(PNSiMe₃)₄(NMe)₆: A Robust Tetravalent Phosphaza‐adamantane Scaffold for Molecular and Macromolecular Construction**

Abstract

Tetraarylmethanes and adamantanes are important rigid covalent connectors that play a four-way scaffolding role in molecular and materials chemistry. We report the synthesis of a new tetravalent phosphazaadamantane cage, (PNSiMe 3 ) 4 (NMe) 6 (2), that shows high thermal, air, and redox stability due to its geometry. It nevertheless participates in covalent four-fold functionalization reactions along its periphery. The combination of a robust core and reactive corona makes 2 a convenient inorganic scaffold upon which tetrahedral molecular and macromolecular chemistry can be constructed. This potential is demonstrated by the synthesis of a tetrakis(bis(phosphine)iminium) ion (in compound 3) and the first all P/N poly(phosphazene) network (5).

Site‐Selective Functionalization of Sila‐Adamantane and Its Ensuing Optical Effects

“…Tetra‐functionalized sila‐adamantanes are anticipated to be useful material building blocks. Sila‐adamantanes with four identical metal‐linking groups may serve as a tetrahedral building blocks in framework materials; [24, 60] sila‐adamantanes with four unique substituents enable access to multifunctional materials with sila‐diamondoid cores [61, 62] …”

Site‐Selective Functionalization of Sila‐Adamantane and Its Ensuing Optical Effects

“…[1,59] Tetrafunctionalized sila-adamantanes are anticipated to be useful material building blocks. Sila-adamantanes with four identical metal-linking groups may serve as a tetrahedral building blocks in framework materials; [24,60] sila-adamantanes with four unique substituents enable access to multifunctional materials with sila-diamondoid cores. [61,62] Marschner and co-workers previously noted the wavelength of maximum absorption for 2 (223 nm) is blue-shifted compared to linear pentasilane chains (Figure S4-S6, Supporting Information Note 1).…”

An Improved Synthesis of PN‐adamantanoid Cages P4(NR)6 and a Mechanistic Study of their Fourfold Oxidation

“…Spectral data matched reported values. [10] 1Bu: nBuN(SiMe 3 ) 2 (3.144 g, 14.46 mmol) and PCl 3 (1.335 g, 9.723 mmol), 24 h. The crude product was taken up into 2 mL of pentane and was filtered through a 5 cm plug of silica. The product was eluted with an additional 10 mL of pentane, and the volatiles of the filtrate were removed under reduced pressure yielding a clear and colourless oil.…”

“…We have previously shown that the high stability of these adamantanoid compounds is a result of atomic motions being coupled in cages, which raises the kinetic barriers for any decomposition processes. [10]…”

“…[9] We recently showed that following exhaustive oxidation with Me 3 SiN 3 , 1Me can be converted into air-stable tetra-silylphosphinimine 2Me, which, due to the high polarity of the SiÀ N bonds, acts as a tetrahedral covalent connector yielding new classes of molecular and macromolecular products. [10] While several derivatives of 1R are known, one of the key factors preventing the widespread study of such PN adamantanoids is that their syntheses are challenging, often requiring specialized equipment or approaches. [11] This can be illustrated for the currently known best synthesis of 1Me (Figure 1a), which involves addition of neat PCl 3 to excess liquid MeNH 2 at À 78 °C.…”