From an Octakis(3‐cyanopropyl)silsesquioxane Building Block to a Highly COOH‐Functionalized Hybrid Organic–Inorganic Material

Abstract

A new nanostructured and highly COOH‐functionalized hybrid organic–inorganic material has been synthesized by the hydrolysis of oligomeric octahedral silsesquioxane (POSS), which contains eight cyanopropyl groups. The hybrid, elemental building block oligomeric octakis(3‐cyanopropyl)silsesquioxane (CN‐POSS) was synthesized from oligomeric octakis(3‐chloropropyl)silsesquioxane (Cl‐POSS) by an exchange reaction. The formation and nanostructuration of the COOH‐functionalized hybrid material were induced by noncovalent hydrogen bonding between COOH‐POSS units without decomposition of the core. The material has been fully characterized by scanning electron microscopy, FTIR and 1H, 13C, and 29Si solid‐state NMR spectroscopy, X‐ray diffraction, and elemental analysis, which confirm that the POSS core remains intact after each chemical modification step. Thermogravimetric analysis indicates that the organic units are thermally stable up to 200 °C. The activation energy related to the proton conductivity of COOH‐POSS has been evaluated and confirms the presence of strong hydrogen bonds. Finally, the accessibility and adsorption capacity of the COOH groups towards transition metal ions have been demonstrated and underline the potential of these hybrid materials in extraction chemistry.

Assembly of Coordination Polymers Using Thioether‐Functionalized Octasilsesquioxanes: Occurrence of (CuX)n Clusters (X=Br and I) within 3D‐POSS Networks

“…Thus, these systems have found a lot of applications such as in the formation of liquid crystals, porous materials, ionic liquids, catalysts, biomaterials, dielectric materials, light‐emitting diode materials,– and nanocomposites . More recently, POSS have been used as building blocks for the formation of high‐ordered structures driven by intermolecular interactions such as hydrophobic interactions, hydrogen bonding or metal coordination to assemble coordination polymers (CPs) . These CPs have been obtained by reacting hard lanthanide (Eu 3+ , Tb 3+ ) or transition metal ions (Cu 2+ , Co 2+ , Fe 2+ , Zn 2+ ) with hard ligands.…”

Ordered Hybrids from Template‐Free Organosilane Self‐Assembly

“…Without sol-gel polymerization, Mehdi et al proved finally that CO 2 H-functionalized POSS could self-assemble spontaneously through hydrogen bonding between carboxylic acid groups. [133]…”

Solid–Liquid Europium Ion Extraction via Phosphonic Acid-Functionalized Polyvinylidene Fluoride Siloxanes

“…The potential risks of pollution by metal ions in aqueous environmental is still a major environmental issue, due to their high toxicity, persistence and potential carcinogenic effects [ 1 ]. Thus, the removal of such ions is vital to the environment and has led to various studies [ 2 ] focusing on the development of methods and techniques for their extraction from heterogeneous media such as liquid–liquid extraction and solid-phase extraction [ 3 , 4 , 5 , 6 ], chemical precipitation [ 7 ], membrane filtration [ 8 ], flotation [ 9 ], electrochemical [ 10 ] and biofiltration methods [ 11 ].…”