Borosulfates—Synthesis and Structural Chemistry of Silicate Analogue Compounds

Borosulfates are oxoanionic compounds consisting of condensed sulfur- and boron-centered tetrahedra. Hitherto, they were mostly achieved from solvothermal syntheses in SO₃-enriched sulfuric acid, or from reactions with the superacid H[B(HSO₄)₄]. The crystal structures are very similar to those of the corresponding class of silicates and their substitution variants, especially regarding the typical structural motif of corner-sharing tetrahedra. However, the borosulfates are supposed to be even more versatile, because (BO₃) units might also be part of the anionic network. The following article deals with detailed reports on the different synthesis strategies, the crystal chemistry of borosulfates in comparison to silicates, and their hitherto identified properties.     

Hydrothermal Synthesis and Characterization of Nd Doped One-dimensional Hexagonal CePO_4 Nanowires

One-dimensional Nd doped CePO4 hexagonal nanowires have been synthesized for the first time at 140 ℃ for 24 hours via a hydrothermal method using P123 surfactant as the template.The products were characterized by X-ray diffraction,transmission electron microscopy,photoluminescence and high-resolution transmission electron microscopy.Compared with CePO4,one-dimensional nanomaterials we have synthesized,Nd doped CePO4 nanomaterials remain their hexagonal one-dimensional morphology and smooth surface.However,their photoluminescence emissions are greatly enhanced at the wavelength of 348 nm.With their novel fluorescence-emission property,the Nd doped CePO4 nanomaterials are potential in many fields such as optics and electronics.     

异喹啉酰肼构筑锌配合物的合成、晶体结构及其性质

采用普通溶液法合成了配合物[Zn(eiqnthz)_2]·DMF(1)和[Zn3(piqnthz)_2Cl_2]·2H_2O(2)(Heiqnthz=N,N′-乙酰异喹啉甲酰肼,H2piqnthz=N,N′-丙酰异喹啉甲酰肼)。通过X射线单晶衍射分析、X射线粉末衍射分析、红外光谱分析、热重分析以及荧光光谱分析等分析方法对2个配合物进行结构测定和性质表征。结构分析表明配合物1是单核结构,单斜晶系,空间群为C2/c,锌离子周围有4个氮原子和2个氧原子与之配位,形成一个畸变的N4O2八面体构型。配合物2属于单斜晶系,C2/c空间群,三核结构。中心原子Zn(1)、Zn(2)、Zn(3)均为5配位,Zn(1)、Zn(3)位于分子两端并且是变形四角锥配位构型,Zn(2)位于中间形成三角双锥配位构型,整体呈V字型。荧光分析表明Heiqnthz、H2piqnthz与锌(Ⅱ)离子配位后其荧光都发生较大的红移。     

对甲苯基硫脲和对溴苯基硫脲的晶体结构和电子结构

本文测定了对甲苯基硫脲(1)和对溴苯基硫脲(2)的晶体结构,并用 CNDO/2程序对生物活性较大的对甲苯基硫脲分子进行了量子化学计算。1属单斜晶系,空间群 P2_1/n,a=0.5618(1),b=0.8487(4),c=1.7865(3)nm,Bβ=93.53(1)°,Z=4,D。=1.298 g·cm~(-3),最终偏离因子 R=0.0396;2属单斜晶系,空间群 P 2_1/n,a=0.9096(6),b=0.8991(4),c=1.0659(8)nm,β=105.59(6)°,Z=4,D。=1.836g·Cm~(-3),最终偏离因子R=0.073。晶体结构测定结果表明,硫脲部分的四个原子组成平面三角形,苯环平面与硫脲平面的夹角分别为63.5°和68.6°。量化计算结果和晶体结构测定相吻合。     

Replacement of the Cobalt Center of Vitamin B12 by Nickel: Nibalamin and Nibyric Acid Prepared from Metal-Free B12 Ligands Hydrogenobalamin and Hydrogenobyric Acid

The (formal) replacement of Co in cobalamin ( Cbl ) by Ni^II generates nibalamin ( Nibl ), a new transition-metal analogue of vitamin B₁₂. Described here is Nibl , synthesized by incorporation of a Ni^II ion into the metal-free B₁₂ ligand hydrogenobalamin ( Hbl ), itself prepared from hydrogenobyric acid ( Hby ). The related Ni^II corrin nibyric acid ( Niby ) was similarly synthesized from Hby , the metal-free cobyric acid ligand. The solution structures of Hbl , and Niby and Nibl , were characterized by spectroscopic studies. Hbl features two inner protons bound at N2 and N4 of the corrin ligand, as discovered in Hby . X-ray analysis of Niby shows the structural adaptation of the corrin ligand to Ni^II ions and the coordination behavior of Ni^II. The diamagnetic Niby and Nibl , and corresponding isoelectronic Co^I corrins, were deduced to be isostructural. Nibl is a structural mimic of four-coordinate base-off Cbls , as verified by its ability to act as a strong inhibitor of bacterial adenosyltransferase.     

Preferential Site Occupation in the Quasi‐Ternary Channel Compounds TlCr5S8–ySey (1 ≤ y ≤ 7) Introducing Anisotropic Variations of Interatomic Interactions: A Systematical Study of their Crystal Structures

The results of single crystal X‐ray investigations of the quasi‐ternary channel compounds TlCr₅S_8–ySe_y (1 ≤ y ≤ 7) show a linear increase of the unit cell volume with increasing Se content as expected for a solid solution. The successive occupation of the four distinct chalcogene sites by Se, however occurs in a nonlinear way. During the substitution the two sites X1 and X2 are strongly preferred by the Se atoms. For site X3 no significant preference is observed and site X4 is clearly less favoured by the Se atoms. This unusual behaviour can be interpreted on the basis of the different polarizabilities of the constituting atoms. The occupation of X1 and X2 by Se gives the strongest covalent bonding interactions, especially between Tl and Se thus being the driving force for the high preference of Se for these two sites. The preferential occupation of the four crystallographically independent chalcogene sites leads to an unexpected and spectacular dependence of the unit cell parameters and of the interatomic distances as function of the Se content. The a axis shows a negative deviation from linearity, whereas the c axis exhibits a positive one. The monoclinic angle β passes a maximum at y = 5, and finally drops to a value comparable with that obtained for the pure sulfide. A detailed analysis demonstrates that the series can be divided into the two different regions 0 ≤ y ≤ 4 and 5 ≤ y ≤ 8, both characterized by a linear variation of the lattice parameters as well as of the interatomic distances.     

Molecular structures of THF-solvated alkali-metal 2,2,6,6-tetramethylpiperidides finally revealed: X-ray crystallographic, DFT, and NMR (including DOSY) spectroscopic studies

The often studied THF solvates of the utility alkali-metal amides lithium and sodium 2,2,6,6-tetramethylpiperidide are shown to exist in the solid state as asymmetric cyclic dimers containing a central M(2)N(2) ring and one molecule of donor per metal to give a distorted trigonal planar metal coordination. DFT studies support these structures and confirm the asymmetry in the ring. In C(6)D(12) solution, the lithium amide displays a concentration-dependent equilibrium between a solvated and unsolvated species which have been shown by diffusion-ordered NMR spectroscopy (DOSY) to be a dimer and larger oligomer, respectively. A third species, a solvated monomer, is also present in very low concentration, as proven by spiking the NMR sample with THF. In contrast, the sodium amide displays a far simpler C(6)D(12) solution chemistry, consistent with the solid-state dimeric arrangement but with labile THF ligands.     

Theoretical and Experimental Exploration of the Energy Landscape of the Quasi‐Binary Cesium Chloride/Lithium Chloride System

As a case study, the energy landscape of the cesium chloride/lithium chloride system was investigated by combining theoretical and experimental methods. Global optimization for many compositions of this quasi‐binary system gave candidates for possible modifications that constitute promising targets for subsequent syntheses based on solid‐state reactions. Owing to the synergetic and complementary nature of the computational and experimental approaches, a substantially better efficiency of exploration was achieved. Several new phases were found in this system, for the compositions CsLiCl₂ and CsLi₂Cl₃, and their thermodynamic ranking with respect to the already‐known phases was clarified. In particular, the new CsLiCl₂ modification was shown to be the low‐temperature phase, whilst the already‐known modification for this composition corresponded to a high‐temperature phase. Based on these results, an improved cesium chloride/lithium chloride phase diagram was derived, and this approach points the way to more rational and more efficient solid‐state synthesis.     

一维链钴配位聚合物{[Co(H2O)4(3,3′-azpy)](3,3′-azpy)3(PF6)2}n的结构和性质的研究

The complex {[Co(H₂O)₄(3,3′-azpy)](3,3′-azpy)₃(PF₆)₂}_n(3,3′-azpy=3,3′-azobispyridine) has been synthesized and characterized. The crystal (C₄₀H₄₀F₁₂CoN₁₆O₄P₂, M_r=1157.75) belongs to the triclinic system, space group P1 with the following crystallographic parameters: a=10.759(2),b=11.012(2), c=23.207(4)?; α=85.330(10), β=83.470(10),γ=69.770(10)°;V=2560.6(8)?³,D_c=1.502g·cm^-3, μ(MoKα)= 0.498mm^-1,F(000)=1178,Z=2, and final R₁=0.0469, wR₂=0.1053 for observed reflections 5549 (I> 2.00σ(I)).The X-ray analysis reveals that cobalt(Ⅱ) cation coordination environment is a distorted octahedral geometry, the Co²⁺ ion is coordinated by four oxygen atoms of water in the equatorial plane, while the two nitrogen atoms of 3,3′-azpy occupy the axial positions. The complex forms a one-dimensional chain structure via 3,3′-azpy bridging ligand. The one-dimensional chain forms three-dimensional network by hydrogen bonds and π-π inter-actions.     

一维链配位聚合物[Mn(acacen){N(CN)2}]n的合成、结构和性质的研究(英)

The manganese(Ⅲ) complex [Mn(acacen){N(CN)₂}]_n [H₂acacen=bis(acetylacetone)ethylenediimine] has been synthesized and the structure has been determined. The complex forms a one-dimensional chain structure via the bidentate bridge ligand μ_1,5-[N(CN)₂]^- linking [Mn(acacen)] moiety. The magnetic property of the compound (75～300 K) shows the existence of an antiferromagnetic exchange interaction among paramagnetic centers along the chain. CCDC: 244940.     

一维链状铜配合物的合成及结构表征

The Copper(Ⅰ) complex [Cu(tpy)(CN)]_n[L=4′-(4-cyanophenyl)-2,2′∶6′,2″-terpyridine ] has been synthe-sized by reaction of ligand L with CuCN using solvothermal method and characterized by IR, elemental analysis and X-ray diffraction single-crystal structure analysis. The crystal structure indicates that the complex crystallizes in monoclinic system, space group P2₁/c with a=0.884 45(18) nm, b=0.819 55(16) nm, c=2.702 90(7) nm, β=102.780(3)°, V=1.910 7(7) nm³, Z=4, D_c=1.495 g·cm^-3, F(000)=864.0, R₁=0.059 3, wR₂=0.123 3. The Cu(Ⅰ) ion in the title complex has a slightly distorted tetrahedron coordination geometry. Each Cu⁺ is coordinated with two nitrogen atoms from two pyridine ring of 4′-(4-cyanophenyl)-2,2′∶6′,2″-terpyridine, and then linked by two CN^- ligands with neighbor Cu⁺ forming a zigzag infinite one-dimensional chain structure. CCDC: 686952.     

The Borosulfate Story Goes on—From Alkali and Oxonium Salts to Polyacids

The structural principles of borosulfates derived from the B/S ratio are confirmed and extended to new representatives of this class showing novel motifs. According to the composition, Na[B(S₂O₇)₂] (P2₁/c; a=10.949(6), b=8.491(14), c=12.701(8) Å; β=110.227(1)°; Z=4) and K[B(S₂O₇)₂] (Cc; a=11.3368(6), b=14.662(14), c=13.6650(8) Å; β=94.235(1)°; Z=8) contain isolated [B(S₂O₇)₂]^? ions, in which the central BO₄ tetrahedron is coordinated by two disulfate units. The alkali cations have coordination numbers of 7 (Na) and 8 (K), respectively. The structure of Cs[B(S₂O₇)(SO₄)] (P2₁/c; a=10.4525(6), b=11.3191(14), c=8.2760(8) Å; β=103.206(1); Z=4) combines, for the first time, sulfate and disulfate units into a chain structure. Cs has a coordination number of 12. The same structural units were found in H[B(S₂O₇)(SO₄)] (P2₁/c; a=15.6974(6), b=11.4362(14), c=8.5557(8) Å; β=90.334(3)°; Z=8). This compound represents the first example of a polyacid. The hydrogen atoms were located and connect the chains to form layers through hydrogen‐bonding bridges. H₃O[B(SO₄)₂] (P4/ncc; a=9.1377(6), c=7.3423(8) Å; Z=4) is the first oxonium compound of this type to be found. The BO₄ tetrahedra are linked by SO₄ tetrahedra to form linear chains similar to those in SiS₂. The chains form a tetragonal rod packing structure with H₃O⁺ between the rods. The structures of borosulfates can be classified following the concept described by Liebau for silicates, which was extended to borophosphates by Kniep et al. In contrast to these structures, borosulfates do not comprise B‐O‐B bonds but instead contain S‐O‐S connections. All compounds were obtained as colourless, moisture‐sensitive single crystals by reaction of B₂O₃ and the appropriate alkali salt in oleum.     

Synthesis and Electronic Structures and Linear Optics of Solid State Compound SrB2O4

The cluster (SrB₂O₄)₂ existing in crystalline states is employed to model the electronic structure and linear optical properties of solid state compound SrB₂O₄. This compound is synthesized by high temperature solution reaction, and it crystallizes in the orthorhombic space group Pbcn with cell dimensions a = 1.1995(3), b = 0.4337(1), c = 0.6575(1) nm, V = 0.34202 nm³, and Z = 4, μ = 15.14 cm^?1, D_caled = 3.36 g/cm³. The dynamic refractive indices are obtained in terms of INDO/SCI following combination with the Sum‐Over‐States method. A width of the calculated gap is 4.424 eV between the valence band and conduction band, and the calculated average refractive index is 1.980 at a wavelength of 1.065 μm. The charge transfers from O^2‐ anion orbitals to Sr²⁺cation orbitals make the significant contributions to linear polarizability in terms of analyses of atomic state density contributing to the valence and conduction bands.