John Roberts – pioneer in physical organic chemistry

John Roberts – pioneer in physical organic chemistry

John Roberts – pioneer in physical organic chemistry

Biography & contributions

John Roberts [John Dombrowski Roberts] an American chemist born on June 08, 1918. Roberts had done major contributions towards various fields of chemistry such as physical chemistry, organic chemistry and spectroscopy techniques to understand chemical reaction rates.

Roberts got many awards and medals in his career like Priestley medal in the year of 1987, National medal of science in the year of 1990, Glenn t. Seaborg medal in the year of 1991, NAS award in chemical sciences in the year of 1999, NAS Award for Chemistry in Service to Society in the year of 2009, AIC gold medal in the year of 2013.

Reaction Rate

The reaction rate (rate of reaction) or speed of reaction for a reactant or product in a particular reaction is intuitively defined as how fast or slow a reaction takes place. It is often expressed in terms of either the concentration (amount per unit volume) of a product that is formed in a unit of time or the concentration of a reactant that is consumed in a unit of time. It may be defined in terms of the amounts of the reactants consumed or products formed in a unit of time.

Chemical reactions proceed at vastly different speeds depending on the nature of the reacting substances, the type of chemical transformation, the temperature, and other factors. In general, reactions in which atoms or ions combine occur very rapidly, while those in which covalent bonds are broken are much slower.

There is another big idea for rates of reaction called collision theory. The collision theory says that as more collisions in a system occur, there will be more combinations of molecules bouncing into each other. If more possible combinations, there is a higher chance that the molecules will complete the reaction.

The reaction will happen faster which means the rate of that reaction will increase. Reactions usually slow down as time goes on because of the depletion of the reactants. In some cases the addition of a substance that is not itself a reactant, called a catalyst, and accelerates a reaction.


Spectroscopy is the method of choice in the determination of structure and function in chemical systems. These are widely used in various fields like optical sensing of chemical and biological transformations, determinations of the structures, dynamical properties of biologically relevant molecules using high resolution lasers, development of high resolution gas-phase separations of proteins, peptides based on ion mobility spectrometry, measuring distance constraints between two units on a macromolecule using pulsed ESR methods, new forms of spectroscopy for the detection of protein folding in real time, femto second laser studies of metal surfaces and semiconductor interfaces.

Types of spectroscopy

  • Astronomical Spectroscopy
  • Atomic Absorption Spectroscopy
  • Attenuated Total Reflectance Spectroscopy
  • Electron Paramagnetic Spectroscopy
  • Electron Spectroscopy
  • Gamma-ray Spectroscopy
  • Infrared Spectroscopy
  • Mass Spectroscopy
  • Raman Spectroscopy
  • X-ray Spectroscopy

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