The synthesis of clathrate-II germanium □24Ge136 in an ionic liquid was recently discovered.1 key step this process, the controlled oxidation reactive precursor phases by a protic acid, successfully applied to silicides M4Si4 (M = Na, K). Through method, clathrate-I compounds composition M8-xSi46 were obtained as crystalline products. synthetic method demonstrates mild oxidative route large class metastable intermetallic compounds.

Abstract The Zintl phase Ba 3 Si 4 has been synthesized from the elements at 1273 K as a single phase. No homogeneity range found. compound decomposes peritectically 1307(5) to BaSi 2 and melt. butterfly‐shaped 6− anion in crystal structure of (Pearson symbol tP 28, space group P / mnm , = 8.5233(3) Å, c 11.8322(6) Å) shows only slightly different Si‐Si bond lengths d (Si–Si) 2.4183(6) Å (1×) 2.4254(3) (4×). is diamagnetic with χ ≈ −50 × 10 −6 cm mol −1 . DC resistivity measurements show...

The clathrate-I phase Ba8−xSi46 (space group Pm3̅n) was synthesized by oxidation of Ba4Li2Si6 with gaseous HCl. Microcrystalline powders the clathrate were obtained within a few minutes. reaction temperature and pressure HCl optimized to achieve good-quality crystalline products composition range 1.3 < x 1.9. new preparation route presented here provides an alternative high-pressure synthesis applied so far.

Abstract The new clathrate‐II K 8.6(4) Ge 136 has been synthesized by mild oxidation of 4 9 in the ionic liquid n ‐dodecyltrimethylammonium chloride (DTAC)/AlCl 3 at 300 °C and subsequent annealing 370 °C. Refinement crystal structure from X‐ray powder diffraction data revealed composition [space group Fd $\bar {3}$ m , a = 15.302(1) Å], which was also confirmed energy‐dispersive spectrometry (EDXS), transmission electron microscopy, scanning microscopy on bulk material. atoms preferably...

A clathrate containing lithium: K8LixGe44−x/4□2−3x/4 constitutes the first intermetallic clathrate-I lithium. Different to phases formed with other alkali metals, Li does not occupy positions within polyhedral cages but substitutes Ge in host framework. Detailed facts of importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, copy-edited or typeset. They made available submitted by authors. Please note: The publisher is responsible for content...

Abstract The clathrate‐I Ba 8– x Si 46 was manufactured from BaSi 2 and α‐Si by high‐pressure high‐temperature synthesis at 5 GPa 900 °C redox reaction 4 Li 6 . transport properties were measured on specimens the synthesis. composition of phase [space group Pm $\bar{3}$ n , a = 10.3051(1) Å] corresponds to 0.8(2) according refined lattice parameter, value determined full‐profile refinement powder X‐ray diffraction data amounts 0.73(1), chemical analysis results in 1.0(1), yielding average...

Under pressure: The new modification Ge(hR8) is obtained upon pressurization of clathrate-type Ge(cF136) or controlled decompression a Ge(tI4)-type high-pressure phase. atomic arrangement comprises four-bonded germanium atoms with topological organization bearing remarkable similarity to host–guest assemblies other main-group elements. Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited typeset. They made...

The formation of framework vacancies in Si- and Ge-based type-I clathrates is studied using density-functional theory as a function filling the cages with K Ba atoms. Our analysis reveals relevance structural disorder, geometric relaxation, electronic saturation well vibrational configurational entropy. In Si clathrates, we find that are unstable, but very differently, Ge up to three per unit cell can be stabilized. This contrasting behavior largely driven by different energy gain on...

A new preparation route to the intermetallic clathrate-I compound Na2Ba6Si46 is introduced, which allows one make large amounts of product with standard laboratory equipment. The precursor Na2BaSi4 oxidized gaseous HCl at 673 K Na2Ba6Si46, NaCl and BaCl2. Full-profile refinement crystal structure from X-ray powder diffraction data revealed a composition close (Na1.94(1)Ba6.06(1)Si46, space group , = 10.281(1) Å). Differential scanning calorimetry showed an exothermic effect 874 K, indicating...

Crystalline nanosized particles of clathrate-II phases KxGe136 and NaxSi136 were obtained from a dispersion alkali metal tetrelides in ionic liquids based on DTAC/AlCl3, which slowly heated to 120–180 °C. The nanoparticles are bullet-shaped with typical dimensions about 40 nm width 140−200 length. Detailed structure investigations using high-resolution transmission electron microscopy (HRTEM) holography reveal the crystallinity dense morphology clathrate nanorods.

The thermal decomposition products of ionic liquids based on n-dodecyltrimethylammonium chloride (DTAC) were used for the preparation metastable allotrope Ge(cF136) by oxidation Na 12 Ge 17 in gas-solid reactions. This method provides a promising low-temperature route synthesis intermetallic phases and elemental modifications. In order to explore reaction mechanism, we investigated DTAC as well DTAC/MgCl 2 DTAC/AlCl 3 in-situ mass spectrometry powder X-ray diffraction. results have revealed...

The clathrate-I phase Ba8AlxSi46-x has been structurally characterized at the composition x = 6.9 (space group Pm3[combining macron]n, no. 223, a 10.4645(2) Å). A crystal structure model comprising distribution of aluminium and silicon atoms in clathrate framework was established: 5.7 Al 0.3 Si occupy crystallographic site 6c, while 1.2 22.8 24k. atomic established based on combination (27)Al (29)Si NMR experiments, X-ray single-crystal diffraction wavelength-dispersive spectroscopy.

Na2Ga7 crystallizes with the orthorhombic space group Pnma (no. 62; a = 14.8580(6) Å, b 8.6766(6) and c 11.6105(5) Å; Z 8) constitutes filled variant of Li2B12Si2 structure type. The crystal consists network icosahedral Ga12 units 12 exohedral bonds four-bonded Ga atoms in which Na occupy channels cavities. atomic arrangement is consistent Zintl [(4b)Ga]- Wade [(12b)Ga12]2- electron counting approach. compound forms peritectically from Na7Ga13 melt at 501 °C does not show homogeneity range....

Abstract The Zintl phase K 2 BaSi 4 has been synthesized from the mixture of precursors KSi and . crystal structure was elucidated X‐ray powder diffraction data: Pearson symbol oP 28, space group Pbcm , a =9.4950(1), b =9.2392(1), c =9.9025(1) Å. main building block are tetrahedral anions Si 4– Analysis chemical bonding for its analogs – molecular H solid state employing electron localizability approach reveals basic agreement with model in terms number basins Si−Si bonds lone pairs at...

Abstract Metastable Ge( cF 136) with empty clathrate-II crystal structure was successfully used for the preparation of otherwise hardly accessible germanium clathrate phases. On reaction potassium vapour at 280 °C 6 days, new phase K 24 Ge 136 formed, in which cages framework are completely filled by atoms. The x is discussed different contents ( =0, 8.6, 24).

In many cases, idealized crystal structure models cannot rationalize the actual properties of intermetallic compounds. For a realistic approach in materials research, microstructures and defects need to be taken into account. case clathrate compounds, particularly intrinsic framework vacancies (denoted as Zintl defects) demand consideration. Consequently, research produces evidence that modern‐day chemistry involves utilization advanced X‐ray diffraction methods combined with elaborated bulk...

Rb8B8Si38 forms under high-pressure, high-temperature conditions at p = 8 GPa and T 1273 K. The new compound (space group Pm3̅n, a 9.9583(1) Å) is the second example for clathrate-I borosilicide. phase inert against strong acids bases thermally stable up to 1300 K ambient pressure. (Rb+)8(B–)8(Si0)38 electronically balanced, diamagnetic, shows semiconducting behavior with moderate Seebeck coefficient below 300 Chemical bonding analysis by electron localizability approach confirms description...

Abstract The clathrate‐I phase Cs 8– x Ge 44+ y □ 2– (space group Pm $\bar{3}$ n ) was prepared by high‐pressure high‐temperature reactions of 4 and α‐Ge. Different reaction conditions were found to have a strong influence on the lattice parameter ranging from 10.8070(2) Å 10.8493(3) Å. A single crystal with composition 8 44.40(2) 1.60(2) obtained sample = 10.8238(2) (niobium ampoule, p 3.4 GPa, T max 1400 °C). Structure analysis based X‐ray data shows unambiguously an excess germanium atoms...

Abstract Abstract. In the crystal structure of clathrate‐I K 8 Li x Ge 44– /4 □ 2–3 , atoms fill polyhedral cages a host framework formed by and atoms. The phase has been obtained in two forms, at elevated temperatures with space group Pm $\bar{3}$ n low 2 0 × superstructure. this work, we report on direct preparation low‐temperature form thermal decomposition precursor 7 LiGe 400 °C. product 2.48(7) 43.37(9) 0.15(6) [ = 21.5489(2) Å, Z 8] was found to be virtually identical one prepared...

Abstract The intermetallic phase [Li x Ba 8− ][Li y Si 46− ] is the first example of a clathrate-I silicide containing lithium with peculiarity that Li atoms occupy both cage and framework positions. was obtained by ambient-pressure solid-state reactions at 400°C between 4 2 6 binary clathrate 46 applying different experimental approaches. In this reaction, substitute site c (space group Pm 3̅ n ) fill up Ba-deficient dodecahedral 20 cages . presence in proven combined X-ray powder...

By using an anodic conversion process at 280 °C, the type II clathrates Na1.7(6)Ge136 and Na23.0(5)Ge136 were obtained from Na12Ge17 as starting material. An alkali-metal iodide molten-salt electrolyte complied with reaction conditions, allowing for formation of microcrystalline products. Characterization by powder X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy also revealed Na4Ge13 intermediate α-Ge Cs8–xGe136 byproducts, latter likely resulting cation...

Abstract The novel host–guest compound [Cs 6 Cl][Fe 24 Se 26 ] ( I 4/ mmm ; a =11.0991(9), c =22.143(2) Å) was obtained by reacting Cs 2 Se, CsCl, Fe, and in closed ampoules. This is the first member of family compounds with unique Fe–Se topology, which consists edge‐sharing, extended fused cubane [Fe 8 8/3 blocks that host guest complex ion, Cl] 5+ . Thus Fe tetrahedrally coordinated divalent strong exchange couplings, results an ordered antiferromagnetic state below T N =221 K. At low...

Abstract The cage compound Ba 3 Ge 16 Ir 4 crystallizes with the Rh type of crystal structure, which represents a hierarchical derivative BaAl type. structure [Pearson symbol tI 46, space group I 4/ mmm ; = 6.5312(2) Å, c 22.2845(6) Å] was refined from single‐crystal X‐ray diffraction data. phase obtained after 10 d at 910 °C small impurities clathrate‐I, BaGe 7 2 and α‐Ge remaining grain boundaries. is Pauli‐paramagnetic metal, becomes superconducting below T 5.1 K. Electronic analysis...