Simultaneous SERS detection of copper and cobalt at ultratrace levels.

We report a SERS-based method for the simultaneous and independent determination of two environmental metallic pollutants, Cu(ii) and Co(ii). This was achieved by exploiting the coordination-sensitive Raman bands of a terpyridine (TPY) derivative for detecting transition metal ions. Changes in the vibrational SERS spectra of dithiocarbamate anchored terpyridine (TPY-DTC) were correlated as a function of each metal ion concentration, with limits of detection comparable to those of several conventional analytical methods.

Calculation of the molecular and atomic properties of selected anions in water.

The polarizability and other properties have been studied for F(-), Cl(-), Br(-), and HCOO(-) in water using a combined quantum chemical statistical mechanics simulation model that explicitly takes into account the Pauli repulsion as well as the electrostatic coupling between the QM system and the classical surroundings. It is shown that the surrounding molecules significantly reduce both the polarizability and the size of the anions. For the formate ions, local properties have been computed.

Planar or nonplanar: what is the structure of urea in aqueous solution?

A combined quantum chemical statistical mechanical method has been used to study the solvation of urea in water, with emphasis on the structure of urea. The model system consists of three parts: a Hartree-Fock quantum chemical core, 99 water molecules described with a polarizable force-field, and a dielectric continuum. A free-energy profile along the transition of urea from planar to a nonplanar structure is calculated.

Inter- and intramolecular potential for the N-formylglycinamide-water system. A comparison between theoretical modeling and empirical force fields.

An intramolecular NEMO potential is presented for the N-formylglycinamide molecule together with an intermolecular potential for the N-formylglycinamide-water system. The intramolecular N-formylglycinamide potential can be used as a building block for the backbone of polypeptides and proteins. Two intramolecular minima have been obtained.