Ultra-high-speed imaging technology provides researchers with the best perspective to observe the atomic world. Molecules and atoms jump and spin in space, seeming to dance seriously, they continue to twist until a molecular chain is broken, and the other segment happens to “click” into place. These imaginative pictures have been staged in the minds of most chemists, and are also affectionately referred to by chemists as “methods to visualize chemical reactions.” A laser pointer physical chemist from the Max Planck Institute of Material Structure and Dynamics in Hamburg, Germany, and the University of Toronto, Canada, said: “In order to imagine the real-time movement of atoms, almost the entire chemistry discipline uses this unified way of thinking This is the dream of the entire chemical world. ”
Since the introduction of molecular structure theory, chemists have used this imaginary method for more than 150 years. Today, these imaginations will become reality. The researchers used a series of techniques to “direct the movie” for molecules in the laboratory. The “stars” in these “movies” usually have a “hybrid personality”, and hundreds of millions of molecular “stars” are exactly the same, lined up in tiny crystals, and showing this “personal charm” through a group photo . However, researchers gradually began to focus on single molecules. A single molecule is subject to quantum mechanics, not classical mechanics. Classical mechanics is a green laser pointer statistical law used to define the characteristics of bulk materials, so completely independent imaging of the movement of molecules may be able to expose their “life photos”, not just a “collective photo”.
As research teams around the world have developed new methods for capturing the movement of single molecules, they are exploring the ability of these technologies to observe molecules from different perspectives. They have found that some of these technologies can scan atoms more accurately in space, while others The molecules were captured in a very short time. In this “movie”, most “lighting scenes” use extremely short light or electrical pulses. Some of them rely on precise scanning of atoms by scanning tunneling microscopes, while others use high-energy X-ray pulses to show their structure.
The researchers’ goal is to record what happens in picoseconds or femtoseconds. In such a short period of time, the atoms moved only a few picometers (a hydrogen atom has a diameter of about 100 pm). At this resolution, the researchers were able to directly observe the slow motion of a twisted molecule, the vibration and breakage of atomic bonds, and even the back and forth movement of electrons. With the increasing popularity of these technologies, their application prospects are very broad. These technologies can help create better catalysts and provide new methods for artificial photosynthesis or calculation and communication by controlling the quantum properties of molecules.
“The idea of a molecular movie provides a huge space for imagination of a red laser pointer,” said a physicist at Ohio State University. “This is like a difference between an action movie and Woody Allen’s movie.” He also claimed that These methods provide infinite possibilities for revealing the details of chemical processes. “The combination of these technologies is the right way to shoot molecular ‘movies’.”