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High hydrophobicity, non-polar structure and large pore volume are among the main criteria demanded breakthrough when designing or selecting materials with ultralow dielectric constants of k. Herein we proved the feasibility of PIM-1 films, a constitutive porous polymer with high free volume, as a rising ultra-low-k material in the field of microelectronics. An ultrathin PIM-1 film of approximate 60 nm in thickness was easily obtained by the spin-coating approach. Thermal treatment on the PIM-1 film (denoted as sPIM-1) enhanced its dielectric performance and the incorporation of cyanopropyltriethoxysilane (CPTES) to sPIM-1 improved the mechanical strength of the film significantly. The sPIM-1 films exhibited an ultralow dielectric constant (k = 1.5 at 10 kHz), substantial mechanical strength, and ability to withstand high humidity (soaking in water for 30 min) without losing their dielectric properties. The easy curing process and extremely stable performances even under the harsh conditions of practical application make it one of the most competitive candidates of low dielectric materials at present.

A support vector machine (SVM) method has been used on the database of aluminophosphate (AlPO) synthesis with ca. 1700 reaction data to predict the formation of AlPOs with (6, 8)-rings based on 20 synthetic parameters associated with the gel composition, solvent and templates. Furthermore, four zeotype structures with different channel systems, such as AEN, AWO, ERI and CHA have been computational classified in the family of (6, 8)-ring-containing AlPOs. Analysis results reveal that several synthetic parameters, particular the molar ratio of solvent/Al 2 O 3 (F3), and the Van der Waals (VDW) volume (F14), the greatest length (F11), and the number of free rotated single bond (F20) of templates have significant effects in directing the formation of target structure. Using single or combinations of several parameters, a better classifier can be trained to distinguish the (6, 8)-ring-containing AlPOs with desired zeotype structure or not, and the classification accuracy is about 85%. This work demonstrates that the computational method together with database of AlPO synthesis provides a possibility to establish the relationship between the synthetic factors and the resulting structures, which is important in guiding the rational synthesis of microporous aluminophosphate materials.

Several experiments have been performed based on the results of four missing value estimation methods on the database of AlPO syntheses. The target products, aluminophosphate molecular sieves with AFI topology, have been prepared by using triethylamine (TEA), N , N -dimethylbenzylamine (BDMA) and N -(2-aminoethyl)-piperazine (AEP) as the structure-directing agents, and their structures have been characterized by PXRD, SEM, TG, CHN, ICP and NMR. The experimental results show that BP impute method is the most effective approach for estimation of missing data of microporous aluminophosphates. This work further indicates that data mining provides a useful guidance for the rational synthesis of inorganic microporous materials.

Database of AlPO syntheses will serve as useful guidance for the rational synthesis of microporous functional materials. But the database contains missing values about 29% of total. In this paper, to deal with the problem of missing values, four missing value estimation methods (back-propagation neural networks imputes, K -nearest neighbor imputes, singular value decomposition imputes and least square imputes) are employed on database of AlPO syntheses for the first time. The efficiency and revise of estimation methods are demonstrated by normalized root mean squared error (NRMSE) and prediction accuracy. A large number of experimental results show that the estimation methods are competent for microporous aluminophosphates and the BPimpute is recommended.

Iron(II)-substituted LAU-zeotype aluminophosphate molecular sieve (denoted as FeAPO-LAU) was synthesized successfully by using imidazole as template in the solvothermal system. The detemplation process was studied to elucidate the stability and microporous characteristics of FeAPO-LAU. In situ temperature-dependent X-ray diffraction analyses indicated that the framework of FeAPO-LAU possessed higher thermal stability and maintained the framework integrity until 923 K. The organic templates could be removed by stage-temperature-programmed calcination using lower heating rate in O 2 atmosphere, which gave rise to the sample with surface areas of ca. 105 m 2 /g. NH 3 -temperature programmed desorption (NH 3 -TPD) analysis showed that detemplated FeAPO-LAU had a weak acidity. Magnetic measurement revealed that both as-synthesized and detemplated FeAPO-LAU showed antiferromagnetic behaviour.

The chiral zeolite germanosilicate ITQ-37 has been prepared by using a new achiral organic structuredirecting agent 30,40-dihydro-10H-spiro[isoindoline-2,20-isoquinolin]-2-ium (denoted as OSDA-1). The crystallization field diagram and the influence of synthetic factors on the synthesis of ITQ-37, such as crystallization temperature, crystallization time, source materials, and water amount have been studied. The as-synthesized samples have been characterized by XRD, ICP, CHN, TG, TEM, DLS, NMR, N2 adsorption and NH3-TPD analysis. The results indicate that the as-synthesized ITQ-37 is a pure phase, and the particle size is of ca. 200 nm. The OSDA-1 cations remain intact in the final product and the framework structure of ITQ-37 maintains up to 500 C after the removal of OSDA. In addition, Al atoms can be introduced into the framework of germanosilicate ITQ-37 with the Al/(Si + Ge) molar ratio of ca. 1/160–1/80, forming Al-ITQ-37 mainly with weak acid sites.

In an attempt to synthesize microporous materials with respect to green chemistry, we investigate the syntheses of cobalt-substituted aluminophosphate molecular sieves by a low-cost approach through recycling waste mother-liquors of two layered aluminophosphates Mu-4 and AlPO-IM prepared in the Al(iPrO)3–H3PO4–Tem–TEG system (Tem: diethylamine or imidazole, TEG: triethylene glycol). A Co-substituted aluminophosphate [C8H24N2][Al8Co2P10O40] (denoted CoAPO-CJ51) was obtained with the addition of Co2+ ions into the mother-liquor of Mu-4. Its structure is analogous to zeotype GIS with 20% occupancy by Co2+ ions in the metal site, and the protonated diethylamine molecules are located in the 8-ring channels. Co-substituted aluminophosphate [C3H5N2][Al2CoP3O12] (denoted CoAPO-CJ52) was obtained with the addition of Co2+ ions into the mother-liquor of AlPO-IM. Its structure is analogous to zeotype LAU with 33.3% occupancy by Co2+ ions in the metal site, and the protonated imidazole molecules are located in the 10-ring channels. Both compounds are characterized by single-crystal X-ray diffraction analysis, ICP and TG analyses.

The rational synthesis of open-framework materials with extra-large micropores is a challenging topic in the field of zeolites science. Employing computational methods, the charge-density matching, space matching, and non-bonding interactions of the host framework and guest template molecules have been studied for some known microporous materials with 14-, 16-, 18-, 20- and 24-ring extra-large micropores. The host–guest relationship in different synthetic systems has been summarized. This study provides a useful guidance for rational choice of templates for the synthesis of extra-large microporous materials with predetermined structures and compositions.

A two-dimensional (2-D) layer aluminophosphate ∣(C2H8N)2∣[Al2(HPO4)(PO4)2] (1) and a 1-D chain aluminophosphate ∣NH3CH2CH2NH3∣[AlP2O8H] (2) have been prepared in the solvothermal system. In the presence of metal M2+ cations (M = Co2+, Mn2+, Mg2+), compounds 1 and 2 transform to the 3-D open frameworks of ∣Al–P–M–O∣–GIS. Single-crystal X-ray diffraction, XRD, TG and compositional analyses show that the structures of ∣Al–P–M–O∣–GIS (M = Co2+, Mn2+, Mg2+) are analogous to zeolite gismondine (zeotype GIS) in which 50% metal sites in the framework are occupied by Co2+, Mn2+ or Mg2+ cations, and protonated dimethylamine cations reside in the 8-ring channels. Interestingly, the edge-sharing 4-ring chain (denoted as AlPO-ESC) featured in compounds 1 and 2 remains in the structures of ∣Al–P–M–O∣–GIS. This study not only provides a potential approach to synthesize complex open frameworks through the reaction of low-dimensional precursors with metal cations, but also further suggests that the AlPO-ESC chain might be a basic building unit for the formation of diverse 3-D open-framework structures.

A new UV/dilute H2O2 method has been developed to remove organic templates from mesoporous silica SBA-15. This method combines UV irradiation and dilute H2O2 treatment, allowing complete removal of the organic templates in 3–4 h at room temperature. Effects of two important factors, pH value and initial H2O2 concentration, have been investigated to search for the optimum condition of template removal. Detailed characterizations of the samples treated by UV/dilute H2O2 method in comparison with other methods are performed with the aid of powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), solid-state 29Si NMR spectra and nitrogen adsorption. The final product resulted from UV/dilute H2O2 treatment has well-defined structure with perfect pore quality. This study provides an easy, cheap, mild and useful method for template removal from mesoporous materials at room temperature.

A new three-dimensional (3-D) open-framework aluminophosphate (denoted AlPO-CJ31), with an Al/P ratio of 4/5, has been synthesized hydrothermally in the presence of diethylenetriamine (DETA) as the structure-directing agent (SDA). Its structure is determined by single-crystal X-ray diffraction and further characterized by X-ray powder diffraction, ICP, TG analyses and solid-state NMR techniques. The alternation of AlO4 tetrahedra, AlO5(H2O) octahedra and PO4 tetrahedra gives rise to an interrupted open-framework structure with parallel 8-membered ring (MR) and 12-membered ring channels along the [0 0 1] directions. Crystal data: C4N3H16 · Al4P5O20(H2O)2, orthorhombic Pbcn (No. 60), a = 24.7293(16) A, b = 8.9442(4) A, c = 9.9806(5) A, V = 2207.5(2) A3, Z = 4, R1 = 0.0720 (I > 2σ(I)), and wR2 = 0.1669 (all data).

Two new members of the zeolite analcime (ANA) family, (NH 4 ) 16 [Zn 16 B 8 P 24 O 96 ] (designated ZnBP–ANA) and (NH 4 ) 16 [Zn 13.4 Co 2.6 B 8 P 24 O 96 ] (designated ZnCoBP-ANA), have been prepared by the boric acid ‘flux’ method and characterized by X-ray powder diffraction, SEM, ICP, TGA, IR and UV–Vis analyses. Single-crystal X-ray diffraction analyses show that their open-framework structures are constructed from the alternation of BO 4 (ZnO 4 , CoO 4 ) and PO 4 tetrahedra through corner-sharing vertex oxygen atoms to generate a three-dimensional (3D) open-framework with distorted eight-membered ring (8-MR) channels along the [1 0 0], [1 0 1] and [0 0 1] directions, respectively. The negative charges of the inorganic framework are balanced by the ammonium ions located in the channels. Crystal data: ZnBP–ANA, cubic I 2 1 3, a = 13.173(6) A, V = 2286.2(0) A 3 , R 1 = 0.0807 ( I > 2 σ ( I )), w R 2 = 0.1752 (all data); ZnCoBP–ANA, cubic I2 1 3, a = 13.1558(15) A, V = 2276.9(4) A 3 , R 1 = 0.0943 ( I > 2 σI )), w R 2 = 0.2069 (all data).

Using 1,3-propyldiamine (1,3-PDA) as the structure-directing agent, a new manganese (II)-substituted aluminophosphate [C3N2H12] · [MnAl3P4O17] · [H3O] (denoted MnAPO-14-PDA) containing five-coordinated Mn2+ ions has been hydrothermally synthesized. The structure has been solved by single-crystal X-ray diffraction analysis and further characterized by X-ray powder diffraction, ICP and TG analyses. Differently from our recently reported MnAPO-14-DABCO built up from MnO4(H2O)2 octohedra, AlO4 and PO4 tetrahedra, MnAPO-14-PDA is made of MnO5 trigonal bipyramid, AlO6 octohedra, AlO4 and PO4 tetrahedra. Its framework is analogous to aluminophosphate zeotype AFN in which 25% of the aluminum sites are replaced by Mn(II) atoms. The diprotonated 1,3-PDA cations and protonated H2O molecules reside in the 8-membered ring (MR) channels. Computational simulations indicate that the substitution sites and coordination modes of Mn atoms in the framework are determined by the structure-directing agent (SDA) through the host-guest interactions. Crystal data: [C3N2H12] · [MnAl3P4O17] · [H3O], triclinic P-1 (No.2), a = 9.799(3) A, b = 9.799(3) A, c = 11.203(4) A, α = 72.708(4)°, β = 72.708(4)°, γ = 88.11(0)°, Z = 2, R1 = 0.0775 (I > 2σ(I)) and wR2 = 0.2079 (all data).

Thermal removals of amine-templated aluminophosphate molecular sieve AlPO 4 -21 have been studied by X-ray powder diffraction (XRD), TG–DTA and temperature-programmed decomposition coupled with mass spectrometer (TPD–MS) analyses (amine: ethylamine, dimethylamine and trimethylamine). It is found that the thermal removal of templates and bridging OH groups between two Al atoms is an endothermic process occurring in a single step in inert atmosphere, which accompanies the structural transformation of AlPO 4 -21 to AlPO 4 -25. The removal temperatures of various organic amines occluded within AlPO 4 -21 are directly related to the shapes and sizes of the templates, as well as the proton affinities of guest cations. These factors also determine the removal mechanisms of templates from AlPO 4 -21.

This work presents our current progress on the rational design and synthesis of aluminophosphates with 2-D layer and 3-D open-framework structures. For the design of theoretical structures, we take two ways, one is using building block construction strategy to construct new 2-D networks and 3-D open frameworks. The other is using computer modeling method to systematically enumerate the theoretical network structures. The templating abilities of various amines in the formation of 2-D network or 3-D open-framework aluminophosphates can be evaluated in terms of non-bonding interaction energies of the guest templates and the host inorganic networks or frameworks. This well assists in the rational synthesis of target materials, with the good examples as 2-D Al 3 P 4 O 16 3− anionic layers, and 3-D Al 4 P 5 O 19 (OH) 2− open frameworks with structures analogous to AlPO–HDA (HDA: 1,6-hexanediamine). On the other hand, 3-D open framework can be rationally assembled by a lower-dimensional chain through incorporation of transition metal cations as illustrated by the successful synthesis of a 3-D open-framework nickel aluminophosphate [NiAlP 2 O 8 ][C 2 N 2 H 9 ].