Old Acquaintances and Novel Complex Structures for the Ni(II) and Cu(II) Complexes of -Chelate Oxime-Amide Ligands.

In the process of systematically studying the methylhydroxyiminoethaneamide -chelate ligands with polymethylene spacers of different lengths, L1-L3, and their transition metal complexes, a number of new Ni(II) and Cu(II) species have been isolated, and their molecular and crystal structures were determined using single-crystal X-ray diffraction. In all of these compounds, the divalent metal is coordinated by the ligand donor atoms in a square-planar arrangement. In addition, a serendipitously discovered new type of neutral Ni(II) complex, where the propane spacer of ligand L2 underwent oxidation to the propene spacer, and one of the amide groups was oxidised to the ketoimine, is also reported.

Do nonbonded H--H interactions in phenanthrene stabilize it relative to anthracene? A possible resolution to this question and its implications for ligands such as 2,2'-bipyridyl.

The problem of whether interactions between the hydrogen atoms at the 1,10-positions in the "cleft" of the "bent" phenanthrene stabilize the latter molecule thermodynamically relative to "linear" anthracene, or whether the higher stability of phenanthrene is due to a more energetically favorable π-system, is considered. DFT calculations at the X3LYP/cc-pVTZ(-f)++ level of the ground state energies (E) of anthracene, phenanthrene, and the set of five benzoquinolines are reported. In the gas phase, "bent" phenanthrene was computed to be thermodynamically more stable than "linear" anthracene by -28.

DNA binding of a proflavine derivative bearing a platinum hanging residue.

New platinum(II) complex of 3,6-diamine-9-[6,6-bis(2-aminohethyl)-1,6-diaminohexyl]acridine, AzaPt, has been synthesised and characterised. Behaviour of AzaPt in solution (protonation and possible self-aggregation phenomena) has been investigated by spectral methods (absorbance and fluorescence) at I=0.1M and 25°C, and the equilibrium parameters of binding to calf thymus DNA have been established.

Ethyl (2E)-2-(hydroxy-imino)propanoate.

The mol-ecule of the title compound, C(5)H(9)NO(3), is essentially planar [the maximum deviation for a non-H atom from the mean plane is 0.021 (3) Å] due to the π-conjugation of the hydroxy-imino and carbonyl groups, which are trans to each other; ab initio calculations in vacuo at the DFT (B3LYP/6-311G**++) level of theory confirmed that E conformer is indeed the lowest in energy. The packing in crystal structure is influenced by strong inter-molecular O-H⋯N hydrogen-bonding inter-actions between oxime groups and also by π-stacking of the mol-ecules due to the carbonyl and oxime group orbital overlap [inter-planar distance between adjacent mol-ecules = 3.