Hydrothermal Synthesis and Crystal Structure of a New Hexa-cobalt-containing POM

A new compound Na3H3[Co（en）3]2[Co4（H2O）2（PW9O34）2]·11H2O 1 （en = ethylenediamine） has been synthesized under hydrothermal conditions and characterized by IR, TGA, and single-crystal X-ray diffraction analysis. Crystal data： monoclinic, space group C21c, a = 26.336（5）, b = 18.135（2）, c = 22.751（4）A, β = 123.039（7）° and Z = 4. X-ray crystallographic study on compound 1 reveals that it includes a Weakley-type sandwich polyoxoanion [Co4（H2O）2（PW9O34）2]^10-, two complex ions [Co（en）3]^2＋, three Na^＋ ions （one Na（1） and two Na（2））, and eleven crystallographic water molecules. The sandwich polyoxoanions are linked by Na2 to form 2D layers parallel to the （100） plane, and these layers are further connected by Nal along the α-axis to generate a 3D structure.     

Mixed-metal tellurites: synthesis, structure, and characterization of Na1.4Nb3Te4.9O18 and NaNb3Te4O16

Two new mixed-metal tellurites, Na1.4Nb3Te4.9O18 and NaNb3Te4O16, have been synthesized by standard solid-state techniques using Na2CO3, Nb2O5, and TeO2 as reagents. The structures of Na1.4Nb3Te4.9O18 and NaNb3Te4O16 were determined by single-crystal X-ray diffraction. Both of the materials exhibit three-dimensional structures composed of NbO6 octahedra, TeO4, and TeO3 polyhedra. The Nb5+ and Te4+ cations are in asymmetric coordination environments attributable to second-order Jahn-Teller (SOJT) effects. The Nb5+ cations undergo an intraoctahedral distortion toward a corner (local C4 direction), whereas the Te4+ cations are in distorted environments owing to their nonbonded electron pair. Infrared and Raman spectroscopy, UV-vis diffuse reflectance spectroscopy, thermogravimetric analysis, and dielectric measurements were also performed on the reported materials. Crystal data: Na1.4Nb3Te4.9O18, monoclinic, space group C2/m (No. 12), with a = 32.377(5) A, b = 7.4541(11) A, c = 6.5649(9) A, beta = 95.636(5) degrees, V = 1576.7(4) A3, and Z = 4; NaNb3Te4O16, monoclinic, space group P2(1)/m (No. 11), with a = 6.6126(13) A, b = 7.4738(15) A, c = 14.034(3) A, beta = 102.98(3) degrees, V = 675.9(3) A3, and Z = 2.     

A New Sandwich Type Transition Metal Substituted Polyoxotungstate under Hydrothermal Conditions:[NH3(CH2)4NH3]6[Co4(HzO)2(B-α-GeW9034)2]}·7H2O

A new sandwich transition metal substituted polyoxotungstate,[NH3(CH2)4NH3]6 [Co4(H2O)2(B-α-GeW9O34)2]·7H2O 1,was hydrothermally synthesized and characterized by IR spectra and single-crystal X-ray diffraction.The single-crystal X-ray analysis reveals that the crystal crystallizes in monoclinic system,space group P21/c with a=16.6073(6),b=15.3333(5),C=19.9869(7)(A),β=103.41(1)°,Mr=5481.38,V=4950.8(3)(A)3,Z=2,Dc=3.677 g/cm3,F(000)=4900,μ(MoKα)=22.165 mm-1,GOOF=1.005,the final R=0.0228 and wR=0.0527.The crystal structure indicates that the[Co4(H2O)2(B-α-GeW9O34)2]12-polyoxoanion contains two trivacant Keggin[B-α-GeW9O34]10-fragments in a staggered fashion linked via a rhomb-like Co4O16 group in a centrosymmetric arrangement(C2h symmetry)leading to a sandwich-type structure.     

穴状化合物(NH_4)_(16)H_2[NaSb_9W_(21)O_(86)]·15.5H_2O的合成及晶体结构(英文)

利用Sb2O3,Na2WO4合成了一个巨型的穴状化合物(NH4)16H2[NaSb9W21O86].15.5H2O.晶体衍射数据显示,该化合物属于六方晶系,P6-2c空间群,a=b=1.78025(9)nm,c=2.2510(2)nm,α=β=90(9)°,γ=120(2)°,V=6.1783(7)nm3,Z=2,Dc=3.722Mg/m3,F(000)=6086,μ=21.494mm-1,R1=0.0365,wR2=0.0871[I≥2σ(I)].晶体解析表明,该化合物多阴离子[NaSb9W21O86]18-由3个[SbW7O24]3-亚单元和2个环形的[Sb3O7]5-基团连接形成双环孔穴,一个Na+阳离子通过配位键作用嵌入该空穴内.整个穴状物阴离子呈涡轮状结构,3个[SbW7O24]3-亚单元作为3个叶片.     

Na(2/7)Gd(4/7)MoO4: a modulated scheelite-type structure and conductivity properties

Scheelite-type compounds with the general formula (A1,A2)(n)[(B1,B2)O(4)](m) (2/3 ≤ n/m ≤ 3/2) are the subject of large interest owing to their stability, relatively simple preparation, and optical properties. The creation of cation vacancies (□) in the scheelite-type framework and the ordering of A cations and vacancies can be a new factor in controlling the scheelite-type structure and properties. For a long time, cation-deficient Nd(3+):M(2/7)Gd(4/7)□(1/7)MoO(4) (M = Li, Na) compounds were considered as potential lasers with diode pumping. They have a defect scheelite-type 3D structure (space group I4(1)/a) with a random distribution of Li(+)(Na(+)), Gd(3+), and vacancies in the crystal. A Na(2/7)Gd(4/7)MoO(4) single crystal with scheelite-type structure has been grown by the Czochralski method. Transmission electron microscopy revealed that Na(2/7)Gd(4/7)MoO(4) has a (3 + 2)D incommensurately modulated structure. The (3 + 2)D incommensurately modulated scheelite-type cation-deficient structure of Na(2/7)Gd(4/7)MoO(4) [super space group I4 (α-β0,βα0)00] has been solved from single-crystal diffraction data. The solution of the (3 + 2)D incommensurately modulated structure revealed the partially disordered distribution of vacancies and Na and Gd cations. High-temperature conductivity measurements performed along the [100] and [001] orientation of the single crystal revealed that the conductivity of Na(2/7)Gd(4/7)MoO(4) at T = 973 K equals σ = 1.13 × 10(-5) Ω(-1) cm(-1).     

钴(Ⅲ)-胺配合物模板导向合成新型草酸盐化合物[Co(dien)2][NaCO2(C2O4)4]·H20

以Co(dien)2·Cl3为模板剂,在水热条件下导向合成出新型草酸盐化合物[Co(dien)2]·[NaC02(C2O4).].H2O,并通过X射线单晶结构分析、元素分析、ICP以及X射线粉末衍射分析对该化合物的结构进行了表征.结果表明,该化合物结构属于单斜晶系,C2/c空间群,晶胞参数a=1.3805(3)nm,b...     

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。     

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.     

A New Sandwich Type Transition Metal Substituted Polyoxotungstate under Hydrothermal Conditions： [NH3（CH2）4NH3]6[Co4（H2O）2（B-α-GeW9O34）2]}·7H2O

A new sandwich transition metal substituted polyoxotungstate, [NH3（CH2）4NH3]6[Co4（H2O）2（B-α-GeW9O34）2]}·7H2O 1, was hydrothermaUy synthesized and characterized by IR spectra and single-crystal X-ray diffraction. The single-crystal X-ray analysis reveals that the crystal crystallizes in monoclinic system, space group P21/c with a = 16.6073（6）, b = 15.3333（5）, c = 19.9869（7） A, β = 103.41（1）°, Mr = 5481.38, V = 4950.8（3） A3, Z = 2, Dc = 3.677 g/cm^3, F（000） = 4900, μ（MoKa） = 22.165 mm^-1, GOOF = 1.005, the final R = 0.0228 and wR = 0.0527. The crystal structure indicates that the [Co4（H2O）2（B-α-GeW9O34）2]^12- polyoxoanion contains two trivacant Keggin [B-α-GeW9O34]^10- fragments in a staggered fashion linked via a rhomb-like Co4O16 group in a centrosymmetric arrangement （C2h symmetry） leading to a sandwich-type structure.     

Crystal Structure and Spectroscopic Properties of a New Ternary Tungstate Li3Ba2Ho3（WO4）8

A single crystal of Li3Ba2Ho3(WO4)8 was obtained from a flux of Li2WO4 under an air atmosphere. The structure of the pure crystal was determined by single-crystal X-ray diffraction method. It crystallizes in the monoclinic system, space group C2/c with a = 5.240(4), b = 12.790(10), c = 19.247(15), β = 91.921(15)°, V = 1289.1(18)3, Z = 2, Mr = 2773.09, Dc = 7.144 g/cm3, μ = 47.732 mm-1, Rint = 0.0693, F(000) = 2340, the final R = 0.0472 and wR = 0.1221 for 1535 observed reflections (I > 2σ(I)). The Li3Ba2Ho3(WO4)8 has a high structure disorder with one 8f site shared by Li(1) and Ho ions with occupancy of 0.25 and 0.75, respectively. The fundamental structure is constituted by distorted square antiprisms Ho/Li(1)O8 with C1 symmetry, distorted Li(2)O6 octahedra and BaO10 polyhedra. The optical properties were investigated by IR and absorption spectroscopy, and the emission cross sections and gain cross sections of 5I7 → 5I8 of Ho3+ were calculated.     

Crystallization of Two Cyanide-bridged Bimetallic Complexes [LN(DMSO)2(H2O)3Co(CN)6]·H2O (LN = Pr or Nd, DMSO = Dimethylsulfoxide)

1INTRODUCTIONRecently,therehasbeenconsiderableinterestinthelanthanide(III)hexacyanoferrates,theanalogoushexacyanocobaltateandhexacyanochromiumatecom-plexesbecauseoftheirpotentialapplicationsascata-lyticandsemi-conductivematerials.InitialstudiesofmetalhexacyanocobaltateswerecarriedoutbyJa-mesandWilland[1]whoreportedtheamountofhy-drationassociatedwithmicroscopiccrystalsofsever-allanthanidecomplexes.FurtherBonnetandParis[2]studiedtheLNCo(CN)6?nH2Oseries(n=4)byusinginfraredandX-raymethod…     

Di- and tricobalt Dawson sandwich complexes: synthesis,spectroscopic characterization,and electrochemical behavior of Na(18)[(NaOH(2))(2)Co(2)(P(2)W(15)O(56))(2)] and Na(17)[(NaOH(2))Co(3)(H(2)O)(P(2)W(15)O(56))(2)

The reaction of the trivacant Dawson anion alpha-[P(2)W(15)O(56)](12-) and the divalent cations Co(2+) is known to form the tetracobalt sandwich complex [Co(4)(H(2)O)(2)(P(2)W(15)O(56))(2)](16-) (Co(4)P(4)W(30)). Two new complexes, with different Co/P(2)W(15) stoichiometry, [(NaOH(2))(2)Co(2)(P(2)W(15)O(56))(2)](18-) (Na(2)Co(2)P(4)W(30)) and [(NaOH(2))Co(3)(H(2)O)(P(2)W(15)O(56))(2)](17-) (NaCo(3)P(4)W(30)), have been synthesized as aqueous-soluble sodium salts, by a slight modification of the reaction conditions. Both compounds were characterized by IR, elemental analysis, and (31)P solution NMR spectroscopy. These species are "lacunary" sandwich complexes, which add Co(2+) cations according to Na(2)Co(2)P(4)W(30) + Co(2+) --> NaCo(3)P(4)W(30) + Na(+) followed by NaCo(3)P(4)W(30) + Co(2+) --> Co(4)P(4)W(30) + Na(+). A Li(+)/Na(+) exchange in the cavity was evidenced by (31)P dynamic NMR spectroscopy. The electrochemical behaviors of the sandwich complexes [(NaOH(2))Co(3)(H(2)O)(P(2)W(15)O(56))(2)](17-) and [(NaOH(2))(2)Co(2)(P(2)W(15)O(56))(2)](18-) were investigated in aqueous solutions and compared with that of [Co(4)(H(2)O)(2)(P(2)W(15)O(56))(2)](16-). These complexes showed an electrocatalytic effect on nitrite reduction.     

Synthesis and Characterization of a New Pure Inorganic 2D Network Based on [H_2W_（12）O_（42）]~（10-）

An isopolytungstate(NH4)6Na4[H2W12O42]·14H2O(1) has been synthesized in an aqueous solution and characterized by elemental analysis,IR spectroscopy,TG analysis,X-ray powder diffraction(XRD) and single-crystal X-ray diffraction.The result indicates a degradation from nitrilotriacetic acid(NTA) to NH3.The electrochemical analysis and thermal stability of 1 were also studied.The crystal data are as follows:H54N6Na4O56W12(Mr = 3332.65),orthorhombic,Pbca,a = 14.1497(15),b = 15.9414(16),c = 22.931(2) ,Z = 4,V = 5172.4(9) 3,Dc = 4.280 Mg/m3,μ = 26.729 mm-1,F(000) = 5904,the final R = 0.0809 and wR = 0.2104 for 4565(Rint = 0.1351) independent reflections.The β-[H2W12O42]10-clusters are linked through {Na2(OH2)3} groups into a 2D layer and are further connected into a 3D framework via hydrogen bonding interactions.     

Crystal growth and structure determination of oxygen-deficient Sr6Co5O15

Large single crystals of oxygen-deficient Sr6Co5O(15-delta) compounds, i.e., Sr6Co5O14.70 and Sr6Co4.9Ni0.1O14.36, were obtained by using K2CO3 flux in the presence of additives of transition metal oxides. The single-crystal structure determination shows that the structures of Sr6Co5O14.70 and Sr6Co4.9Ni0.1O14.36 crystallize in the space group R and can be described as one-dimensional face-sharing CoO3 polyhedral chains and Sr cation chains. Unlike the other known 2H-perovskite-related oxides in which the polyhedral chains consist of octahedra (Oh) and trigonal prism (TP), the structure of Sr6Co5O14.70 and Sr6Co4.9Ni0.1O14.36 contain Oh and intermediate polyhedra (IP) and can be attributed to a general structure formula A6A'2B3O(15-delta), which is closely related to the known A6A'B4O15 phases by shifting of a B atom and the O3 triangle along the c axis. Further study on O3 reveals that this oxygen position splits into two independent positions, corresponding to polyhedral geometry of IP and TP, respectively. Therefore, the polyhedral chain in the structure should be more precisely described as a random composite of the 4Oh + TP and 3Oh + 2IP. This model is used to interpret the magnetic properties, although not quantitatively. The 4-D structure analysis was also conducted for both Sr6Co5O14.70 and Sr6Co4.9Ni0.1O14.36 with a commensurate modulated structure in a 4-D superspace group, R3m(00gamma)0s, gamma = p/k = 3/5. By considering the same 4-D superspace group R3m(00gamma)0s but different t-phases, one can understand the structure relationship between Sr6Co5O14.70 and Sr6Rh5O15.     

Preparation, crystal structure, and thermal stability of the cadmium sulfide nanoclusters Cd6S44+ and Cd2Na2S4+in the sodalite cavities of zeolite A (LTA)

The crystal structure and thermal stability of two cadmium sulfide nanoclusters prepared in zeolite A (LTA) have been studied by XPS, TGA, and single-crystal and powder XRD. The crystal structures of Cd2.4Na3.2(Cd6S4)0.4(Cd2Na2S)0.6(H2O)> or =5.8[Si12Al12O48]-LTA (a = 12.2919(7) A, crystal 1 (hydrated)) and /Cd4Na2(Cd2O)(Na2O)/[Si12Al12O48]-LTA (a = 12.2617(4) A, crystal 2 (dehydrated)) were determined by single-crystal methods in the cubic space group Pm3m at 294(1) K. Crystal 1 was prepared by ion exchange of Na12-LTA in an aqueous stream 0.05 M in Cd2+, followed by washing in a stream of water, followed by reaction in an aqueous stream 0.05 M in Na2S. Crystal 2 was made by dehydrating crystal 1 at 623 K and 1 x 10(-6) Torr for 3 days. In crystal 1, Cd6S4(4+) nanoclusters were found in and extending out of about 40% of the sodalite cavities. Central to each Cd6S4(4+) cluster is a Cd4S4 unit (interpenetrating Cd2+ and S2- tetrahedra with near Td symmetry, Cd-S = 2.997(24) A, Cd-S-Cd = 113.8(12) degrees, and S-Cd-S = 58.1(24) degrees). Each of the two remaining Cd2+ ions bonds radially through a 6-ring of the zeolite framework to a sulfide ion of this Cd4S4 unit (Cd-S = 2.90(8) A). In each of the remaining 60% of the sodalite cavities of crystal 1, a planar Cd2Na2S4+ cluster was found (Cd-S/Na-S = 2.35(5)/2.56(14) A and Cd-S-Cd/Na-S-Na = 122(5)/92(7) degrees). Cd6S4(4+) and Cd2Na2S4+ are stable within the zeolite up to about 700 K in air. Upon vacuum dehydration at 623 K, all sulfur was lost (crystal 2). Instead as anions, only two oxide ions remain per sodalite unit. One bridges between two Cd2+ ions (Cd2O2+, Cd-O = 2.28(3) A) and the other between two Na+ ions (Na2O, Na-O = 2.21(10) A).     

Solid-state synthesis and characterization of novel aluminophosphates,A3Al2P3O12 (A = Na,K, Rb,Tl): influence of A+ ions on the coordination of aluminum

Four aluminophosphates, A3Al2P3O12 (A = Na, K (1), Rb (2), Tl (3)), have been synthesized by solid-state reactions and characterized by X-ray diffraction and NMR and IR spectroscopic techniques. Aluminum has trigonal bipyramidal coordination in the thallium compound and tetrahedral coordination in the others. Potassium, rubidium and thallium analogues have been structurally characterized by single-crystal X-ray diffraction and found to possess three-dimensional (Al2P3O12)3- anionic frameworks with channels occupied by A+ countercations. These frameworks are built from corner connections of PO4 tetrahedra with AlO4 tetrahedra in 1 and 2 and with AlO5 trigonal bipyramids in 3. Pertinent crystal data are as follows: for 1, orthorhombic space group Pna2(1), a = 8.685(2) A, b = 16.947(2) A, c = 8.458(3) A, Z = 4; for 2, orthorhombic space group Cmc2(1), a = 17.164(2) A, b = 8.6270(6) A, c = 8.8140(14) A, Z = 4; for 3, orthorhombic space group Pna2(1), a = 6.1478(15) A, b = 10.396(3) A, c = 17.787(5) A, Z = 4. Compound 3 is a rare example of an oxide possessing aluminum exclusively in trigonal bipyramidal coordination.     

Synthesis,Crystal Structure and Characterization of a Cobalt Coordination Polymer： [Co（1,4-ndc）（L） （H2O）]n

The title coordination polymer, [Co（1,4-ndc）（L）（H2O）]n 1 （1,4-H2ndc = 1,4-na- phthalenedicarboxylic acid and L =1-（5-（1H-imidazol- 1-yl）pentyl）- 1H-imidazole） has been hydrothermally synthesized and characterized by IR and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/n with a = 12.4333（12）, b = 13.2963（13）, c = 13.4678（13）A, α =β = 90°, y =107.302（2）°, V= 2125.7（4）A^3, Z = 4, CoC22H22N4O5, Mr = 481.37, De = 1.504 g/cm^3, F（000） = 996, μ（MoKa） = 0.850 mm^-1, R = 0.0472 and wR = 0.0984. Compound 1 exhibits a two-dimensional layer structure. The O-H...O and C-H...O hydrogen bonds stabilize the structure of 1.     

Na3PbII[B(O3POH)4]: an alkali-metal lead borophosphate with heterocubane-like units Na3PbO4

Na 3Pb (II)[B(O 3POH) 4] was synthesized under hydrothermal conditions. The crystal structure determination from single-crystal X-ray diffraction data ( I4 1/ a, Z = 4, a = 6.9182(8) A, c = 27.309 (3) A, V = 1307.0(3) A (3)) revealed the presence of [B(O 3POH) 4] (5-) oligomers and heterocubane-like units Na 3PbO 4 with mixed-occupied metal cation sites.     

Na5[MB24O34(OH)12].nH2O (M = Cr(3+), Al(3+)): unprecedented spherelike polyborate clusters from boric acid flux synthesis

Two novel isotypic polyborate cluster compounds Na 5[MB 24O 34(OH) 12]. nH 2O (M = Cr (3+), Al (3+)) have been synthesized in a boric acid flux closed system at 220 degrees C by using gel as precursors. The structure of the Cr compound was determined by low-temperature single-crystal X-ray diffraction, and the Al compound was confirmed to be isostructural by powder X-ray diffraction and similar FT-IR spectra and thermal behavior. Na 5[CrB 24O 34(OH) 12]. nH 2O crystallizes in the monoclinic space group P2 1/ c with the cell parameters a = 17.4549(3) A, b = 11.1976(2) A, c = 21.2403(3) A, beta = 94.644(2) degrees , V = 4137.85(12) A (3), and Z = 4. The predominant feature of the structure are the spherelike polyborate clusters [MB 24O 34(OH) 12] (5-). The M (3+) cation is located at the center of the cluster, around which four hexaborate units ([B 6O 10(OH) 3] (5-)) are tetrahedrally assembled in almost a perfect T d symmetry. To the best of our knowledge, [MB 24O 34(OH) 12] (5-) is the first example of a polyborate cluster that contains 24 boron atoms. Upon heating, the compounds show two steps of weight loss, including the loss of the disengaged water and dehydration of the hydroxy groups. The first step is reversible, retaining the structure framework. The second weight loss is continuous and irreversible.