Open-framework Zinc Phosphites Research Articles

Studies on the Genesis and Proton Conductivity of Imidazole-Based Linear and Open-Framework Zinc Phosphites.

Three new zinc phosphites, [HIm]2[Zn3(HPO3)4] (1), [Zn2(HPO3)2Im2] (2), and [Zn(HPO3)Im] (3) (Im = imidazole), have been synthesized from the hydro/solvothermal reaction of zinc acetate, dimethyl phosphite, and imidazole by varying the temperature and solvent of the reaction medium. The structure of 1 is built from vertex-sharing of four HPO3-capped Zn3P3 units and adopts an open framework with 12-ring channels stabilized by HIm cations via N-H···O hydrogen bonds. For 2, the inorganic skeleton is comprised of alternating ZnO4 and HPO3 tetrahedra, while the coordinatively associated ZnN2O2 fragments occupy the 12-ring hexagonal channels. Compound 3 adopts a ladder-type one-dimensional structure and exhibits N-H···O hydrogen-bonding interactions to afford a supramolecular assembly. A plausible rationale on the genesis of 1-3 has been put forth by reacting the preformed inorganic zinc phosphites Zn{OP(O)(OMe)H}2 or [Zn2(HPO3)2(H2O)4]·H2O with imidazole as the structure-directing ligand. Alternating-current impedance measurements reveal that 1 and 3 exhibit proton conductivities on the order of 10-3-10-4 S cm-1 between 25 and 100 °C under 35 and 77% relative humidity in repeated impedance cycles (Ea = 0.22-0.35 eV). On the contrary, the conduction property is completely impaired in 2 under similar conditions.

Two open-framework zinc phosphites constructed from different secondary building units

Presented here are two new zinc phosphites, formulate as Zn3(dabco)2(HPO3)3 (1, dabco=1,4-diazabicyclo[2·2·2]octane), and H2pmdeta⋅Zn3(HPO3)4 (2, pmdeta=N,N,N′,N″,N″-pentamethyldiethylenetriamine). Compound 1 has 12-membered-ring (12 MR) channels with a 5-connected bnn topology containing 4=1 secondary building units. Compound 2 has multidirectional 10 MR channels with a pcu topology constructed from 6*1 secondary building units. The gas adsorption and fluorescent properties of compound 1 were also investigated.

Amine-Ligated Approach for the Synthesis of Extra-Large-Pore Zinc Phosphites with qtz-h and bnn Topologies.

Presented here are two open-framework zinc phosphites, namely, Zn(dabco)0.5(HPO3) (SCU-18) and Zn4(Hdabco)2(CH3COO)2(HPO3)4 (SCU-20), where dabco = 1,4-diazabicyclo[2.2.2]octane. SCU-18 features a rare 3-connected inorganic skeleton with a chiral qtz-h topology. It contains 18-membered-ring (18 MR) channels displaying porosity and second-harmonic-generation response. SCU-20 has a bnn topology containing large 20 MR channels that shows a strong blue emission as a result of excitation at 375 nm.

Hydrothermal synthesis of a new zinc phosphite (C5H7N2)2·[Zn3(HPO3)4] with intersecting 8- and 12-ring channels

Using 4-aminopyridine as the structure-directing agent(SDA), a new open-framework zinc phosphite, (C5H7N2)2·[Zn3(HPO3)4](ZnHPO-CJ70), was synthesized under hydrothermal condition. Single-crystal X-ray diffraction analysis reveals that ZnHPO-CJ70 is constructed by the strictly alternating ZnO4 tetrahedra and HPO3 pseudo-pyramids, with their vertexes linked to generate a three-dimensional(3D) open framework with intersecting 8- and 12-ring channels. Further characterizations of ZnHPO-CJ70 were performed by means of X-ray powder diffraction(XRD), elemental analysis(ICP, CHN), infrared spectroscopy(IR) and thermogravimetric(TG) analyses. The results of luminescent test shows that ZnHPO-CJ70 exhibits strong fluorescence emissions in the solid state at room temperature.

Synthesis, Structure, and Characterisation of Two New Open-Framework Zinc Phosphites of Varying Dimensionality

Using homopiperazine (hpip) as a structure directing agent, two new zinc phosphites [H2hpip][Zn2(HPO3)3] (1) and [H2hpip][Zn3(HPO3)4] (2), have been synthesised and structurally characterised by IR spectroscopy, elemental analysis, thermogravimetric analysis, and powder and single-crystal X-ray diffractions. Although both compounds are constructed from the same ZnO4 and HPO3 building units, the final frameworks are distinctly different due to their different connectivity. Compound 1 displays a 2D layered structure with 8-membered ring apertures, while compound 2 possesses a (3,4)-connected 3D architecture with multidirectional intersecting 8- and 12-ring channels. In addition, the simultaneous occurrence of four types of 8-ring channels intersecting the large 12-ring apertures in 2 is unique and observed here for the first time.

Synthesis and structural characterization of two open-framework zinc phosphites with (3,4)-connected networks

Two new organically templated zinc phosphites, [H2dmpip][Zn3(HPO3)4] (1) and [HMedmpip][Zn3(HPO3)4] (2), where dmpip=2,6-dimethyl-piperazine and Medmpip=N-methyl-2,6-dimethyl-piperazinium, have been synthesized and structurally characterized. Note that the new Medmpip2+ template in 2 is generated from in situ N-methylation reaction between CH3OH and the dmpip amine precursor, which is used to serve as template in 1. Such direct N-methylation transformation is unique, and quite different from conventional Eschweiler–Clarke methylation in which an excess of formic acid and formaldehyde was required. Both compounds are constructed from strictly alternating ZnO4 and HPO3 units, and possess different (3,4)-connected interrupted frameworks with intersecting 8-, 10- and 12-ring channels (for 1), and 8-, 12-ring channels (for 2), respectively. The occurrence of helical channels in the open structure of 1, and fascinating hydrogen-bonded helices between the host inorganic chains and guest organic templates are also noteworthy.

Two new three-dimensional zinc phosphites templated by piperazine: [H2pip][Zn3(HPO3)4(H2O)2] and K[H2pip]0.5[Zn3(HPO3)4

Two three-dimensional open-framework zinc phosphites with the same organically templated, [H2pip][Zn3(HPO3)4(H2O)2] (1) and K[H2pip]0.5[Zn3(HPO3)4] (2) (pip=piperazine), have been solvothermally synthesized and structurally characterized by IR, elemental analysis, thermogravimetric analysis, powder and single-crystal X-ray diffractions. Compound 1 consists of ZnO4 tetrahedra, [HPO3] pseudopyramids and [ZnO4(H2O)2] octahedra, which are linked through their vertexes to generate three-dimensional architecture with intersecting 8-membered channels along the [100], [001] and [101] directions. Compound 2 is constructed from strictly alternating ZnO4 tetrahedra and [HPO3] pseudopyramids, and exhibits (3,4)-connected inorganic framework with 8-, and 12-membered channels, in which the K+ and diprotonated H2pip2+ extra-framework cations reside, respectively. The coexistence of inorganic K+ and organic piperazine mixed templates in the structure is unique and, to the best of our knowledge, firstly observed in metal-phosphite materials. In addition, the participation of left-handed and right-handed helical chains in construction of the puckered 4.82 sheet structure in 2 is also noteworthy.

A new hybrid zinc phosphite with a pillared layered structure: Synthesis and characterization of [C6N2O2H16][Zn(HPO3)

Abstract By using flexible 1,2-bis(2-aminoethoxy)ethane (BAEOE) as a pillaring ligand, a new inorganic–organic hybrid open-framework zinc phosphite, [C 6 N 2 O 2 H 16 ][Zn(HPO 3 )] 2 ( 1 ), has been hydrothermally synthesized and structurally characterized by IR, elemental analysis, thermogravimetric analysis, powder and single-crystal X-ray diffractions. The structure of 1 consists of neutral layers of zinc phosphite which are further pillared through linear BAEOE ligands, generating a 3D framework with unusual (3, 4)-connected dmc topology. The participation of left-handed and right-handed helical chains in the construction of puckered sheet structure with 4.8 2 -net is also noteworthy.

In situ template generation via N-alkylation in the syntheses of open-framework zinc phosphites and phosphate

In methanol-aqueous solutions, three novel structure-directing agents (SDAs) were generated in situ and presented. These in situ reactions feature N-methylation transformations between CH3OH solvent and organic cyclic aliphatic and aromatic amines, i.e. 2-methylpiperazine, 1,4-diazabicyclo[2,2,2]octane (dabco) and 3-(aminomethyl)pyridine. Distinct from conventional Eschweiler-Clarke methylation containing excess formic acid and formaldehyde, such a direct methylation transformation from methanol molecules is unique. In the presence of new SDAs, three organically templated zinc phosphites/phosphates, [pmpip][Zn3(HPO3)4] I (pmpip = N,N,N',N'-tetramethyl-2-methylpiperazinium), [dmdabco][Zn3(HPO3)4] II (dmdabco = N,N'-dimethyl-1,4-diazabicyclo[2,2,2]octane) and [Hmampy][Zn2(HPO4)3] III (mampy = N-methyl-3-(aminomethyl)pyridine), have been prepared and structurally characterized by elemental analysis, IR, thermogravimetric analysis, powder and single-crystal X-ray diffraction. Compound I exhibits a 2D layer with eight-membered apertures, compounds II and III possess a 3D interrupted framework with intersecting 8-, 10- and 12-ring channels (for II), and 8-, 10-ring channels (for III), respectively.

Syntheses and structures of two open-framework zinc phosphites with extra-large 24-ring channels

Two new three-dimensional open-framework zinc phosphites, [HCHA]2[Zn3(HPO3)4] (1) and [HCHPA]2[Zn3(HPO3)4] (2), have been synthesized under hydrothermal conditions, where CHA = cyclohexylamine and CHPA = cycloheptylamine. Both compounds are isostructural and exhibit a similar three-dimensional 3, 4-connected framework constructed by strictly alternating ZnO4 tetrahedra and HPO32− pseudopyramids. The occurrence of extra-large tubular channels constructed by the concatenation of 24- and 30-ring windows along the [001] direction in the two structures is very unusual in known extra-large micropore materials. Crystal data: 1, rhombohedral, R-3, a = 32.9618(5) Å, c = 13.2818(3) Å, V = 12497.1(4) Å3, Z = 18, R1 = 0.0445, wR2 = 0.1068; 2, rhombohedral, R-3, a = 33.2184(4) Å, c = 13.1697(6) Å, V = 12585.3(6) Å3, Z = 18, R1 = 0.0401, wR2 = 0.0974.

Three-Dimensional Open-Framework Zinc Phosphite: Synthesis and Characterization

Generally, open-framework metal phosphites like phosphates, are synthesized under hydrothermal or solvothermal conditions in the presence of organic amines, which may act as structure-directing agent or template to avoid the formation of dense phase, but few of them has been successfully prepared at room temperature which seems to be difficult to synthesize these compounds. In this work, at room temperature, employing n-propylamine as a template, a three-dimensional zinc phosphite (C3H10N) 2·[Zn3(HPO3)4] has been prepared and characterized by single-crystal X-ray diffraction, FTIR, elemental analysis, powder X-ray diffraction, and thermogravimetric analysis. The compound crystallizes in the orthorhombic space group Pccn, with cell parameters, a = 9.839(3) Å, b = 23.356(8) Å, c = 8.970(3) Å, V = 2050.2(8) nm3 and Z = 4.

Three-Dimensional Open-Framework Zinc Phosphite: Synthesis and Characterization

Generally, open-framework metal phosphites like phosphates, are synthesized under hydrothermal or solvothermal conditions in the presence of organic amines, which may act as structure-directing agent or template to avoid the formation of dense phase, but few of them has been successfully prepared at room temperature which seems to be difficult to synthesize these compounds. In this work, at room temperature, employing n-propylamine as a template, a three-dimensional zinc phosphite (C3H10N) 2·[Zn3(HPO3)4] has been prepared and characterized by single-crystal X-ray diffraction, FTIR, elemental analysis, powder X-ray diffraction, and thermogravimetric analysis. The compound crystallizes in the orthorhombic space group Pccn, with cell parameters, a = 9.839(3) Å, b = 23.356(8) Å, c = 8.970(3) Å, V = 2050.2(8) nm3 and Z = 4.

Synthesis and characterization of three open-framework zinc phosphites with (3,4)-connected frameworks

By using different monoamines as the structure-directing agents, three new open-framework zinc phosphite compounds, [C 4H 10ON] 2·[Zn 3(HPO 3) 4] ( 1), [CH 3CH 2NH 3] 2·[Zn 3(HPO 3) 4] ( 2) and [H 2N(CH 3) 2] 2·[Zn 3(HPO 3) 4] ( 3), have been synthesized under hydro/solvothermal conditions. The three compounds have different (3,4)-connected frameworks constructed from strictly alternating ZnO 4 tetrahedra and HPO 3 pseudo pyramids. The presence of 12-ring channels in their structures is noteworthy. The removal of organic cations in the free voids of compound 1 by an ion-exchange process will make the structure collapse.

Synthesis, characterization, and catalytic behavior of two open-framework zinc phosphites with 2D and 3D structures

Abstract Two new zincophosphites are obtained via a hydrothermal process. Single crystal data indicate that 1 has a two dimensional motif with the organic amine template embedded between the layers, while 2 has a three-dimensional structure with the organic amine template enclosed into the cavities. Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate is carried out with these two complexes as support in ethanol at 333 K respectively. Experimental results indicate that only 1 is efficient for the catalysis. The catalytic ability depends on their structural characters.

Flux synthesis of two new open-framework zinc phosphites with 16-ring channels

Two new three-dimensional open-framework zinc phosphites, (H 2aep) 2·Zn 6(HPO 3) 8 ( 1) and H 3taea·Zn 3(HPO 3) 4.5 ( 2) have been synthesized by the H 3PO 3 flux method, where aep = 1-(2-aminoethyl)piperazine and taea = tris(2-aminoethyl)amine. Compound 1 has a 3,4-connected framework with (4,6,8) sheets connected by corner-sharing 4-ring chains. Compound 2 has 3-connected sheets built from quintuple-fused 4-rings, which are further linked by HPO 3 units to form the three-dimensional structure. The presence of large 16-ring channels in the two structures is noteworthy. Crystal data: 1, monoclinic, P2 1/c, a = 18.8613(7) Å, b = 9.0856(5) Å, c = 24.9485(8) Å, β = 107.211(6)°, V = 4083.9(3) Å 3, Z = 4, R 1 = 0.0457, wR 2 = 0.1050; 2, monoclinic, C2/c, a = 28.911(2) Å, b = 8.302(3) Å, c = 19.513(3) Å, β = 103.715(16)°, V = 4549.8(17) Å 3, Z = 4, R 1 = 0.0428, wR 2 = 0.1165.

Ionothermal synthesis of a new open-framework zinc phosphite NIS-3 with low framework density

The first ionothermal case of open-framework metal phosphite, Zn3(HPO3)4·2C6H11N2, denoted NIS-3, was prepared using 1-ethyl-3-methyl imidazolium bromide as solvent and template.

Flux synthesis of (3,4)-connected zinc phosphites with different framework topologies

Two three-dimensional open-framework zinc phosphites, H 2aem·Zn 3(HPO 3) 4·0.5H 2O ( 1) and H 2apm·Zn 3(HPO 3) 4 ( 2), have been synthesized by a phosphorous acid flux method, where aem=4-(2-aminoethyl)morpholine and apm=4-(3-aminopropyl)morpholine. Compound 1 crystallizes in the monoclinic system, P2 1/ c, a=9.5852(7) Å, b=20.3941(8) Å, c=10.5339(8) Å, β=94.125(9)°, V=2053.8(2) Å 3, Z=4, R 1=0.0319, w R 2=0.0628. Compound 2 crystallizes in the monoclinic system, P2 1/ n, a=8.589(2) Å, b=14.020(3) Å, c=16.606(3) Å, β=97.190(8)°, V=1983.9(7) Å 3, Z=4, R 1=0.0692, w R 2=0.1479. Both compounds are based on (3,4)-connected networks with 8- and 12-ring channels, which are constructed from Zn 3(HPO 3) 4 clusters as the same secondary building units. These inorganic clusters are spatially organized by different structure-directing agents into different three-dimensional frameworks.

Flux synthesis of three-dimensional open-framework zinc phosphite and manganese phosphite-oxalate with 12-ring channels

New three-dimensional open-framework zinc phosphite and manganese phosphite-oxalate, H 2dah·Zn 3(HPO 3) 4 ( 1) and H 2dab·Mn 2(HPO 3) 2(C 2O 4)(H 2O) 2 ( 2), were prepared in a flux of phosphorous acid without the addition of water as a solvent (dah = 1,7-diaminoheptane, dab = 1,4-diaminobutane). Compound 1 is constructed from strictly alternating ZnO 4 tetrahedra and HPO 3 pseudo pyramids, and has zigzag 12-ring channels running along the [0 0 1] direction. Compound 2 consists of neutral manganese phosphites layers, which are pillared by oxalate ligands to form a three-dimensional hybrid framework with 12-ring channels running along the [0 1 0] direction. Magnetic susceptibility measurements demonstrate the existence of antiferromagnetic interaction in 2. Crystal data: 1, orthorhombic, Pbcn, a = 9.9096(8) Å, b = 15.6780(6) Å, c = 13.8022(6) Å, V = 2144.3(2) Å 3, Z = 4; 2, monoclinic, P2 1/ n, a = 5.616(3) Å, b = 15.431(3) Å, c = 9.445(3) Å, β = 91.72(2)°, V = 818.2(5) Å 3, Z = 2.

Transformation of a Layered Zinc Phosphite to a Three-Dimensional Open-Framework Structure with Intersecting 16- and 12-Ring Channels

A new layered zinc phosphite, H(2)tmdp x Zn(3)(HPO(3))(4) (tmdp = 4,4'-trimethylenedipiperidine), was prepared in a flux of phosphorous acid without the addition of water as a solvent. The compound could be transformed into a new three-dimensional open-framework zinc phosphite, Zn(2)(H(2)O)(4)(HPO(3))(2) x H(2)O, with intersecting 16- and 12-ring channels at room temperature.

Template-Designed Syntheses of Open-Framework Zinc Phosphites with Extra-Large 24-Ring Channels

The rational selection of the templating agents or structure-directing agents (SDAs) is important for the designed synthesis of open-framework materials with specific channel structures. By utilizing organic amines that are predicted by computer simulations as the templates or SDAs, such as cyclohexylamine (CHA), cyclopentylamine (CPA), and n-propylamine, three new open-framework zinc phosphites, including (C6H14N)2[Zn3(HPO3)4] (ZnHPO-CJ2), (C5H12N)2[Zn3(HPO3)4] (ZnHPO-CJ3), and (C3H10N)2[Zn3(HPO3)4] (ZnHPO-CJ4), have been hydrothermally prepared with desired extra-large 24-ring channels analogous to (C4NH12)2[Zn3(HPO3)4] (ZnHPO-CJ1). Their structures are characterized by single-crystal and powder X-ray diffraction, inductively coupled plasma (ICP), IR, and thermogravimetric analyses. These organic amines predicted based on nonbonding interactions of host–guest show good matching in the space and charge density with the host inorganic framework. As with ZnHPO-CJ1 and other known extra-large micropore materials with high framework charge density, the 24-rings of these compounds are assembled around multiple small amines, exemplifying the cooperative templating mechanism of multiple small organic cations in the formation of extra-large micropore open-framework materials. This work demonstrates a useful strategy toward the template-designed synthesis of microporous materials with extra-large micropores.