Polyanionic silicon clusters are provided by the Zintl phases K 4 Si 4 ,comprising [Si 4 ] 4À units,and K 12 Si 17 ,consisting of [Si 4 ] 4À and [Si 9 ] 4À clusters.Acombination of solid-state MAS-NMR, solution NMR, and Raman spectroscopy, electrospray ionization mass spectrometry,a nd quantum-chemical investigations was used to investigate four-a nd nine-atomic silicon Zintl clusters in neat solids and solution. The results were compared to 29 Si isotope-enriched samples. 29 Si-MAS NMR and Raman shifts of the phase-pure solids K 4 Si 4 and K 12 Si 17 were interpreted by quantum-chemical calculations.Extraction of [Si 9 ] 4À clusters from K 12 Si 17 with liquid ammonia/222crypt and their transfer to pyridine yields in ared solid containing Si 9 clusters.T his compound was characterized by elemental and EDX analyses and 29 Si-MAS NMR and Raman spectroscopy. Charged Si 9 clusters were detected by 29 Si NMR in solution. 29 Si and 1 HNMR spectra reveal the presence of the [H 2 Si 9 ] 2À cluster anion in solution.
BrF 5 can be prepared by treating BrF 3 with fluorine under UV light in the region of 300 to 400 nm at room temperature. It was analyzed by UV-Vis, NMR, IR and Raman spectroscopy. Its crystal structure was redetermined by X-ray diffraction, and its space group was corrected to Pnma. Quantum-chemical calculations were performed for the band assignment of the vibrational spectra. A monoclinic polymorph of BrF 5 was quantum chemically predicted and then observed as its low-temperature modification in space group P2 1 /c by single crystal X-ray diffraction. BrF 5 reacts with the alkali metal fluorides AF (A = K, Rb) to form alkali metal hexafluoridobromates(V), A[BrF 6 ] the crystal structures of which have been determined. Both compounds crystallize in the K[AsF 6 ] structure type (R � 3, no. 148, hR24). For the species [BrF 6 ] + , BrF 5 , [BrF 6 ] À , and [IF 6 ] À , the chemical bonds and lone pairs on the heavy atoms were investigated by means of intrinsic bond orbital analysis.
The cocrystallization of aw eakly luminescent platinum complex [Pt(btpy)(PPh 3 )Cl] (1)( Hbtpy = 2-(2benzothienyl)pyridine;e mission quantum yield F em = 0.03) with fluorinated bromo-and iodoarenes C 6 F 6-n X n (X = Br,I; n = 1, 2) results in the formation of efficient halogen-bonding (XB) interactions Pt À Cl···X À R. An up to 22-fold enhancement (F em = 0.65) in the luminescence intensity of the cocrystallized compound is detected, without as ubstantial change of the emission energy.B ased on crystallographic,p hotophysical, and theoretical investigations,t he contribution of the XB donors C 6 F 6-n X n to the amplification of luminescence intensity is attributed to the enhancement of spin-orbit coupling through the heavy-atom effect, and simultaneously to the suppression of the nonradiative relaxation pathwaysbyincreasing the rigidity of the chromophore center.Noncovalent attractive interactions,s uch as hydrogen, halogen, or metallophilic bonding as well as p-p stacking, are widely used for the design and fabrication of avariety of functional materials,c onstructed from organic, inorganic,o r organometallic building blocks.T hese diverse assemblies of different levels of complexity are capable of certain unique actions,such as adetectable response to an external physical or chemical stimulus,energy transfer,orenergy conversion. [1] In yet another approach, halogen bonding (XB) [2] has been recognized as an effective tool in crystal engineering. [3] A deeper understanding of XB-driven aggregation in the solid state led to an umber of supramolecular systems with attractive physical characteristics,w hich include modified surfaces, [4] organic gels, [5] charge-transfer electroactive species, [6] liquid crystals, [7] and optically active compounds. [8] Despite the considerable progress which has been achieved in the construction of XB-stabilized architectures,t he explo-ration of the XB phenomenon for the development of lightgenerating materials remains in its infancy. Thevast majority of reports on this topic deal with the activation of phosphorescence from purely organic compounds by cocrystallization with as uitable haloaromatic partner.[8] Cocrystallization induces XB formation, leading to an enhanced externalheavy-atom effect facilitating spin-orbit coupling and consequently intersystem crossing, resulting in efficient triplet emission.In contrast, very few studies on the effect of XB on the optical properties of transition-metal complexes,alarge class of luminophores,have been reported to date.Halogen bonds were used to construct supramolecular assemblies containing weakly luminescent cyanometallates [Ru(diimine)(CN) 4 ] 2À
All-solid-state batteries are promising candidates for safe energy-storage systems due to nonflammable solid electrolytes and the possibility to use metallic lithium as an anode. Thus, there is a challenge to design new solid electrolytes and to understand the principles of ion conduction on an atomic scale. We report on a new concept for compounds with high lithium ion mobility based on a rigid open-framework boron structure. The host-guest structure Li 6 B 18 (Li 3 N) comprises large hexagonal pores filled with ∞ 1 ½Li 7 N] strands that represent a perfect cutout from the structure of α-Li 3 N. Variable-temperature 7 Li NMR spectroscopy reveals a very high Li mobility in the template phase with a remarkably low activation energy below 19 kJ mol À 1 and thus much lower than pristine Li 3 N. The formation of the solid solution of Li 6 B 18 (Li 3 N) and Li 6 B 18 (Li 2 O) over the complete compositional range allows the tuning of lithium defects in the template structure that is not possible for pristine Li 3 N and Li 2 O.
Die bislang einzigen Polyhalogenkationen, in denen verbrückende Fluoratome vorliegen, wurden synthetisiert und charakterisiert. Das [Br2F5]+‐Kation enthält eine symmetrische [F2Br‐μ‐F‐BrF2]‐Brücke, das [Br3F8]+‐Kation enthält unsymmetrische μ‐F‐Brücken. Die Fluoronium‐Ionen wurden in Form ihrer [SbF6]−‐Salze erhalten und Raman‐ und 19F‐NMR‐spektroskopisch sowie durch Röntgenbeugung am Einkristall untersucht. Quantenchemische Rechnungen, sowohl für die isolierten Kationen in der Gasphase als auch für die Festkörper selbst, wurden durchgeführt. Populationsanalysen ergaben, dass die μ‐F‐Atome die am stärksten negativ partialgeladenen Atome der Kationen sind.
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