How Strong Is a Covalent Bond?

作者：Michel Grandbois, Martin K. Beyer, Matthias Rief, Hauke Clausen‐Schaumann, Hermann E. Gaub · 发表于：Science · 年份：1999 · DOI：10.1126/science.283.5408.1727 · 被引用次数：1110 · 研究领域：Force Microscopy Techniques and Applications、Mechanical and Optical Resonators、Molecular Junctions and Nanostructures

The rupture force of single covalent bonds under an external load was measured with an atomic force microscope (AFM). Single polysaccharide molecules were covalently anchored between a surface and an AFM tip and then stretched until they became detached. By using different surface chemistries for the attachment, it was found that the silicon-carbon bond ruptured at 2.0 +/- 0.3 nanonewtons, whereas the sulfur-gold anchor ruptured at 1.4 +/- 0.3 nanonewtons at force-loading rates of 10 nanonewtons per second. Bond rupture probability calculations that were based on density functional theory corroborate the measured values.