How Strong Is a Covalent Bond?

+ See all authors and affiliations

Science  12 Mar 1999:
Vol. 283, Issue 5408, pp. 1727-1730
DOI: 10.1126/science.283.5408.1727

You are currently viewing the abstract.

View Full Text


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.

View Full Text