Israel Journal of Chemistry最新文献

Cucurbiturils are popular macrocyclic receptors that bind complementary guest molecules with high affinity in aqueous environments. They are recognized for their ability to selectively bind positively charged guest molecules, including ionizable ammonium cations which frequently display much higher affinity than their neutral counterparts. This selectivity for the protonated species is translated into an increase in the basicity of encapsulated guests (i. e. into complexation-induced positive pK_a shifts). However, despite being very rare, negative pK_a shifts can be observed for specific guests. Following a previous work from our group reporting slightly negative pK_a shifts for flavylium and chalcone dyes featuring N-diethylamino substituents (ΔpK_a=− 0.2), herein we report a systematic study on the complexation of N-dialkylaminochalcones with CB7. The results show that the pK_a shifts of these host-guest complexes can be rationally tuned by the nature of the N-dialkylamino groups and as well by target substitutions on the skeleton of the dye, allowing the design of a CB7 1 : 1 host-guest complex with a ΔpK_a=− 0.6.

Dan Shechtman's discovery of quasicrystals in 1982 introduced the scientific world to aperiodic crystals with unique rotational symmetries, redefining traditional crystallography. Although superconductivity in related periodic approximants has since been observed, true bulk superconductivity in quasicrystals was confirmed only in 2018. This recent discovery opens a new horizon not only for the study of correlated quasicrystals but more generally for the study of superconductivity with nontrivial spatial order. The theoretical understanding of superconducting quasicrystals poses challenges due to their lack of periodicity. Notably, they exhibit non-BCS type superconductivity and distinct electromagnetic responses, reminiscent of the so-called FFLO state. In this review, we provide an overview of superconducting quasicrystals, along with some “behind-the-scenes” information.

We outline an approach to fabricate nanoscale artificial quasiperiodic tilings with thermal-scanning probe lithography. Quasiperiodic tilings such as the Ammann-Beenker, Square Fibonacci tiling, and Penrose are fabricated and imaged with thermal-conductance feedback microscopy, followed by electron microscopy. The design implementation, chemical, and physical challenges involved in fabricating such artificial systems using nanolithography are discussed. Additionally, the potential applications of fabricated quasiperiodic tilings are explored.

The growth of antimony (Sb) thin films on the fivefold surface of icosahedral Ag−In−Yb quasicrystal has been studied by scanning tunneling microscopy (STM) and x-ray photoelectron spectroscopy (XPS). At low coverage, the deposited Sb yields a network of pentagons of different sizes and heights. These Sb pentagons can be mapped by a pentagonal tiling of the substrate and thus exhibit quasicrystalline long-range order. Subsequent deposition of Sb yields a disordered film. XPS observations of the growth mode are consistent with the STM results.

This special issue commemorates the life and work of Prof. Richard A. Lerner. Prof. Lerner's mix of creativity, fearlessness, and unboundedness conceived and conceptualized inventions like catalytic antibodies, antibody libraries, and DNA-encoded small molecule libraries.

Richard Lerner was a singularity. During his tenure, Scripps Research was transformed into a biomedical powerhouse. He rapidly built remarkable strength in chemical and structural biology, immunology, cell and molecular biology, and molecular medicine. Not to stop there, he also instituted a new graduate program that consistently ranked in the top ten in the US. At the same time, he was a prolific author of scientific papers, which poured out of his own laboratory with colleagues at Scripps Research and collaborators throughout the world. These and many other aspects of his brilliant career and contributions are well documented and discussed elsewhere.

Here I chose to avoid redundancy and focus instead on a few of the personal encounters, which give some sense of Richard's character and spirit. An essential part of Richard's success was his wife Nicola (Nicky), herself an MD, who worked tirelessly to enable him to achieve what he did. Early on, my wife Cleo and Nicky became close friends. This relationship facilitated social occasions, where we would be with the Lerner's at a dinner or event, sometimes at our home or at theirs, but also with guests at various restaurants in La Jolla. As a result, my understanding of Richard was broadened beyond that received from the many discussions and meetings at Scripps Research. This understanding was helpful during those times when we faced serious challenges and he, like all of us when under stress, needed support.

In what is written below, I have used plain language to relate some of my memories and reflections. Richard was a friend and colleague and taught me much, especially the power of a vision, of belief in that vision and of the will to make the effort to bring it to pass.

Dear Reader,

This Special Issue has been put together to honor the life and work of Prof. Richard A. Lerner (August 28, 1938–December 2, 2021), whose visionary presidential leadership and guidance for over a quarter century (1987–2012) catapulted The Scripps Research Institute (La Jolla, California and Jupiter, Florida) into a powerhouse at the interface of chemistry, biology, and medicine. Following is a colorful assortment of twenty contributions that collectively paint a picture of a man who intuitively and ingeniously blended organic chemistry and immunology to arrive at new molecular compositions and concepts that have defined contemporary small and large-molecule drug discovery.

Prof. Lerner's mix of creativity, fearlessness, and unboundedness conceived and conceptualized inventions like catalytic antibodies, antibody libraries, and DNA-encoded small molecule libraries. Several articles in this Special Issue pay tribute to these transformative discoveries, depicted in the cover image. Other articles add additional facets to the theme of bioinspired chemistry. Sprinkled in are numerous anecdotes of Prof. Lerner's rebellious and humorous nature that made him, as his friend and presidential successor at Scripps Research, Prof. Peter G. Schultz, notes, “one of a kind […] who defied boundaries and lived life to its fullest.”

Above all, Prof. Lerner was an enabler of ideas who recruited, protected and connected brilliant minds at every academic level at The Scripps Research Institute (now Scripps Research). He cherished their discoveries at least as much as his own, corroborated by one of his mentees, Prof. Benjamin F. Cravatt, who writes in his contribution, “I have never met someone so accomplished who took their greatest joy in the accomplishments of others.” Prof. Lerner's infectious energy and enthusiasm catalyzed the careers of graduate students, postdocs, and faculty on both the Pacific and Atlantic campuses of Scripps Research, as well as beyond the United States, as reflected here by contributions from Israel, Korea, Russia, Sweden, Switzerland, and the United Kingdom. Many of us have come together for this Special Issue as a tribute to the unconventional explorer, builder, and leader who transformed and empowered our thinking and doing. We are fortunate to have crossed paths with him.

Since the Israel Journal of Chemistry is the official Journal of the Israel Chemical Society (ICS), we welcome the recently established ICS-Lerner Prize and Lectureship that commemorates the legacy of Prof. Richard A. Lerner. This international Prize has become possible based on a $100 K endowment fund, which secures the Prize perpetually. All ICS members thank and congratulate the donors, Professors Phil S. Baran, Benjamin F. Cravatt, Jeffery W. Kelly, Chi-Huey Wong, Jin-Quan Yu, and Dr. Phillip Frost. The Organic Chemistry Section of the ICS will handle the ICS-Lerner Prize annually, planning to announce the first winner in Jan

Richard Lerner had many achievements in his outstanding career. He will perhaps be remembered most for taking the helm of Scripps Research, following the founding by and tenure of Frank Dixon, and building one of the most successful biomedical research institutes in the world. Two Nobel prizes at Scripps in the past two years and one of them a second Nobel speaks for itself. But I want to cover what many consider Richard's finest scientific achievement- the development of a whole new approach to making antibodies that has been revolutionary to many aspects of basic science and medicine. I was very fortunate to be a part of that development and I give an account here and my memories of Richard during that time.

Richard was mainly known as a gifted scientist, a charismatic leader, and an original and creative President. And he was my good friend and a role model for over three decades. The term impossible was not part of his vocabulary. I′ve learned from him that there is no limit to imagination and creativity, no limit to the number of assignments one can fulfill, and no limit to the magnitude of a dream one can turn into reality. Richard was blessed with the unique talent to quickly decipher the essence of people‘s thoughts and discover the hidden parts of their personalities, which allowed him to focus on what he defined as the most valuable issues and productive discussions. My experience with him included the joy of scientific discovery, the silent mode of human communication, the power of commitment and dedication, and the wildest sense of humor. Now, nearly two years after his departure, I feel free and obliged to share unknown stories and anecdotes that illuminate various facets of his personality.