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The synthesis and characterization of cct-RuH(SH)2(CO)2(PPh3)2 is described. The ruthenium (II) complex is formed by the treatment of THF solutions of cct-RuH2(CO)2(PPh3)2 or Ru(CO)2(PPh3)3 with H2S. Structural analysis shows that the complex crystallizes in the space group P1. The location of the mercapto protons are shown and indicates non-participation in SH/pi interactions with the phenyl rings. In addition, a mechanism for the H/D exchange reactions of the ruthenium-mercapto complex is proposed.

The surface structure of the (square root of 3 X square root of 3)-R30 degree dodecanethiolate self-assembled monolayers (SAMs) on Au(111) surfaces, formed from the liquid phase, is analyzed. By considering the length of the hydrocarbon chain and the adsorption time, the two-site model can be used as a tool to describe the controversial results obtained in this experiment.

Linear free energy relationships can be used to examine the ozonolysis reaction. Observations are made on systems(super 1-3) and a range of para and meta substituents of styrenes. The experiments are performed at 25 degrees centigrade while noting the process of ozonolysis. The study finds that the route of intermediate trioxolane is free from the effect of the styrene substitute.

A strategy based on postcolumn electrophoretic mobility control (EMC) was developed to alleviate the adverse effect of trifluoroacetic acid (TFA) on the liquid chromatography-mass spectrometry (LC-MS) analysis of peptides. The device created to achieve this goal consisted of a poly(dimethylsiloxane) (PDMS)-based junction reservoir, a short connecting capillary, and an electrospray ionization (ESI) sprayer connected to the outlet of the high-performance liquid chromatography (HPLC) column. By apply different voltages to the junction reservoir and the ESI emitter, an electric field was created across the connecting capillary. Due to the electric field, positively charged peptides migrated toward the ESI sprayer, whereas TFA anions remained in the junction reservoir and were removed from the ionization process. Because TFA did not enter the ESI source, ion suppression from TFA was alleviated. Operation of the postcolumn device was optimized using a peptide standard mixture. Under optimized conditions, signals for the peptides were enhanced 9-35-fold without a compromise in separation efficiency. The optimized conditions were also applied to the LC-MS analysis of a tryptic digest of bovine serum albumin. [ABSTRACT FROM AUTHOR]

Raman mapping measurements were performed on the cross section of the ternary-phase biodegradable double-walled microsphere (DWMS) of poly(D,L-lactide-co-gly-colide) (50:50) (PLGA), poly(L-lactide) (PLLA), and polyfc-caprolactone) (PCL), which was fabricated by a one-step solvent evaporation method. The collected Raman spectra were subjected to a band-target entropy minimization (BTEM) algorithm in order to reconstruct the pure component spectra of the species observed in this sample. Seven pure component spectral estimates were recovered, and their spatial distributions within DWMS were determined. The first three spectral estimates were identified as PLLA, PLGA 50:50, and PCL, which were the main components in DWMS. The last four spectral estimates were identified as semicrystalline polyglycolic acid (PGA), dichloromethane (DCM), copper-phthalocyanine blue, and calcite, which were the minor components in DWMS. PGA was the decomposition product of PLGA. DCM was the solvent used in DWMS fabrication. Copper-phthalocyanine blue and calcite were the unexpected contaminants. The current result showed that combined Raman microscopy and BTEM analysis can provide a sensitive characterization tool to DWMS, as it can give more specific information on the chemical species present as well as the spatial distributions. This novel analytical method for microsphere characterization can serve as a complementary tool to other more established analytical techniques, such as scanningelectron microscopy and optical microscopy. [ABSTRACT FROM AUTHOR]