In the crystalline state, the trinuclear mercury(II) complex [(o-C(6)F(4)Hg)(3)*mu(3)-acetone] forms cofacial dimers which are held by two mercurophilic interactions of 3.51 A. In this form, the complex displays an intense photoluminescence with a sharp emission centered at 480 nm.

A series of adducts formed by the interaction of trimeric perfluoro-ortho-phenylene mercury (2) with various organic carbonyls including acetaldehyde, acetone, acetophenone, and benzophenone have been characterized. The crystal structures of [2· μ 3-acetaldehyde] (3) and [2· μ 3-benzophenone] (7), respectively, reveal the formation of 1:1 complexes in which one molecule of the organic carbonyl is concomitantly coordinated to the three mercury centers of 2 via the oxygen atom. In the benzophenone adduct 7, one of the phenyl rings of the coordinated benzophenone molecule engages in an intramolecular arene−fluoroarene interaction with a tetrafluorophenylene ring of 2 (intercentroid distance:  3.687 Å). When 2 is combined with acetone and acetophenone, adducts [2·(acetone)(μ 3-acetone)2] (4) and [2·(μ 3-acetophenone)2] (6) are obtained. In both cases, two molecules of the ketone are positioned on each side of the planar trifunctional Lewis acid and are complexed via their respective oxygen atom to the three mercury centers of 2. In 4, a third molecule of acetone acts as a terminal ligand and forms a relatively long bond with one of the mercury atoms. In 3, 4, 6, and 7 the Hg−O bonds formed by the triply bridging carbonyl substrate range from 2.813(6) to 3.056(14) and are within the sum of the van der Waals radii of oxygen and mercury. In all cases, the carbonyl stretching vibration of the carbonyl substrate is shifted to a lower wavenumber, which suggests a weakening of the CO bond.

We describe the data-dependent analysis of protein phosphorylation using rapid-acquisition nano-LC-linear quadrupole ion trap Fourier transform ion cyclotron resonance mass spectrometry (nano-LC-FTMS). The accurate m/z values of singly, doubly, and triply charged species calculated from the theoretical protonated masses of peptides phosphorylated at all Ser, Thr, or Tyr residues of the human checkpoint 2 (Chk2) protein kinase were used for selected ion extraction and chromatographic analysis. Using a kinase-inactive Chk2 mutant as a control, accurate mass measurements from FTMS and collision-induced dissociation spectra, 11 novel Chk2 autophosphorylation sites were assigned. Additionally, the presence of additional Chk2 phosphorylation sites in two unique peptides was deduced from accurate mass measurements. Selected ion chromatograms of all Chk2 phosphopeptides gave single peaks except in three cases in which two closely eluting species were observed. These pairs of phosphopeptides were determined to be positional isomers from MS/MS analysis. In this study, it was also found that ions due to the neutral loss of phosphoric acid from the parent peptide ion were not prominent in 18 of 36 MS/MS spectra of O-linked Chk2 phosphopeptides. Thus, accurate mass-driven analysis and rapid parallel MS/MS acquisition is a useful method for the discovery of new phosphorylation sites that is independent of the signature losses from phosphorylated amino acid residues.

Robust gold−carbon nanoparticles were synthesized by the sodium borohydride reduction of the diazonium tetrachloroaurate(III) complex [C 8 F 17 -4-C 6 H 4 NN]AuCl 4 . FT-IR, 1 H NMR, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) of the ruby red gold nanoparticles indicated the absence of the diazonium nitrogen and the presence of the organic shell C 8 F 17 -4-C 6 H 4 . Temperature-dependent Xray powder diffraction (TD-XRD) measurements showed intense cubic gold nanoparticle diffraction patterns in the temperature range 300−500 °C.The effective hydrodynamic size measured by a nanoparticle track analyzer (NTA) in ethanol is 45 nm, and the average core size estimated by transmission electron microscopy (TEM) is 3.2 ± 0.2 nm. The core−shell bonding is strong and is able to withstand prolonged sonication in ethanol and acetonitrile and indefinite exposure to ambient conditions in the solid state.

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