Long Chain ketimine synthesis in a gold-thallium polymer

The heteropolynuclear complex [Tl{Au(C6Cl5)2}]n reacts with sterically demanding diamines as tetramethylenediamine (TMDA), 2,20-(ethylenedioxy)bis(ethylamine) (NOON), or triethylenetetramine (trien) in 1:1 molar ratio in tetrahydrofuran (THF), leading to products of stoichiometry [Tl{Au(C6Cl5)2}(L)]n (L=TMDA(1),NOON(2), or trien (3)) or [Tl2{Au(C6Cl5)2}2(L)]n (L=trien (4)) when the solvent used is toluene. Addition of acetylacetone to the diamine complexes in 1:1 molar ratio generates [Tl{Au- (C6Cl5)2}{OdC(CH3)CHC(CH3)NH(CH2)4NH2}]n (5) and in 1:2 molar ratio [Tl{Au(C6Cl5)2}(Lx)]n (Lx = {OdC(CH3)CHC(CH3)NHCH2CH2}2 (6), {OdC(CH3)CHC(CH3)NHCH2CH2OCH2}2 (7)). When the molar ratio is 1:2, with the exception of 3, all these complexes display luminescence in the solid state at room temperature and at 77 K. The origin of the luminescence could be assigned to a delocalizated exciton along the heterometallic chain formed by Au3 3 3 Tl interactions. In addition, a red shift is observed when the temperature decreases, which is attributed to the shortening of the Au-Tl distance at lower temperatures.The emissive properties of solutions of 5-7 and [Tl{Au(C6Cl5)2}]n inTHFwere studied after adding increasing amounts of different metal ions (Zn2þ ,Cd2þ ,Hg2þ ,Pb2þ ,Cu2þ ,Al3þ ,Ni2þ ,Ag þ ,Mn2þ , Bi3þ ) and anions (F-, Cl-, Br-, I-, H2PO4 -, ClO4-, Bz-, Ac-, HSO4-, NO3-). Interestingly, an enhancement of the fluorescence emission intensity was observed for the complexes considered only upon addition of Br-, Cl-, and Ac-

The spontaneous formation and plasmonic properties of ultrathin gold-silver nanorods and nanowires stabilized in oleic acid

Ultrathin Au-Ag alloy nanorods and nanowires of different lengths and ca. 1.9 nm diameter are prepared through a low-temperature decomposition of the precursor [Au2Ag2(C6F5)4(OEt2)2]n in oleic acid. This nanostructure formation has been studied through TEM, HRTEM, EDS, HS-SPME-GC-MS and 19F NMR spectroscopy. The UNRs and UNWs display a length-dependent broad band in the mid-IR region that is related to the longitudinal mode of the surface plasmon resonance of the ultrathin nanostructures

Synthesis and plasmonic properties of monodisperse Au-Ag alloy nanoparticles of different compositions from a single-source organometallic precursor

Monodisperse Au-Ag alloy nanoparticles of different compositions are prepared through the mild decomposition of the bimetallic precursor [Au 2Ag2(C6F5)4(OEt 2)2]n in an organic solvent using hexadecylamine (HDA) as a stabilizing ligand. The effects of different reaction parameters on the size and composition of the nanoparticles, such as the metal:HDA ratio, the use of H2 reducing gas or the solvent (toluene, THF or mesitylene), have been studied through TEM, HRTEM, EDS, UV/Vis and 19F NMR spectroscopy. The localized surface plasmon resonance (LSPR) displayed by the spherical Au-Ag nanoparticles can be tuned as a function of the metal composition

Multiple Evidence for Gold(I)center dot center dot center dot Silver(I) Interactions in Solution

[AuAg3(C6F5)(CF3CO 2)3 (CH2PPh3)Jn (2) was prepared by reaction of [Au(C6F5)(CH2PPh3)] (1) and [Ag(CF3CO2)] (1:3). The crystal structures of complexes 1 and 2 were determined by X-ray diffraction, and the latter shows a polymeric 2D arrangement built by Au-Ag, Ag-Ag, and Ag-O contacts. The metallophilic interactions observed in 2 in the solid state seem to be preserved in concentrated THF solutions, as suggested by EXAFS, pulsed-gradient spin-echo NMR, and photophysical studies, which showed that the structural motif [AuAg3(C6F5)(CF3CO2) 3(CH2PPh3)] is maintained under such conditions. Time-dependent DFT calculations agree with the experimental photophysical energies and suggest a metalto-ligand charge-transfer phosphorescence process. Ab initio calculations give an e timated interaction energy of around 60 kJ mol-1 for each Au-Ag interaction. © 2009 Wiley-VCH. Verlag GmbH & Co. KGaA

Experimental and theoretical studies of the d8-d10 interactions between Pd(II) and Au(I): bis(chlorophenylthiomethyldiphenylphosphine gold(I))dichloropalladium(II) and related systems.

The reaction between thioether phosphine gold(I) precursors such as [AuCl(Ph2PCH2SPh)], 1, or [Au(Ph2PCH2-SPh)2]CF3SO3 and PdCl2(NCPh)2 affords the new compounds [{AuCl(Ph2PCH2SPh)}2PdCl2], 2, and [AuPdCl2(Ph2-PCH2SPh)2]CF3SO3, 3. The crystal structure of complex 2 has the sterically unhindered Pd(II) and Au(I) at a distance of 314 pm: Quasirelativistic pseudopotential calculations on [AuPdCl3(PH2CH2SH)(SH2)] models give short Au - Pd distances at the second-order Moller - Plesset (MP2) level and long Au - Pd distances at Hartree - Fock (HF) level. A detailed analysis of the Au - Pd interaction shows dominant dispersion, some ionic contributions, and no net charge transfer between the metals

First-line antiretroviral therapy with a protease inhibitor versus non-nucleoside reverse transcriptase inhibitor and switch at higher versus low viral load in HIV-infected children: An open-label, randomised phase 2/3 trial

Background: Children with HIV will be on antiretroviral therapy (ART) longer than adults, and therefore the durability of first-line ART and timing of switch to second-line are key questions. We assess the long-term outcome of protease inhibitor and non-nucleoside reverse transcriptase inhibitor (NNRTI) first-line ART and viral load switch criteria in children. Methods: In a randomised open-label factorial trial, we compared effectiveness of two nucleoside reverse transcriptase inhibitors (NRTIs) plus a protease inhibitor versus two NRTIs plus an NNRTI and of switch to second-line ART at a viral load of 1000 copies per mL versus 30 000 copies per mL in previously untreated children infected with HIV from Europe and North and South America. Random assignment was by computer-generated sequentially numbered lists stratified by age, region, and by exposure to perinatal ART. Primary outcome was change in viral load between baseline and 4 years. Analysis was by intention to treat, which we defined as all patients that started treatment. This study is registered with ISRCTN, number ISRCTN73318385. Findings: Between Sept 25, 2002, and Sept 7, 2005, 266 children (median age 6\ub75 years; IQR 2\ub78-12\ub79) were randomly assigned treatment regimens: 66 to receive protease inhibitor and switch to second-line at 1000 copies per mL (PI-low), 65 protease inhibitor and switch at 30 000 copies per mL (PI-higher), 68 NNRTI and switch at 1000 copies per mL (NNRTI-low), and 67 NNRTI and switch at 30 000 copies per mL (NNRTI-higher). Median follow-up was 5\ub70 years (IQR 4\ub72-6\ub70) and 188 (71%) children were on first-line ART at trial end. At 4 years, mean reductions in viral load were -3\ub716 log10copies per mL for protease inhibitors versus -3\ub731 log10copies per mL for NNRTIs (difference -0\ub715 log10copies per mL, 95% CI -0\ub741 to 0\ub711; p=0\ub726), and -3\ub726 log10copies per mL for switching at the low versus -3\ub720 log10copies per mL for switching at the higher threshold (difference 0\ub706 log10copies per mL, 95% CI -0\ub720 to 0\ub732; p=0\ub756). Protease inhibitor resistance was uncommon and there was no increase in NRTI resistance in the PI-higher compared with the PI-low group. NNRTI resistance was selected early, and about 10% more children accumulated NRTI mutations in the NNRTI-higher than the NNRTI-low group. Nine children had new CDC stage-C events and 60 had grade 3/4 adverse events; both were balanced across randomised groups. Interpretation: Good long-term outcomes were achieved with all treatments strategies. Delayed switching of protease-inhibitor-based ART might be reasonable where future drug options are limited, because the risk of selecting for NRTI and protease-inhibitor resistance is low. Funding: Paediatric European Network for Treatment of AIDS (PENTA) and Pediatric AIDS Clinical Trials Group (PACTG/IMPAACT). \ua9 2011 Elsevier Ltd