Structural description of the Na(2)B(4)O(7)-Na(3)AlF(6)-TiO(2) system. 1. IR and Raman study of the solidified melts

The pseudo-binary Na2B4O7-[Na3AlF6-TiO2]11 system has been investigated at room temperature by means of X-ray diffraction, IR, Raman, and UV-vis spectroscopies. Evolution of the different spectra with Na2B4O7 and TiO2 contents evidenced the breaking-up of the large borate rings in favor of small borate units, the diminution of the BIV fraction, and the partial substitution of oxygen by fluorine with the formation of oxyfluoride species. Two domains of compositions are described: a TiO2-rich region with 20-50% Na2B4O7 with the lowering of boron coordination and formation of Ti(O,F)6 units and a TiO2-poor region with 60-90% Na2B4O7 where the Na3AlF6 modifier behavior is predominant. The enhanced modifier effect of [Na3AlF6-TiO2]11 in comparison with pure Na3AlF6 on the vitreous network of Na2B4O7 consists of fluorine preference for binding to higher strength cations, Ti4+, over Al3+ and Na+ respectively, when TiO2 addition exceeds 5 wt %.     

Na2CsBe6B5O15: an alkaline beryllium borate as a deep-UV nonlinear optical crystal

A new deep-UV nonlinear optical crystal, Na(2)CsBe(6)B(5)O(15), has been grown through spontaneous crystallization with a molten flux based on Na(2)O-Cs(2)O-B(2)O(3). Na(2)CsBe(6)B(5)O(15) contains two-dimensional alveolate beryllium borate layers [Be(2)BO(5)](∞) that are bridged via planar [BO(3)] groups. UV-vis diffuse reflectance analysis on a powder sample of Na(2)CsBe(6)B(5)O(15) indicates that the short-wavelength absorption edge of Na(2)CsBe(6)B(5)O(15) is below 200 nm. Second-harmonic generation (SHG) on the powder sample was measured with a 1064 nm laser using the Kurtz and Perry technique, which showed that Na(2)CsBe(6)B(5)O(15) is a phase-matchable material, and its measured SHG coefficient is ~1.17 times as large as the d(36) coefficient of potassium dihydrogen phosphate. The relatively larger SHG coefficient of Na(2)CsBe(6)B(5)O(15) originates from its shorter distance between the adjacent layers bridged via the small [BO(3)] groups.     

Syntheses, structures, ionic conductivities, and magnetic properties of three new transition-metal borophosphates Na5(H3O){M(II)3[B3O3(OH)]3(PO4)6}.2H2O (M(II) = Mn, Co, Ni)

Three new open-framework transition-metal borophosphates Na5(H3O){M(II)3[B3O3(OH)]3(PO4)6}.2H2O (M(II) = Mn, Co, Ni) (denoted as MBPO-CJ25) have been synthesized under mild hydrothermal conditions. Single-crystal X-ray diffraction analyses reveal that the three compounds possess isostructural three-dimensional (3D) open frameworks with one-dimensional 12-ring channels along the [001] direction. Notably, the structure can also be viewed as composed of metal phosphate layers [M(II)(PO4)2]4- with Kagomé topology, which are further connected by [B3O7(OH)] triborates, giving rise to a 3D open framework. The guest water molecules locate in the 12-ring channels. Partial Na+ ions reside in the 10-ring side pockets within the wall of the 12-ring channels, and the other Na+ ions and protonated water molecules locate in the 6-ring windows delimited by MO6 and PO4 polyhedra to compensate for the negative charges of the anionic framework. These compounds show a high thermal stability and are stable upon calcinations at ca. 500 degrees C. Ionic conductivities, due to the motion of Na+ ions, are measured for these three compounds. They have similar activation energies of 1.13-1.25 eV and conductivities of 2.7 x 10(-7)-9.9 x 10(-7) S cm(-1) at 300 degrees C. Magnetic measurements reveal that there are very weak antiferromagnetic interactions among the metal centers of the three compounds. Crystal data: MnBPO-CJ25, hexagonal, P6(3)/m (No. 176), a = 11.9683(5) A, c = 12.1303(6) A, and Z = 2; CoBPO-CJ25, hexagonal, P6(3)/m (No. 176), a = 11.7691(15) A, c = 12.112(2) A, and Z = 2; NiBPO-CJ25, hexagonal, P6(3)/m (No. 176), a = 11.7171(5) A, c = 12.0759(7) A, and Z = 2.     

苯并18－冠－6与M2[Pt(SCN)6](M=Na,K)配合物的合成、结构

合成了苯并18－冠－6(B18C6)与M2[Pt(SCN)6](M=Na,K)的配合物：{[Na (B18C6)]6[Pt(SCN)6]}[Pt(SCN)6](SCN)2(1),[K(B18C6)]2[Pt(SCN)6]·4H2O(2). 通过元素分析、红外光谱、单晶X射线衍射进行了表征.1为单斜晶系、空间群R3^-, a=b=1.9933(3)nm,c=2.9760(6)nm,α=β=90°,γ=120°,V=10.240(3)nm^3,Z=3, Dcalcd=1.564g/cm^3,F(000)=4908,R1=0.0535,wR2=0.1030.2为三斜晶纱、空间群 P1^-,a=1.1692(3)nm,b=1.1853(4)nm,c=1.2381(5)nm,α=61.419(5)°,β=80.757 (8)°,γ=89.003(5)°,V=1.4836(9)nm^3,Z=1,Dcalcd=1.476g/cm^3,F(000)=666, R1=0.0696,wR2=0.1346.1由{[Na(B18C6)]6[Pt(SCN)6]}^4+配阳离子、[Pt(SCN)6] ^2-配阴离子和SCN^-阴离子组成。相邻{[Na(B18C6)]6[Pt(SCN)6]}^4+通过Na-O键 形成三维网状结构。[Pt(SCN)6]^2-和SCN^-仅起平衡电荷的作用.2由两个[K (B18C6)]^+配阳离子和一个[Pt(SCN)6]^2-配阴离子组成。相邻[K(B18C6)]2[Pt (SCN)6]离子对通过K－O键形成一维链状结构。     

空气中合成M2B4O7:Eu3+(M=Na,K)荧光体及其性质表征

以M2B4O7(M=Na,K)为基质,在空气中掺杂稀土元素Eu3+得到了Na2B4O7:Eu3+和K2B4O7:Eu3+荧光体.探讨了体系的烧结条件和荧光性质,分析了晶体的结构.结果表明,虽然两种体系的最佳合成条件不同,但是体系中都同时存在[BO4]和[BO3]结构;稀土离子Eu3+的发光以电偶极跃迁5D0-7F2为主,处于非中心对称的格位上,并且可以很好地存在于基质中,Na2B4O7:Eu3+具有较强的发光强度.     

273 K下Na2CO3-Na2SO4-Na2B4O7-H2O四元体系介稳相平衡的实验研究

采用等温蒸发法研究了四元体系Na2CO3-Na2SO4-Na2B4O7-H2O在273 K时的介稳相平衡及平衡液相的密度. 利用溶解度数据绘制了该四元体系273 K下的相图. 研究结果表明, 该四元体系有异成分复盐2Na2SO4·Na2CO3形成. 相图中有2个共饱点、5条单变量曲线和4个结晶相区. 4个结晶相区分别为盐Na2CO3·10H2O, Na2SO4·10H2O, Na2B4O7·10H2O和2Na2SO4·Na2CO3的结晶区. 复盐2Na2SO4·Na2CO3同时存在于包含Na2CO3-Na2SO4-H2O三元体系的其它四元体系或高元体系中. 在273 K介稳平衡相图中, 碳酸钠以Na2CO3·10H2O形式析出; 硫酸钠以Na2SO4·10H2O的形式析出; 硼酸钠的完整分子式为Na2B4O5(OH)4·8H2O. Na2CO3对Na2B4O7有盐析作用.     

Liquidus Temperatures of System Na3AlF6-K3AlF6-AlF3 for Aluminum Electrolysis at Lower Temperature

Liquidus temperatures in the molten salt system Na3AlF6-K3AlF6-AlF3 of interest for aluminum electrolysis were determined by thermal analysis method. The results were presented and an empirical equation describing liquidus temperatures for primary crystallization was derived t=1003.5–0.081×A2.3159–5.87×B0.657–0.024×A2.22×B1.14+ 0.035×A2.17×B1.084, where t is the liquidus temperature in degree Celsius, A denotes the mass fraction of AlF3 in system Na3AlF6-K3AlF6- AlF3, and B denotes K3AlF6/(Na3AlF6+K3AlF6 ) in mass(%, the value was defined as KR in this paper). The composition limitations are 0相似文献   

苯并15-冠-5与Na_2[M(SCN)_4](M=Pd,Pt)配合物的合成与结构

合成了苯并15-冠-5与Na_2[M(SCN)_4] (M = Pd, Pt)生成的配合物：[Na(B15- C-5)]_2[Pd(SCN)_4] (1), {[Na(B15-C-5)][Na(B15-C-5)(H_2O)]}[Pt(SCN)_4] (2)。1为单斜晶系，空间群P2_1/n，a = 1.0164(6) nm，b = 1.3743(3) nm，c = 1.4987(7) nm，β = 95.248(6)°，V = 2.0847 nm~3，Z = 2，D_(calcd) = 1. 47 g/cm~3，F(000) = 944，R = 0.053，wR = 0.072。2为三斜晶系，空间群P(1- bar)，a = 1.1484(2) nm，b = 1.4210(3) nm，c = 1.5026(3) nm，α = 62.500 (3)°，β = 72.393(3)°，γ = 73.106(4)°，V = 2.0398(7) nm~3，Z = 2， D_(calcd) = 1.674 g/cm~3，F(000) = 1028，R_1 = 0.0327，wR_2 = 0.0885。1 由两个[Na(B15-C-5)]~+配阳离子和一个[Pd(SCN)_4]~(2-)配阴离子组成，两者通 过Na-N键形成中性配合物，[Na(B15-C-5)]~+A相对钯原子呈反式排列。2由[Na (B15-C-5)]~+和[Na(B15-C-5)(H_2O)]~+配阳离子和一个[Pt(SCN)_4]~(2-)配阴离 子组成，它们也通过Na-N键形成中性配合物，配阳离子相对铂原子呈顺式排列。2 的两个分子通过氢键形成二聚结构。     

K2B4O7-Na2B4O7-Li2B4O7-H2O四元体系273 K介稳相平衡

采用等温蒸发平衡法研究了四元体系K2B4O7-Na2B4O7-Li2B4O7-H2O在273 K时的介稳相平衡及平衡液相的密度. 研究发现该四元体系为简单共饱和型, 无复盐及固溶体形成, 根据溶解度数据绘制了相图, 相图中有一个共饱点E, 三条单变度曲线E3E, E2E, E1E; 三个平衡固相分别为K2B4O7·4H2O、Na2B4O7·10H2O 和LiBO2·8H2O. 并简要讨论了实验结果.     

Reactions of M[CH(SiMe3)2] (M = Na or K) with PhCN, and related chemistry

A number of metal complexes containing one of the following ligands: the 1-azaallyl [N(R)C(Ph)C(H)R]- ([triple bond]L-), the 1,3-diazaallyl([triple bond]LL'-) and the isomeric beta-diketiminate [{N(R)C(Ph)]}2CH]- ( identical with LL-) have been prepared (R = SiMe(3)). These are the crystalline compounds H(LL) (2), Na(LL) (3), [Na(LL)(thf)2] (4), Na(L) (6), [Na(mu-LL')]8 (7), [K(mu-L)(eta6-C6H6)]2 (8), [K(mu-LL')(thf)]2 (9), [K(thf)2(mu-LL)](infinity) (10) and [Ni(LL')2] (11). A new synthesis of Na[C(H)R2] (1) involved Hg[C(H)R2]2 and Na/Hg as reagents. The beta-diketimine 2 was obtained from Li(LL) and cyclopentadiene. Under different conditions compounds 3, 6 and 7 were isolated from 1 and benzonitrile, and compounds 8, 9 and 10 from K[C(H)R2] and PhCN. Complex 11 was derived from [Li(LL')]2 and [NiBr(2)(dme)]. The solution obtained from 1 + 2 PhCN in Et2O at ambient temperature was a mixture (5) of 3 (predominantly) and 7. The 1-azaallyl complex 8 has the ligand bound to the metal as the enamide, and this is also probably (NMR) the case for 6. The molecular structures of the crystalline complexes 7, 8 and 11 are presented; that of 10 was published earlier. Compound 7, a cyclooctamer, is particularly interesting, in that each LL'- ligand is bridging via one of its N atoms to two neighbouring sodium ions and is not only N,N'- but also (eta2-C[=]C)-chelating to one of them.     

Synthetically persistent, self assembled [V(IV)2V(V)4] polyoxovanadates: facile synthesis, structure and magnetic analysis

Slow diffusion in a H-tube at room temperature of a methanolic solution of [VO(acac)(2)] (Hacac = acetylacetone) and 1,10-phenanthroline (phen) or 2,2'-bipyridine (bipy) into an aqueous solution of sodium pyrophosphate (Na(4)P(2)O(7)) resulted in the serendipitous formation of X-ray quality crystals of mixed-valent, hexameric oxovanadates of general formula [V(6)O(12)(OCH(3))(4)(L)(4)]·solv [L = 1,10-phenanthroline (phen) for 1· 2CH(3)OH · 4H(2)O (1a), and 2,2'-bipyridine (bipy) for 2· 4H(2)O (2a)]. These were characterized by single-crystal X-ray diffraction, IR, elemental and thermogravimetric analysis (TGA). A facile, rationalized synthetic route for the isolation of 1a and 2a could be established following structural determination, involving NaOH in place of Na(4)P(2)O(7) as pH modulator. The use of distilled water (pH 7) as methanolic co-solvent also resulted in crystallization of the two complexes, proving the presence of a base in the reaction scheme is not vital, with slightly pH-depended yields noted for 2a only. A survey of the literature revealed the occurrence of several other procedures, from classical methods to hydrothermal routes, leading to different solvates of 1, the crystal structure of 2 being unreported in any form to date. The precise nature of the molecular assembly in these type of hybrid organic-inorganic poly-vanadates is contradictory in published reports. On the basis of newly acquired high resolution crystal data and supported by magnetic investigation of the samples, we propose herein a formulation as [(V(IV)O)(2)(V(V)O(2))(4)(μ(3)-O)(2)(μ-OCH(3))(4)(L)(4)], with two oxovanadyl(IV) and four dioxovanadyl(V) units per molecule. A net ferromagnetic coupling between the two isolated V(IV) metal centers was measured with literature-consistent J values of +16.1(1) and +19.7(1) cm(-1) for 1a and 2a, respectively [H = -JS(A)·S(B) + S(A)·D·S(B) + βH (g(A)S(A) + g(B)S(B))], suggesting that crystal packing forces do not significantly influence the magnetic properties of this class of materials. A facile route toward the synthesis of the fully-oxidized [V(V)(4)O(8)(CH(3)O)(4)(bipy)(2)] and [V(V)(4)O(6)(CH(3)O)(6)(acac)(2)] tetraoxovanadates is also reported.     

Crystal Structure and Properties of a Sodium Terbium Borate Na2.67Tb2.11B3O9

A new nonlinear optical crystal of sodium terbium borate (Na2.67Tb2.11B3O9, Mr=573.14) was synthesized by solid reaction method. The colorless transparent single crystals were grown from the high temperature solution by employing NaBO2 as flux. The structure was determined by single-crystal X-ray diffraction method. The compound crystallizes in the orthorhombic system, space group Amm2 with a=5.0744(10), b=10.990(2), c=6.9078(14) , V=385.24(13) ·3, Dc=4.941 g/cm3, F(000)=250, Z=2, μ=9.205 mm-1, the final R=0.0253 and wR=0.0610. Its three-dimensional network structure is constructed from isolated BO33-, Na(1)O8, Na(2)O6, Na(3)O6 and Tb(1)O9 polyhedra. Variable-temperature magnetic susceptibility measurements show the compound is paramagnetic (μj=7.04 μb). The intensity of the second harmonic generation of Na2.67Tb2.11B3O9 is 2.5 times that of KDP.     

Iodide, azide, and cyanide complexes of (N,C), (N,N), and (N,O) metallacycles of tetra- and pentavalent uranium

In contrast to the neutral macrocycle [UN*(2)(N,C)] (1) [N* = N(SiMe(3))(3); N,C = CH(2)SiMe(2)N(SiMe(3))] which was quite inert toward I(2), the anionic bismetallacycle [NaUN*(N,C)(2)] (2) was readily transformed into the enlarged monometallacycle [UN*(N,N)I] (4) [N,N = (Me(3)Si)NSiMe(2)CH(2)CH(2)SiMe(2)N(SiMe(3))] resulting from C-C coupling of the two CH(2) groups, and [NaUN*(N,O)(2)] (3) [N,O = OC(═CH(2))SiMe(2)N(SiMe(3))], which is devoid of any U-C bond, was oxidized into the U(V) bismetallacycle [Na{UN*(N,O)(2)}(2)(μ-I)] (5). Sodium amalgam reduction of 4 gave the U(III) compound [UN*(N,N)] (6). Addition of MN(3) or MCN to the (N,C), (N,N), and (N,O) metallacycles 1, 4, and 5 led to the formation of the anionic azide or cyanide derivatives M[UN*(2)(N,C)(N(3))] [M = Na, 7a or Na(15-crown-5), 7b], M[UN*(2)(N,C)(CN)] [M = NEt(4), 8a or Na(15-crown-5), 8b or K(18-crown-6), 8c], M[UN*(N,N)(N(3))(2)] [M = Na, 9a or Na(THF)(4), 9b], [NEt(4)][UN*(N,N)(CN)(2)] (10), M[UN*(N,O)(2)(N(3))] [M = Na, 11a or Na(15-crown-5), 11b], M[UN*(N,O)(2)(CN)] [M = NEt(4), 12a or Na(15-crown-5), 12b]. In the presence of excess iodine in THF, the cyanide 12a was converted back into the iodide 5, while the azide 11a was transformed into the neutral U(V) complex [U(N{SiMe(3)}SiMe(2)C{CHI}O)(2)I(THF)] (13). The X-ray crystal structures of 4, 7b, 8a-c, 9b, 10, 12b, and 13 were determined.     

Synthesis, structure, and catalytic oxidation chemistry from the first oxo-imido Schiff base metal complexes

The molybdenum oxo-imido complex, [Mo(O)(NtBu)Cl2(dme)] (1), was obtained from the reaction between [MoO2Cl2(dme)] and [Mo(NtBu)2Cl2(dme)]. Reactions between [Mo(O)(NR)Cl2(dme)] (where R = tBu or 2,6-iPr2C6H3) and the disodium Schiff base compounds Na(2)(3,5-tBu2)2salen, Na(2)(3,5-tBu2)2salpen, and Na(2)(7-Me)2salen afforded the first oxo-imido transition metal Schiff base complexes: [Mo(O)(NtBu)[(3,5-tBu2)2salen]] (2), [Mo(O)(NtBu)[(3,5-tBu2)2salpen]] (3), and [Mo(O)(N-2,6-iPr2C6H3)[(7-Me)2salen]] (4), respectively. The compounds [Mo(NtBu)2[(3,5-tBu2)2salpen]] (5) from [Mo(NtBu)2(NHtBu)2] and [Mo(N-2,6-iPr2C6H3)(2)[(7-Me)2salen]](6) from [Mo(N-2,6-iPr2C6H3)(2)(NHtBu)2] (7) are also reported. Compounds 1-7 were characterized by NMR, IR, and FAB mass spectroscopy while compounds 3, 4, and 5 were additionally characterized by X-ray crystallography. In conjunction with tBuOOH as oxidant, compound 3 is a catalyst for the oxidation of benzyl alcohol to benzaldehyde and cis-cyclooctene and 1-octene to the corresponding epoxides.     

Group 1 coordination chains and hexagonal networks of host cyclotriveratrylene with halogenated monocarbaborane anions

Halogenated carbaborane ions [CB(11)H(6)X(6)](-) in which X=Cl or Br have been combined with the host molecule cyclotriveratrylene (CTV) and Group 1 metal cations to give crystalline materials. The complexes [Na(ctv)(H(2)O)(CB(11)H(6)X(6))](CF(3)CH(2)OH) feature chiral Na-CTV coordination chains with complexation of the [CB(11)H(6)X(6)](-) ion by the Na(+) ion, together with the CTV molecular cavity. The coordination chains are hydrogen bonded together to give a puckered two-dimensional hexagonal grid structure. [K(ctv)(CB(11)H(6)Cl(6))(CF(3)CH(2)OH)(0.5)] is essentially isostructural. Complexes [Rb(ctv)(CB(11)H(6)Br(6))(H(2)O)] and [Cs(ctv)(CB(11)H(6)X(6))(CH(3)CN)] are coordination polymers with related distorted hexagonal grid structures. Use of N,N'-dimethylformamide (DMF) as a solvent results in an entirely different type of assembly, with [Na(2)(dmf)(4)(H(2)O)(2)(ctv)][(dmf)(0.5)(ctv)][CB(11)H(6)Br(6)](2) showing unusual [Na-mu-(dmf)-Na] bridges, and once again forming a distorted hexagonal coordination polymer.     

A Porous Organic-inorganic Hybrid Compound Constructed from Polyoxovanadium Borate Anions,Dinuclear Na Sites and Metal-organic Units

A polyoxovanadium borate [Na(H2O)]2[Na(H2O)2]2[Cu(en)2][V12B18O54(OH)6]·(H3O)2·(H2O)18 1(en = ethylenediamine) has been hydrothermally synthesized and characterized by IR,two-dimensional infrared(2D IR) correlation spectroscopy with magnetic and thermal perturba-tion,thermal IR spectroscopy,thermal gravimetric analysis and single-crystal X-ray diffraction.It crystallizes in triclinic,space group P1 with a = 12.981(3),b = 13.044(3),c = 14.208(3) ,α = 63.98(3),β = 77.17(3),γ = 14.208(3)°,V = 2001.0(8) 3,Z = 1,Mr = 2518.05,Dc = 2.090 g/cm-1,F(000) = 1255.0,Mu(mm-1) = 1.756,λ(MoKα) = 0.71073 ,R = 0.0625 and wR = 0.1952.In 1,the [V12B18O54(OH)6]8-units are connected by [Cu(en)2]2+,binuclear Na(1) and Na(2) to form a three-dimensional porous framework.     

Mapping the synthesis of low nuclearity polyoxometalates from octamolybdates to Mn-Anderson clusters

A comprehensive study of the isomer-independent synthesis of TRIS ((HOCH(2))(3)CNH(2)) Mn-Anderson compounds from Na(2)MoO(4)·2H(2)O, via the corresponding octamolybdate species, is presented. Three octamolybdate salts of [Mo(8)O(26)](4-) in the β-isomer form, with tetramethylammonium (TMA), tetraethylammonium (TEA) and tetrapropylammonium (TPA) as the counter cation, were synthesised from the sodium molybdate starting material. Fine white powdery products for the three compounds were obtained, which were fully characterised by elemental analysis, TGA, solution and solid state Raman, IR and ESI-MS, revealing a set ratio of Na and organic cations for each of the three compounds; (TMA)(2)Na(2)[Mo(8)O(26)] (1), (TEA)(3)Na(1)[Mo(8)O(26)] (2) and (TPA)(2)Na(2)[Mo(8)O(26)] (3), and the analyses also confirmed that the three compounds all consisted of the octamolybdate in the β-isomeric form. ESI-MS analyses of 1, 2 and 3 show similar fragmentation for these β-isomers compared to the previously reported study for the α-isomer ((TBA)(4)[α-Mo(8)O(26)]) (A) in the synthesis of ((TBA)(3)[MnMo(6)O(18)((OCH(2))(3)CNH(2))(2)]) (B), and compounds 1, 2 and 3 were successfully used to synthesise equivalent TRIS Mn-Anderson compounds: (TMA)(3)[MnMo(6)O(18)((OCH(2))(3)CNH(2))(2)] (4), (TEA)(3)[MnMo(6)O(18)((OCH(2))(3)CNH(2))(2)] (5) and (TPA)(2)Na(1)[MnMo(6)O(18)((OCH(2))(3)CNH(2))(2)] (6), as well as Na(3)[MnMo(6)O(18)((OCH(2))(3)CNH(2))(2)] (7). This is the first example where symmetric organically-grafted Mn-Anderson compounds have been synthesised in DMF from anything but the {Mo(8)O(26)} α-isomer.     

Ca(1)(-)(x)Na(2)(x)Al(2)B(2)O(7): a structure with tunable density of Na(+) vacancies

A series of samples with the composition Ca(1)(-)(x)Na(2)(x)Al(2)B(2)O(7) (0 < x < or = 1) was investigated and a hexagonal structure with unusually large range of homogeneity (at least from x = 0.01 to 0.95) was revealed. The hexagonal phase consists of [Al(2)B(2)O(7)](infinity)(2)(-) lamellae stacked along the c axis, as in CaAl(2)B(2)O(7) and Na(2)Al(2)B(2)O(7). Nevertheless, the configuration and stacking sequence of the [Al(2)B(2)O(7)](infinity)(2)(-) lamellae are different in these three structures. In the hexagonal structure of Ca(1)(-)(x)()Na(2)(x)()Al(2)B(2)O(7), Ca and half Na cations (Na1) statistically occupy the same crystallographic site which is located between the [Al(2)B(2)O(7)](infinity)(2)(-) lamellae, the other half Na cations (Na2) distribute in the planes bisecting the [Al(2)B(2)O(7)](infinity)(2)(-) lamellae. Depending on the composition, the site occupation factor of Na2 site can vary in the same range as x, leading to a tunable density of Na(+) vacancies in the structure. The AlO(4) tetrahedra and BO(3) triangles in the structure tilt in appropriate ways to improve the bond valence sum of Na2 cations which are not sufficiently bonded to the anions.     

二维网状冠醚配合物－苯并15－冠－5、二苯并18－冠－6与Na_2[Pt(SCN)_6]配合物的合成与结构

合成了苯并15-冠-5、二苯并18-冠-6与Na_2[Pt(SCN)_6]的配合物：[Na(B15- C-5)]_2[Pt(SCN)_6] (1),[Na(DB18-C-6)]_2[Pt(SCN)_6] (2),并通过元素分析 、红外光谱、单晶X射线衍射进行了表征。1为单斜晶系,空间群P2_1/c,a = 1. 0974(5) nm,b = 1.5187(7) nm,c = 1.3632(6) nm,β = 96.407(7)°,V = 2. 2568(18) nm~3,Z = 2,D_(calcd) = 1.746 g/cm~3,F(000) = 1184,R_1 = 0. 0357,wR_2 = 0.0868。 2为三斜晶系,空间群 P1-bar,a = 1.2500(3) nm,b = 1.2825(3) nm,c = 1.9342(4) nm,α = 106.82(3)°,β = 102.51(3)°,γ = 103.04(3)°,V = 2.7562 nm~3,Z = 2,D_(calcd) = 1.579 g/cm~3,F(000) = 1316,R_1 = 0.0364,wR_2 = 0.0771。配合物分别由两个[Na(B15-C-5)]~+, [Na(DB18-C-6)]~+配阳离子和一个[Pt(SCN)_6]~(2-)配阴离子组成。配阳离子和配 阴离子通过Na-N键形成二维网状结构。