Organic Analogues Research Articles

Optical Constants of a Solar System Organic Analog and the Allende Meteorite in the Near- and Mid-infrared (1.5–13 μm)

Abstract Measurements of visible and near-infrared reflection (0.38–5 μm) and mid-to-far-infrared emission (5–200 μm) from telescope and satellite remote-sensing instruments make it possible to investigate the composition of planetary surfaces via electronic transitions and vibrational modes of chemical bonds. Red spectral slopes at visible and near-infrared wavelengths and absorption features at 3.3 and 3.4 μm observed in circumstellar disks, in the interstellar medium (ISM), and on the surfaces of solar system bodies are interpreted to be due to the presence of organic material and other carbon compounds. Identifying the origin of these features requires measurements of the optical properties of a variety of relevant analog and planetary materials. Spectroscopic models of dust within circumstellar disks and the ISM, as well as planetary regoliths, often incorporate just one such laboratory measurement despite the wide variation in absorption and extinction properties of organic and other carbon-bearing materials. Here we present laboratory measurements of transmission spectra in the 1.5–13 μm region and use these to derive real and imaginary indices of refraction for two samples: (1) an analog to meteoritic insoluble organic matter and (2) a powdered Allende meteorite sample. We also test our refractive index retrieval method on a previously published transmission spectrum of an Mg-rich olivine. We compare optical measurements of the insoluble organic matter analog to those of other solar system and extrasolar organic analogs, such as amorphous carbon and tholins, and find that the indices of refraction of the newly characterized material differ significantly from other carbonaceous samples.

GEOMETRIC PROBLEMS IN URBANISM

The article considers the phenomenon of urban geometry and the essence of geometric problems in urban planning. The proposed approach corresponds to the generally accepted understanding of cities through knowledge of the arts, humanities, social sciences and engineering. Geometry expands the understanding of cities and processes in them both in the historical context and in modern realities and conditions. The definiteness of the geometric dimension in the problems of spatial organization and development of urbanized systems is confirmed. Professional consideration and use of geometric indicators and properties is a condition for increasing the validity of architectural and urban planning decisions. The geometry of the functional city was based on ideas and solutions that focused on process control. The geometry of the space of today's city, according to the author, should stimulate its development by analogy with a living organism. Historical analysis expands the idea of the geometry of the city and its spatial implementation. The characteristics of the geometric measurement of different periods allowed us to conclude that the principles of geometry apply to cities of any time and any culture, are associated with the patterns of urban growth. Urban forms change depending on the scale: increasing the scale of the city to hypercomplex urban systems, the organic analogy grows, pure geometric planning is preserved on a local scale. The theoretical provisions of urban geometry, geometric problems and methods of their solution are substantiated. Identified dichotomies are important for understanding, researching and designing the development of urban systems. They are useful for generalizing different worldviews of space, time and urban geometry: the opposition of the concepts of simplicity and complexity; division and integrity; continuous and intermittent; homogeneity and heterogeneity of the system; certainty and uncertainty. New paradigms and thinking of the city as a hypercomplex system of organic complexity are covered. Geometry determines complexity, scale and shape. Views on space and geometry on the scale of human history have been studied. An attempt is made to understand the "reality" of development and spatial organization of cities. Geometry is used to display order and regularity, as well as in solving urban problems of today. The article highlights, structures and reveals the role of geometry and geometric problems in urban systems, their relationship with other dimensions and problems of spatial organization and urban development. In the model of multidimensional urban space "human - functions - conditions - geometry - time", which was substantiated by the author to solve problems of urban planning (spatial organization and development of urban systems) a special role is given to the geometric dimension, which is described in detail in the article. It includes many characteristics and indicators: size, configuration, shape, concentration of elements, as well as properties related to scale, intrasystem connections and location in the environment. The importance of urban geometry is illustrated using the author's model of multidimensional urban space on the example of geometric problems of Lviv, in particular placement, relocation and division. The solution of the communication and transport problem in the city is characterized and substantiated taking into account the requirements of the new geometry.

The role of monodentate tetrahedral borate complexes in boric acid binding to a soil organic matter analogue

Boron is an essential plant micronutrient responsible for several important functions. Boron availability in soils may be influenced by binding with soil organic matter (SOM), particularly with aromatic diol and polyphenol groups on SOM. The mechanism by which aromatic diols bind boron, however, remains unclear. The objective of this work is to further investigate interaction between boric acid and varying concentrations of an aromatic, polyphenolic SOM analogue (tannic acid at 5, 10 and 20 g L−1) from pH = 5–9. UV/Visible spectroscopy showed boric acid enhanced tannic acid deprotonation at pH = 7.0 and 9.0, resulting in singly deprotonated tannic acid subunits. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) showed boric acid/tannic acid binding for all concentrations at pH = 7 and 9, whereas binding at pH = 5.0 was observed only at 20 g L−1 tannic acid. Uncomplexed boron species were not evident at pH = 9.0, but were detectable at pH = 7.0 at lower tannic acid concentrations and prevalent at pH = 5.0, qualitatively indicating binding affinity increases from pH = 5.0 to 9.0. ATR-FTIR results indicated tetrahedral coordination of boron upon complexation to tannic acid with a monodentate mechanism. These results collectively highlight a transition of solution planar boric acid to a tetrahedral, monodentate coordination with a single phenol group in tannic acid polyphenols. This contrasts with previous spectroscopic studies, which indicated bidentate tetrahedral or monodentate trigonal planar orientations prevail at aromatic diol sites. This work presents a previously unobserved boric acid coordination mechanism to an SOM analogue and, therefore, may better inform prediction and modeling of boron behavior in soils.

Hydrogen isotopic exchange kinetics between organic matter and water: Implications for chemical evolution during meteorite parent body processing

AbstractThe large variations in hydrogen isotope ratios found in insoluble organic matter (IOM) in chondritic meteorites may be attributed to hydrogen isotopic exchange between IOM and water during aqueous alteration. We conducted D–H exchange experiments (1) during synthesis of IOM simulant (hereafter called chondritic organic analog, COA) from formaldehyde, glycolaldehyde, and ammonia with water, and (2) with the synthesized COA with a secondary reservoir of water. The changes in the D/H ratios obtained by infrared spectra of the COA suggest that most of the hydrogen in the COA is derived from water during synthesis. We further investigated the kinetics of D–H exchange between D‐rich COA and D‐poor water, as well as the opposite case, D‐poor COA and D‐rich water. To help assess understanding exchange kinetics, two‐dimensional isotope imaging obtained using isotope microscope revealed that no gradient D–H exchange profiles were present in the COA grains, indicating that the rate‐limiting step for D–H exchange is not diffusion. Thus, the changes in D/(D + H) ratios were fit by the first‐order reaction rate law. Apparent kinetic parameters—the rate constants, the activation energies, and the frequency factors—were obtained with the Arrhenius equation. Using these kinetic expressions, hydrogen isotopic exchange profiles were estimated for time and temperature behavior. The D–H exchange between organic matter and water is apparently relatively fast and this implies that the aqueous alteration temperatures should have been very low, likely close to 0 °C to maintain hydrogen isotopic disequilibrium between organic matter and liquid water for millions of years.

Probing BRD Inhibition Substituent Effects in Bulky Analogues of (+)‐JQ1

AbstractA series of bulky organometallic and organic analogues of the bromodomain (BRD) inhibitor (+)‐JQ1 have been prepared. The most potent, N‐[(adamantan‐1‐yl)methyl]‐2‐[(9S)‐7‐(4‐chlorophenyl)‐4,5,13‐trimethyl‐3‐thia‐1,8,11,12‐tetraazatricyclo[8.3.0.02,6]trideca‐2(6),4,7,10,12‐pentaen‐9‐yl]acetamide, 2e, showed excellent potency with an KD=ca. 130 nm vs. BRD4(1) and a ca. 2‐fold selectivity over BRD4(2) (KD=ca. 260 nm). Its binding to the first bromodomain of BRD4 was determined by a protein cocrystal structure.

Effects of minerals on metamorphism of organic matter during thermal processes in meteorite parent bodies

Molecular structures and chemical compositions of organic matter in primitive meteorites reflect the conditions of the parent bodies, as well as the preaccretional history. During the parent body processing, co-existing minerals could have effects on structural changes of organics, in addition to temperature and redox state. Here, we performed heating experiments of a primordial organic matter analog with and without minerals to understand the effects of minerals on organic matter in conditions simulating metamorphism in thermally metamorphosed type 3 chondrites. The primordial analog materials were heated up to 400 °C, and the experimental products were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and gas chromatography mass spectrometry (GC/MS). Montmorillonite and olivine, particularly montmorillonite, enhanced decomposition of oxygen containing species due to decarboxylation and/or cracking, while olivine enhanced esterification at lower temperature. Our results further imply that the variations of insoluble organic matter in CV, CO, and type 3 ordinary chondrites could be partially due to different mineral compositions. We also tested the effects of pressure on the degradation of the organic matter at 400 °C up to 268 atm, however no significant pressure effects were observed by FTIR and GC/MS.

Metallaaromatic Chemistry: History and Development.

Since the prediction of the existence of metallabenzenes in 1979, metallaaromatic chemistry has developed rapidly, due to its importance in both experimental and theoretical fields. Now six major types of metallaromatic compounds, metallabenzenes, metallabenzynes, heterometallaaromatics, dianion metalloles, metallapentalenes and metallapentalynes (also termed carbolongs), and spiro metalloles, have been reported and extensively studied. Their parent organic analogues may be aromatic, non-aromatic, or even anti-aromatic. These unique systems not only enrich the large family of aromatics, but they also broaden our understanding and extend the concept of aromaticity. This review provides a comprehensive overview of metallaaromatic chemistry. We have focused on not only the six major classes of metallaaromatics, including the main-group-metal-based metallaaromatics, but also other types, such as metallacyclobutadienes and metallacyclopropenes. The structures, synthetic methods, and reactivities are described, their applications are covered, and the challenges and future prospects of the area are discussed. The criteria commonly used to judge the aromaticity of metallaaromatics are presented.

Microfabricated and 3-D printed electroconductive hydrogels of PEDOT:PSS and their application in bioelectronics

Biofabrication techniques such as microlithography and 3-D bioprinting have emerged in recent years as technologies capable of rendering complex, biocompatible constructs for biosensors, tissue and regenerative engineering and bioelectronics. While instruments and processes have been the subject of immense advancement, multifunctional bioinks have received less attention. A novel photocrosslinkable, hybrid bioactive and inherently conductive bioink formed from poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) nanomaterials within poly(2-hydroxyethyl methacrylate-co-polyethyleneglycol methacrylate) p(HEMA-co-EGMA) was used to render complex hydrogel constructs through microlithographic fabrication and 3-D printing. Constructs were directly compared through established metrics of acuity and fidelity, using side-by-side comparison of microarray grids, triangles incorporating angles 15–90°, and a multi-ink hydrogel disk array. Compositional variation from 0.01 to 1.00 wt% PEDOT:PSS produced hydrogels of varying and tunable electrical and electrochemical properties, while maintaining similar rheological properties (up to 0.50 wt% PEDOT:PSS). Furthermore, hydrogel membrane resistances extracted from equivalent circuit modeling of electrical impedance spectroscopy data varied only according to the included wt% of PEDOT:PSS and were agnostic of fabrication method. An in-silico variable frequency active low-pass filter was developed using a microlithographically fabricated Individually Addressable Microband Electrode (IAME) as the filtering capacitor, wherein 3-D printed lines of varying wt% of PEDOT:PSS hydrogels were shown to alter the cutoff frequency of the analog filter, indicating a potential use as tunable 3-D printed organic electronic analog filtering elements for biosensors. Bioinks of different PEDOT:PSS (0.0, 0.1, and 0.5 wt%) manufactured into hydrogel disks using the two methods were shown to yield similarly cytocompatible substrates for attachment and differentiation of PC-12 neural progenitor cells.

Direct-Write Deposition of Thermogels.

The use of biocompatible hydrogels has widely extended the potential of additive manufacturing (AM) in the biomedical field leading to the production of 3D tissue and organ analogs for in vitro and in vivo studies.In this work, the direct-write deposition of thermosensitive hydrogels is described as a facile route to obtain 3D cell-laden constructs with controlled 3D structure and stable behavior underphysiological conditions.

Short path to a complex ring

Organic Chemistry Nucleotide analogs are valuable tools and therapeutics because of their ability to interfere with processes such as DNA synthesis, which are vital to rapidly dividing cells and replicating viruses. These molecules are challenging to synthesize chemically. Meanwell et al. developed a “ribose last” synthetic strategy in which a fluorinated acyclic nucleic acid is formed by an l- or d-proline–catalyzed aldol reaction (see the Perspective by Miller). This intermediate can then be cyclized to yield the nucleic acid analog in one pot with control of anomeric conformation based on cyclization conditions. Nucleotide analogs accessible by this strategy include those with modifications at C2′ and C4′, purines and pyrimidines, and locked and protected products. Science , this issue p. [725][1]; see also p. [623][2] [1]: /lookup/doi/10.1126/science.abb3231 [2]: /lookup/doi/10.1126/science.abd1283

Adolf Behne e a construção do Movimento Moderno – Parte 2

O livro A Construção Funcional Moderna, escrito por Adolf Behne em 1923, contém discussões fundamentais para a compreensão e condução da Arquitetura Moderna na década de 20. No livro, o autor identifica algumas correntes de pensamento em curso e as explora em três momentos, determinando os três capítulos de seu livro. No segundo deles, objeto deste texto e tradução, o autor discute os princípios da arquitetura alemã de viés expressionista, cujo desenho específico espelha o estudo detalhado da função. Se a cada necessidade interna resulta uma configuração particular, também se sobrepõem princípios formais oriundos de analogias orgânicas e dinâmicas que estão impregnados no pensamento da época. O autor situa o ponto alto desta vertente na obra de Erich Mendelsohn, e aponta os aspectos negativos da radicalização desta abordagem: ao atender prioritariamente a demandas internas à obra arquitetônica, criam-se edifícios únicos que comprometem a totalidade do conjunto urbano.

Sustainable Metal Recovery from Secondary Resources: Screening and Kinetic Studies Using Analogue Heterotrophic Metabolites

This study presents a sustainable approach for metal extraction from a range of secondary resources. Organic acids analogue to those commonly produced by heterotrophic microbes are applied via a two-step heterotrophic bioleaching approach. New insights into leaching mechanisms are developed and the potential use of the leaching residues as cementitious component is evaluated. Tested materials include a jarosite sludge from Zn refining, four ferrous metallurgy residue sludges and two dry automotive recycling shredder residues. Screening experiments tested three organic acids (i.e. citric, gluconic, oxalic acid) and their combinations. Four physicochemical factors were varied, i.e. the solid/liquid ratio between 5 and 15%, total organic acid concentration between 20 and 200 mM, leaching times of 2 to 4 h and horizontal stirring reactor mixing rate. The highest extraction capacity was achieved for a Cr/Ni rich sludges from steel treatment with up to 96% Ni and 91% Cr extraction at a 5% S/L and a mixture of 100 mM citric and 100 mM oxalic acid. Further scale-up kinetic studies on this Cr/Ni sludge validated the optimal leaching conditions. Modelling of kinetic leaching data indicated pore diffusion rate as a bottleneck of the overall leaching process. Screening tests of the leached residue indicated potential use as sulfate-rich addition to cement, or as part of low-performance binders for large scale civil works.

Stable perovskites with ionic salts

Solar Cells Ionic liquids have been shown to stabilize organic-inorganic perovskite solar cells with metal oxide carrier-transport layers, but they are incompatible with more readily processible organic analogs. Lin et al. found that an ionic solid, a piperidinium salt, enhanced the efficiency of positive-intrinsic-negative layered perovskite solar cells with organic electron and hole extraction layers. Aggressive aging testing showed that this additive retarded segregation into impurity phases and pinhole formation in the perovskite layer. Science , this issue p. [96][1] [1]: /lookup/doi/10.1126/science.aba1628

A piperidinium salt stabilizes efficient metal-halide perovskite solar cells.

Longevity has been a long-standing concern for hybrid perovskite photovoltaics. We demonstrate high-resilience positive-intrinsic-negative perovskite solar cells by incorporating a piperidinium-based ionic compound into the formamidinium-cesium lead-trihalide perovskite absorber. With the bandgap tuned to be well suited for perovskite-on-silicon tandem cells, this piperidinium additive enhances the open-circuit voltage and cell efficiency. This additive also retards compositional segregation into impurity phases and pinhole formation in the perovskite absorber layer during aggressive aging. Under full-spectrum simulated sunlight in ambient atmosphere, our unencapsulated and encapsulated cells retain 80 and 95% of their peak and post-burn-in efficiencies for 1010 and 1200 hours at 60° and 85°C, respectively. Our analysis reveals detailed degradation routes that contribute to the failure of aged cells.

Synthesis, Characterization and Biological Studies of Ether–Based Ferrocenyl Amides and their Organic Analogues

Ferrocenyl amides (FB1-FB13) and their organic analogues (BZ1-BZ13) were prepared by a low-temperature condensation method. Ferrocenyl amides were synthesised using 4-ferrocenylbenzoyl chloride and ether-based amines and diamines. Benzoyl chloride was used to synthesise organic analogues by reacting with various amines. The synthesised compounds were characterised by elemental, spectroscopic (FT-IR and NMR) and single crystal X-ray diffraction methods. Crystal structures of the representative organic analogues (BZ2 and BZ6) were solved by single crystal X-ray diffraction. BZ2 crystallises in the triclinic space group P 1 ¯ with a unit cell volume of V = 1056.6(3) Å3 and with two formula units per unit cell. Whereas BZ6 assembles in the orthorhombic space group Pbca with four formula units per unit cell and a unit cell volume of V = 1354.7(2) Å3. Spectral studies confirmed the presence of amide linkages in the synthesised compound with a strong N—H·····O=C hydrogen bonding network established between amide groups of neighbouring molecular scaffolds further stabilising the molecular stacking in accordance with the archetypal crystal structures. The bioactive nature of each compound was assessed by DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity, hydrogen peroxide scavenging activity and total antioxidant activity. Antidiabetic, anticholinesterase enzyme inhibition tests, as well as antibacterial activities, were performed showing significant biological activity for ferrocenyl amides as compared to their organic analogues.

Alteration and Stability of Complex Macromolecular Amino Acid Precursors in Hydrothermal Environments.

The early Solar System comprised a broad area of abiotically created organic compounds, including interstellar organics which were integrated into planetesimals and parent bodies of meteorites, and eventually delivered to the early Earth. In this study, we simulated interstellar complex organic compounds synthesized by proton irradiation of a gas mixture of CO, NH3, and H2O, which are known to release amino acids after acid hydrolysis on the basis of Kobayashi et al. (1999) who reported that at the first stage of chemical evolution, the main compounds formed abiotically are complex organic compounds with high molecular weights. We examined their possible hydrothermal alteration and stabilities as amino acid precursors under high temperature and pressure conditions simulating parent bodies of meteorites by using an autoclave. We reported that all samples treated at 200-300°C predominantly released glycine and alanine, followed by α-aminobutyric acid, and serine. After heating, amino acid concentrations decreased in general; however, the recovery ratios of γ-aminobutyric acid increased with temperature. The interstellar complex organic analog could maintain as amino acid precursors after being treated at high temperature (200-300°C) and pressure (8-14MPa). However, the molecular structures were altered during heating to form organic compounds that are more stable and can survive in elevated hydrothermal conditions.

Electron Paramagnetic Resonance Characteristics and Crystal Structure of a Tutton Salt Analogue: Copper-Doped Cadmium Creatininium Sulfate.

Electron paramagnetic resonance and crystallographic studies on copper-doped cadmium creatininium sulfate (CdCrnS) were undertaken to study the characteristics of a copper-hexahydrate complex in an organic analogue of Tutton's salt. X-ray diffraction experiments determined the crystal structure of CdCrnS at both 100 and 298 K. CdCrnS, like Tutton salt, crystallizes in the monoclinic space group P21/n. The unit cell contains two cadmium hexahydrate complexes, four creatininium ions, four sulfates, and four additional solvation waters. Both crystallography and EPR find that the doped copper replaces the cadmium in the structure. Single-crystal EPR measurements at room temperature determined the g and copper hyperfine (ACu) tensors (principal values: g = 2.437, 2.134, and 2.080 and ACu = -327, -84.8, and 7.33 MHz). EPR spectra of the powder at room temperature gave g = 2.448, 2.125, and 2.085 and ACu = -315, -75.0, and 35.0 MHz and at 110 K gave g = 2.462, 2.116, and 2.077 and ACu = -340, -30.0, and 35.0 MHz. The room-temperature tensors are close to the "rigid lattice limit" values found in copper-doped Tutton salts but with a higher gmin and weaker ACux coupling than average. A small but measurable temperature dependency of the tensors indicated the presence of a dynamic Jahn-Teller (JT) effect. In addition, the EPR line width changed dramatically with temperature, which is like that found in all copper-doped Tutton crystals. Utilizing the model of Silver-Getz for the g-value variation gave an estimate for the energy difference (δ12 = 640 cm-1) between the ground and next highest JT configurations. An empirical correlation appears to exist between δ12 and gmin and ACux for the copper hexahydrates studied in similar crystals. This suggests a relationship between the amount of unpaired spins in the copper d-orbital x lobe and the gap between wells of the adiabatic potential surface.

Molecular Insight into Fluorocarbon Adsorption in Pore Expanded Metal-Organic Framework Analogs.

The rapid growth in the global energy demand for space cooling requires the development of more efficient environmental chillers for which adsorption-based cooling systems can be utilized. Here, in this contribution, we explore sorbents for chiller use via a pore-engineering concept to construct analogs of the 1-dimensional pore metal-organic framework MOF-74 by using elongated organic linkers and stereochemistry control. The prepared pore-engineered MOFs show remarkable equilibrium adsorption of the selected fluorocarbon refrigerant that is translated to a modeled adsorption-based refrigeration cycle. To probe molecular level interactions at the origin of these unique adsorption properties for this series of Ni-MOFs, we combined in situ synchrotron X-ray powder diffraction, neutron powder diffraction, X-ray absorption spectroscopy, calorimetry, Fourier transform infrared techniques, and molecular simulations. Our results reveal the coordination of fluorine (of CH2F in R134a) to the nickel(II) open metal centers at low pressures for each Ni-MOF analog and provide insight into the pore filling mechanism for the full range of the adsorption isotherms. The newly designed Ni-TPM demonstrates exceptional R134a adsorption uptake compared to its parent microporous Ni-MOF-74 due to larger engineered pore size/volume. The application of this adsorption performance toward established chiller conditions yields a working capacity increase for Ni-TPM of about 400% from that of Ni-MOF-74, which combined with kinetics directly correlates to both a higher coefficient of performance and a higher average cooling capacity generated in a modeled chiller.

MOF-mimetic molecules: carboxylate-based supramolecular complexes as molecular metal–organic framework analogues

This review covers MOF-like molecules, an emerging class of potentially porous, soluble, and discrete cages.

Influence of chelated forms of trace elements on the live weight and livability of rearing stock of broilers

Nowadays, organic forms of trace elements, which have a high bioavailability, and, as a consequence, have a beneficial effect on the body of animals and birds, are increasingly used in feeding. In this area, quite a lot of research has been carried out on the use of chelates in poultry feeding, but mainly for broiler chickens and laying hens. Therefore, the purpose of our study was the use of organic forms of trace elements such as iron, manganese, copper, zinc, and selenium in the diets of rearing stock of the parent flock of the ROSS cross. The experiment was carried out in the production conditions of the Novosafonovskaya poultry farm of Kuzbasskiy Broiler LLC and at the Small animal science department of the Altai State Agrarian University in 2020. The results of the experiment indicate that replacing 50% of the need for inorganic forms of iron, manganese, copper, zinc and selenium with organic analogs contributed to an increase in live weight, absolute and average daily gains of rearing stock. There was an increase in the uniformity of the flock in terms of live weight, both males and females. The crop percent of poultry in the experimental group was 3.2-4.6% higher due to a decrease not only in mortality, but also in culled chickens.