Near-infrared emitting copper(I) complexes with a pyrazolylpyrimidine ligand: exploring relaxation pathways.

Mononuclear copper(I) complexes [CuL]I (1), [CuL][CuI]·2MeCN (2) and [CuL]PF (3) with a new chelating pyrazolylpyrimidine ligand, 2-(3,5-dimethyl-1-pyrazol-1-yl)-4,6-diphenylpyrimidine (L), were synthesized. In the structures of complex cations [CuL], Cu ions coordinate two L molecules (,-chelating coordination). Extended π-systems of the L molecules in [CuL] favor the formation of paired π-π stacking intramolecular interactions between the pyrimidine and phenyl rings leading to significant distortions of tetrahedral coordination cores, CuN.

Surface-Enhanced IR-Absorption Microscopy of Bacteria on Bactericidal Nanostructured Si Surfaces.

Surface-enhanced IR absorption (SEIRA) microscopy was used to reveal main chemical and physical interactions between bacteria and different laser-nanostructured bactericidal Si surfaces via simultaneous chemical enhancement of the corresponding IR-absorption in the intact functional chemical groups. A cleaner, less passivated surface of Si nanoripples, laser-patterned in water, exhibits much stronger enhancement of SEIRA signals compared to the bare Si wafer, the surface coating of oxidized Si nanoparticles and oxidized/carbonized Si (nano) ripples, laser-patterned in air and water. Additional very strong bands emerge in the SEIRA spectra on the clean Si nanoripples, indicating the potential chemical modifications in the bacterial membrane and nucleic acids during the bactericidal effect.