Ligand Degradation Study of Unsymmetrical β-Diketiminato Copper Dioxygen Adducts: The Length Chelating Arm Effect.

An investigation on the reactivity of O binding to unsymmetrical β-diketiminato copper(I) complexes by spectroscopic and titration analysis was performed. The length of chelating pyridyl arms (pyridylmethyl arm vs pyridylethyl arm) leads to the formation of mono- or di-nuclear copper-dioxygen species at -80 °C. The pyridylmethyl arm adduct (CuO) forms mononuclear copper-oxygen species and shows ligand degradation, resulting in the formation of (2,3)--(2,6-diisopropylphenyl)-4-((()-pyridin-2-ylmethylene)amino)pent-3-en-2-imine, which slowly converts to its cyclization isomer 1-(2,6-diisopropylphenyl)-4,6-dimethyl-2-(pyridin-2-yl)-1,2-dihydropyrimidine after addition of NHOH at room temperature.

Reactivity Study of Unsymmetrical β-Diketiminato Copper(I) Complexes: Effect of the Chelating Ring.

β-Diketiminato copper(I) complexes play important roles in bioinspired catalytic chemistry and in applications to the materials industry. However, it has been observed that these complexes are very susceptible to disproportionation. Coordinating solvents or Lewis bases are typically used to prevent disproportionation and to block the coordination sites of the copper(I) center from further decomposition.

Chicken HSP70 DNA vaccine inhibits tumor growth in a canine cancer model.

Immunization with xenogeneic DNA is a promising cancer treatment to overcome tolerance to self-antigens. Heat shock protein 70 (HSP70) is over-expressed in various kinds of tumors and is believed to be involved in tumor progression. This study tested a xenogeneic chicken HSP70 (chHSP70) DNA vaccine in an experimental canine transmissible venereal tumor (CTVT) model.