The Mutation of the “Nobel Prize in Chemistry” into the “Nobel Prize in Chemistry or Life Sciences”: Several Decades of Transparent and Opaque Evidence of Change within the Nobel Prize Program

Over the past several decades, the Nobel Prize program has slowly but steadily been modified in both transparent and opaque ways. A transparent change has been the creation of the Nobel Prize in Economic Sciences, officially known as the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel. An opaque change has been the mutation of the Nobel Prize in Chemistry into what is effectively the “Nobel Prize in Chemistry or Life Sciences.” This paper presents a detailed study of this opaque change, including evidence that the disciplines of chemistry and biochemistry cover, today, intellectually quite distinct and generally scientifically-unrelated intellectual territory. This paper supports the evolution of the Nobel Prizes, and encourages the Nobel Prize program to move from opaque to transparent change processes for the next generations of achievement in the sciences.     

Introducing the γ function in quantum theory

Through a series of postulates, we define a function γ(x) whose square acts as Dirac's δ(x) and exhibits several unusual properties. Though the square root of δ cannot be defined among distributions, it appears in quantum theory if one wants to associate a wave function to a (quasi)classical particle having charge distribution δ(x) . The newly defined function γ(x) serves to describe quasi-classical particles using part of the quantum formalism (eg, wave functions, operators, expectation values) but exhibiting classical properties. The function γ(x) appears to be useful to define model wave functions for simple (quasi)quantum systems. In a spherical coordinate system, γ(r − r₀) leads to a quasi-classical “bubble” model of the hydrogen atom, where the electron is distributed on the surface of a sphere with radius r₀, and it provides exact quantum mechanical energies of its total symmetric levels. For other simple quantum systems, it provides approximate but meaningful energies. In particular, exact energy differences for harmonic oscillator levels are obtained, with the zero-point energy missing.     

Introducing the Chiral Constrained α-Trifluoromethylalanine in Aib Foldamers to Control,Quantify and Assign the Helical Screw-Sense**

Oligomers of α-aminoisobutyric acid (Aib) are achiral peptides that adopt 3₁₀ helical structures with equal population of left- and right-handed conformers. The screw-sense preference of the helical chain may be controlled by a single chiral residue located at one terminus. ¹H and ¹⁹F NMR, X-ray crystallography and circular dichroism studies on new Aib oligomers show that the incorporation of a chiral quaternary α-trifluoromethylalanine at their N-terminus induces a reversal of the screw-sense preference of the 3₁₀-helix compared to that of a non-fluorinated analogue having an l -α-methyl valine residue. This work demonstrates that, among the many particular properties of introducing a trifluoromethyl group into foldamers, its stereo-electronic properties are of major interest to control the helical screw sense. Its use as an easy-to-handle ¹⁹F NMR probe to reliably determine both the magnitude of the screw-sense preference and its sign assignment is also of remarkable interest.     

Carbon–Carbon Bond Forming Reactions Promoted by Aluminyl and Alumoxane Anions: Introducing the Ethenetetraolate Ligand

[K{Al(NON^Dipp)}]₂ (NON^Dipp=[O(SiMe₂NDipp)₂]²⁻, Dipp=2,6-iPr₂C₆H₃) reacts with CS₂ to afford the trithiocarbonate species [K(OEt₂)][Al(NON^Dipp)(CS₃)] 1 or the ethenetetrathiolate complex, [K{Al(NON^Dipp)(S₂C)}]₂ [ 3 ]₂. The dimeric alumoxane [K{Al(NON^Dipp)(O)}]₂ reacts with carbon monoxide to afford the oxygen analogue of 3 , [K{Al(NON^Dipp)(O₂C)}]₂ [ 4 ]₂ containing the hitherto unknown ethenetetraolate ligand, [C₂O₄]⁴⁻.     

Introducing Field Environmental–Analytical Chemistry in the Quantitative Analysis Laboratory

Advances in instrumentation and technology now provide the ability to perform many quantitative determinations in the field. Additionally, the potential for sample degradation and analyte decomposition make it necessary to determine certain analytes (e.g., dissolved oxygen) in the field when conducting environmental analyses. Unfortunately, field environmental—analytical chemistry is not a substantial portion of the analytical chemistry curriculum at many institutions. Students in lower-level analytical chemistry courses are often non-chemistry science majors, particularly at institutions with small chemistry departments. We report here on an experiment in which field environmental-analytical chemistry is introduced in the quantitative analysis laboratory. In the context of a water quality assessment of a local river, students determine temperature, pH, ORP, nitrate nitrogen, and ammonia nitrogen at several points in the river. The experimental objective is to determine the potential effects local agricultural practices and treated wastewater discharge may be having on the water composition. The pedagogical objective is to expose these students to the difficulties involved in making analytical determinations in unfamiliar and/or disruptive settings.     

CE-MS for metabolomics: Developments and applications in the period 2018–2020

Capillary electrophoresis-mass spectrometry (CE-MS) is now a mature analytical technique in metabolomics, notably for the efficient profiling of polar and charged metabolites. Over the past few years, (further) progress has been made in the design of improved interfacing techniques for coupling CE to MS; also, in the development of CE-MS approaches for profiling metabolites in volume-restricted samples, and in strategies that further enhance the metabolic coverage. In this article, which is a follow-up of a previous review article covering the years 2016–2018 (Electrophoresis 2019, 40, 165–179), the main (technological) developments in CE-MS methods and strategies for metabolomics are discussed covering the literature from July 2018 to June 2020. Representative examples highlight the utility of CE-MS in the fields of biomedical, clinical, microbial, plant and food metabolomics. A complete overview of recent CE-MS-based metabolomics studies is given in a table, which provides information on sample type and pretreatment, capillary coatings, and MS detection mode. Finally, some general conclusions and perspectives are given.     

Introducing lanthanide metal–organic framework and perovskite onto pulp fibers for fluorescent anti-counterfeiting and encryption

The research of anti-counterfeiting and encryption has always been a subject of universal concern all over the world. Herein, lanthanide metal–organic framework (Eu-MOF) and CH₃NH₃PbBr₃ (MAPbBr₃) perovskite were introduced onto pulp fibers (PFs) to prepare fluorescent anti-counterfeiting and encryption papers. Eu-MOF@PFs paper emitted red fluorescence at 254 nm UV excitation. The optimum preparation conditions of Eu-MOF@PFs were 2.5 mmol of Eu(NO₃)₃, 4 h of reaction time and room temperature. When MABr ink was written on Pb/Eu-MOF@PFs paper, the green fluorescent handwriting and red fluorescent paper were observed under 365 nm and 254 nm UV excitation, respectively. The appropriate addition amount of lead nitrate was 0.6 mmol. Pb/Eu-MOF@PFs paper was immersed in MABr solution to prepare MAPbBr₃@Pb/Eu-MOF@PFs paper. Under 254 nm and 365 nm UV irradiations, MAPbBr₃@Pb/Eu-MOF@PFs paper emitted red-green double fluorescence and the quantum yields of which were 3.11% and 2.48%, respectively. The crystal structure of MAPbBr₃ was easily destroyed by polar solution, which realized on/off switching of the luminescence signal for multistage information encryption. The above paper-based fluorescence materials were potential for advanced anti-counterfeiting and encryption applications.

     

Accelerating Ethanol Complete Electrooxidation via Introducing Ethylene as the Precursor for the C−C Bond Splitting

The crucial issue restricting the application of direct ethanol fuel cells (DEFCs) is the incomplete and sluggish electrooxidation of ethanol due to the chemically stable C−C bond thereof. Herein, a unique ethylene-mediated pathway with a 100 % C1-selectivity for ethanol oxidation reaction (EOR) is proposed for the first time based on a well-structured Pt/Al₂O₃@TiAl catalyst with cascade active sites. The electrochemical in situ Fourier transform infrared spectroscopy (FTIR) and differential electrochemical mass spectrometry (DEMS) analysis disclose that ethanol is primarily dehydrated on the surface of Al₂O₃@TiAl and the derived ethylene is further oxidized completely on nanostructured Pt. X-ray absorption and density functional theory (DFT) studies disclose the Al component doped in Pt nanocrystals can promote the EOR kinetics by lowering the reaction energy barriers and eliminating the poisonous species. Strikingly, Pt/Al₂O₃@TiAl exhibits a specific activity of 3.83 mA cm⁻²_Pt, 7.4 times higher than that of commercial Pt/C and superior long-term durability.     

Adjusting Aggregation Modes and Photophysical and Photovoltaic Properties of Diketopyrrolopyrrole-Based Small Molecules by Introducing B←N Bonds

The packing mode of small-molecular semiconductors in thin films is an important factor that controls the performance of their optoelectronic devices. Designing and changing the packing mode by molecular engineering is challenging. Three structurally related diketopyrrolopyrrole (DPP)-based compounds were synthesized to study the effect of replacing C−C bonds by isoelectronic dipolar B←N bonds. By replacing one of the bridging C−C bonds on the peripheral fluorene units of the DPP molecules by a coordinative B←N bond and changing the B←N bond orientation, the optical absorption, fluorescence, and excited-state lifetime of the compounds can be tuned. The substitution alters the preferential aggregation of the molecules in the solid state from H-type (for C−C) to J-type (for B←N). Introducing B←N bonds thus provides a subtle way of controlling the packing mode. The photovoltaic properties of the compounds were evaluated in bulk heterojunctions with a fullerene acceptor and showed moderate performance as a consequence of suboptimal morphologies, bimolecular recombination, and triplet-state formation.     

NPK 2.0: Introducing tensor decompositions to the kinetic analysis of gas–solid reactions

A method for deriving kinetic models of gas–solid reactions for reactor and process design is presented. It is based on the nonparametric kinetics (NPK) method and resolves many of its shortcomings by applying tensor rank-1 approximation methods. With this method, it is possible to derive kinetic models based on the general kinetic equation from any combination of experiments without additional a priori assumptions. The most notable improvements over the original method are that it is computationally much simpler and that it is not limited to two variables. Two algorithms for computing the rank-1 approximation as well as a tailored initialization method are presented, and their performance is assessed. Formulae for the variance estimation of the solution values are derived to improve the accuracy of the model identification and to provide a tool for diagnosing the quality of the kinetic model. The methods effectiveness and performance are assessed by applying it to a simulated data set. A Matlab implementation is available as Supporting Information.     

Introducing Environmentally Benign Synthesis into the Introductory Organic Lab—A Greener Friedel–Crafts Acylation

An example of a more environmentally benign Friedel—Crafts acylation reaction constitutes the first step of a two step synthesis of p-anisic acid. The greener Friedel—Crafts acylation involves reaction, on acidic alumina in the absence of solvent, of anisole with a mixed anhydride derived from acetic acid and trifluoroacetic anhydride. The acylated anisole is then oxidized, employing the haloform reaction to produce p-anisic acid. Students identify the anisic acid isomer obtained through spectral analysis and/or melting-point determination and then infer the regioselectivity of the initial acylation. The experiment offers opportunities for instruction in the tenets of green chemistry and reinforcement of the theory of electrophilic aromatic substitution presented in lecture.     

Introducing the Chiral Transient Directing Group Strategy to Rhodium(III)-Catalyzed Asymmetric C−H Activation

The chiral transient directing group (TDG) strategy has been successfully introduced to the rhodium(III)-catalyzed asymmetric C−H activation. In the presence of a catalytic amount of a chiral amine and an achiral rhodium catalyst, various chiral phthalides were synthesized from simple aldehydes with high chemoselectivity, regioselectivity, and enantioselectivity (53 examples, up to 73 % yield and >99 % ee). It is noteworthy that the chiral induction model is different from the previously reported chiral TDG system using amino acid derivatives and palladium salts. The imino group generated in situ from chiral amine and aldehyde acts as the monodentate TDG to promote the C−H activation, stereoselectively generating the chiral rhodacycle bearing a chiral metal center. Moreover, the stereogenic center of the product is created and stereocontrolled during the Grignard-type addition of the C−Rh bond to aldehyde, rather than during the C−H activation step.