Discovery of a new type of ultra-strong chemical bond

Researchers have identified a new type of hydrogen bond that exhibits similar or even greater strength than certain covalent bonds. These bonds could be involved in many chemical reactions and used in the field of biology or fuel cells.

You will also be interested


[EN VIDÉO] The unsuspected beauty of chemical reactions
Science and art can meet in unexpected ways. Chemical reactions, for example, lead to complex interactions and amazing spectacles. No need to search for the nearest laboratory, come and discover the hidden beauty of chemical reactions here on video.

It exists in chemistry three types of connection: covalent bond, which results from the pooling ofelectrons between dos atoms, the ionic bond where the electrons of a ion are transferred to a neighboring atom, and the enlace intermolecular o Van der Waals (al que el hydrogen bonds), which are lower than the previous two. These three links are all relatively stable. But researchers have long known that in a chemical reaction there are intermediate states in which atoms can bond together for fractions of a second and are therefore more difficult to observe.

Strong hydrogen bonds

A new study published in the journal Sciences managed for the first time to observe one of these intermediate states, revealing a new type of Chemical bond : a hydrogen bond but with the force of a covalent bond (in principle, the hydrogen bond is about 20 times weaker). To do this, the researchers dissolved a hydrogen fluoride compound in water and observed how hydrogen atoms and fluorine interacted thanks to a spectroscopy device that records the vibrations atoms under the light infrared. They found that fluorine atoms were attracted to hydrogen atoms due to an imbalance of positive and negative charges, as in a standard hydrogen bond. In solvinganion bifluoride, each hydrogen atom tends to be “sandwiched” between two fluorine atoms.

But the researchers found that these sandwiches were United stronger than typical hydrogen bonds. In these short hydrogen bonds, the atoms join together in a structure looking like a molecule, which is normally characteristic of a covalent bond. But the mechanism of the new bond is of the nature electrostaticThis means that the link is still of the Van der Waals nature.

According to the researchers’ measurements, these new links have a Energy 45.8 kcal / mol (about 192 kJ / mol), which is higher than some covalent bonds. A molecule re’nitrogen it is formed for example by two atoms united by a bond of force 38 kcal / mol. Hydrogen bonds have a binding energy of 1 to 5 kcal / mol. This finding isn’t entirely a surprise, but it blurs the definitions of chemical bonds and molecules. In fact, atoms connected by covalent bonds are considered a molecule, while atoms connected by via a hydrogen bond can remain in independent molecules.

A possible strong bond between water molecules?

According to researchers from the Max-Planck Institute (not participating in the study), it is possible that this type of connection exists in the water, where a hydrogen ion is sandwiched between two water molecules. These links have never yet been conclusively observed because their duration life would be much shorter than with fluoride. ” The study of these movements molecules and how they can be oriented in a desired direction could find Applications in the transport of protons in biology and in technologies such as fuel cell membranes »Say the researchers.

Interested in what you just read?

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.