Syntheses,Structures,and Charaterizations Of Novel Aluminophosphates,Aluminophosphite,and Gallium Phosphites Templated By DMAP

Inorganic microporous open-framework materials,i.e.,siliceous zeolites and aluminophosphate molecular sieves,have been widely used in numerous industrial fields,such as catalysis,gas adsorption and separation,and ion exchange,etc,due to their regular pore systems,open-framework structures,high thermal stabilities,and abundant active centers.The syntheses,structures,and properties of novel inorganic open-framework materials have been one of the most important research topics of these materials,where the organic structure-directing agents?OSDA?are the most important factors in their syntheses.In this thesis,we carried out the researches from the syntheses to the structures and characterizations of novel aluminophosphates,aluminophosphite,and gallium phosphites via utilizing the 4-N,N-dimethylaminopyridine?DMAP?as the OSDA.The main results are summarized as follows:?1?ThefirstcrystallineAlPO₄-5intermediate,[(C₇H₁₁N₂)₂?H₃O?][Al₃P₄O₁₆]·?H₂O?_2.5?Al-1?,was successfully synthesized by regulating the hydrothermal synthesis conditions carefully,especially simultanaeously increasing the amounts of H₃PO₄ and DMAP to suppress the the condensation reactions between the parental aluminophosphate chains.The layered Al-1 framework is constructed by the alternation of the organic DMAP layers and the inorganic[Al₃P₄O₁₆]^3-anionic aluminophosphate layers,where the protonated DMAP molecules interact with each other and with the aluminophosphate layers via the?-?stacking and the hydrogen-bonding interactions,respectively,thus correlating the organic and the inorganic species.Later,the heating process and the steam-assisted conversion experiments confirmed the crystalline AlPO₄-5 nature of Al-1.To unravel the decisive factor in the transformation process,AlPO₄-5 was also directly synthesized by simply alternating the synthesis conditions,where the location of the DMAP molecules in the AlPO₄-5 structure was determined for the first time via powder X-ray diffraction refinement.Thus,it was speculated that the initial AlPO₄-5 structure was formed around the?-?stacked DMAP molecules.?2?Based on the synthesis of Al-1,the first crystalline SSZ-51 intermediate,[C₇H₁₁N₂]₂[Al₄P₄O₁₆?OH?F]?Al-2?,was hydrothermally or solvothermally synthesized by altering the initial state of the DMAP molecules with the addition of HF.The layered Al-2 framework is constructed by the alternation of the organic DMAP layers and the inorganic[Al₄P₄O₁₆?OH?F]^2-anionic aluminophosphate layers composed of only the sti units.Al-2 is the first layered aluminophosphate constructed by only the sti units and the first compound with the undulating sti layers;it is also the third layered framework material with the Al/P ratio of 1/1 and the strict alternation of AlO₄ and PO₄ tetrahedra.Similar to Al-1,Al-2 could also transform to SSZ-51 via the topological condensation reaction in the heating process and steam-assisted conversion experiments,confirming the crystalline SSZ-51 intermediate nature.Meanwhile,it was also spectulated that the?-?stacked DMAP molecules were crucial for the Al-2 tranformation property.?3?Introducing DMAP as the OSDA into the metal phosphite system for the first time,anovelmicroporousopen-frameworkaluminophosphite,[(C₇H₁₁N₂)?H₃O?_0.21][Al₃?HPO₃?_4.67O_0.13?OH?_0.62?H₂O?₂]·?H₂O?_2.09?Al-3?,was hydrothermally synthesized.Al-3 possesses a two-dimensional honeycomb-like extra-large 14-ring channel system,numerous chiral 4=1 units,chiral channel window structures,and very rare face-sharing AlO₆ octahedra dimers.The alternation of the chiral species with opposite chirality conduces to the achiral framework structure of Al-3,and the very rare conner-sharing AlO₄ tetrahedra dimers with a small amount also coexist with the face-sharing AlO₆ octahedra dimers.The protonated DMAP molecules reside in the Al-3 channel via the triangular arrangement and interact with the 14-ring channel windows through the hydrogen-bonding interactions.Al-3 is the the fourth and also the first extra-large-channel aluminophosphite possessing the largest 14-ring channels,and also the first material with a novel Al/P ratio of 9/14.?4?Based on the synthesis of Al-3,DMAP was also introduced to the gallium phosphitesystem.Thus,anAl-3isostructuralgalliumphosphite,[(C₇H₁₁N₂)?H₃O?_0.33][Ga₃?HPO₃?_4.67?OH??H₂O?₂]?Ga-1?,washydrothermally synthesized.Similar to the structure descriptions of Al-3,Ga-1 also possesses a two-dimensional honeycomb-like extra-large 14-ring channel system,numerous chiral4=1 units and chiral channel window structures,as well as very rare face-sharing GaO₆octahedra dimers.The alternation of the chiral units with opposite chirality conduces to the achiral framework structure of Ga-1,but different from Al-3,no conner-sharing GaO₄ tetrahedra dimers coexist with the face-sharing GaO₆ octahedra dimers.The protonated DMAP molecules reside in the Ga-1 channel via the triangular arrangement and interact with the 14-ring channel windows through the hydrogen-bonding interactions.Ga-1 is the first inorganic microporous material possessing a novel Ga/P ratio of 9/14 and face-sharing GaO₆ octahedra dimers,and it is also the second gallium phosphite with extra-large channels.?5?Based on the synthesis of Ga-1,a novel organic-inorganic hybrid layered gallium phosphite,[C₇H₁₀N₂][GaF?HPO₃?]?Ga-2?,was hydrothermally synthesized via utilizing Ga₂O₃ as the gallium source.In the hybrid layered structure of Ga-2,Ga atoms firstly coordinate with the N atoms from the pyridine rings of the DMAP molecules to form the hybrid 6-coordinated GaO₃F₂N octahedra,which further connect the pseudopyramidal[HPO₃]^2-groups and the GaO₃F₂N octahedra through the bridge O and F atoms via corner-and edge-sharing,respectively,thus forming the organic-inorganic hybrid two-dimensional gallium phosphite layers with the hexagonal honeycomb-like hcb or Kagome lattice's kgm topology.These hybrid layers stack in the ABCABC sequence along the c-axis,where the?-?interactions are later formed between the DMAP molecules from adjacent layers to constitute the crystalline structure of Ga-2with a complex arrangement pattern of the DMAP molecules.Ga-2 is the second organic-inorganic hybrid layered gallium phosphite.?6?Based on the synthesis of Ga-1,another one-dimensional gallium phosphite,[C₇H₁₁N₂]₃[?GaF?₃(H_1.5PO₃)₆]?Ga-3?,was also hydrothermally synthesized via simultaneously increasing the amounts of H₃PO₃,DMAP,and HF.In the structure of Ga-3,the GaO₄F₂ octahedra are connected with each other by sharing two F atoms to form the unprecedented Ga-F-Ga chain,and the pseudopyramidal[H_1.5PO₃]^1.5-groups are further ultilized to connect the adjacent GaO₄F₂ octahedra.Therefore,the one-dimensional gallium phosphite chains with numerous hydrogen-bonding interactions are formed,whose interlayer voids are later occupied by every two protonated DMAP molecules with opposite orientation and?-?stacking interactions to constitute the framework structure of Ga-3.Ga-3 also possesses a hydrogen-bonding network,which is also the first one-dimensional gallium phosphite.