Further Understanding of the Reactivity Control of Bisphosphonates to a Metal Source for Fabricating Highly Ordered Mesoporous Films

Abstract

Mesoporous metal organophosphonates having embedded organic functions are a promising platform to hybridize organics and non‐siliceous inorganic frameworks in their molecular scale. However, the reactivity between a bisphosphonate and a metal source is dramatically different for their combination and then hampers to construct ordered mesoporous structures even when using amphiphilic organic molecules. By proposing an advanced method to adjust such reactivity, we recently succeeded in fabricating ordered mesoporous aluminum organophosphonate (AOP) films with chemically designable benzene units inside their hybrid frameworks. The reactivity of the organically bridged bisphosphonates has been controlled by utilizing dissimilar reactivities of acid–base pairs like P−OH and P−OEt groups to AlCl3. Here, we further prove our reactivity‐control concept through the introduction of organic groups, such as those having symmetric thiophene, asymmetric amide, and hydrophilic ether units. Liquid‐state 31P NMR measurements further clarified the usefulness of the control of the −OH/ −OEt ratio in the same bisphosphonate molecules for obtaining highly ordered mesostructured AOP films.

Surfactant-Assisted Synthesis of Mesoporous Metal Phosphonates to Control Surface Properties Including an Opportunity to Organize a Bulky Biphenyl Linker

“…The powder sample (1.5 g) was dried at 50 °C for more than 6 h, dispersed in 50 mL of dehydrated acetone, and heated statically at 90 °C into a Teflon tube for about 16 h. The resultant sample was filtered and washed with dehydrated acetone. Other powder samples were also obtained by the same spray-drying process of corresponding precursor solutions prepared from partially acidified bisphosphonate compounds. , …”

“…46 This methodology gave us a next challenge to integrate other organic linkers, such as aniline and benzene sulfonic acid, as well as unique units like symmetric sulfide (−CSC−), asymmetric amide (−NHCO−), and hydrophilic ether (−COC−). 46,47 In this study, we succeeded in preparing mesoporous metal phosphonates containing a bulky aromatic linker that originated from 4,4′biphenylenebisphosphonate. Surveying the latest trend of PMO-type materials, the success in integrating such a −Ph− Ph− group is the first step for incorporating a variety of bulky organic groups, as well as the emerging design of exceptional functions combined with additional organic molecules.…”

“…In the case of AOP-type materials, small alkylene (e.g., −CH 2 –, −C 2 H 4 –, −C 3 H 6 −) linkers were successfully integrated through the development of a new method to eliminate polymeric amphiphilic organic molecules. , With an advance in the synthetic strategy for adjusting the reactivity of a bisphosphonate to metal sources like aluminum chloride (AlCl 3 ) by designing the molecular structure of 1,4-benzenebisphosphonate, a −Ph– containing AOP-type mesoporous film can be fabricated by versatile spin-coating . This methodology gave us a next challenge to integrate other organic linkers, such as aniline and benzene sulfonic acid, as well as unique units like symmetric sulfide (−CSC−), asymmetric amide (−NHCO−), and hydrophilic ether (−COC−). , In this study, we succeeded in preparing mesoporous metal phosphonates containing a bulky aromatic linker that originated from 4,4′-biphenylenebisphosphonate. Surveying the latest trend of PMO-type materials, the success in integrating such a −Ph–Ph– group is the first step for incorporating a variety of bulky organic groups, as well as the emerging design of exceptional functions combined with additional organic molecules.…”

Advances and Challenges in the Creation of Porous Metal Phosphonates

“…The partial hydrolysis allows to tune the reactivity towards aluminum chloride [89]. This synthesis methodology allowed the incorporation of a variety of organic linkers such as amides, thiophene, and ether moieties into porous metal phosphonate networks [90]. Another novel approach has been utilizing the non-hydrolytic sol-gel methodology to synthesize hybrid titanium phosphonate by the use of biphenyl bisphosphonate ester and titanium isopropoxide in acetic anhydride.…”

Lamellar assembly and nanostructures of amphiphilic boron(iii) diketonates through suitable non-covalent interactions

“…34,35 Among various amphiphilic compounds, the family of thiophene derivatives has been one of the most intriguing candidates for research focus because of their rich photophysical and electronic properties as well as their hydrophobic character with well-ordered packing structures and potential applications as sensors. 36–42 The subtle balance between multiple noncovalent interactions will affect the self-assembly behaviors, in that a change of self-assembly mechanisms from isodesmic growth to nucleation–elongation growth and then back to isodesmic growth has been reported upon a gradual increase in hydrophobic interaction. 43 In the meantime, the study of materials based on boron( iii ) diketonate derivatives with four-coordinated boron centers has aroused much interest because of their potential applications in optoelectronics, anion-sensing and supramolecular self-assembly 44–65 due to their inherent electron-deficiency, which makes them a remarkable acceptor moiety for π-conjugated molecules.…”