JERUSALEM — Israeli and Chinese scientists have developed an advanced method for examining the spatial structure of molecules, as published Thursday by the Weizmann Institute of Science (WIS) in the center of Israel.
The WIS researchers, together with scientists of Shanghai’s East China Normal University (ECNU), showed how very short and fast laser pulses align molecules in a certain direction.
This enables to examine the structure of the molecules by measuring the radiation that bypasses them and disperses from them.
Understanding the structure of complex molecules can lead to technological inventions, the development of advanced methods of medical treatment, and more.
So far, an examination of molecules structure required molecular crystals – when the crystallization process in many cases is difficult and complex.
In the new method, the radiation is used on individual molecules, which are not arranged in a crystal, so no crystallization process is needed.
The scientists demonstrated the new method on sulfur oxide molecules consisting of two oxygen atoms and a sulfur atom. The two oxygen atoms create an axis for the molecule, with the sulfur freely rotating around this axis.
First, the researchers launched laser pulses in the direction of the oxygen atoms – aligning the axis of the molecules in the same direction.
Then, pulses of additional laser, resulting from the first and coordinated with it, caused also the sulfur atoms to line up in the desired direction.
The time taken for molecules to line up as a result of the laser pulses is about 10 femtoseconds (10 millionths of a billionth of a second).