Solvothermal Syntheses and Crystal Structures of Two Novel Borates: [(CH3)3NH][B5O6(OH)4] and Na2[H2TMED][B7O9(OH)5]2

Two novel borates [(CH₃)₃NH][B₅O₆(OH)₄] (I) and Na₂[H₂TMED][B₇O₉(OH)₅]₂ (II) have been synthesized under solvothermal conditions, and characterized by elemental analyses, FT-IR spectroscopy, and single crystal X-ray diffraction. Crystal data for I: monoclinic, P2₁/c, a = 9.3693(11) Å, b = 14.0375(17) Å, c = 10.0495(9) Å, β = 91.815(9)°, Z = 4. Crystal data for II: monoclinic, P2₁/c, a = 11.6329(2) Å, b = 11.9246(3) Å, c = 10.2528(2) Å, β = 100.178(2)°, Z = 4. Their crystal structures both have 3D supramolecular framework with large channels constructed by O–H···O hydrogen-bonding among the polyanions of [B₅O₆(OH)₄]^? or [B₇O₉(OH)₅]^2? clusters. The templating organic amines cations in I and II are both located in the channels of 3D supramolecular frameworks, respectively, and interact with the polyborate frameworks both electrostatically and via hydrogen bonds of N–H···O. Na₂[H₂TMED][B₇O₉(OH)₅]₂ is the first example of heptaborate co-templated by alkali metal and organic base, which is also rare in borates. The photoluminescence property of the synthetic sample of Na₂[H₂TMED][B₇O₉(OH)₅]₂ in the solid state at room temperature was also investigated by fluorescence spectrophotometer.     

Two new organic borates with the large [B14O20(OH)6]4− oxoboron clusters

Two new borate clusters, [NH₃(CH₂)₃NH₃]₂[B₁₄O₂₀(OH)₆] (1) and [NH₃(CH₂)₆NH₃]₂[B₁₄O₂₀(OH)₆] (2), have been made under solvothermal conditions and characterized by single-crystal X-ray structural analysis. Also their IR and UV–Vis spectroscopy, thermogravimetric analysis, and elemental analysis have been investigated, respectively. Crystal data for 1: triclinic, P-1, a = 8.8049(4) Å, b = 9.1585(5) Å, c = 10.1912(5) Å, α = 74.925(4)°, β = 80.987(4)°, γ = 67.495(5)°, Z = 1. Crystal data for 2: triclinic, P-1, a = 9.2010(4) Å, b = 9.8663(4) Å, c = 11.4191(4) Å, α = 107.014(4)°, β = 92.514(3)°, γ = 107.265(4)°, Z = 1. The structures consist of isolated 8-membered boron ring made of the [B₇O₁₀(OH)₃]^2?cluster subunits. UV–Vis spectral investigation indicates that they are wide-band-gap semiconductors. Fluorescence spectroscopy indicates that they are potential blue light materials.     

Synthesis,characterization, and thermochemical property of a novel mixed alkali metal borate: NaCs[B10O14(OH)4]

A novel mixed alkali metal hydrated borate NaCs[B₁₀O₁₄(OH)₄] was synthesized under hydrothermal conditions. Its structure was determined by single-crystal X-ray diffraction and further characterized by FT-IR spectroscopy, TG-DTA, powder X-ray diffraction, and chemical analysis. NaCs[B₁₀O₁₄(OH)₄] crystallizes in monoclinic space group P2/c with a = 7.6588(3) Å, b = 9.0074(3) Å, c = 11.8708(6) Å, and β = 115.682(3)°. The crystal structure of NaCs[B₁₀O₁₄(OH)₄] consists of Na–O, Cs–O polyhedral, and [B₁₀O₁₄(OH)₄]^2? polyborate anions. [B₁₀O₁₄(OH)₄]^2? units are connected together through common oxygen atoms forming a 1D helical chain-like structure, which are further connected by O–H···O hydrogen bonds forming a 3D supramolecular structure. Through a designed thermochemical cycle, the standard molar enthalpy of formation of this borate was determined to be ?7888.6 ± 8.1 kJ mol^?1 by using a heat conduction microcalorimeter.     

Syntheses and Crystal Structures of Two New Pentaborates Templated by Transition-Metal Complexes

Two new pentaborates [M(dap)₃][B₅O₆(OH)₄]₂·H₂O (M = Co (1) and Ni (2); dap = 1,2-diaminopropane) have been hydrothermally synthesized. Both structures were determined by single crystal X-ray diffraction and further characterized by elemental analysis, FT-IR, thermogravimetric analysis and photoluminescence spectroscopy. Two compounds are isostructural and consist of isolated pentaborate [B₅O₆(OH)₄]^? anions and [M(dap)₃]²⁺ complex cations. The anionic [B₅O₆(OH)₄]^? groups are linked by extensive hydrogen bonds to form a 3-D supramolecular framework with large channels, in which the transition-metal complex templates are located. The luminescent properties of 1 and 2 were studied, and blue luminescence occurs with an emission maximum at 405 and 408 nm upon excitation at 332 and 328 nm respectively. Crystal data: 1, monoclinic, space group P2₁/c (No. 14), a = 9.7159(5) Å, b = 29.3372(19) Å, c = 11.5121(6) Å, β = 103.286(5)°, V = 3193.6(3) ų, Z = 4; 2, monoclinic, space group P2₁/c, a = 9.7264(4) Å, b = 29.3810(16) Å, c = 11.5185(6) Å, β = 103.249(4)°, V = 3204.0(3) ų, Z = 4.     

Preparation and study of hydrogen hexamolybdometallates(III) with the hexamminecadmium cation

Hydrogen hexamolybdogallate and hexamolybdoaluminate with the hexamminecadmium cation [Cd(NH₃)₆] · H[GaMo₆O₁₈(OH)₆] · 6H₂O (I) and [Cd(NH₃)₆] · H[AlMo₆O₁₈(OH)₆] · 6H₂O (II) were synthesized and studied by mass spectrometry, thermogravimetric analysis, powder X-ray diffraction, and IR spectroscopy. The crystals are monoclinic; I: a = 10.82 Å, b = 3.69 Å, c = 11.99 Å, β = 91.06°, V= 469.72 ų, ρ_calcd = 2.34 g/cm³, Z = 2; II: a = 10.81 Å, b = 3.67 Å, c =11.98 Å, β = 91.08°, V = 469.78 ų, ρ_calcd = 2.38 g/cm³, Z = 2.     

Synthesis,Crystal Structure,Vibrational Spectroscopy and Thermal Behavior of the First Alkali Metal Hydrated Hexaborate： K2[B6O9（OH）2]

New hydrated potassium hexaborate K2[B6O9（OH）2] has been synthesized under mild solvothermal conditions. The structure was determined by single-crystal X-ray diffraction and further characterized by FT-IR, Rarnan spectra and DTA-TG. It crystallizes in the monoclinic system with space group P21/n, a=0.9036（2） nm, b=0.66052（18） nm, c=1.5997（4） nm, β=91.862（4）°, V=0.9543（4） nm^3 and Z=4. Its crystal structure consists of K-O polyhedra and 1-D stepped polyborate chains constructed by new [B6O9（OH）2]2- fundamental building blocks. 1-D polyborate chains contain 3,8-membered boron rings. Adjacent chains are further linked via H-bonding interactions into 2-D layers. The K^＋ cations reside not only between the layers but also in the 8-membered boron rings of the chains, compensating the negative charges of the borate chains and holding the layers together into the 3-D structure through bonding with oxygen atoms of the chains.     

Tetramminenickel hydrogen hexamolybdometalates(III)

Tetramminenickel hydrogen hexamolybdoaluminate and hexamolybdogallate(III) of compositions [Ni(NH₃)₄] · H[AlMo₆O₁₈(OH)₆] · 10H₂O (I) and [Ni(NH₃)₄] · H[GaMo₆O₁₈(OH)₆] · 10H₂O (II) were synthesized and characterized by mass spectrometry, thermogravimetry, X-ray powder diffraction, and IR spectroscopy. Their crystals are triclinic. For compound I, a= 17.30 Å, b= 14.69 Å, c= 10.45 Å, α = 129.07, β = 65.91°, γ = 138.01°, V = 1338.7l ų, ρ_calcd = 2.75g/cm³, Z = 2; for compound II, a = 17.38 Å, b= 14.75 Å, c= 10.51 Å, α = 131.38°, β= 65.96°, γ = 138.09, V = 1338.15 ų, ρ_calcd = 2.68 g/cm³, Z = 2.     

Preparation and surface photoelectric properties of Fe(II/III) complexes

Four Fe(II/III) supramolecules, {[Fe(Hpdc)₂(H₂O)₂]·2H₂O} (1), [Fe(HImbc)₂(H₂O)₂] (2), [Fe(phen)₂(CN)₂]·CH₃CH₂OH·2H₂O (3), K[Fe(tp)₂]·SO₄ (4) (H₂pdc = 2,5-Pyridinedicarboxylic acid, H₂Imbc = 4,5-Imidazoledicarboxylic acid, phen = 1,10-phenanthroline, tp⁻ = poly(pyrazolyl)borate), were synthesized by hydrothermal and room temperature stirring methods. They were characterized by single crystal X-ray diffraction, surface photovoltage spectroscopy (SPS), field-induced surface photovoltage spectroscopy (FISPS), electron paramagnetic resonance (EPR), UV–Vis absorption spectra (UV–Vis), infrared spectra (IR) and element analysis. The structural analyses indicate that complex (1) is a supramolecule with 2D structure connected by hydrogen bonds. Complex (2) is a supramolecule with hydrogen-bonded 3D structure. Complexes (3) and (4) are both 1D supramolecules connected by hydrogen bonds. The electronic state of central metal Fe(II) ions in complexes (1) and (2) is d⁶ with FeN₂O₄ coordination mode, lying in weaker distorted octahedral field. The electronic state of Fe(II) ion in complex (3) is d⁶ with Fe(CN)₂N₄ mode in the strong distorted octahedral field. The electronic state of Fe(III) ion in complex (4) is d⁵ with FeN₆ mode, lying in the strong octahedral field. The micro-environment of Fe(II/III) ions in the four complexes is further investigated by EPR. The SPS of four complexes all exhibit photovoltage responses in the range of 300–700 nm. This indicates that they all possess certain photoelectric conversion capability. The effects of component, structure, type of ligands of the complexes, valence state and coordination micro-environment of the central metal ions on the SPS were discussed. Furthermore, the SPS and UV–Vis absorption spectra were interrelated.     

Ligand-based luminescence in lead-containing complexes: The effect of conjugated organic ligands on fluorescence

The asymmetrically substituted heterocyclic alkyne 5-(pyridin-3-ylethynyl) picolinate (P3PA) was synthesized via a one-pot Sonogashira coupling. After purification, P3PA was reacted with Pb(NO₃)₂ into the two-dimensional coordination polymer Pb(P3PA)₂(H₂O)₂ (1) under hydrothermal conditions. Coordination polymer 1 crystallizes into the monoclinic space group I2/a, with a = 15.5775(10) Å, b = 5.9949(4) Å, c = 24.8380(16) Å, and β = 90.7500(10)°. In addition, the luminescent fluorene-based ligands, fluorene-9-carboxylate (FCA) and fluorenone-2,7-dicarboxylate (FDCA), were incorporated into hybrid materials via coordination to the lead (II) cation. Coordination polymer Pb(FCA)₂ (2) crystallizes in the monoclinic space group P2₁/c (a = 8.0518(9) Å, b = 25.338(3) Å, c = 10.5842(12) Å, β = 94.913(2)°), and forms a 1-D polymeric chain. Coordination polymer Pb₃(FDCA)₃(H₂O)₃ (3) crystallizes in the triclinic space group P1 (a = 6.6990(5) Å, b = 10.1529(7) Å, c = 13.6935(9) Å, α = 81.884(2)°, β = 87.260(2)°, γ = 84.399(2)°), and forms pillared 3-D layers. These three compounds have been identified via single crystal X-ray diffraction and characterized via powder X-ray diffraction, UV–Vis spectroscopy, and fluorescence spectroscopy.     

Synthesis,Structure and Thermodynamic Property of a New Lithium Borate: Li4[B8O13(OH)2]·3H2O

A new hydrated lithium borate, Li₄[B₈O₁₃(OH)₂]·3H₂O, has been hydrothermally synthesized and characterized by single crystal X‐ray diffraction, FT‐IR spectroscopy, simultaneous TGA‐DTA and chemical analysis. It crystallizes in the triclinic, space group , a=8.4578(5) Å, b=8.7877(5) Å, c=10.8058(7) Å, α=87.740(3)°, β=71.819(3)°, γ=61.569(3)°, Z=2, V=665.26(7) ų, D_c=2.043 g/cm³. Its crystal structure features polyborate anionic layers with the larger odd 13‐membered boron rings constructed by [B₈O₁₃(OH)₂]^4? FBBs. Through designing the thermochemical cycle, the standard molar enthalpy of formation of this borate was determined to be ?(7953.8±6.6) kJ·mol^?1 by using a heat conduction microcalorimeter.     

Hydrothermal Syntheses and Crystal Structures of Two New Heteropolyoxovanadoborates Containing {(VO)<Subscript>12</Subscript>O<Subscript>6</Subscript>[B<Subscript>3</Subscript>O<Subscript>6</Subscript>(OH)]<Subscript>6</Subscript>(H<Subscript>2</Subscript>O)} Cluster

Two new heteropolyoxovanadoborates (H₂dap)₂H₆{(VO)₁₂O₆[B₃O₆(OH)]₆(H₂O)}·13H₂O (1, dap = 1,2-diaminopropane) and {[Zn(dien)]₂[Zn(dien)(H₂O)]₄(VO)₁₂O₆[B₃O₆(OH)]₆(H₂O)}₂·15H₂O (2, dien = diethylenetriamine) have been hydrothermally synthesized and structurally characterized. Both 1 and 2 contain {(VO)₁₂O₆[B₃O₆(OH)]₆(H₂O)} cluster (denoted on V₁₂B₁₈), which is constructed by a puckered B₁₈O₃₆(OH)₆ ring sandwiched between two triangles of six alternating cis and trans edge-sharing vanadium atoms, and a central water molecule. 1 consists of discrete [V₁₂B₁₈]¹⁰⁻ cluster anions with H₂dap²⁺ as counterions, while 2 consists of discrete neutral {[Zn(dien)]₂[Zn(dien)(H₂O)]₄[V₁₂B₁₈]} clusters, which are built from two types of zinc(II) complex fragments connecting with V₁₂B₁₈ cluster through two Zn-(μ ₃-O)-B bonds. Interestingly, 2 is the only example of the V₁₂B₁₈ cluster decorated by two types of zinc(II) complex fragments.     

Synthesis and study of hydrogen hexamolybdonickelate and hydrogen hexamolybdozincate with the cobaltammine cation

[Co(NH₃)₆] · H₂[NiMo₆O₁₈(OH)₆] · 6H₂O (I) and [Co(NH₃)₆] · H₂[ZnMo₆O₁₈(OH)₆] · 6H₂O (II) have been synthesized and studied by mass spectroscopy, thermogravimetry, and X-ray powder diffraction. The crystals of compounds I and II are monoclinic, Z = 1; for compound I: a = 16.10 Å, b = 5.58 Å, c = 12.22 Å, β = 117.86°, V = 1045.14 ų, and ρ_calcd = 2.26 g/cm³; for compound II: a = 16.12 Å, b = 5.52 Å, c = 12.12 Å, β = 117.90°, V = 1043.21 ų, and ρ_calcd = 2.21 g/cm³.     

Synthesis and study of tetraamminecobalt hydrogen hexamolybdometalates(III)

Tetraamminecobalt hydrogen hexamolybdoferrate [Co(NH₃)₄] · H[FeMo₆O₁₈(OH)₆] · 6H₂O (I) and tetraamminecobalt hydrogen hexamolybdogallate(III) [Co(NH₃)₄] · H[GaMo₆O₁₈(OH)₆] · 6H₂O (II) were synthesized and studied by mass spectrometry, thermogravimetry, IR spectroscopy, and X-ray diffraction. Crystals of I and II are monoclinic; a = 16.21 Å, b = 5.43 Å, c = 12.32 Å, β = 119.63°, V = 1092.11 ų, ρ_calcd = 2.21 g/cm³, and Z = 1 for I; a = 16.24 Å, b = 5.59 Å, c = 12.29 Å, β = 119.79°, V = 1064.05 ų, ρ_calcd = 2.15 g/cm³, and Z = 1 for II. Compounds I and II were used as catalysts for soft oxidation of natural gas.     

Synthesis,Structural Characterization and Properties of Two Strontium Borates Constructed from Oxo Boron Clusters

Two strontium borates Sr₂[B₆O₉(OH)₄] (1) and Sr₂B₅O₉(OH)·H₂O (2), with acentric structures have been synthesized under hydro/solvothermal conditions. Compound 1 is reported for the first time in the strontium borates system, and it crystallizes in the monoclinic space group P2₁ with unit cell parameters a = 6.8445(5) Å, b = 8.7033(6) Å, c = 8.4632(6) Å, β = 100.581(6)°, V = 495.58(6) ų and Z = 2. Its structure consists of unusual borate layers of 3, 11-membered rings, which are interconnected via Sr–O ionic bonds and hydrogen bonds to generate a 3D supramolecular network. Compound 2 is a known strontium borate, crystallizing in the monoclinic space group C ₂ with a = 10.161 (13) Å, b = 7.965(4) Å, c = 6.393(11) Å, β = 128.0(2)°, V = 407.7(14) ų and Z = 2. Second-harmonic generation measurements on the powder samples reveal that 1 and 2 exhibits good SHG efficiency about 1.5 and 2 times that of KDP (KH₂PO₄) powder respectively.     

A new type of orthoborates: ASr4La3(BO3)6 (A = Li,Na)

Two new rare earth containing orthoborate crystals ASr₄La₃(BO₃)₆ (A = Li, Na) have been obtained by spontaneous nucleation from high-temperature melts of A₂O–SrO–La₂O₃–B₂O₃–AF. X-ray diffraction analyses show that they both crystallize in the rhombohedral space group R-3 with cell parameters of a = 12.309(7) Å, c = 9.316(7) Å and a = 12.4049(13) Å, c = 9.348(2) Å for the Li and Na compounds respectively. Similar to the large A′₆MM′(BO₃)₆ family, these compounds are all related to the structure of Sr₃Y(BO₃)₃ with La and Sr statistically occupy the Sr site, and the alkaline elements and remaining Sr enter the ordered Y1 and Y2 sites, which can be approximately represented as (La_2.91Sr_3.09)(La_0.09Sr_0.91)Li[B₆O₁₈] and (La_2.85Sr_3.15)(La_0.15Sr_0.85)Na[B₆O₁₈]. The characteristic of the structure is that the La/Sr and isolated BO₃ groups form a network with tunnels along the c-axis where the alkaline A and Sr ions alternatively reside. The optical transmission spectrum shows that the ultraviolet absorption edge of NaSr₄La₃(BO₃)₆ crystal is about 193 nm and Raman spectra reveal that both crystals possess sharp peaks at 930 cm⁻¹.     

Synthesis, crystal structure and NLO property of a nonmetal pentaborate [C6H13N2][B5O6(OH)4]

A nonmetal pentaborate [C₆H₁₃N₂][B₅O₆(OH)₄] (1) has been synthesized by 1,4-diazabicyclo[2.2.2] octane (DABCO) and boric acid, and characterized by single-crystal X-ray diffraction, FTIR, elemental analysis, and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic system with space group Cc (no. 9), a=10.205(2) Å, b=14.143(3) Å, c=11.003(2) Å, β=113.97(3)°, V=1451.1(5) Å³, Z=4. The anionic units, [B₅O₆(OH)₄]⁻, are interlinked via hydrogen bonding to form a three-dimensional (3D) supramolecular network containing large channels, in which the protonated [C₆H₁₃N₂]⁺ cations are located. Second-harmonic generation (SHG) measurements on the powder samples reveal that 1 exhibits SHG efficiency approximately 0.9 times that of potassium dihydrogen phosphate (KDP).     

Synthesis and study of hexaamminecadmium hydrogen hexamolybdocobaltate(III) and hexamolybdochromate(III)

Hexaamminecadmium hydrogen hexamolybdocobaltate(III) and hydrogen hexamolybdochromate(III) of compositions [Cd(NH₃)₆] · H[CoMo₆O₁₈(OH)₆] · 6H₂O (I) and [Cd(NH₃)₆] · H[CrMo₆O₁₈(OH)₆] · 6H₂O (II), respectively, were synthesized and studied by mass spectroscopy, thermo-gravimetry, X-ray powder diffraction, and IR spectroscopy. Crystals of I and II are monoclinic. For I: a = 10.79 Å, b = 3.70 Å, c = 11.95 Å, β = 91.05°, V = 470.12 ų, ρ_calc = 2.37 g/cm³, Z = 2; and for II: a = 10.80 Å, b = 3.68 Å, c = 11.97 Å, β = 91.07°, V = 468.98 ų, ρ_calc = 2.36 g/cm³, Z = 2.     

Barium vanadium(III) hydrogen ­phosphate,Ba3V2(HPO4)6

Hydro­thermally prepared Ba₃V₂(HPO₄)₆ contains a three‐dimensional network of V^IIIO₆ octahedra [d_av(V—O) = 2.014 (2) Å] and HPO₄ [d_av(P—O) = 1.537 (3) Å] tetrahedra, sharing vertices. 12‐coordinate Ba²⁺ cations [d_av(Ba—O) = 2.944 (4) Å] complete the structure.     

Synthèse et étude structurale du polyanion [AsIII 4Mo6W14O72(H2O)2]12– isomorphe de [AsIII 4W20O72(H2O)2]12–

Synthesis and X-ray study of the polyanion [As^III ₄Mo₆W₁₄O₇₂(H₂O)₂]^12– isomorphous of [As^III ₄W₂₀O₇₂(H₂O)₂]^12–. The addition of an excess of MoO₄^2– to a solution of [As^III₂W₈O₃₀(OH)]^7– led at pH=4 to a new polyanion [As^III ₄Mo₆W₁₄O₇₂(H₂O)₂]^12– isostructural of [As^III ₄W₂₀O₇₂(H₂O)₂]^12–. The structure of this compound was determined by X-ray diffraction: a=11.183(4) Å, b=13.432(3) Å, c=19.626(5) Å, α=77.87(2), β=73.57(3), γ=67.44(3)°, V=2 594(1) ų, P1̄. Reliability factors are R=7.89 and R_w=9.97. The starting compound underwent an isomerisation β→α and one tungsten was formally substituted by one molybdenum atom; two other molybdenum atoms were incorporated. The polyanion is formed of two units αB–As^IIIMo₂W₇O₃₃ connected by a double chain As^IIIOMo₂O₂(H₂O). Arsenic and molybdenum are both bound to two octahedrons WO₆ of one unit As^IIIOMoO₂W₇O₃₃, both molybdenum atoms of which are contiguous. © 2000 Académie des sciences / Éditions scientifiques et médicales Elsevier SASpolymolybdotungstate / arsenomolybdotungstate / crystal structure / (hexamolybdenumtetradecatungsten)ate / synthesis of a new mixed polytungstate     

Two novel Keggin tungstocobaltates grafted by cobaltII complex group(s): K[Co(phen)2(H2O)]2[HCoW12O40]·2H2O and [Co(2,2′-bipy)3]1.5{[Co(2,2′-bipy)2(H2O)][HCoW12O40]}·0.5H2O

Two novel inorganic–organic hybrid compounds composed of Keggin tungstocobaltate framework and cobalt(II)–N coordination complexes, K[Co(phen)₂(H₂O)]₂[HCoW₁₂O₄₀]·2H₂O (1) (phen = 1,10-phenanthroline) and [Co(2,2′-bipy)₃]_1.5{[Co(2,2′-bipy)₂(H₂O)][HCoW₁₂O₄₀]·0.5H₂O (2) (bipy = bipyridine), have been synthesized under hydrothermal conditions by directly using Keggin POMs as starting materials, which were characterized by elemental analyses, IR, TG analyses and X-ray single crystal diffraction. Crystal data for compound 1: C₄₈H₄₁Co₃KN₈O₄₄W_12, triclinic, space group P-1, a = 10.918(5) Å, b = 13.401(5) Å, c = 13.693(5) Å, α = 69.291(5)°, β = 71.568(5)°, γ = 78.421(5)°, V = 1768.9(12) Å³, Z = 1; for compound 2: C₁₃₀H₁₀₄Co₇N₂₆O₈₃W_24, orthorhombic, space group, C2/c, a = 46.839(9) Å, b = 14.347(3) Å, c = 26.147(5) Å, α = β = γ = 90°, V = 17,570(6) Å³, Z = 4. Compound 1 exhibits a pseudo-1D chainlike structure, in which potassium ions act as linkages of Keggin unit doubly grafted by [Co(phen)₂(H₂O)] complex. Compound 2 represents a [Co(2,2′-bipy)₂(H₂O)]²⁺ mono-grafted Keggin tungstocobaltate derivative with 1.5[Co(2,2′-bipy)₃]²⁺ countercations. The cyclic voltammetric behavior of 1-CPE is similar to the parent 3-CPE, but the cyclic voltammetric behavior of Co^II shows a little difference. Variable-temperature magnetic susceptibility measurement of compound 1 demonstrates the presence of antiferromagnetic interactions.