Pyrolyses of the anion dihydridotetracarbonylrhenate. Crystal and molecular structure of bis(tetraethylammonium) μ-hydrido-dodecacarbonyl-triangulo-trirhenate(2—)

The pyrolyses of [NEt₄][H₂Re(CO)₄] in boiling n-heptane, n-octane and n-nonane are described. Mixtures of polynuclear carbonyl- and hydridocarbonylrhenium species are obtained, the principal products being [Re₄(CO)₁₆]^2?, [H₂Re₃(CO)₁₂], [H₃Re₃(CO)₁₀]^2?, [H₃Re₃O(CO)₉]^2? and [H₆Re₄(CO)₁₂]^2?. A red-orange crystalline species was isolated from the reaction in n-heptane and shown by X-ray diffraction to be [Net₄]₂[HRe₃(CO)₁₂]. It gives orthorhombic crystals, space group Pbca, with cell constants a 16.07(1), b 23.39(2), c 19.49(1) Å. The structure was solved by Patterson and Fourier methods and refined by least-squares up to a final R value of 0.061, for 1303 independent counter data. The anion [HRe₃(CO)₁₂]^2? contains an isosceles metal atom triangle, with two short edges of 3.014(3) and 3.018(3) Å and a long hydrogen-bridged edge of 3.125(3) Å.     

Combined mass quantitation and phenotyping of intact extracellular vesicles by a microarray platform

The interest towards extracellular vesicles (EVs) has grown exponentially over the last few years; being involved in intercellular communication and serving as reservoirs for biomarkers for tumors, they have a great potential for liquid biopsy development, possibly replacing many costly and invasive tissue biopsies.     

Alkaline phosphatase enzymatic signal amplification for fast, sensitive impedimetric DNA detection

Enzymatic signal amplification by the deposition of insoluble product on the electrode surface enhances impedimetric DNA detection sensitivity. This work demonstrates a method which gives the required detection sensitivity at significantly reduced enzyme reaction times, and demonstrates the capability for DNA SNP discrimination of biologically relevant sequences. This opens up the prospect of more rapid and relevant multiparameter impedimetric bioassays.     

In-beam Mössbauer spectroscopy:57Fe in Si and Ge

Fe has been studied in the semiconductors Si and Ge with the Coulomb excitation recoil implantation technique in a wide temperature range. In the case of Fe inSilicon it was found that one third of the implanted atoms land on interstitial sites. The long range diffusion of these atoms could be observed microscopically at temperatures around 600 K. The isomer shift of interstitial Fe in Si was determined. The remaining atoms exhibit a strong quadrupole splitting on disturbed sites. This component seems to relax into a state with higher symmetry above 700 K. InGermanium a similar situation is found. Whereas iron on disturbed sites dominates the spectra, the direct implantation into interstitial sites is also observed below 200 K. At higher temperatures the substitutional position is preferred. The isomer shifts for interstitial and substitutional Fe in Si and in Ge are in good agreement with calculated electron densities.     

Mixed Ruthenium–Iridium Carbonyl Cluster Complexes. Synthesis of the Anions [Ru3Ir2(CO)14]2− and [Ru3Ir2(CO)14H]− and Crystal Structures of Their [tetraphenylphosphonium]+ Salts

The reaction of Ru₃(CO)₁₂ and [Ir(CO)₄]^- (as [PPh₄]⁺ or [N(PPh₃)₂]⁺ salts) yields the anion [Ru₃Ir₂(CO)₁₄]^2- (1) which has been found to derive from the intermediate [Ru₃Ir(CO)₁₃]^- anion. Treatment of (1) with acids gives the conjugated hydrido species [Ru₃Ir₂(CO)₁₄H]^- (2). The two anions were characterized by single-crystal X-ray diffraction of their [PPh₄]⁺ salts. [PPh₄]₂[Ru₃Ir₂(CO)₁₄]: space group C2/c, Z=4, a=22.121(5) Å, b=10.546(5) Å, c=25.931(5) Å, =103.870(5)°, R=0.052 and R_w=0.130 for 3128 independent reflections with I>2(I ). [PPh₄][Ru₃Ir₂(CO)₁₄H]: space group P2₁/c, Z=8, a=22.833(5) Å, b=13.893(5) Å, c=25.810(5) Å, =92.650(5)°, R=0.070 and R_w=0.150 for 12141 independent reflections with I>2(I). Both anions 1 and 2 have a trigonal bipyramidal metal frame. There are two independent anions in the asymmetric unit of 2 differing in their ligand stereochemistry.     

High nuclearity PtRh carbonyl clusters. Synthesis and X-ray characterization of the [Pt2Rh9(CO)22]3− trianion

The new mixed PtRh cluster trianion [Pt₂Rh₉(CO)₂₂]^3? has been isolated as a minor product of the pyrolysis of [PtRh₅(CO)₁₅]^?, and has been characterized by X-ray diffraction. The metal skeleton, which has ideal D_3h symmetry, consists of three face-to-face condensed octahedra, as previously found in the isoelectronic species [Rh₁₁CO)₂₃]^3?, with the Pt atoms on the three-fold axis, in the positions of maximum MM connectivity.     

Reaction of the unsaturated anion [Re3H4(CO)10]− with mercaptans. Synthesis and X-ray Characterization of the anion [ Re3H3 (CO)9(μ3-SBut)]−

The novel anion [Re₃H₃(CO)₉(μ₃-SBu^t)]^?, obtained by reaction of [Re₃H₄(CO)₁₀]^? with t-butyl mercaptan, has been characterized by IR, NMR and X-ray diffraction studies. It contains an equilateral Re₃ triangle (mean ReRe 3.091 Å), with nine terminal carbonyl groups, three for each metal atom, and a triply-bridging thiolate ligand (mean ReS 2.393 Å). The three hydrides are bridging on the edges of the triangle of metal atoms.