Data from: Mechanochemistry of cubane

Here, we report the mechanochemical reactivity of the highly strained pentacyclic hydrocarbon cubane. The mechanical reactivity of cubane is explored for three regioisomers with 1,2-, 1,3- and 1,4-substituted pulling attachments. Whereas all compounds can be activated thermally, mechanical activation is observed via pulsed ultrasonication of cubane-containing polymers only when force is applied via 1,2-attachment. The single observed product of the force-coupled reaction is a thermally inaccessible syn-tricyclooctadiene, in contrast to cyclooctatetraene (observed thermally) or a pair of cyclobutadienes that would result from sequential cyclobutane scission. We further quantify the mechano-chemical reactivity of cubane by single molecule force spectroscopy, and force-coupled rate constants for ring opening reach ~33 s-1 at a force of ~1.55 nN, lower than forces of 1.8-2.0 nN that are typical of conventional cyclobutanes.本研究报道了高张力五环烃立方烷（cubane）的机械化学反应活性。我们针对带有1,2-、1,3-及1,4-位牵拉取代位点的三种区域异构体，探究了立方烷的机械反应活性。尽管所有目标化合物均可通过热途径活化，但仅当通过1,2-位位点施加外力时，含立方烷的聚合物经脉冲超声处理方可实现机械活化。力偶联反应所观测到的唯一产物为热法无法获得的顺式三环辛二烯，这与热反应生成环辛四烯、或经连续环丁烷断裂得到一对环丁二烯的反应路径均不相同。我们进一步通过单分子力谱对立方烷的机械化学反应活性进行了定量分析：在约1.55纳牛顿的外力作用下，开环过程的力偶联速率常数可达~33 s⁻¹，该作用力低于常规环丁烷典型的1.8~2.0纳牛顿外力。