Tuning the dihedral angle (DA) of axially chiral compounds can impact biological activity, catalyst efficiency, molecular motor performance, or chiroptical properties. Herein, we report gradual, controlled, and reversible changes in molecular conformation of a covalently linked binaphthyl moiety within a 3D polymeric network by application of a macroscopic stretching force. We managed direct observation of DA changes by measuring the circular dichroism signal of an optically pure BINOL‐crosslinked elastomer network. Stretching the elastomer resulted in a widening of the DA between naphthyl rings when the BINOL was doubly grafted to the elastomer network; no effect was observed when a single naphthyl ring of the BINOL was grafted to the elastomer network. We have determined that ca. 170 % extension of the elastomers led to the transfer of a mechanical force to the BINOL moiety of 2.5 kcal mol⁻¹ Å⁻¹ (ca. 175 pN) in magnitude and results in the opening of the DA of BINOL up to 130°.

中文翻译：

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通过在3D高分子网络中进行交联来对联芳构象进行可逆的软机械化学控制。

调整轴向手性化合物的二面角（DA）会影响生物活性，催化剂效率，分子运动性能或手性。在本文中，我们报告了通过施加宏观拉伸力，共价连接的联萘部分在3D聚合物网络内的分子构象的逐渐，受控和可逆变化。我们通过测量光学纯BINOL交联的弹性体网络的圆二色性信号来直接观察DA的变化。当将BINOL双重接枝到弹性体网络上时，拉伸弹性体会导致萘环之间DA的加宽。当BINOL的单个萘环接枝到弹性体网络上时，未观察到任何影响。我们已经确定^-1 埃^-1（约175 PN）在DA的BINOL向上的开口130的大小和结果°。