MISSOULA – Scientists and students studying at the subnanometer level can rejoice: the University of Montana has purchased a single-crystal X-ray diffractometer valued at $515,000.
The device is the only small-molecule diffractometer in Montana and this part of the Rocky Mountain West.
“This is a state-of-the-art instrument,” said Orion Berryman, a UM assistant professor of chemistry. “We are really excited to have it here.”
The device was installed the last week of January in the basement of UM’s Interdisciplinary Science Building. It did its first imaging Feb. 3.
Berryman said the diffractometer measures tiny crystal samples to determine composition at atomic resolution. This tells scientists what the crystals are made of and how the atoms are arranged. The device produces 3-D maps that illustrate the locations and composition of atoms within the sample.
A crystal is composed of an ordered and repeating molecule in the solid state. The diffractometer shines an intense X-ray source into the crystal to take measurements. The X-rays bounce off the electrons of the atoms at varying angles.
“Based on the angle that the X-rays diffract off the atoms’ electrons, we can calculate the position of the atom and also how many electrons are involved,” Berryman said. “If the diffraction has a particular intensity, it has to be a certain type of atom. And then we can make pictures of what the structure looks like.”
He said the new UM instrument has a lot of capabilities because it has two X-ray sources – one copper and one molybdenum – that produce X-rays with different wavelengths. This makes the device capable of handling both large crystals or small samples that don’t defract well.
Though the diffractometer is valued a $515,000, UM paid significantly less. Berryman earned a $265,000 grant from the National Science Foundation to fund purchase of the instrument, and UM’s research administration office, chemistry department, pharmacy college and College of Humanities and Sciences provided a 30 percent match. The manufacturer also provided a substantial discount.
“I think they were pretty excited to see one of their instruments in our region,” Berryman said.
He wants to spread the word that the device is now available to chemists, geoscientists, pharmacy researchers, biologists and others. It uses liquid nitrogen to cool down the samples enough to obtain high-resolution data. He said a small fee will be charged to people at UM to maintain the facility and instrument. People from off campus will pay slightly more.
“This is intended to be an intercollegiate instrument,” Berryman said. “We hope to have students from UM, Montana State and elsewhere using the instrument.”
In his own lab, Berryman works to develop new catalysts, which increase the rate of chemical reactions. In the first uses of the diffractometer, he studied how a catalyst his lab designed interacted with an anionic substrate.
“It confirmed our hypothesis – that these molecules interact the way we designed,” he said. “There is no other instrument that gives us such direct confirmation of our structure. We can’t wait to train students to use this instrument. It’s pretty user-friendly. Analyzing the data takes more time, but certainly anyone interested in doing it can learn.”
Photo: An image produced by the single crystal X-ray diffractometer at the University of Montana.
Western Montana, Dailies