In Memoriam

Prof. Zeev Luz (1932-2018)

Luz passed away October 2, 2018. Until about half a year ago he would still come every day to his office in the Perlman Building of the Weizmann Institute, and would work on modeling dynamic lineshapes, on characterizing the influence of chirality on NMR spectra, and on perfecting his recently gained Matlab skills by performing numerical simulations on “the physics of soap bubbles”. His door was never closed, and both professors and graduate students could always come in and discuss with him issues. Discussing with Luz meant asking a question, and receiving in reply a set of questions that would in turn guide us to the answer. For us Luz was a mentor, a dear friend, and an ultimate example of a curious scientist endowed with a unique ability to explain the most complex ideas in a clear and accurate manner.

 

Zeev Luz was born Wolfgang Emmanuel Nussbaum, in Munich on Feb 20 1932. It didn't take long for Luz’s family to fathom which way the winds were blowing then and there, and in the summer of 1934 they settled in the village of Binyamina of the Palestine Mandate, where his father served as the region’s doctor. Zeev’s childhood was anything but boring, and included attending an agricultural boarding school that offered him a university scholarship in exchange for remaining as school teacher (a position in which Luz became acquainted with Alex Pines, another of the school’s boardees). Luz’s research career started in 1957, when he arrived to the Weizmann Institute after receiving his BSc and MSc degrees in Chemistry from the Hebrew University. At Weizmann he became the youngest member in the research group of Shaul Meiboom, spending half the week teaching in his high school and the other half (including weekends, holidays and frequent teachers’ strikes) working in the lab. By then Meiboom had constructed one of the world’s first NMR spectrometers, and together with Luz and other members of his group they were doing pioneering work on the quantum interpretation of spin-spin couplings and their influence on NMR spectra, showing the potential of NMR to study the nature and the kinetics of chemical reactions, discovering the double quantum effects in NMR, and introducing new pulse sequences such the CPMG train. Meiboom departed Weizmann for the Bell Labs in 1958, where Luz joined him as a postdoc after completing his PhD in 1961. There he studied by ESR and NMR the complexation of paramagnetic metal ions in solution, with an emphasis on chemical dynamics. These works formed the basis for understanding the solvation of metal ions, and the essential processes underlying paramagnetic relaxation.

 

Luz rejoined the Weizmann as an independent researcher in 1964, and started his own research group at the Isotopes Department focusing on ESR and NMR spectroscopies. In those CW days he laid down groundwork on the use of 17O-NMR to study chemical reactions at equilibrium, and to understand the molecular structure of organic crystals. In addition he advanced the understanding of the hyperfine interaction in free radicals. Later on he became interested in the molecular structure and dynamics of liquid crystals, and utilized NMR’s unique features to better understand the molecular motion, macroscopic order and phase transitions in these materials. Luz and his group also studied the behavior of small molecules dissolved in a variety of lyotropic and thermotropic liquid crystalline phases, in a series of combined theoretical and experimental studies that help him lay down the pillars of this field. A common denominator of these studies was using magnetic resonance for studying dynamics of molecules. For that purpose new experimental methodologies were designed, and mathematical tools were created to interpret the results in terms of motional mechanisms and rate constants. In the 1970’s he developed, together with his colleague and close friend Shlomo Alexander, new theoretical and computational approaches to interpret lineshapes in ESR and NMR of molecules undergoing dynamic processes including conformational changes, rotational and translational diffusions and chemical exchange. Over the years Luz’s experimental methods became more sophisticated, and together with Raphy Poupko, Herbert Zimmermann, Hans Spiess and others, he developed during over three decades new 1D and 2D NMR methods to follow slow dynamic process in solids .

 

In addition to a vast body of research on the interplay between magnetic resonance, the structure of materials and molecular dynamics, Luz educated and promoted generations of scientists in Israel and elsewhere. He was an exceptional educator who gave spectacular lectures about Science to layman audiences –particularly to middle- and high-school students, which he visited often and hosted at Rehovot’s numerous scientific festivals. Most sought-after among his lectures was one on the physics of soap bubbles, where with enthusiasm he showed kids on huge projected experiments the magic of differential equations and of their solutions –even long after he had himself lost the ability to see due to macular degeneration. He greatly stimulated the establishment and flourishing of Magnetic Resonance in Israel, while also being a major and influential figure in the Weizmann Institute. In the latter character he served as department chair, chair of the Chemistry board of studies, dean of Chemistry and vice president for academic affairs –all of these demanding administrative positions, which never affected his research performance nor level of innovation. Luz was also a particularly warm host to the many students, post-docs and visiting scientists that from all over the world came to work with him: to them –and to us– he and his late wife Abigail opened their house numerous times.

To all of us that knew him personally, Zeev Luz was and will remain a role model both inside and outside the lab; a “mentsch” in every respect. We shall miss him dearly.

Daniella Goldfarb, Lucio Frydman and Shimon Vega

Rehovot, October 2018