Obituary: Prof. Siegfried Niese 1932 Oct 23–2021 Apr 02

Journal of Radioanalytical and Nuclear Chemistry -     

Yakov Vul'fovich Rashkes (1932–1993)

Obituary

Yakov Vul'fovich Rashkes (1932–1993)     

Lev V. Vilkov (1931–2010): scientist,friend, editorial board member

Torvard C. Laurent (1930–2009) was one of the pioneers of hyaluronan science and in particular of its structural aspects. He was the first who ever established the metrical characteristics of hyaluronan. He determined many of its physicochemical properties and their relationship to the versatile biological functions of this noted molecule. He also contributed to its medical applications. He was a leading personality in science administration and science policy in Sweden and internationally.     

Aleksandr Georgievich Tyurin (1953–2015) and his research in corrosion science

This paper is a tribute to one of the leading Russian scientists in the field of corrosion science and my supervisor, Aleksandr Georgievich Tyurin, who suddenly and unexpectedly passed away in 2015. A short biographical note is given together with an outline of his contributions to corrosion and electrochemical science.     

Donald L.D. Caspar (1927–2021)—pioneer of virus structures

Structural Chemistry - Donald L.D. Caspar (1927–2021) devoted his career to understanding the structure of viruses. He interacted with leading structural scientists of his time and...     

Richard A. Lerner (1938–2021)—a structural biochemist and president of Scripps Institute

Structural Chemistry - Richard A. Lerner (1938-2021) was both a chemist and an MD. He investigated the structure of peptides and proteins, identified a sleep-inducing lipid, and is best known for...     

Baruch S. Blumberg (1925–2011): Researcher of Hepatitis B,polysaccharides, other areas of science

Baruch S. Blumberg’s career started with investigating the physical chemistry of polysaccharides. It culminated with the discovery of the Hepatitis B virus and the vaccine to prevent infection with it. It was concluded with studying life forms under extreme terrestrial conditions as part of the new science astrobiology.     

Nadrian C. Seeman (1945–2021): pioneer of DNA nanotechnology

Structural Chemistry - Nadrian (Ned) Seeman (1945-2021) was a crystallographer turned nanoscientist who pioneered a new direction of research at the borderline of the two fields. He constructed new...     

Enantiospecific Synthesis of (–)-Cuspareine and (–)-Galipinine

An enantiospecific route to the synthesis of tetrahydroquinoline alkaloids (–)-cuspareine and (–)-galipinine is reported. Coupling of an iodide derivative of D-serine with aromatic dithianes and Pd-catalyzed intramolecular C–N coupling are the key steps in the synthesis.     

Effect of molecular association and reactivity on substitution in chromium(III)–salprn complexes

A new chromium(III)–Schiff base complex, [Cr(5-chlorosalprn)(H₂O)₂]ClO₄, where salprn = N,N-propylenebis(salicylideneimine) has been prepared and characterized by electrospray ionization mass spectrometric (ESIMS) analysis and other spectroscopic techniques. Single crystal X-ray data reveal that the complex assumes a trans-diaquo structure, [Cr(C₁₇H₁₈Cl₂N₂O₄)]ClO₄ · H₂O. The effect of phenyl ring substituents on the rate of formation of [O=Cr^V Schiff base]⁺ has been investigated. The bimolecular rate constant for the formation of O=Cr^V species by the [Cr(Schiff base)(H₂O)₂]ClO₄, where the Schiff base = salprn, (1) and 5-chlorosalprn, (2) with PhOI was compared. In the case of (2) the rate was found to be faster by an order of magnitude at pH = 4 compared to (1). The introduction of a chloro-substituent on the phenyl ring not only influences the rate of redox reactivity but also the pKa values of aquo ligands of the complexes, indicating the difference in the electronic environment around the metal ion in both (1) and (2).     

Iodophthalocyaninato(2–)thallium(III) – Synthese und Kristallstruktur

Iodophthalocyaninato(2–)thallium(III) – Synthesis and Crystal Structure Oxidation of dithalliumphthalocyaninate(2–) with excess iodine yields crystalline, blue-green iodophthalocyaninato(2–)thallium(III). It crystallizes in the orthorhombic space group Pnma (no. 62) with lattice parameters: a = 13.778(3) Å, b = 14.649(2) Å, c = 14.907(1) Å, Z = 4. The Tl atom coordinates four N_iso atoms (isoindole N atoms) and one I atom in a tetragonal pyramidal arrangement. The Tl atom is located out of the centre of the (N_iso)₄ plane towards the iodine atom by 0.959(3) Å. The Tl–I distance is 2.674(1) Å, the Tl–N_iso distances range from 2.20(1) to 2.23(1) Å (average 2.22(1) Å). The phthalocyaninate(2–) is severely distorted from planarity (concave distortion).     

UHV–EC and EC–STM studies of molecular chemisorption at well-defined surfaces: hydroquinone and benzoquinone on Pd(hkl)

The chemisorption, from aqueous solutions, of hydroquinone and benzoquinone onto well-defined Pd(111) and Pd(100) electrode surfaces has been studied by tandem electrochemistry, high-resolution electron energy loss spectroscopy and in situ scanning tunneling microscopy. The results indicate that hydroquinone is oxidatively chemisorbed to form a quinonoid species that is oriented parallel to the surface but with a slight tilt in which one of the para-oxygens is topographically just higher than the other. The same surface species is obtained when adsorption is from aqueous benzoquinone.     

N. K. Kochetkov (18.05.1915–21.12.2005)

In Memoriam

N. K. Kochetkov (18.05.1915–21.12.2005)