Ru(II) bipyridine complexes were synthesized and their spectroscopic properties studied. The replacement of 2,2‘-bipyridine (bpy) by 6,6‘-dimethyl-substituted 2,2‘-bipyridine (dmbpy) is suggested to change the steric and electronic factors involved in these complexes, which in turn affect the coordination ability of Ru. In the case of thiocyanate ligand, the metal center is able to coordinate to either its S or N end, the bonding mode being dependent on both steric and electronic factors.

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The ability of noble metal-based nanoparticles (NPs) (Au, Ag) to drastically enhance Raman scattering from molecules placed near metal surface, termed as surface-enhanced Raman scattering (SERS), is widely used for identification of trace amounts of biological materials in biomedical, food safety and security applications. However, conventional NPs synthesized by colloidal chemistry are typically contaminated by nonbiocompatible by-products (surfactants, anions), which can have negative impacts on many live objects under examination (cells, bacteria) and thus decrease the precision of bioidentification. In this article, we explore novel ultrapure laser-synthesized Au-based nanomaterials, including Au NPs and AuSi hybrid nanostructures, as mobile SERS probes in tasks of bacteria detection. We show that these Au-based nanomaterials can efficiently enhance Raman signals from model R6G molecules, while the enhancement factor depends on the content of Au in NP composition. Profiting from the observed enhancement and purity of laser-synthesized nanomaterials, we demonstrate successful identification of 2 types of bacteria (Listeria innocua and Escherichia coli). The obtained results promise less disturbing studies of biological systems based on good biocompatibility of contamination-free laser-synthesized nanomaterials.

The triarylphosphanes, (o‐thiomethylphenyl)diphenylphosphane (SP, 1), (o‐N,N′‐dimethylaminophenyl)diphenylphosphane (NP, 2), and (o‐methoxyphenyl)diphenylphosphane (OP, 3) have been structurally characterized. Detailed information on the stereochemistry of the ligands was gathered by spectroscopic (1H, 31P, 13C NMR) and X‐ray crystallographic studies. Molecular modeling methods for investigation of the structures were also applied. It is shown that the geometrical optimization of the ligand can be performed accurately by the ab initio Hartree−Fock method. Furthermore, the steric contribution of the coordinated ligands can be estimated by studying the different conformational states of the free ligands. The coordination abilities of the ligands were studied in reactions with the rhodium compounds Rh2(CO)4Cl2 and Rh(NO3)3 under different reaction conditions. The SP and NP ligands yielded mononuclear chelate complexes, while the OP ligand coordinated solely in a monodentate fashion through the phosphorus atom. The crystal structures of the ligands 1−3 and the rhodium(I) complexes [RhCl(CO)(NP)] (5) and [RhCl(CO)(OP)2] (6) are reported.