Claflin University Professor and Undergrad Use Microcrystallography to Screen Candidate Materials for Nonlinear Optics

A chemistry professor and a student researcher from Claflin University have made the first link in bringing big science to a small city in South Carolina. Assistant Professor of Chemistry Jie Ling and junior biology major Dawanye Burgess visited NSF’s ChemMatCARS for an intensive visit in July 2018 to collect structural data on microcrystals of hybrid organic-inorganic materials that may have advanced optical properties. Ling visited for four weeks; Burgess joined him for the last two. Their results were excellent, setting the stage for Claflin to continue using the ChemMatCARS microcrystallography beamline to expand this research program.

Claflin is a liberal arts university with an enrollment of about 2000 located in Orangeburg, South Carolina, a city of about 14,000 residents. It is among the top-ranked historically black colleges and universities (HBCUs) and emphasizes experiential and applied learning, along with a focus on STEM education. Undergraduate research is encouraged through a spring six-week program on campus and a focus on summer internships.

Ling, an inorganic chemist by training, joined the Claflin faculty two years ago, after postdoctoral work at Notre Dame University and several years in industry. In starting his own lab, he began by working with compounds familiar from his Ph.D.— nonlinear optical materials. Unlike conventional optics, these materials have the property of changing the frequency of laser light. “For a laser coming in at a frequency of 200, after it goes through the crystal the frequency may be 400. That’s the kind of material we’re trying to make,” Ling said. His current candidates are tellurite- and lanthanide-based metal-organic frameworks. 

Nonlinear optical properties are directly related to crystal structure (the crystal must be non-centrosymmetric). Thus, Jing needs good structural data on his candidate compounds—which he can’t (quite) get from the x-ray diffraction equipment in his home lab. “A lot of times we have a good crystal but we can’t solve [the structure] because the crystal is too small and it doesn’t diffract well,” Ling said. Data quality is quantified in an “R-value,” which is a measure of how well a proposed structure fits the x-ray data. To be publishable, the R-value must be under 5%. With his home diffraction equipment, Ling can achieve an R-value of 5–6%; “It’s barely publishable,” Ling observed. For his first data from ChemMatCARS, with the same compound, the R-value was 1%. “It’s way much better than we get before,” said a delighted Ling; “It’s awesome!” 

In 2017, Ling received a research grant from the U.S. Department of Energy’s Minority Serving Institutions Partnership Program that includes support for four undergraduate researchers. Burgess has been working in Ling’s lab under this program, growing crystals and screening them against known compounds. “I think it’s pretty cool being here [at ChemMatCARS]; it was very different from what I see at school and it has many resources and materials. I learned how to pick up crystals with the tool we use to mount the crystal to be x-rayed; I was able to move from the simple steps to the more complex part of the crystallography process,” Burgess said. He also got a glimpse of the bigger science picture at APS, because the team shared beamtime with two other summer visitors, both graduate students. “I got the idea that everyone’s crystal does not work the same. It’s amazing to see how differently it functions based on the materials they used,” he said.

The team will take their experience back to Orangeburg and prepare to publish the newly solved structures. Ling is also working to establish a collaboration with ChemMatCARS scientist Yu-Sheng Chen, who (along with other staff members) mentored the team during their visit. “We’re working on a joint workshop on synchrotron x-ray diffraction at Claflin, and we plan to accommodate 25 students and 5 faculty from Claflin and other HBCU schools, including Benedict College, South Carolina State University, Allen University, and Voorhees College, in South Carolina,” Ling wrote in an email after the visit. He is especially excited about the possibilities of the many techniques he has learned about: “This is a very fancy and powerful facility; it can do a lot of things I cannot do at my home institution. I’m thinking about doing high pressure. For nonlinear optical materials, maybe at high pressure the structure changes so maybe the property changes. We would like to know what that could be,” Ling said.

The Claflin team’s visit was sponsored under the Faculty and Student Team Research Award at ChemMatCARS (FaSTRAC). This competitive-admission program supports the use of ChemMatCARS by Minority-Serving Institution faculty members and their research students. In the program, faculty/student teams are fully supported for travel, housing, research materials, and stipend for a stay of four to six weeks. In addition to the monetary support, the Claflin team received 24 hours of beamtime. 

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Dawanye Burgess: visit summary

Jie Ling: visit summary | faculty profile