[PhSiO1.5]8 promotes self-bromination to produce [o-BrPhSiO1.5]8: further bromination gives crystalline [2,5-Br2PhSiO1.5]8 with a density of 2.32 g cm−3 and a calculated refractive index of 1.7 or the tetraicosa bromo compound [Br3PhSiO1.5]8

Roll, Mark F.; Mathur, Priyanka; Takahashi, Kunio; Kampf, Jeffrey W.; Laine, Richard M.

doi:10.1039/c1jm11536g

Cited by 16 publications

(51 citation statements)

References 47 publications

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“…10,11 These results coupled with our recent discovery of methods of making very pure [o-BrPhSiO 1.5 ] 8 , [2,5-Br 2 PhSiO 1.5 ] 8 , [Br 3 PhSiO 1.5 ] 8 , provided the impetus to explore the functionalization of these compounds. 18 In principle, these brominated [PhSiO 1.5 ] 8 or OPS (octaphenylsilsesquioxane) derivatives offer the potential to introduce 8, 16 or z 24 functional groups in the same volume. Furthermore, these functional groups are expected to offer extended conjugation via the central phenyl ring and through the center of the cage.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and photophysical properties of polyfunctional phenylsilsesquioxanes: [o-RPhSiO1.5]8, [2,5-R2PhSiO1.5]8, and [R3PhSiO1.5]8. compounds with the highest number of functional units/unit volume

2011

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The availability of pure samples of o-Br 8 OPS, 2,5-Br 16 OPS, and Br 24 OPS provides a rare opportunity to synthesize sets of corresponding stilbene derivatives: o-RStyr 8 OPS, RStyr 16 OPS, and RStyr 24 OPS where R ¼ 4-methyl (Me), Boc-protected 4-amino (NBoc), or 4-acetoxy (Ace). These derivatives show unique UV-Vis absorption and photoluminescent behavior that points to interesting interactions between the organic tethers and the silsesquioxane cage. o-RStyr 8 OPS shows blue-shifts in the absorption spectra compared to p-MeStyr 8 OPS, suggesting that the stilbene groups sit over and interact with the face of the electrophilic silsesquioxane cage as is the case with the parent molecule, o-Br 8 OPS. The emission spectra of o-RStyr 8 OPS are similar to p-MeStyr 8 OPS indicating similar excited states involving the core LUMO. RStyr 16 OPS exhibits absorption and emission spectra as well as F PL similar to 1,4-distyrylbenzene, pointing to disruption in conjugation with the silsesquioxane cage because of steric interactions. RStyr 24 OPS offers absorption maxima that are blue-shifted and emission maxima that are red-shifted relative to RStyr 16 OPS. We speculate that RStyr 24 OPS is so sterically hindered that interactions with the cage face must occur. NBocStyr 24 OPS and AceStyr 24 OPS show moderate F PL and high two photon cross-section values, leading us to conclude that there are two excited states of nearly equivalent energy in these molecules with similar decay rates: a normal radiative p-p* transition and charge transfer involving the silsesquioxane cage. These same functional groups can be anticipated to offer much greater two photon absorption if different methods can be found for protecting the free amine from oxidation or replacing the acetoxy group (e.g. perhaps using alkyl or aryl groups).

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Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and photophysical properties of polyfunctional phenylsilsesquioxanes: [o-RPhSiO1.5]8, [2,5-R2PhSiO1.5]8, and [R3PhSiO1.5]8. compounds with the highest number of functional units/unit volume

2011

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“…It is observed in bromine-containing liquids and polymers [33,34] and it can be ascribed to the higher molar refraction contributions of the two Br atoms replacing one C]C double bond. For instance, Roll et al [34] calculated a refractive index of 1.7 for [2,5-Br 2 PhSiO 1.5 ] 8 crystals. The ClausiuseMossotti equation relates the refractive index n of a substance to its polarizability which can be described by the molar refraction [33].…”

Section: Resultsmentioning

confidence: 95%

A one-step method to coat polystyrene particles with an organo-silica shell and their functionalization

Deng

Bongard

Marlow

2015

Materials Chemistry and Physics

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“…Studies on stilbene derivatives of silsesquioxanes were also conducted. One of the aspects to be studied was the usage of octa(halogenephenyl)silsesquioxane reagents substituted with bromine at phenyl ring in different places (i.e., octa(o-bromophenyl)silsesquioxane, but also octa(2,5-dibromophenyl)silsesquioxane and octa(2,4,5-dibromophenyl)silsesquioxane) [59]. This provided more functionalities per unit volume, exceeding the density when compared to POSS-based dendrimers.…”

Section: Catalytic Reactions Leading To Functionalized Silsesquioxmentioning

confidence: 99%

Synthetic Routes to Silsesquioxane-Based Systems as Photoactive Materials and Their Precursors

2019

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Over the past two decades, organic optoelectronic materials have been considered very promising. The attractiveness of this group of compounds, regardless of their undisputable application potential, lies in the possibility of their use in the construction of organic–inorganic hybrid materials. This class of frameworks also considers nanostructural polyhedral oligomeric silsesquioxanes (POSSs) with “organic coronae” and precisely defined organic architectures between dispersed rigid silica cores. A significant number of papers on the design and development of POSS-based organic optoelectronic as well as photoluminescent (PL) materials have been published recently. In view of the scientific literature abounding with numerous examples of their application (i.e., as OLEDs), the aim of this review is to present efficient synthetic pathways leading to the formation of nanocomposite materials based on silsesquioxane systems that contain organic chromophores of complex nature. A summary of stoichiometric and predominantly catalytic methods for these silsesquioxane-based systems to be applied in the construction of photoactive materials or their precursors is given.

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[PhSiO1.5]8 promotes self-bromination to produce [o-BrPhSiO1.5]8: further bromination gives crystalline [2,5-Br2PhSiO1.5]8 with a density of 2.32 g cm−3 and a calculated refractive index of 1.7 or the tetraicosa bromo compound [Br3PhSiO1.5]8

Cited by 16 publications

References 47 publications

Synthesis, characterization and photophysical properties of polyfunctional phenylsilsesquioxanes: [o-RPhSiO1.5]8, [2,5-R2PhSiO1.5]8, and [R3PhSiO1.5]8. compounds with the highest number of functional units/unit volume

Synthesis, characterization and photophysical properties of polyfunctional phenylsilsesquioxanes: [o-RPhSiO1.5]8, [2,5-R2PhSiO1.5]8, and [R3PhSiO1.5]8. compounds with the highest number of functional units/unit volume

A one-step method to coat polystyrene particles with an organo-silica shell and their functionalization

Synthetic Routes to Silsesquioxane-Based Systems as Photoactive Materials and Their Precursors

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