The chemists take a closer look at where the water meets the air

Water, despite its central place in so many processes essential to life on Earth, remains a chemical mystery in many ways. One of these mysteries is the nature of the water at the point where it comes in contact with the air.

A lab study of Yale's chemistry professor Mark Johnson and Washington University chemistry professor Anne McCoy offers a new level of observation and analysis.

They are the first direct measure of the frequency and complexity variations associated with the bound oxygen and hydrogen (OH) atoms perched on the surface of the water, when one of the OH groups comes out of it. The researchers also offer the first measure of how these OH groups are coupled together in terms of the surface of the water.

"Our work is truly a fundamental scientific contribution, and its importance lies in the fact that elemental mechanics and the chemical properties of water are important in many fields, and many researchers are involved in simulating this behavior. Based on basic principles, we provide a quantitative benchmark on which to calibrate such simulations, "said Johnson, Arthur T. Kemp Professor of Chemistry at Yale.

Johnson's work has highlighted a number of chemical properties of water, often with the help of instruments designed and manufactured at Yale. Among the laboratory's many discoveries are the innovative uses of electrospray ionization, developed by the late John Fenn, Yale's Nobel laureate, and ways to quickly freeze chemical processes in the water in order to reveal contorted atom arrangements during a reaction.

The new study appears in the April 18 online edition of Science. The first author of the study is Nan Yang and his co-authors are Chinh Duong and Patrick Kelleher, all of Yale.