New Heteroleptic Cobalt Precursors for Deposition of Cobalt-Based Thin Films

A new series of heteroleptic complexes of cobalt were synthesized using aminoalkoxide and ??-diketonate ligands. The complexes, [Co(dmamp)(acac)]2 (3), [Co(dmamp)(tfac)]2 (4), [Co(dmamp)(hfac)]2 (5), [Co(dmamp)(tmhd)]2 (6), and [Co(dmamb)(tmhd)]2 (7), were prepared by two-step substitution reactions and studied using Fourier transform infrared spectroscopy, mass spectrometry, elemental analysis, and thermogravimetric analysis (TGA). Complexes 3-7 displayed dimeric molecular structures for all of the complexes with cobalt metal centers interconnected by ??2-O bonding by the alkoxy oxygen atom. TGA and a thermal study of the complexes displayed high volatilities and stabilities for complexes 6 and 7, with sublimation temperatures of 120 ??C/0.5 Torr and 130 ??C/0.5 Torr, respectively

Facile synthesis of various phosphine-stabilized monodisperse palladium nanoparticles through the understanding of coordination chemistry of the nanoparticles

We developed facile synthetic procedures to produce monodisperse palladium nanoparticles stabilized with various phosphine ligands by a better understanding of their coordination chemistry. Compared to small sized phosphines such as triphenylphosphine (TPP), trioctylphosphine (TOP) showed weaker coordination ability to palladium nanoparticles. This result was ascertained based on the P-31 NMR spectroscopic results of in situ generated molecular palladium complexes. Since TOP acts as a more efficient surfactant in the preparation of high quality monodisperse palladium nanoparticles than smaller sized phosphines, we conducted surfactant exchange reactions of TOP-stabilized palladium nanoparticles in order to produce monodisperse palladium nanoparticles stabilized with various other phosphines. These monodisperse nanoparticles include monodisperse Pd nanoparticles stabilized with chiral ligands and water-dispersable Pd nanoparticles.

Diagnostic strategy for elderly patients with isolated greater trochanter fractures on plain radiographs

Abstract Background Isolated greater trochanter (GT) fractures are relatively rare and few studies have assessed the appropriate diagnostic and therapeutic strategies for these fractures. When initial plain radiographs show an isolated GT fracture, underestimation of occult intertrochanteric extension may result in displacement of a previously non-displaced fracture. This study examined the clinical results and value of different diagnostic strategies in elderly patients with isolated GT fractures on plain radiographs. Methods Between January 2010 and January 2015, 30 patients with initial plain radiographs showing isolated GT fractures were examined using MRI, bone scanning and/or CT for suspected occult intertrochanteric extension. We assessed the sensitivity, specificity, and positive and negative predictive value of each test. In addition, we noted the location of the fracture or soft-tissue injury on MRI in addition to treatment results. Results All 30 patients had osteoporosis and fractures caused by minor trauma. MRI revealed isolated GT fractures in nine patients and occult intertrochanteric fractures in 21 patients. Using the MRI-based diagnosis as a reference, the results showed that plain radiographs, bone scans, and CT scans can be used for supplementary examination but they are not appropriate as confirmatory tests for these fractures. However, in patients with both isolated GT fractures seen on plain radiographs and increased uptake in only the GT area on bone scans, MRI revealed isolated GT fractures. The fractures were treated surgically in 20 patients and conservatively in 10 patients with satisfactory clinical results. Conclusions We confirmed that MRI-based examination is useful in all symptomatic elderly patients whose plain radiographic findings reveal isolated GT fractures. However, we suggest that there is a need to establish a diagnostic strategy through increased understanding of the available diagnostic methods. We believe that surgical treatment should be considered in patients with occult intertrochanteric fractures that are detected on MRI