Synthesis and characterization of a new layered gallium phosphate [Co(en)3][Ga3(H2PO4)6(HPO4)3] templated by cobalt complex

A new layered gallium phosphate [Co(en)₃][Ga₃(H₂PO₄)₆(HPO₄)₃], denoted as GaPO-CJ14, has been synthesized solvothermally by using a racemic mix of chiral metal complex Co(en)₃Cl₃ as a template. Its structure was determined by single-crystal X-ray diffraction analysis and further characterized by X-ray powder diffraction, ICP, and TG analyses. The compound crystallizes in the monoclinic space group P2₁/m (No. 11) with a=9.2103(3), b=22.0936(8), c=9.5458(4) Å, β=108.278(2)°, Z=2, R₁=0.0497 and wR₂=0.1122 for all data. The inorganic layer is built up by alternation of Ga-centered octahedra (GaO₆) and P-centered tetrahedra (PO₃(OH), PO₂(OH)₂ , PO₂(O)(OH) and PO(O)(OH)₂) forming a 4.12-net. The sheet structure is featured by a series of structural units composed of two centrosymmetrically related [3.3.3] propellane-like chiral motifs. The metal complex cations locate in the interlayer region and interact with the host network through H-bonds.     

Reaktionen des Gallium‐haltigen Heterocyclus [Me2Ga{HNC(Me)}2CCN]

Reactions of the Gallium‐containing Heterocycle [Me₂Ga{HNC(Me)}₂CCN] The reaction of [Me₂Ga{HNC(Me)}₂CCN] ( 1 ) with fac‐[Mo(CO)₃(MeCN)₃] leads after addition of TMEDA to the molybdenum complex fac‐[Mo(CO)₃( 1 )(TMEDA)] ( 2 ). Under identical reaction conditions with fac‐[W(CO)₃(MeCN)₃] only the tetracarbonyle complex [W(CO)₄(TMEDA)] ( 3 ) could be isolated. Treatment of dilithiated 1 with Me₂SiCl₂ or InCl₃ initiate a fragmentation of the skeleton in 1 . Obtained were the salt [Me₂Ga(TMEDA)][Me₂GaCl₂] ( 4 ) and the indium complex [Me₂InCl(TMEDA)] ( 5 ), respectively. 2 — 5 were investigated by spectroscopical and spectrometrical methods as well as by X‐ray structure determinations. According to these 1 occupies a facial site in 2 by donation of the N‐Atom from the NC group in 1 . The molecules 2 are forming a network of hydrogen bonds. In 3 , the TMEDA ligand acts as an intramolecular chelate ligand. In the salt 4 , the cation as well as the anion are coordinated in a distorted tetrahedral environment, while in 5 a distorded trigonal‐bipyramidal coordination‐sphere is present, leading to a elongated In1‐Cl1 distance of 261.74(9) pm.     

Enhanced Resolution of Copper and Bismuth by Addition of Gallium in Anodic Stripping Voltammetry with the Bismuth Film Electrode

This paper presents the enhanced analysis of copper on a bismuth electrode upon addition of gallium(III). The presence of gallium alleviates the problems of overlapping stripping signals usually observed between copper and bismuth when using the Bismuth Film Electrode. In addition, it has been found that the presence of gallium improves the reproducibility of the bismuth stripping signal. Simultaneous deposition of copper and bismuth at ?1500 mV for 2 minutes in a supporting electrolyte composed of 0.1 M pH 4.75 acetate buffer with 250 μg L^?1 gallium yields well resolved copper and bismuth signals when analyzed with square‐wave anodic stripping voltammetry. Simultaneous analysis of copper and lead yielded linear calibration plots in the range 10 to 100 μg L^?1 with regression coefficients of 0.997 and 0.994 respectively. The theoretical detection limit for copper was calculated to be 4.98 μg L^?1 utilizing a 2 minutes deposition time. The relative standard deviation for a copper concentration of 50 μg L^?1 was 1.6% (n=10).     

Laser-induced breakdown spectroscopy for branching ratio and atomic lifetime measurements in singly-ionized neodymium and gallium

Precision laboratory astrophysics measurements can be made in laser-induced plasmas created for laser-induced breakdown spectroscopy. Branching ratios from highly-energetic levels in singly-ionized neodymium may be measured by observing spontaneous emission in laser-induced plasmas in an argon environment at decreased pressures (~ 7.7 mbar). Utilizing a broadband Èchelle spectrometer with a spectral range from 200–840 nm, the spontaneous emission intensities from hundreds of transitions originating in 138 energy levels in Nd I, Nd II, and Nd III have been observed simultaneously, allowing the determination of branching ratios for these energy levels for branches greater than 1% in the visible wavelength range. In this study, eight branching ratios from the 23,229.991 cm^− 1 level in Nd II were measured and compared to previously determined values as a method for optimizing experimental conditions such as buffer gas pressure and observation delay time. The branching ratios of the eight branches were found to be in excellent agreement with three previously determined values from both experiment and theory. A plan to utilize this laser-induced plasma apparatus to measure the lifetime of the 4s5p³P₂ level at 118,727.89 cm^− 1 in singly-ionized gallium using a cascade-photon-coincidence method is also presented. Utilizing a solid Ga target ablated in a helium environment, “start photons” at 541.6 nm from a transition into the 4s5p³P₂ level and “stop photons” at 633.4 nm from a transition out of that Ga II energy level were observed. Single-photon detection will be accomplished using avalanche photodiodes with narrowband interference filters and delay times between the detection of coincident photons from these two transitions will be measured.     

The structures,stability, and photoelectron spectroscopy of GaPX (X = C,Si, Ge; O,S; P and Ga) clusters

The equilibrium geometries and vibrational frequencies of GaPX⁻ and GaPX (X = C, Si, Ge; O, S; P and Ga) have been studied by hybrid B3LYP functional at cc-PVTZ and aug-cc-PVTZ levels. The results predict that the most stable structure of GaPC⁻ is linear while the others are trigonal. As for GaPX (X = C, Si, Ge; O, S; P and Ga), the ground structures of GaPC and GaPO are linear while the others are trigonal. The adiabatic electron affinities (AEAs) and vertical detachment energies (VDEs) of GaPX⁻ are calculated at B3LYP/aug-cc-PVTZ level. And the order of the AEAs and VDEs of GaPX⁻ are C < O < Ge ≈ Si < P < S < Ga and C < Ge ≈ Si < P < O < S < Ga, respectively. GaPC exhibits the lowest adiabatic electron affinities of all the clusters studied, indicating a particularly stable neutral species.