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Creators/Authors contains: "Settineri, Nicholas S."

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  1. Abstract

    Reactions of the IrVhydride [MeBDIDipp]IrH4{BDI=(Dipp)NC(Me)CH(Me)CN(Dipp); Dipp=2,6‐iPr2C6H3} with E[N(SiMe3)2]2(E=Sn, Pb) afforded the unusual dimeric dimetallotetrylenes ([MeBDIDipp]IrH)2(μ2‐E)2in good yields. Moreover, ([MeBDIDipp]IrH)2(μ2‐Ge)2was formed in situ from thermal decomposition of [MeBDIDipp]Ir(H)2Ge[N(SiMe3)2]2. These reactions are accompanied by liberation of HN(SiMe3)2and H2through the apparent cleavage of an E−N(SiMe3)2bond by Ir−H. In a reversal of this process, ([MeBDIDipp]IrH)2(μ2‐E)2reacted with excess H2to regenerate [MeBDIDipp]IrH4. Varying the concentrations of reactants led to formation of the trimeric ([MeBDIDipp]IrH2)3(μ2‐E)3. The further scope of this synthetic route was investigated with group 15 amides, and ([MeBDIDipp]IrH)2(μ2‐Bi)2was prepared by the reaction of [MeBDIDipp]IrH4with Bi(NMe2)3or Bi(OtBu)3to afford the first example of a “naked” two‐coordinate Bi atom bound exclusively to transition metals. A viable mechanism that accounts for the formation of these products is proposed. Computational investigations of the Ir2E2(E=Sn, Pb) compounds characterized them as open‐shell singlets with confined nonbonding lone pairs at the E centers. In contrast, Ir2Bi2is characterized as having a closed‐shell singlet ground state.

     
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  3. Abstract

    Self‐sorting is commonly observed in complex reaction systems, which has been utilized to guide the formation of single major by‐design molecules. However, most studies have been focused on non‐covalent systems, and using self‐sorting to achieve covalently bonded architectures is still relatively less explored. Herein, we first demonstrated the dynamic nature of spiroborate linkage and systematically studied the self‐sorting behavior observed in the transformation between spiroborate‐linked well‐defined polymeric and molecular architectures, which is enabled by spiroborate bond exchange. The scrambling between a macrocycle and a 1D helical covalent polymer led to the formation of a molecular cage, whose structures are all unambiguously elucidated by single‐crystal X‐ray diffraction. The results indicate that the molecular cage is the thermodynamically favored product in this multi‐component reaction system. This work represents the first example of a 1D polymeric architecture transforming into a shape‐persistent molecular cage, driven by dynamic covalent self‐sorting. This study will further guide the design of spiroborate‐based materials and open the possibilities for the development of novel complex yet responsive dynamic covalent molecular or polymeric systems.

     
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  4. Abstract

    Self‐sorting is commonly observed in complex reaction systems, which has been utilized to guide the formation of single major by‐design molecules. However, most studies have been focused on non‐covalent systems, and using self‐sorting to achieve covalently bonded architectures is still relatively less explored. Herein, we first demonstrated the dynamic nature of spiroborate linkage and systematically studied the self‐sorting behavior observed in the transformation between spiroborate‐linked well‐defined polymeric and molecular architectures, which is enabled by spiroborate bond exchange. The scrambling between a macrocycle and a 1D helical covalent polymer led to the formation of a molecular cage, whose structures are all unambiguously elucidated by single‐crystal X‐ray diffraction. The results indicate that the molecular cage is the thermodynamically favored product in this multi‐component reaction system. This work represents the first example of a 1D polymeric architecture transforming into a shape‐persistent molecular cage, driven by dynamic covalent self‐sorting. This study will further guide the design of spiroborate‐based materials and open the possibilities for the development of novel complex yet responsive dynamic covalent molecular or polymeric systems.

     
    more » « less