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Updated: Apr 21, 2026

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of PhosphorusI
Published on: November 22, 2016
Why do the [PhSiO(1.5)](8,10,12) cages self-brominate primarily in the ortho position? Modeling reveals a strong cage
1Dept. of Mater. Sci. & Eng, Univ. of Michigan, Ann Arbor, MI 48109, USA. talsdad@umich.edu.
Abstract:
(PhSiO1.5)8,10,12 cages are bulky, electron withdrawing like CF3; yet self-brominate (60 °C), favoring ortho substitution: PhT8 (≈85%), PhT10 (≈75%) and PhT12 (60%). First-principles calculations suggest bromination initiates when Br2 is "trapped" via H-bonding to ortho-H's, followed by polarization via strong interactions with cage faces, possibly cage LUMOs.
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