The recent discovery of methods of obtaining quite pure ortho stilbene derivative of brominated OPS products, has allowed us to revisit some of these reactions especially given that we can make half and fully functionalized stilbene of deca and dodeca PS. Synthesizing sets of corresponding stilbene derivatives where R = 4-methyl, 4-methoxy, Boc-protected 4-amino (NBoc), and 4-cyano provides an overview of their photophysical properties.In an earlier paper, the synthesis of a series of (BrPh)x(Ph)8-xOS compounds has been described, which was used as the starting point for the synthesis via Heck coupling of a p-methylstilbene derivative. In this paper, we extend our efforts to synthesize a series of high ortho-substituted stilbene derivatives. Here we used (BrPh)x(Ph)10-xS and (BrPh)x(Ph)12-xS, where x indicates the average degree of Br substitution on the cage. These derivatives were characterized by GPC, TGA, MALDI-TOF, UV-Vis and Photoluminescence spectrometry. Within each series of compounds with the same R group, we observed the same trends. The absorption and emission spectra of NBocStyrxDPS and NBocStyrxDDPS are only slightly red-shifted from those of MeStyrxDPS and MeStyrxDDPS and MethoxyStyrxDPS and MethoxyStyrxDDPS. This is expected given that the amino groups are masked by the Boc protecting groups, which are electron withdrawing. Cyano substituents should exhibit electron-withdrawing properties. But the result is similar to methoxy group.      Figure 1.  Synthesis of (RStil)x(Ph)10-xDS from (BrPh)x(Ph)10-xDS.

Synthesis, characterization, and photophysical properties of polyfunctional nanobuilding phenylsilsesquioxanes: [R0.5PhSiO1.5]10, [RPhSiO1.5]10, [R 0.5PhSiO1.5]12, and [RPhSiO1.5]12 compounds

248th National Meeting (2014)

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