Rb2Hg3Te4: A New Layered Compound Synthesized from Solvothermal Reactions

Ionothermal Approach to Homo- and Heteroleptic Alkylation of Tellurido Mercurate Clusters for Assembly in Lamellar Crystal Structures

The selective methylation and butylation of chalcogenido metalate clusters by utilizing imidazolium-based ionic liquids turned out to be not only a comparably mild but at the same time also the only known method for postsynthetic alkylation of such species in order to increase their solubility. For additional impact on the crystal structures, selective alkylation with longer alkyl chains was addressed by utilizing the ionic liquid (C10C1Im)[BF4] (C10 = decyl group at position 1 and C1 = methyl group at position 3 of the cation's Im = imidazolium ring) for ionothermal syntheses of functionalized tellurido mercurate clusters. Herein, we report three novel compounds, two of which comprise cluster anions that exhibit a selective organic functionalization of their terminal telluride ligands upon in situ alkylation with the ionic liquid: [Hg6Te6(Te2)2(TeDec)2]6- (in 1; Dec = decyl) represents the first decylated chalcogenido metalate cluster. A unique heteroleptic functionalization, combining methylation and decylation, was achieved for the second cluster, [Hg6Te6(Te2)2(TeDec)(TeMe)]6- (in 2; Me = methyl). The third cluster is purely inorganic, but based on the same cluster core architecture: [Hg4Te2(Te2)2(Te3)2]4- (in 3) comprises a tritelluride unit instead of two HgTeR groups (R = Me, Dec). As a consequence of the long alkyl chains, both at the cluster and at the charge-compensating cations, all three crystal structures are characterized by lamellar assemblies of cations and anions. For further comparison of the properties of the organometallic versus purely inorganic compounds, vibrational and optical properties of crystalline samples of the compounds comprising clusters 1 and 3 were studied by means of infrared, Raman, and UV-visible spectroscopy. The results clearly show the effect of the presence of an organic decoration (in 1) relative to its absence (in 3), reflected by a red shift of the band gap energy (1 → 3) and a replacement of the Te-C bands (in 1) with bands for tritelluride units (in 3).

Ba2HgTe5: a Hg-based telluride with giant birefringence induced by linear [HgTe2] units

Ba2HgTe5, the first Hg-based telluride birefringent material, was successfully synthesized. The analysis of the response electron distribution anisotropy illustrates that the large birefringence of Ba2HgTe5 originates from the linear [HgTe2] unit.

Crystal structure of dirubidium trimercury(II) tetraselenide, Rb2Hg3Se4

Rb2Hg3Se4, orthorhombic, Ibam (no. 72), a = 6.4183(9) Å, b = 11.626(2) Å, c = 14.454(2) Å, V = 1078.5(3) Å3, Z = 4, R gt (F) = 0.038, wR ref (F 2 ) = 0.142, T = 173 K.

Solvothermal processes in Materials Synthesis

A solvothermal reaction can be described as a chemical reaction involving a solvent either in subcritical or supercritical conditions between different precursors. Such a solvent can act as a chemical component or a fluid phase able, through its physico-chemical properties, to induce the synthesis reactions. During the last fifteen years, solvothermal reactions have been used in different scientific areas involving basic or applied research. Several domains have been developed in Materials Chemistry: (i) the synthesis of novel materials, (ii) the development of new low temperature processes able to prepare functional materials, and in Materials Science: (i) new crystal growth processes, (ii) thin film deposition and (iii) sintering processes at low temperature. In Materials Chemistry three illustrations are described: (i) the synthesis through “geomimetism” of a new family of layered oxides: the phyllosiloxides, (ii) the synthesis of inorganic-organic materials, (iii) the potential of solvothermal processes for producing c-BN.

Metal-Complex-Decorated Homochiral Heterobimetallic Telluride Single-Stranded Helix

Solvothermal reaction of a mixture of Sn, Mn, and Te at 200 degrees C using teta as the solvent yields a novel inorganic-organic hybrid solid [Mn(teta)(en)].[Mn(teta)][Mn(SnTe4)2.Mn(teta)] (teta=triethylenetetramine and en=ethylenediamine; 1), which has a homochiral single-stranded helical structure. The material is a semiconductor with a band gap of 0.88 eV and shows paramagnetic behavior between 2 and 300 K.

Rb(4)Hg(5)(Te(2))(2)(Te(3))(2)Te(3), [Zn(en)3](4)In(16)(Te2)4(Te3)Te22, and K2Cu2(Te2)(Te3): novel metal polytellurides with unusual metal-tellurium coordination

Three novel metal polytellurides Rb(4)Hg(5)(Te(2))(2)(Te(3))(2)Te(3) (I), [Zn(en)(3)](4)In(16)(Te(2))(4)(Te(3))Te(22) (II), and K(2)Cu(2)(Te(2))(Te(3)) (III) have been prepared by solvothermal reactions in superheated ethylenediamine at 160 degrees C. Their crystal structures have been determined by single-crystal X-ray diffraction techniques. Crystal data for I: space group Pnma, a = 9.803(2) A, b = 9.124(2) A, c = 34.714(7) A, Z = 4. Crystal data for II: space group C2/c, a = 36.814(7) A, b = 16.908(3) A, c = 25.302(5) A, beta = 128.46(3) degrees, Z = 4. Crystal data for III: space group Cmcm, a = 11.386(2) A, b = 7.756(2) A, c = 11.985(2) A, Z = 4. The crystal structure of I consists of 1D infinite ribbons of [Hg(5)(Te(2))(2)(Te(3))(2)Te(3)](4-), which are composed of tetrahedral HgTe(4) and trigonal HgTe(3) units connected through the bridging Te(2-), (Te(2))(2-), and (Te(3))(2-) ligands. II is a layered compound containing InTe(4) tetrahedra that share corners and edges via Te, Te(2), and Te(3) units to form a 2D slab that contains relatively large voids. The [Zn(en)(3)](2+) template cations are filled in these voids and between the slabs. The primary building blocks of III are CuTe(4) tetrahedra that are linked by intralayer (Te(3))(2-) and interlayer (Te(2))(2-) units to form a 3D network with open channels that are occupied by the K(+) cations. All three compounds are rare polytelluride products of solvothermal reactions that contain both Te(2) and Te(3) fragments with unusual metal-tellurium coordination.