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Recently, polymer mechanochemistry has attracted much scientific interest due to its potential to develop degradable polymers. When the two ends of a polymer chain experience a linear pulling stress, molecular strain builds up, at sufficiently strong force, a bond scission of the weakest covalent bond results. In contrast, bond‐breaking events triggered by conformational stress are much less explored. Here, we discovered that a Zn salen complex would undergo conformational switching upon allosteric complexation with alkanediammonium guests. By controlling the guest chain length, the torsional strain experienced by Zn complex can be modulated to induce bond cleavage with chemical stimulus, and reactivity trend is predicted by conformational analysis derived by DFT calculation. Such strain‐release reactivity by a Zn(salen) complex initiated by guest binding is reminiscent of conformation‐induced reactivity of enzymes to enable chemical events that are otherwise inhibited. [ABSTRACT FROM AUTHOR]

The reaction of C2H4 and β-SiH containing azasilazirconacycle Cp2Zr{κ2-N(SiHMe2)SiHMeCH2} (3), formed via a γ-abstraction reaction of Cp2Zr{N(SiHMe2)2}H (1), follows an unusual pathway in which a rare σ-bond metathesis reaction of ethylene generates a vinyl intermediate. That species undergoes a β-hydrogen abstraction under the reaction conditions to form a zirconium silanimine ethylene adduct en route to the metallacyclopentane product. [ABSTRACT FROM AUTHOR]