S⁺I^- Ionic Formation Mechanism to New Mesoporous Aluminum Phosphonates and Diphosphonates

Abstract

Pure mesoporous aluminum phosphonates and diphosphonates have been synthesized through an S + Isurfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from aluminum atrane complexes and phosphonic and/or diphosphonic acids. A soft chemical extraction procedure allows opening the pore system of the parent mesostructured materials by exchanging the surfactant without mesostructure collapse. The hybrid nature of the pore wall can be modulated continuously from organic-free mesoporous aluminum phosphates (ALPOs) up to total incorporation of organophosphorus entities (mesoporous phosphonates and diphosphonates). The organic functional groups become basically attached to the pore surface or inserted into the ALPO framework (homogeneously distributed along the surface and inner pore walls) depending on the use of phosphonic or diphosphonic acids, respectively. X-ray powder diffraction, transmission electron microscopy, and surface analysis techniques show that these new hybrid materials present regular unimodal pore systems whose order decreases as the organophosphorus moiety content increases. NMR spectroscopic results not only confirm the incorporation of organophosphorus entities into the framework of these materials but also provide us useful information to elucidate the mechanism through which they are formed.

Insights into mesoporous metal phosphonate hybrid materials for catalysis

“…[75][76][77] And a series of mesoporous aluminum monophosphonates and diphosphonates were successfully synthesized on the basis of this "atrane route". 76,77 In addition to the alcohols, crown ethers of hydrophobic alkyls not only could capture metal ions to effectively isolate the innerly embedded metal cations from the organic functionalities and thus to slow down the reaction rate, but also allowed the assembly between surfactants and hybrids, as well as the surrounding coordination expansion. 78,79 A great deal of progress has recently been made in the field of mesoporous metal phosphonates.…”

“…Ionic and oligomeric surfactants generally produce small mesopores in the range of 2-5 nm. 26,27,[51][52][53]76,77,85,86 Higher molecular weight Pluronic block copolymers can template mesopores of 6-10 nm in diameter, 39,51 even larger mesopores using polystyrene-block-poly(oxyethylene) colloidal templates. Note that judicious choice of suitable synthetic technologies would result in various types of mesostructured micromorphologies, such as nanospheres, nanofibers and films, of which the pore size could be precisely controlled by the involved soft supermolecules.…”

Synthesis and pore formation study of amorphous mesoporous aluminophosphates in the presence of citric acid

“…Recently, increasing attention has been focused on the synthesis of mesoporous aluminophosphates [6][7][8][9][10], since the characteristics of mesoporous materials, such as high surface area and large pore size, make it possible to diffuse and/or to activate large molecules and are also suitable for supporting catalytically active sites bearing large organic functionalities [11][12][13].…”

Advances in Mesoporous Metal Phosphonate Hybrid Materials

“…[4] . 基于 S ＋ I -机理, 以甲基膦 酸和亚乙基二膦酸为膦源, 可合成出有序介孔膦酸铝和 二膦酸盐 [37,38] . 我们课题组在非离子表面活性剂 Brij 56 的存在下, 通过高压水热法和挥发诱导自组装(EISA)的 方法合成了有序介孔膦酸钛材料(PMTP-1) [39] .…”