural form.

Halogen bonding of the aldehyde oxygen atom in cocrystals of aromatic aldehydes and 1,4-diiodotetrafluorobenzene

Novel halogen bonded cocrystals of aromatic aldehydes have been synthesized. We present the halogen bond acceptor potential of the aldehyde group oxygen atom in competition with the hydroxy, methoxy and pyridine groups.

Structural Systematics of Rare Earth Complexes. I. Structural Characterization of Lanthanoid(III) Picrate Hydrates: Monoclinic (P21/C) (Quasi-)Dodecahydrates of the Related La → Pr and Nd → Tb Families

Single-crystal room-temperature X-ray studies on hydrated specimens (deposited from aqueous solutions) of the sequence of trivalent lanthanoid picrates La → Tb have shown, with certain qualifications/reservations discussed herein and in Parts III and IV following, their existence as dodecahydrates in two closely related but subtly different monoclinic P21/c structural types. Nd → Tb generally conform to a 'low-β' type: a 7.767(1) → 7.603(3), b 27.525(9) → 27.440(10), c 18.198(11) → 18.182(8) Ǻ, β 105.11(3) → 105.18(4)°, V 3712(3) → 3674(3) Ǻ3, Z = 4 formula units, while La → Pr are a 'higher-β' type: a 7.933(1) → 7.9435(9), b 26.856(6) → 26.74(1), c 18.244(6) → 18.215(2) Ǻ, β 107.96(2) → 108.238(8)°, V 3697(2) → 3675(2) Ǻ3, Z = 4 formula units; the latter form is frequently found partially desolvated toward the undecahydrate without loss of crystal integrity, as water is lost from tunnels in the lattice, with the actual hydrate stoichiometry dependent on the history of the specimen. In both sets of compounds, similar complex species [ Ln ( pic )2(OH2)6]+ are observed, with one picrate uncoordinated as counter ion, and six lattice water molecules. The lanthanoid ion is >8-coordinate, one of the coordinated picrate moieties being quasi-bidentate , with an ortho-nitro group oxygen atom having a long contact to the metal atom in both series.