Hedgehog Buckyball: A High-Symmetry Complete Polyhedral Oligomeric Silsesquioxane (POSS)

Abstract

Abstract:In this study, we report UV-MALDI-TOF MS evidence of a fullerene-like silsesquioxane, a high-symmetry polyhedral oligomeric silsesquioxane (POSS or SSO) formulated as R 60 -Si 60 O 90 or T 60 (T = RSiO 1.5 ). The T 60 preparation can be performed using a normal hydrolytic condensation of [(3-methacryloxy)propyl]trimethoxysilane (MPMS) as an example. Theoretically, four 3sp 3 hybrid orbitals (each containing an unpaired electron) of a Si atom are generated before the bond formation. Then it bonds to another four atom electrons using the four generated hybrid orbitals which produced a stable configuration. This fullerene-like silsesquioxane should exhibit much more functionality, activity and selectivity and is easier to assemble than the double bonds in a fullerene.Keywords: polyhedral oligomeric silsesquioxane (POSS); high-symmetry; fullerene-like silsesquioxane; synthesis and characterization The fullerene buckyball (FBB), C 60 , was named "Molecule of the Year" for 1991 by Science [1]. Since the discovery of the C 60 buckyball, fullerene science has continued to accelerate, investigating both the basic science and its potential applications [2,3]. One investigation involves a major focus on its analogue, the Si 60 cluster [4,5]. For Si 60 clusters, the cages should not be very stable due to the use of three (3sp 3 ) orbitals to bond to other Si atoms. Thus, the cages need some other atoms for the fourth bond whereas the C 60 fullerene uses the second period sp 2 orbitals along with a π bond to bond exclusively with other C atoms. Most investigations focus on endohedral Si 60 isomers (using the fourth bond of the 3sp 3 orbital) which are unstable [6]. To produce a stable Si 60 configuration, Wang and Yang conducted ab initio calculations based on density functional theory on a Si 60 fullerene-like cage passivated with F or Cl atoms [7]; however, this research is limited by a complex experimental synthesis.In this study, we report UV-MALDI-TOF MS evidence of a fullerene-like silsesquioxane, a high-symmetry polyhedral oligomeric silsesquioxane (POSS or SSO) formulated as R 60 -Si 60 O 90 or T 60 (T = RSiO 1.5 ) [8]. Theoretically, four 3sp 3 hybrid orbitals (each containing an unpaired electron) of a Si atom are generated before the bond formation. Then it bonds to another four atom electrons using the four generated hybrid orbitals which produced a stable configuration. A significant difference between a FBB and T 60 POSS is that the cage in the former is the four-bond (three 2sp 2 hybrid orbits and one original 2p orbital) connection of each C atom on the FBB surface, while it is the three-bond (three of four 3sp 3 hybrid orbits) connection of each Si atom on the POSS surface. The remaining bond to each silicon connects to a pendant organic group adorning the surface of the T 60 cage, showing a hedgehog buckyball (HBB, see Figure 1). These organic groups exhibit much more functionality, activity and

Polyhedral Oligomeric Silsesquioxane (POSS) as Reinforcing Agent for Waterborne Polyurethane Coatings on Wood

“…A functional organic/inorganic hybrid material has attracted widespread interest. The synergistic combination of organic polymers and inorganic silica has received considerable attention because of the potential for the development of new materials with designed properties by molecularlevel structural manipulation [36][37][38][39][40][41][42] , specifically, polyhedral oligomeric silsesquioxane (POSS)-based hybrid polymers have emerged as unique materials for various applications. The empirical formula of POSS nanostructure is RSiO 1.5.…”

A Rapid One-Pot Synthesis of Novel High-Purity Methacrylic Phosphonic Acid (PA)-Based Polyhedral Oligomeric Silsesquioxane (POSS) Frameworks via Thiol-Ene Click Reaction

“…Additionally, it has strong attention due its unique physico-chemical properties and reactive organic terminal functional substituents [ 4 , 5 , 6 , 7 , 8 ]. The three-dimensional structure of the silicon–oxygen (Si–O) core is inevitably responsible for high thermal stability and stiffness, whereas the terminal organic reactive functional groups can be enabled to make the covalent bond between POSSs and polymers, which results in the solid progress of organic–inorganic hybrid materials [ 9 , 10 ]. POSS properties have been tuned [ 11 , 12 , 13 , 14 , 15 ] by incorporating various end-group moieties (functionalities), such as acrylates, methacrylate, alcohols, amines, carboxylic acids, epoxides, fluoroalkyls, halides, and imides, through self-polymerization reactions, which include self-condensing vinyl polymerization, poly-condensation reactions, ring-opening polymerization, and “ene-click” reactions [ 16 , 17 , 18 ].…”

Thermal protection materials based on epoxy‐containing and phenyl‐containing polyhedral oligomeric silsesquioxane modified phenolic resin and phenolic resin/carbon fiber composites

“…1 H NMR, and 28 Si NMR were taken on a Bruker AV 600 NMR spectrometer (600 M) that operated in Fourier transform mode, utilizing tetramethylsilane as an internal reference. using deuterated acetone ((CD 3 ) 2 CO), deuterated chloroform (CD2Cl 3 ), or deuterated dichloromethane (CD 2 Cl 2 ) as solvent.…”

“…19 Ali Akbari 27 et al designed and synthesized incompletely condensed silsesquioxane with three allyl groups (TAP-POSS), which has both phenyl groups and allyl groups. Zixuan Lei 28 et al used POSS only containing epoxy group in PR and found that after modification, the char yield of the resin at 800 C increased by 26.9%, the crosslinking density of the resin increased by 31.62%, and the mechanical properties were also improved. He also found that when EPOSS was added too much, the PR's crosslinking network was broken, resulting in poor thermal stability and mechanical deterioration.…”

“…7,17,30 At the same time, the introduction of CF also helps to fix the original material that is being pyrolyzed in the ablative region, effectively preventing the resin from falling off after carbonization. 4,7,30,31 Hu Yu 28,32 prepared POSS modified vitreous silica fiber/ phenolic composite. Ablation test showed that the composite had better ablation performance than the unmodified composite, and its linear ablation rate was reduced by 60%.…”