Solvothermal synthesis of new open-framework metal phosphites with structure-directing agents generated in situ

By using amide molecules and a urea derivative as the source of structure-directing agents (SDAs), three open-framework metal phosphites, (CH₃NH₃)₂·[Be₃(HPO₃)₄] (1), (CH₃CH₂NH₃)₂·[Be₃(HPO₃)₄] (2), and [(CH₃)₂NH₂]_1.5·(H₃O)_0.5·[Al₄(HPO₃)₇(H₂O)₃]·(H₂O)_0.5 (3), have been synthesized under solvothermal conditions. Compound 1 has left- and right-handed helical channels running along the [001] directions. Compound 2 possesses zigzag 12-ring channels running along the [001] direction. Compound 3 contains multidirectional 12-ring channels running along the [100], [010], and [110] directions. It is noteworthy that the direct use of methylamine, ethylamine and dimethylamine as SDAs can't produce corresponding single crystals of compounds 1–3, demonstrating the slow release of amines from amide molecules and urea derivative is a key process for the crystal growth.     

Solvent-free synthesis of new metal phosphites with double-layered,pillared-layered,and framework structures

Three new metal phosphites, formulated as (H₃O)₂·Mn₂(HPO₃)₃ (1), Co(bpy) (H₂O) (HPO₃) (2), and H₂tmpda·Zn₃(HPO₃)₄ (3), have been synthesized under solvent-free conditions, where bpy = 4,4′-bipyridine, and tmpda = N,N,N′,N′-tetramethyl-1,3-propanediamine. Compound 1 has a double-layered structure with a thickness of 5.68 Å. Compound 2 has an inorganic-organic hybrid framework with cobalt phosphite layers pillared by bpy ligands. Compound 3 has a three-dimensional open-framework structure containing 8-ring channels. The temperature dependence of the magnetic susceptibility of compounds 1 and 2 were also investigated.     

The first organically templated gallium phosphite–oxalates: Synthesis,structures, and characterizationseer

Three new gallium phosphite–oxalates formula as (C₆N₂H₁₄)₂[Ga₂(OH)₂(C₂O₄)₂(HPO₃)₂]·2H₂O (1), (C₆N₂H₁₈)_0.5[Ga(OH)(C₂O₄)_0.5(HPO₃)] (2), and Ga(C₂O₄)_0.5(C₃N₂H₄)(HPO₃) (3) have been hydrothermally synthesized by controlling the pH value of the reaction system. Compound 1 possesses a one-dimensional ladder-like chain structure, in which the C₂O₄^2? anion is coordinated to one Ga center and acts as mono-bidentate ligand. In 2 and 3, the C₂O₄^2? anions serve as bis-bidentates ligands bridging between two Ga atoms to form the two-dimensional layered structures. Furthermore, compound 3 displays a neutral layered network, which is decorated by the directly coordinated organic ligand.     

Synthesis and characterization of a new organically templated open-framework beryllium phosphite with 3, 4-connected networks

Employing diethylenetriamine (=dien) as a structure-directing agent, a new open-framework beryllium phosphite H₂dien·Be₃(HPO₃)₄ (1), has been synthesized hydrothermally and structurally characterized by single crystal X-ray diffraction. The structure of 1 features a (3, 4)-connected framework with 8- and 12-ring channels, which is constructed from strictly alternating BeO₄ tetrahedra and HPO₃²⁻ pseudopyramids. The 3-D framework possesses a pcu topology when the heptameric [Be₃(HPO₃)₄] clusters are regarded as 6-connected secondary building units. Crystal data: 1, monoclinic, C2/c (no. 15), a = 8.7350(3) Å, b = 15.1704(6) Å, c = 13.0851(4) Å, β = 101.223(5)°, V = 1700.79(10) Å³, Z = 4, R₁ = 0.0625, wR₂ = 0.1692.     

Two distinct manganese molybdenum(V) phosphates directed by different organic amines

By employing different organic amines as structure-directing agents, two new distinct 3D porous inorganic frameworks based on molybdenum(V) phosphates and Mn^II, (H₂en)₂{[Mn(H₂O)]₂[MnMo₁₂O₂₄(OH)₆(H₂PO₄)₂(HPO₄)₄(PO₄)₂]}·7H₂O (en = ethylenediamine) (1) and (H₃dien)₂{[Mn(H₃O)₂][Mn₃Mo₁₂O₂₄(OH)₆(HPO₄)₂(PO₄)₆]}·5H₂O (dien = diethylenetriamine) (2), have been hydrothermally synthesized, and characterized by routine physical methods. In compound 1, Mn^II all adopt octahedral coordination mode and each sandwich cluster Mn[Mo₆P₄O₃₁]₂ (abbreviated as Mn[Mo₆P₄]₂) acts as an octa-dentate ligand linking eight Mn^II, which result in a 3D inorganic (4, 8)-connected framework with the (4⁶)(4¹⁰·6¹²·8⁶) topology. Compound 2 shows a 3D (4, 10)-connected framework with the (3¹·4⁴·6¹)(3⁴·4⁹·5⁷·6¹⁷·7⁴·8⁴) topology, in which Mn^II ions exhibit both tetrahedral and octahedral coordination modes, and each Mn[Mo₆P₄]₂ links ten Mn^II. Interestingly, there exist channels along the a and b axes in 1, while along the a and c axes in 2. The differences between the two compounds should be ascribed to the distinctions of the organic amines. Primary de-/rehydration behaviors and electrochemistry properties have also been studied for the two compounds.     

Magnetic and catalytic properties of the 2D copper(II) functionalized VPO hybrid system [{Cu(bpy)}2(VO)3(PO4)2(HPO4)2]·2H2O

The hybrid 2D compound [{Cu(bpy)}₂(VO)₃(PO₄)₂(HPO₄)₂]·2H₂O (1), has been investigated due to its interesting magnetic and catalytic properties. Compound (1) acts as an efficient catalyst in the epoxidation of cyclohexene and styrene. The chemoselectivity towards the epoxidation of cyclohexene is notoriously higher than the one observed towards styrene. The bulk antiferromagnetic behaviour of [{Cu(bpy)}₂(VO)₃(PO₄)₂(HPO₄)₂]·2H₂O (1) can be well described with a pentanuclear model, using five J values. Both antiferromagnetic and ferromagnetic interactions mediated by phosphate bridges are found to be present in this hybrid copper(II)–vanadium(IV) material.     

Assembly of two novel inorganic–organic hybrid solids based on 3-(aminomethyl)pyridine ligand

Two new inorganic–organic hybrids, (Hampy)Zn₂(PO₄) (HPO₃) (1) and (ampy)Zn₂(HPO₃)₂ (2), where ampy = 3-(aminomethyl)pyridine, have been solvothermally prepared and structurally characterized. Compound 1 exhibits an unusual two-dimensional layer structure, which possesses a central 4.8² zincophosphate sheet wrapped by infinite zincophosphite chains. Left- and right-handed helical chains participate in the formation of the zincophosphate layer. Compound 2 features a three-dimensional pillared-layer structure, in which two-dimensional Zn^II(HPO₃) inorganic sheets were cross-linked by ampy ligands. The simultaneous occurrence of zinc-amine helical chains in 2 is unique and, to the best of our knowledge, firstly encountered in phosphite/phosphate hybrid materials. Different coordination modes and roles of the same ampy ligand were observed in the formation of the hybrid structures.     

Hydrothermal synthesis and structure characterization of two six-connected metal–organic frameworks based on the mixed ligands

Two metal–organic frameworks, namely, [Ni₂(BIMB)₂(ndd)₂·H₂O]_n (1) and [Zn₃(ndd)_2.5(μ₃-OH)(1,3-dpp)]_n (2) (H₂ndd = 2,2′-(naphthalene-1,5-diylbis(oxy))diacetic acid, BIMB = 1,4-bis[(1H-imidazol-1-ly)methyl]benzene, 1,3-dpp = 1,3-di(pyridin-4-yl)propane) have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction and thermogravimetric analysis. Compound 1 presents a two-dimensional network with point symbol of (3⁶·4⁶·5³)-hxl topology. Moreover, compound 2 displays a novel 2-fold interpenetrated structure with the point symbol of (4¹²·6³)-pcu topology based on the hexanuclear [Zn₆(CO₂)₁₀(N)₄] unit as a six-connected node. Meanwhile, compound 2 shows good fluorescence property in the solid state at room temperature.     

Structure and spectral characteristics of (NH4)2[Re2(HPO4)4 · 2H2O]

The compound (NH₄)₂[Re₂(HPO₄)₄ · 2H₂O] has been synthesized and characterized by electronic and vibrational spectroscopy. The molecular structure has been determined by X-ray diffraction (MoK _α radiation, λ = 0.71073 Å). The (NH₄)₂[Re₂(HPO₄)₄ · 2H₂O] coordination units form centrosymmetrical binuclear ordering with each metal atom being coordinated in a distorted octahedron incorporating one rhenium atom, one oxygen atom of the water molecule, and four phosphate oxygen atoms in the equatorial plane. The rhenium-rhenium bond length (2.2207 Å) corresponds to a quadruple bond between the atoms. The [Re₂(HPO₄)₄ · 2H₂O]^2- complex anions in the crystal are associated through strong hydrogen bonds formed by the phosphate O-H···O groups. The stability of dirhenium(III) tetra-μ-phosphates in aqueous solutions is considered.     

Synthesis and structural characterization of two cobalt phosphites: 1-D (H3NC6H4NH3)Co(HPO3)2 and 2-D (NH4)2Co2(HPo3)3

Two new cobalt phosphites, (H₃NC₆H₄NH₃)Co(HPO₃)₂ (1) and (NH₄)₂Co₂(HPO₃)₃ (2), have been synthesized and characterized by single-crystal X-ray diffraction. All the cobalt atoms of 1 are in tetrahedral CoO₄ coordination. The structure of 1 comprises twisted square chains of four-rings, which contain alternating vertex-shared CoO₄ tetrahedra and HPO₃ groups. These chains are interlinked with trans-1,4-diaminocyclohexane cations by hydrogen bonds. The 2-D structure of 2 comprises anionic complex sheets with ammonium cations present between them. An anionic complex sheet contains three-deck phosphite units, which are interconnected by Co₂O₉ to form complex layers. Magnetic susceptibility measurements of 1 and 2 showed that they have a weak antiferromagnetic interaction.     

A series of novel 1D coordination polymers constructed from metal–quinolone complex fragments linked by aromatic dicarboxylate ligands

Self-assembly of quinolones with metal salts in the presence of aromatic dicarboxylate ligands affords a series of novel 1D metal–quinolone complexes, namely [Mn(Hppa)(oba)]·3H₂O (1), [Co(Hppa)(oba)]·3.25H₂O (2), [Zn(Hppa)(sdba)]·1.5H₂O (3), [Mn(Hcf)(bpda)(H₂O)]·2H₂O (4), [Mn(Hppa)₂(bpdc)] (5) and [Mn(Hlome)₂(bpdc)]·4H₂O (6) (Hppa = Pipemidic acid, Hcf = ciprofloxacin, Hlome = lomefloxacin). The structures of compounds 1–3 consist of novel polymeric chains spanning two different directions, which display an intriguing 1D → 3D inclined polycatenation of supramolecular ladders. Compound 4 exhibits a chain compound formed from the interconnection of [Mn₂(Hcf)₂(μ-CO₂)₂] dimers with bpda ligands. Compounds 5 and 6 are similar chain compounds constructed from [Mn(Hppa)₂] (or [Mn(Hlome)₂]) fragments linked by bpdc ligands. The magnetic properties of 4 have been studied, which indicate the existence of antiferromagnetic interactions. Furthermore, the luminescent properties of compound 3 are discussed.     

Coordination polymer with the framework structure [Zn2(DMA)(Atc)] · DMA: Synthesis, structure, and properties

Crystals of a new coordination polymer with the framework structure, [Zn₂(DMA)(Atc)] · DMA (I), were prepared by heating a solution of Zn(NO₃)₂ · 6H₂O and H₄Atc (H₄Atc is 1,3,5,7-adamantanetetracarboxylic acid) in N,N′-dimethylacetamide (DMA). Colorless crystals of Zn₂(Atc) · 2MeOH · 4H₂O (II) were obtained by soaking the crystals of compound I in methanol. The structure of compound I was determined by X-ray diffraction analysis. Compounds I and II were characterized by X-ray powder diffraction, IR spectroscopy, thermal gravimetric analysis, and elemental analysis. The luminescence properties of compound I were studied.     

Self-assembly of four new extended architectures based on reduced polyoxometalate clusters and cadmium complexes

Four new [P₄Mo₆] cluster-based extended structures containing cadmium complexes, [Cd₃(4,4′-Hbpy)₂(4,4′-bpy)₂(H₂O)₈][Cd(H₂PO₄)₂(HPO₄)₄(PO₄)₂(MoO₂)₁₂(OH)₆]·7H₂O 1, (4,4′-Hbpy)₂[Cd(4,4′-bpy)₃(H₂O)₃][Cd(4,4′-bpy)(H₂O)]₂[Cd(H₂PO₄)₂(HPO₄)₄ (PO₄)₂(MoO₂)₁₂(OH)₆]·H₂O 2, [Cd₄(phen)₂(H₂O)₄][Cd(phen)(H₂O)]₂[Cd(HPO₄)₄ (HPO₄)₄(MoO₂)₁₂(OH)₆]·5H₂O 3 and [Cd₄(2,2′-bpy)₂(H₂O)₄][Cd(2,2′-bpy)(H₂O)]₂ [Cd(HPO₄)₄(HPO₄)₄(MoO₂)₁₂(OH)₆]·3H₂O 4 (4,4′-bpy=4,4′-bpyridine, phen=1,10-phenanthroline, 2,2′-bpy=2,2′-bpyridine), have been synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. The structure of compound 1 is constructed from the Cd[P₄Mo₆]₂ dimers linked by [Cd₃(4,4′-Hbpy)₂(4,4′-bpy)₂(H₂O)₈] subunits to generate a plane layer. Compound 2 consists of the positive 2D sheets that constructed from Cd[P₄Mo₆]₂ dimers linked by [Cd(4,4′-bpy)(H₂O)] complexes, then the 2D sheets are further linked up together to form a 3D supramolecular framework via extensive hydrogen-bonding interactions among the [P₄Mo₆] clusters, free 4,4′-bpy molecules, dissociated [Cd(4,4′-bpy)₃(H₂O)₃]²⁺ complexes and water molecules. Compounds 3 and 4 show new 2D layered structure, with Cd[P₄Mo₆]₂ building blocks connected by tetra-nuclear [Cd₄{(phen)₂/(2,2′-bpy)₂}(H₂O)₄] clusters and [Cd(phen/2,2′-bpy)(H₂O)] complexes. The fluorescent activities of compounds 3 and 4 are reported.     

Syntheses and structures of p-HOOCC6F4COOH · H2O (H2L · H2O) and luminescent coordination polymers [Tb2(H2O)4(L)3 · 2H2O] n and Tb2(Phen)2(L)3 · 2H2O

Compounds p-HOOCC₆F₄COOH · H₂O (H₂L · H₂O), [Tb₂(H₂O)₄(L)₃ · 2H₂O] _n (I), and Tb₂(Phen)₂(L)₃ · 2H₂O (II) are synthesized. According to the X-ray structure analysis data, the crystal structure of H₂L · H₂O is built of centrosymmetric molecules H₂L and molecules of water of crystallization. The crystal structure of compound I is built of layers of coordination 2D polymer [Tb₂(H₂O)₄(L)₃] _n and molecules of water of crystallization. The ligands are the L^2? anions performing both the tetradentate bridging and pentadentate bridging-chelating functions. The coordination polyhedron TbO₉ is a distorted three-capped trigonal prism. Acid H₂L manifests photoluminescence in the UV region (??_max = 368 nm). Compounds I and II have the green luminescence characteristic of the Tb³⁺ ions, and the band with ??_max = 545 nm (transition ⁵ D ₄?? ⁷ F ₅) is maximum in intensity. The photoluminescence intensity of compound II is higher than that for compound I.     

Examples of cation exchange in new ionic oxovanadium(IV) complexes with anions of cyclobutane-1,1-dicarboxylic acid

The results on the synthesis and study of the crystal structures of compounds based on anionic fragments {VO(Cbdc)₂}^2– formed by oxovanadium(IV) (vanadyl, VO²⁺) and two chelate-bound anions of cyclobutane-1,1-dicarboxylic acid (H₂Cbdc = C₄H₆(COOH)₂) are presented. The use of ammonium cation NH₄⁺ as a counterion in the synthesis leads to the formation of the mononuclear complex (NH₄)₂[VO(Сbdc)₂(H₂O)] · 2H₂O (I). In the case of K⁺ cation, compound [K₄(VO)₂(Сbdc)₄(H₂O)₄] _n (II) with the 3D polymeric crystal structure is formed. The reaction of compound II with Mg(NO3)2 · 6H₂O in an aqueous solution involves the partial substitution of K⁺ by Mg²⁺ cations to form 1D polymeric compound {[KMg_0.5(VO)(Сbdc)₂(H₂O)_6.5] · 3H₂O} _n (III), while a similar reaction of compound I does not afford the product of substitution of NH₄⁺ by Mg²⁺ cations (CIF files CCDC 1551021–1551023 for compounds I–III, respectively).     

(C5H6N)4[Be6(HPO3)8]·H2O: A low-density open-framework beryllium phosphite with multidirectional 12-ring channels

Employing the common pyridine (=py) solvent as the source of structure-directing agents (SDAs), a novel three-dimensional open-framework beryllium phosphite (Hpy)₄[Be₆(HPO₃)₈]·H₂O (1), has been solvothermally synthesized and structurally characterized by IR, elemental analysis, thermogravimetric analysis, powder and single-crystal X-ray diffractions. It crystallizes in the orthorhombic system, space group Pbca (No. 61), a = 20.0034(4) Å, b = 20.2188(4) Å, c = 20.9731(3) Å, V = 8482.5(3) Å³, and Z = 8. The alternating connection of BeO₄ tetrahedra and HPO₃ pseudopyramids give rise to a (3, 4)-connected network with multidirectional intersecting 12-ring channels. The compound possesses a low density and a new {4.8.10}{4².6.8.10.12}{4².6}₃{4².8.10².12}{4³.6².8} topology.     

Four novel linear trinuclear assemblies containing bridging triazole ligands. Crystal structure,magnetic, semiconducting and fluorescent properties

Four homotrinuclear linear coordination compounds with bridging ligand of (m-phenol)-1,2,4-triazole, [Mn₃(L)₆(H₂O)₆](ClO₄)₆ (1), [Ni₃(L)₆(H₂O)₆](BF₄)₆·4DMF (2), [Cd₃(L)₆(H₂O)₆](ClO₄)₆· 2H₂O·2DMF·2EtOH (3), [Zn₃(L)₈(H₂O)₄](BF₄)₄(SiF₆)·2EtOH·12H₂O (4), have been synthesized and structurally determined. The structures consist of three metal ions in linear arrangements, linked to each other by two pairs of three N1, N2 bridging triazole ligands. The negative value of J suggests that antiferromagnetic interaction exists in 1. Green fluorescence of 2 and 4 with emissions at 518 nm for 2 and 524 for 4 is possibly assigned to LMCT. The energy gaps of the compounds 2 and 4 are 1.82 and 1.97 eV, respectively, which suggests that the two materials behave as semiconductors.     

Two zincophosphite frameworks templated by 1,4-diaminobenzene: syntheses and structures of C6N2H10·Zn(HPO3)2 and (C6N2H8)0.5·ZnHPO3

The solution-mediated syntheses and single crystal structures of C₆N₂H₁₀·Zn(HPO₃)₂ (I) and (C₆N₂H₈)_0.5·ZnHPO₃ (II) are reported. Slight variation of the synthesis conditions led to two quite different phases. I contains infinite chains of ZnO₄ and HPO₃ groups with the protonated organic moiety acting as a template and interacting with the chains by NH⋯O hydrogen bonds and possible CH⋯O interactions. In II, the neutral 1,4-diamino benzene molecule bonds to Zn (as a ligand) and an unusual composite, “pillared”, structure results, with the organic species bridging 6³ polyhedral sheets, although NH⋯O bonds are also present. Similarities and differences to other zinc phosphites and phosphates are briefly discussed for I and II. Crystal data: C₆N₂H₁₀·Zn(HPO₃)₂, M_r=335.48, monoclinic, C2/c (No. 15), a=17.2471 (14) Å, b=9.0720 (8) Å, c=7.6529 (6) Å, β=103.752 (2)°, V=1163.09 (7) Å³, Z=4, R(F)=0.038, wR(F²)=0.084. (C₆N₂H₈)_0.5·ZnHPO₃, M_r=199.42, orthorhombic, Pbca (No. 61), a=8.0314 (16) Å, b=8.1299 (16) Å, c=18.830 (4) Å, V=1229.5 (4) Å³, Z=8, R(F)=0.026, wR(F²)=0.055.     

Hydrothermal synthesis and characterization of the first 1-D indiumphosphate chain In2(HPO4)2(H2PO4)2F2·C4N2H12, a precursor for high dimensional structures

The first one-dimensional (1-D) indiumphosphate chain, In₂(HPO₄)₂(H₂PO₄)₂F₂·C₄N₂H₁₂ (1), has been hydrothermally prepared using piperazine (PIP) as a template. The structure consists of infinite chains of trans,trans-corners-sharing InO₄F₂ octahedra with the adjacent octahedra being bridged by tetrahedral PO₃(OH) and PO₂(OH)₂ units, which are H-bonded with amine groups of the organic cations. Interestingly, this macroanionic chain InP₂O₈H₃F⁻ is similar to that found in the mineral tancoite-like chains and has potential to further set up higher-dimensional networks. On heating 1 in the presence of additional phosphoric acid at 180 °C under hydrothermal condition, compound 2, In₂(OH)(H₂O)(PO₄)₂·H₃O·H₂O, possessed a 3-D structure building from the repetition of a secondary building unit is obtained. When 1 is heated with additional PIP, an unknown phase, compound 3 is formed. Finally, on treatment with another amine, such as diethylenetriamine or 1,4-diaminobutane, at 180 °C, 1, as a precursor, can convert into a previously known 3-D framework structure with 16-membered ring compound 4. Compounds 1 and 2 are determined by single-crystal X-ray diffraction. Furthermore, 1 is characterized by X-ray powder diffraction, IR spectroscopy, inductively coupled plasma analysis, thermogravimetric analysis and differential thermal analysis.     

Cobalt(II) coordination polymers built on isomeric dipyridyl triazole ligands with pyromellitic acid: Synthesis, characterization and their effects on the thermal decomposition of ammonium perchlorate

Three new cobalt(Ⅱ) coordination compounds,[Co(3,3’-Hbpt)2(H2pm)(H2O)2]·2H2O(1),[Co(4,4’-Hbpt)(pm)0.5(H2O)]·3H2O (2) and [Co(3,4’-Hbpt)(pm) 0.5 (H2O)3]·2H2O(3)(3,3’-Hbpt=3,5-bis(3-pyridyl)-1H-1,2,4-triazole;4,4’-bpt=3,5-bis(4-pyridyl)1H-1,2,4-triazole,3,4’-Hbpt=3-(3-pyridyl)-5-(4’-pyridyl)-1H-1,2,4-triazole and H4pm=pyromellitic acid) have been synthesized by hydrothermal reactions.Single-crystal X-ray diffraction reveals that compound 1 has a one-dimensional (1D) chain network,2 exhibits a four-connected three-dimensional (3D) structure with 1D open channels encapsulated by water molecules,while 3 displays a regular two-dimensional (2D) architecture connected through 1D metal helical chains.In addition,the efficacy of compounds 1-3 as additives to promote the thermal decomposition of ammonium perchlorate (AP) is explored by differential scanning calorimetry (DSC).