Anhydrous EuII–acetylenedicarboxylate (EuADC; ADC2− = −O2C‐C≡C‐CO2−) was synthesized by reaction of EuBr2 with K2ADC or H2ADC in degassed water under oxygen‐free conditions. EuADC crystallizes in the SrADC type structure (I41/amd, Z=4) forming a 3D coordination polymer with a diamond‐like arrangement of Eu2+ nodes (msw topology including the connecting ADC2− linkers). Deep orange coloured EuADC is stable in air and starts decomposing upon heating in an argon atmosphere only at 440 °C. Measurements of the magnetic susceptibilities (μeff=7.76 μB) and 151Eu Mössbauer spectra (δ=−13.25 mm s−1 at 78 K) confirm the existence of Eu2+ cations. Diffuse reflectance spectra indicate a direct optical band gap of Eg=2.64 eV (470 nm), which is in accordance with the orange colour of the material. Surprisingly, EuADC does not show any photoluminescence under irradiation with UV light of different wavelengths. Similar to SrADC, EuADC exhibits a negative thermal volume expansion below room temperature with a volume expansion coefficient αV=−9.4(12)×10−6 K−1.
The chemical composition of a black powder confiscated by German customs was elucidated. Black powders are occasionally used as a 'transporter' for cocaine and are obviously especially designed to cloak the presence of the drug. The material consisting of cocaine, copper, iron, thiocyanate, and graphite was approached by analytical tools and chemical modelling. Graphite is added to the material probably with the intention of masking the typical infrared (IR) fingerprints of cocaine and can be clearly detected by powder X-ray diffraction (XRD) and Raman spectroscopy. Cu(2+) and NCS(-) ions, when carefully reacted with cocaine hydrochloride, form the novel compound (CocH)2 [Cu(NCS)4 ] (CocH(+) = protonated cocaine), which has been characterised by single crystal XRD, IR, NMR, UV/Vis absorption and EPR spectroscopy. Based on some further experiments the assumed composition of the original black powder is discussed.
Abstract. Alkali metal (Na, K) and tetraorganopnictonium (AsPh 4 , PPh 4 ) salts were prepared from 2,6-bis(1H-tetrazol-5-yl)pyridine (H 2 pydtz) and characterized by multinuclear NMR, IR, and UV/Vis absorption spectroscopy. Single crystal XRD of (AsPh 4 ) 2 (pydtz)·5H 2 O reveals isolated pydtz 2-dianions sandwiched between two AsPh 4 + cations and an interesting hydrogen bridging network comprising the five co-crystallized water molecules and the three pydtz N atoms. (PPh 4 ) 2 (pydtz)·5H 2 O is isostructural to (AsPh 4 ) 2 (pydtz)·5H 2 O as re-
Abstract. The crystal structure of cesium phenylacetylide, CsC 2 C 6 H 5 , was solved and refined from synchrotron powder diffraction data (Pbca, Z = 8). Each Cs + cation is coordinated by five ligands: four acetylide groups coordinate side-on and one end-on. A similar arrangement is found in the crystal structure of NaC 2 H (P4/nmm, Z = 2). There is a group-subgroup relationship between both structures. Most
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