Beilstein J. Org. Chem.2022,18, 1225–1235, doi:10.3762/bjoc.18.128
molecule mechanochemistry sometimes overlap, evidencing the connection between both approaches.
Keywords: ball milling; mechanochemistry; mechanophore; polymer; pulsed ultrasonication; Introduction
In the past two decades, the growth in popularity of mechanochemistry has been unmistakable. During this
BMPF mechanophore into glassy and rubbery polymeric networks such as poly(butyl methacrylate) and a poly(hexyl methacrylate) [28]. Upon treatment of the polymeric material 2 in a mixer mill (Figure 1b), the BMPF units underwent a mechanical homolytic fragmentation of the O−O peroxide bond, releasing
fluorescent 9-fluorenone (3) via β-scission (Scheme 1b). To highlight the importance of the polymer network in the transduction of the mechanical stimulus to the mechanophore, the authors demonstrated that ball milling monomeric BMPF-OH at 30 Hz for 3 h only generated traces of 3 (1% after isolation
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Graphical Abstract
Figure 1:
Representation of (a) cavitation and elongational flow caused by pulsed ultrasonication, (b) mixer ...
Beilstein J. Org. Chem.2017,13, 1099–1105, doi:10.3762/bjoc.13.109
temperature. Ultrapure water (18.2 MΩ·cm) has been used as subphase. A solution of the flipper mechanophore in chloroform/DMSO (8:2 vol%/vol%) was spread onto an expanded air/water interface. After evaporation and dissolution of the organic solvents, the size of the air/water interface was decreased with
. However, this apparently low slope is connected with the experimental problem of measuring the surface tension of stiff films and the organization of this particular flipper mechanophore. The stiffness of the layer leads to a tilting of the Wilhelmy plate (expansion leads shortly to a surface pressure
molecule, suggesting that the flipper mechanophore is standing upright on the air/water interface. The strong π–π interactions stabilize this upright orientation of the flipper molecules in the monolayer. Even the expansion to 2 mN/m does not lead to changes in the condensed monolayer thickness.
It is
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Graphical Abstract
Figure 1:
Structure of the (bis)dithienothiophene mechanosensitive flipper probe. Twisted out of planarity by...