Ion/molecule reactions of the protonated serine octamer

The protonated homochiral octamer of serine exchanges all 33 of its labile hydrogens with CH(3)OD and undergoes ligand switching reactions with amines in a quadrupole ion trap mass spectrometer.     

Specific chemical behavior of NdII and DyII iodides in reactions with aromatic compounds

Benzene, toluene, tert-butylbenzene, or biphenyl virtually do not react with NdI₂ (1) or DyI₂ (2) in THF at –20 °C but appreciably accelerate the reactions of these salts with solvents, resulting in LnI₃ and intractable mixtures of products of the general composition [LnI(H)(R)(THF)] (R are fragments of the THF molecule). The same effect is induced by the addition of diphenylmercury or tetraphenyltin to solutions of 1 or 2. Phenol easily oxidizes 1 and 2 to give at 0 °C the PhOLnI₂(THF) _x complexes (x = 3, 4) in 55—95% yields. At –90 °C, iodide 2 is converted into a similar complex PhODyI₂(THF)₄, whereas 1 gives a mixture of PhONdI₂(THF)₄, (PhO)₂NdI(THF)₅, NdI₃(THF)₃, and [NdI(H)R(THF)]. A plausible pathway of the reactions including the intermediate formation of extremely reactive monovalent lanthanide iodides LnI is discussed.     

Study of thermochemical properties of lanthanides pentafluorophenolates with coordination ligands

Saturated vapor pressure of lithium pentafluorophenolate and the lanthanide complexes as a function of temperature has been determined by the Knudsen effusion method. Processing of the pressure data allowed the calculation of thermodynamic parameters of the compounds sublimation. Mass spectra and differential scanning calorimetry data are presented.     

Investigations into beam monitors at the AEg ̄ IS experiment

Detailed diagnostic of antiproton beams at low energies is required for essentially all experiments at the Antiproton Decelerator (AD), but will be particularly important for the future Extra Low ENergy Antiproton ring (ELENA) and its keV beam lines to the different experiments. Many monitors have been successfully developed and operated at the AD, but in particular beam profile monitoring remains a challenge. A dedicated beam instrumentation and detector test stand has recently been setup at the AE \(\bar {g}\) IS experiment (Antimatter Experiment: Gravity, Interferometry, Spectroscopy). Located behind the actual experiment, it allows for parasitic use of the antiproton beam at different energies for testing and calibration. With the aim to explore and validate different candidate technologies for future low energy beam lines, as well as the downstream antihydrogen detector in AE \(\bar {g}\) IS, measurements have been carried out using Silicon strip and pixel detectors, a purpose-built secondary emission monitor and emulsions. Here, results from measurements and characterization of the different detector types with regard to their future use at the AD complex are presented.     

Reduction of nitrogen with neodymium(II) and dysprosium(II) diiodides and selected properties of the resulting nitrides

The diiodides NdI₂ and DyI₂ react with nitrogen at an atmospheric pressure at 2704-550 °C to give the nitrides (LnI₂)₃N (Ln = Nd and Dy). The products obtained are insoluble in organic solvents; in THF, they rapidly disproportionate into LnI₃(THF)₃ and the iodide nitrides (NdI)₃N₂ of unclear structures. The nitrides (NdI₂)₃N and (DyI₂)₃N can be completely hydrolyzed into ammonia, the triiodide hydrates LnI₃(H₂O)₂, and the monoiodide hydrates LnI(OH)₂(H₂O). A reaction of (NdI₂)₃N with excess iodobenzene in THF gives Ph₃N and PhNH₂ in 9 and 5% yields, respectively. Reactions of (NdI₂)₃N with propyl chloride, benzyl chloride, and acetyl chloride produce no nitrogen-containing products. A reaction of (NdI₂)₃N with CpK gives Cp₃Nd(THF) in 63% yield.