Hydrogen bond research adds to scientific community’s knowledge

Hydrogen bond research adds to scientific community’s knowledge

Two Indiana State
University undergraduates will present their research findings about how
molecules interact at a national conference this spring.
One might recall from
science classes that particles of the same charge, such as two negatives or two
positives, repel each other and that particles of opposite charge attract.
“Electrostatics” describes this idea.
Students Rebecca
Rudisell and Patrick Cheek, under the guidance of Eric Glendening, chair of the
physics and chemistry department, examined a class of like-charged compounds
held together by hydrogen bonds — anti-electrostatic hydrogen bonds — that
defy this well-known rule.
“Hydrogen bonds are
extremely important, because our proteins, our DNA — it’s all held together by
these strange interactions called hydrogen bonds,” Glendening said.
“What we find in these anti-electrostatic hydrogen bonding systems is that
pairs of molecules that have the same charge nevertheless stick together, and
they stick together because of these hydrogen bonds. And so, there’s maybe
something a little more special to hydrogen bonds than what has been known
before.”
This special ability of
hydrogen bonds recently caused a controversy in the scientific community when
researchers from the University of Wisconsin and England published the article
“Anti-electrostatic Hydrogen Bonds.” The controversy highlights the
capacity of current chemical models to account for this phenomenon, which may
occur in water when larger, oppositely charged molecules come in contact,
Glendening said.
“The problem is
that some models that chemists use would never be able to predict that
something like this could form in water and that is, to some extent, where the
debate is,” Glendening said. “We want models that are very accurate,
but how do we develop those models?”
Glendening, Rudisell and
Cheek wanted to gain insight into the controversy. The students completed their
study as part of Indiana State’s Summer Undergraduate Research Experience
(SURE) program. They presented their findings, “The Nature of the
Anti-Electrostatic Hydrogen Bond,” at the Center for Student Research and
Creativity’s Fall Exposium on Oct. 8.
The students used
quantum mechanical models to make predictions about the chemical systems,
forgoing the crude chemical models that were currently in use for simulating
proteins and DNA. Developing models is common in chemistry and physics to study
concepts that cannot be directly observed. As best as Glendening is aware, the
anti-electrostatic hydrogen bond systems have not been observed previously in
the laboratory — but calculations suggest that they can exist.
“When students have
a research experience, they are really doing science,” Glendening said.
“Research has been published on (anti-electrostatic hydrogen bonding), but
nothing like we’ve done here. Rebecca and Patrick know something now about
these systems that most chemists out there are not aware of.
They learned something
from their effort that contributes to the overall knowledge that we have about
chemical systems. Ultimately, that’s the best part of engaging students in
research activity.”
Rudisell, a sophomore
history major from Harmony who is minoring in science, said she values the
hands-on learning and increased understanding of chemistry, as well as the
indirect benefits of the experience.
“It was
interesting, and because of the knowledge I gained, I feel like I can
understand my chemistry classes easier,” said Rudisell, who is completing
pre-requisites for veterinary medicine. “Presenting the research during
(SURE’s) weekly meetings got me used to talking in front of people.”
Learning to use this
technology was a valuable addition to the students’ skills.
“(It’s) sometimes
hard to understand what you are really plugging in and especially the results
you are receiving,” Cheek said. “You really must know how to
interpret your data, whether it is computational or physical. If you don’t know
what your data means then you really have nothing – that was certainly a big
takeaway from the research.”
Cheek, a senior from
Franklin double-majoring in biology and chemistry with a concentration in
biochemistry, also vouched for the benefits of exploring the subject matter.
“I learned so much
in so little time, and it was cool to think that (we) were working and focusing
on something that is not fully understood,” Cheek said. “Especially
towards the end, I was really able to understand what it is like to perform
research and be able to push the bounds of that research and provoke questions
and ideas and even test those theories and ideas.”
Cheek also said he felt
the project gave him a more solid understanding of chemical systems and a
promising addition to his resume.
Rudisell and Cheek will
travel to San Diego during spring break to attend the National American
Chemical Society Meeting, presenting their research in an undergraduate
session. More than 12,000 chemists from around the world will attend this
meeting.
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Contact: Eric
Glendening, chair, department of chemistry and physics, 812-237-2235 or
[email protected]
Writer: Kristen Kilker,
media relations assistant, Office of Communications and Marketing, 812-237-3773
or [email protected]