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Saturday, January 25, 2014

Chemistry Literature Feature Vol. I

This week marks the beginning of a new blog segment where I'll post one article from each cluster in the chemistry department at Michigan. If you come across an article (or have published one yourself!) that you'd like to see highlighted here, by all means send it in! E-mail treetownchem@gmail.com with your suggestions - I would love to hear them.

This week, we'll see some molecular fences with interesting fluorescence properties, explore the inside of tiny balls of silica, learn why coffee is good for your brain, and more. But first, a bit of fun:

Overheard at Michigan
     "The more words there are in front of the word 'spectroscopy,' the more excited I get."

Analytical: Are Reactive Oxygen Species Generated in Electrospray at Low Currents?
This ASAP article in Analytical Chemistry (ACS) examines the potential for electrospray ionization, a common ionization technique for mass spectrometry, to generate highly reactive by-products that can destroy analytes and confound results during measurement. The authors confirm that oxygen species generated in electrospray have a direct effect on a urease analyte and demonstrate how the damage can be avoided.

Biochemistry: Post-study Caffeine Administration Enhances Memory Consolidation in Humans
Published in Nature Neuroscience and highlighted by C&EN Magazine, this study seeks to determine the effect that caffeine has on long-term memory. The authors adapt a simple behavioral study previously applied in animal subjects to human participants. Caffeine doses are administered at careful times to avoid confounding the influence of caffeine on memory with other known effects on brain and body activity. If you're a coffee drinker, this one's for you.

Inorganic: On the Observation of Intervalence Charge Transfer Bands in Hydrogen-Bonded Mixed-Valence Complexes
In this article, published in the Journal of the American Chemical Society, the authors set out to investigate the nature of light absorption in ruthenium carboxylate cluster complexes. Using spectroelectrochemistry, a simultaneous combination of spectroscopy and electrochemistry by which an experimenter can learn about states of a molecule that may not be stable long-term, the authors expertly identify the intensity and rate of long-range charge transfer in cluster dimers.

Materials: Crystalline Carbon Nitride Nanosheets for Improved Visible-Light Hydrogen Evolution
A large part of materials chemistry is concerned with creating nanomaterials - materials in a form where the individual pieces are so small that the properties change (sometimes drastically) from the properties of larger pieces of "bulk" material. In this Journal of the American Chemical Society paper, the authors investigate the ability of special nanosheets of only a few atomic layers in thickness to produce hydrogen from water under solar illumination. The sheets perform almost 20 times better than the same material at bulk scale.

Organic: The Effects of Cyclic Conjugation and Bending on the Optoelectronic Properties of Paraphenylenes
Published in Organic Letters (ACS), this communication from Professor Ramesh Jasti's group demonstrates the synthesis and unique absorption/fluorescence properties of cycloparaphenylenes. (I picture them as little fences and it makes me laugh.) The molecules are created using clever application of well-known organic reactions, and the optical properties are contrary to what you might expect - I won't spoil them here. If you missed Professor Jasti's seminar presentation last week at the U of M, this is a good paper to catch up with!

Physical: Water Confinement in Nanoporous Silica Materials
Both experimental and theoretical evidence are piling up around the idea that water trapped between big solutes or inside pores of extended solids is fundamentally different from the free bulk water composing most of the solution. This paper, published in the Journal of Chemical Physics (AIP), adds to the theoretical part of that pile with some molecular dynamics simulations examining the structure of water trapped in tiny holes of a common material like silica. These kinds of studies are interesting to me because of the implications for reactivity at solid-fluid interfaces - if we understand how solvents change at these interfaces, how can we extend that to more accurately describe how reactions proceed in those areas?

Remember, if you come across an article that you think should be featured here, send it in! treetownchem@gmail.com

Abbreviations:
ACS: American Chemical Society
AIP: American Institute of Physics
C&EN: Chemical & Engineering News

Monday, January 20, 2014

In Remembrance of Three African American Chemists

In honor of Martin Luther King, Jr. Day, while setting up my reactions this morning I reflected on African American scientists I knew of that had been influential in shaping science as  I know it today. A few jumped to mind immediately. George Washington Carver, of course, was a scientific jack-of-all-trades, taking his studies in botany and extending them into chemistry and agricultural science, collecting fistfuls of patents along the way. Astronomer Neil DeGrasse Tyson has been very visible lately, providing many a profound opinion on the place of science in our society. However, when I challenged myself to name an influential African American chemist, I was stumped.

Well, that won't do.

Below are three brief biographical sketches of notable African American chemists and biochemists and their work. Some of this information, along with sketches for many other African American scientists of all disciplines, is freely available here.


Percy Lavon Julian (1899-1975) [ref]
Credit Howard University via
wikipedia.org.

On April 11, 1899, Percy Julian was born in Montgomery, AL. Dr. Julian was able to attend school through the 8th grade but was barred from attending high school. Despite his lack of a diploma, he was accepted to DePauw University in Greencastle, IN, where he pulled a double class load to bring him up to speed with his peers. He would end up graduating first in his class with a B.S. in chemistry in 1920. After a brief stint as a chemistry instructor at Fisk University (Nashville, TN), Dr. Julian entered Harvard University to pursue a Master's degree. After completing the Master's degree, he was blocked by the university from proceeding to a doctorate. After a few more years as a chemistry instructor, this time at Howard University, he was awarded a Rockefeller Fellowship to travel to Austria in pursuit of a Ph. D. at the University of Vienna, which he earned in 1931.

Dr. Julian's independent research career began at his alma mater DePauw University. In 1935 he made the discovery of his career, successfully synthesizing a drug called physostigmine, which originally broke ground as a glaucoma treatment and has been researched for other applications as well. However, due to his race DePauw would not allow him to become a full professor. He left academia and became an industrial researcher, working for the Glidden Company. In 1953 Dr. Julian left Glidden to begin his own research laboratory, Julian Laboratories. He sold the company in 1961, using the substantial profits to found the Julian Research Institute, a non-profit research organization, which he operated until his death in 1975.

Dr. Percy Julian was the first African American chemist elected to the National Academy of Sciences, one of the United States' eminent societies of scholars. His physostigmine synthesis (subscription required) is hailed as one of the top achievements in American chemistry, and in 1999 was honored by the American Chemical Society as a National Historic Chemical Landmark.

Henry Ransom Cecil McBay (1914-1995) [ref]
Henry McBay was born in the oil town of Mexia, TX on May 29, 1914. After attending grade school, he was accepted into Wiley College in Marshall TX, where he graduated with a B.S. degree in chemistry in 1934. McBay's primary interest was in organic chemistry. He went on to earn a Master's degree at Atlanta University in 1936. After holding positions as a chemistry instructor at his alma mater Wiley College (1936-1938) and also at Western University in Kansas City, he entered a doctoral program at the University of Chicago, graduating with his Ph. D. in 1945.

Dr. McBay's research focused mostly on the reaction mechanisms of organic peroxides, and his work with these dangerous compounds helped to pave the way for their widespread use as inexpensive oxidants for organic transformations. A sample paper, which summarizes a portion of his research, can be found in the Journal of Organic Chemistry (subscription required).

In addition to an accomplished chemist, Dr. McBay was by all accounts a passionate educator. The bulk of his teaching career was carried out at Morehouse College in Atlanta, GA (1945-1981) which included a 21-year stint as chair of the chemistry department. Along with chemist Dr. Lloyd Noel Ferguson and others, he founded the National Organization for the Professional Advancement of Black Chemists and Chemical Engineers (NOBCChE) in 1972. The organization now operates at 49 chapters nationwide.

Regarding Dr. McBay's response to racist attitudes and obstacles he encountered, in a Jan. 25,1991 interview, Boston Globe journalist David Chandler recorded this quote: "As [McBay] sees it, 'nature distributes its talents and its capabilities and its faults at random throughout the human species. People are not yet willing to accept that.' But to him, 'that's a part of my religious faith.'"

Credit chemheritage.org via
wikipedia.org.
Marie Maynard Daly (1916-2003) [ref]
Born in Queens, NY on April 16, 1916, biochemistry drew the primary scientific interest of Marie Daly. She attended Queens University, graduating with a B.S. in 1942. She went on to receive a Master's degree from New York University (New York, NY) in 1943. Marie continued her education immediately afterwards, enrolling in Columbia University (New York, NY) where she completed her Ph. D in 1948 with a dissertation focused on the exact chemical function of pancreatic proteins. Dr. Daly became the first African American woman chemist to achieve the academic milestone.

In terms of scientific research, Dr. Daly held a number of scientific research positions, both in academic laboratories and at sponsored research institutions in New York.To name a few, she was employed by Columbia University, Yeshiva University, the American Heart Association, and the Rockefeller Institute of Medicine, all in New York City. Dr. Daly became an expert in many aspects of cardiovascular function and is credited with improving our understanding of the relationship between cholesterol and high blood pressure. For a sample publication in the American Journal of Physiology, click here (sub. required).

The Future
To this day, African Americans are still disproportionately underrepresented in the physical sciences. As recently as 2012, only about 6% of Ph. D.s awarded in STEM disciplines go to blacks or African Americans (though this has increased from 4% ten years earlier). Neither has an African American ever won or shared a Nobel Prize in Chemistry, Physics, or Medicine.

The three individuals mentioned in this article found their way into scientific prominence despite significant racial barriers imposed upon them. These chemists, and many others from their time period, embody virtues extolled in the American Civil Rights Movement which we honor today: perseverance, nonviolence, and excellence in the face of adversity. With the example set by these first generations of African American chemists, we should continue to encourage increased participation in STEM disciplines by underrepresented groups. Perhaps most importantly, we should anticipate the depth of perspective that all of our fields stand to gain via inclusion of scientists from different cultural and economic backgrounds.