Prof. Yuri Tsvetkov

The International EPR(ESR) Society is sorry to announce the death of Prof. Yuri Tsvetkov, former president of the IES.  Below is a condolences letter sent by IES president.

Dear Colleagues from Novosibirsk, from Russia and from the whole world. It is with great sadness to hear that Prof. Yuri D. Tsvetkov, member of the RAS and for many years head of the Institute of Chemical Kinetics and Combustion in Novosibirsk, died last Saturday.

Yuri Tsvetkov headed one of the pioneering institutes for the development of modern pulsed EPR methods. So many famous scientist, working in this field of spectroscopy are related to this institute and worked together with Prof. Yuri Tsvetkov over decades. They were at the forefront of technolog-ical development of pulsed EPR spectroscopy in the 1960ies, explored in much detail the hyperfine oscillations, which arise in solid samples after ex-citation with strong microwave pulses and other dynamical effects related to spin relaxation. Both of these features of pulsed EPR time traces are nowa-days used regularly in many laboratories worldwide for quantitative analysis of paramagnetic molecules.

In the 1980ies the Novosibirsk EPR group pioneered another very important field by pulsed EPR: Pulsed Electron-Electron Double Resonance (PELDOR), which is momentarily one of the most active areas of EPR spec-troscopy. It describes the dipolar interaction between two (or more) radicals in a solid powder sample, which can be used to extract intermolecular dis-tances in the nanometer range with high precision. The publication in Chem-ical Physical Letters from 1984 is 300 times cited and created a new field of applications for pulsed EPR spectroscopy: the determination of structural distance restraints in disordered macromolecules. This method, renamed to Double Electron-Electron Resonance (DEER) in 1993 and later-on extended to a 4-pulse sequence, is at the moment probably the most widely used ap-plication of pulsed EPR methods. The Novosibirsk group of scientists around Yuri Tsvetkov explored the methodology and potential application fields in much detail and should get much credit for the discovery and in-vention of this powerful application.

Prof. Yuri Tsvetkov received many awards for his scientific contributions. Just to name a few: the Silver Medal in Chemistry from the IES in 1999 (and fellow of IES since 2010), the Bruker Lecture of the Royal Society of Chem-istry EPR group in 2006 and the Zavoisky Award in 2013. He also served as president for the IES from 2002-2005.

As sad as it is to hear, that one of the pioneers of pulsed EPR spectroscopy died, it is good to see that so many excellent scientists out of his laboratory emerged and continue working in this spirit.

All my regards and compassion to his family and to his scientific family

Prof. Dr. Thomas Prisner

(President of the International EPR Society)