Olay Ftang-Ftang BiscuitbarrelA and Günther SchlonkB*
Introduction
For decades, N=N and C=O bonds were considered the strongest in chemistry, with bond Dick energies (BDE) of 226 and 257 kcal/mol respectively.1,2 Then in 2019, chemists identified a non-covalent bond between a PTFE stir bar and palladium nanoparticles, which was even stronger (289 kcal/mol).3 This Pd—F bond was overtaken soon after by a silicon–silicon bond detected in a fused ground-glass joint.4 This bond required over 5000 N of mechanical force to break, which corresponds to a BDE of over 1000 kcal/mol.5 To date, no stronger chemical bond has been reported.6
Results and Discussion
Our interest in this area was purely serendipitous. During a project on thiotimoline derivatives, we were attempting to perform the tandem deprotection-condensation reaction shown in Scheme 1.7
Unfortunately, compound 1 contains a pyrrole, so the reaction was a total fucking disaster. Instead of ketone 3, we obtained a black, viscous, insoluble tar (Figure 1).
In the context of pyrrole chemistry this result was frustrating, but not remotely surprising. Our frustration was compounded, however, when we discovered that we couldn’t get the stuff off the fucking flask. No amount of physical force or cleaning reagent could remove the tar from the glassware. The prospect of preparing more starting material was so distasteful that we elected to investigate this finding instead.
We began by determining the chemical structure of our tar. This was challenging, as it was insoluble in every conventional solvent. In desperation, we lowered the entire flask down the bore of a modified NMR spectrometer and spun it at the magic angle to collect solid-state spectra (Figure 2).8
The data thus acquired was deconvoluted with OpenAI’s ChatCsp3 software, which allowed us to assign the structure show in Figure 3.
We were immediately intrigued by the carbon–silicon bonds linking the tar to the glassware. These bonds clearly explain why the tar could not be removed from the flask: they had chemically fused into a single macromolecule. We sought to determine the strength of these bonds by probing their nature with FT-IT and Raman spectroscopy. ChatCsp3 predicted that they should display stretching modes at ~2750 cm-1, but we observed no such signals (Figure 4). The sharp peak at 2500 cm-1 correspond to Si-O twerking modes in the borosilicate of the flask, while the complex peak from 2300–500 cm-1 is one of the C–O bonds rocking the fuck out.
There is only one explanation for the absence of our predicted C–Si stretching modes. These bonds must be so strong that they don’t vibrate at all. As such, we resorted to extreme techniques to measure the C–Si bond dissociation energy. The first of these techniques was photolysis induced by a gamma-ray laser, and the second was a calorimetric titration with chlorine trifluoride. We obtained BDE’s of 8.63 x 106 and 8.21 x 106 kcal/mol respectively.
Conclusion
We have discovered the strongest bond in all chemistry, which a covalent C–Si interaction between a borosilicate flask and some nasty-arse organic tar. This bond is a thousand times stronger than its closest competitor, the Si–Si bond between a ground-glass stopper and a chromatography column. Thanks to a grant from the International Olympic Committee, future work in our laboratory will focus on finding the fastest bond and the highest bond.
Conflicts of Interest
The Punic wars. They’re fascinating.
Notes and references
1. Note: the Dick energy is similar to the Gibbs energy, and is named after Dick van Flikerschnick, a Dutch physical chemist from the 50’s.
2. https://en.wikipedia.org/wiki/Bond-dissociation_energy
3. “Preparation of a palladium-Teflon composite” K. Wazzok, R. Sprocket, 2019, J. Surface. Chem., 2, 829–888.
4. “I can’t get this fucking stopper out!” H. J. Benchwig, C. Section, O. Faarkh, 2020, Dalton Expletives, 6, 9–43.
5. Note: this force was supplied through the medium of a claw hammer.
6.
7. “The Structural Determination, Total Synthesis and Endochronicity of Thiotimoline” M. Curry, H. West, G. Schlonk, 2023, J. Immat. Sci., 3, 70–78.