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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Structure of 43 P and 42 Si in a two-level shape-coexistence model

Exclusive cross sections for the 43 P(-1p) 42 Si reaction to the lowest 0 + and 2 + states, measured at NSCL with GRETINA and the S800, are interpreted in terms of a two-level mixing (collective) model of oblate and prolate co-existing shapes. Here, using the formalism developed for deformed nuclei we calculate the spectroscopic amplitudes and exclusive cross-sections in the strong coupling limit, where for 43 P the schematic wavefunction includes the coupling of the Nilsson [211] 1/2 proton orbit. Good agreement with the experimental data is obtained when the amplitude of the oblate configuration is larger or equal than 80%, suggesting that both nuclei are predominantly oblate, in line with theoretical expectations. Model predictions for excitation energies and electromagnetic observables, that could motivate further studies of both nuclei, are also presented.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

N* Physics with CLAS12 at Jefferson Lab

Nucleons are the most fundamental bound three-body systems in Nature. With the CLAS12 spectrometer at Jefferson Lab, the spectrum and the structure of nucleon resonances is explored. This includes studies of exclusive piN, pi+pi-p, KLambda, and KSigma electroproduction reactions and the evolution of the electrocouplings of resonances with photon virtuality Q^2. Such type of studies with CLAS have revealed a complex interplay between a core of dressed quarks and an external meson-baryon cloud inside of the excited nucleon states. With CLAS12, also measurements of N -> N* transitions in the DIS region have been performed, addressing the three-dimensional structure of nucleon resonances through their transition GPDs (generalized parton distributions). In the future, the increase of the CEBAF energy and the upgrade of the CLAS12 spectrometer to study exclusive electroproduction channels at higher luminosities and photon virtualities will offer a unique opportunity to study the nucleon excitation mechanisms.

Achenbach, Patrick↗
DOE OSTI2020

Two-neutron knockout as a probe of the composition of states in Mg 22 , Al 23 , and Si 24

Simpson and Tostevin proposed that the width and shape of exclusive parallel momentum distributions of the A - 2 residue in direct two-nucleon knockout reactions carry a measurable sensitivity to the nucleon single-particle configurations and their couplings within the wave functions of exotic nuclei. We further report here on the first benchmarks and use of this new spectroscopic tool. Exclusive parallel momentum distributions for states in the neutron-deficient nuclei Mg 22 , Al 23 , and Si 24 populated in such direct two-neutron removal reactions were extracted and compared to predictions combining eikonal reaction theory and shell-model calculations. For the well-known Mg 22 and Al 23 nuclei, measurements and calculations were found to agree, supporting the dependence of the parallel momentum distribution width on the angular momentum composition of the shell-model two-neutron amplitudes. In Si 24 , a level at 3439(9) keV, of relevance for the important Al 23 ( p , γ ) Si 24 astrophysical reaction rate, was confirmed to be the 2 2 + state, whereas the 4 1 + state, expected to be strongly populated in two-neutron knockout, was not observed. This puzzle is resolved by theoretical considerations of the Thomas-Ehrman shift, which also indicates that a previously reported 3471-keV state in Si 24 is, in fact, the ( 0 2 + ) level with one of the largest experimental mirror-energy shifts ever observed.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

Formation of Gas-Phase Allyl Radicals from Glycerol on Rutile TiO2(110)

The reaction pathways of glycerol on partially reduced TiO2(110) have been studied by a combination of molecular beam dosing and temperature-programmed desorption (TPD). Glycerol is found to bind more strongly to TiO2(110) than glycols due to an additional hydroxyl group in the molecule. When the Ti surface sites are saturated by glycerol, the majority of glycerol molecules (~ 95%) undergo further reactions to yield carbon-free (water and hydrogen) and carbon-containing products that are desorbed during the TPD ramp. In contrast to glycols for which both water and hydrogen arise exclusively from the cleavage of glycol O-H bonds, we identify two distinct reaction channels resulting from the cleavage of O-H and C-H bonds, respectively, for both water and hydrogen evolution from glycerol on TiO2(110). Quantitative determination of the desorption yields of water and hydrogen reveals that the C-H bond scission channel which occurs at higher temperature than the O-H bond scission channel, is a minor reaction channel for water formation, while it is a major reaction channel responsible for hydrogen evolution. For the carbon-containing products, we exclude both carbon deposition and carbon oxides (CO and CO2) formation, and identify the allyl radical as the major carbon-containing product. The formation of the allyl radical is accompanied by the formation of various minor carbon-containing products including propylene, acrolein, allyl alcohol, acetone, formaldehyde and ethylene. The different surface chemistries observed between glycerol and simpler alcohols and glycols on TiO2(110), suggest that smaller oxygenates cannot serve as models for larger oxygenates in probing their reaction pathways on oxide surfaces. The new reaction channels observed for glycerol on TiO2(110) may open up a new way to convert bio-renewable glycerol directly to pure hydrogen and hydrocarbons on TiO2. This work was supported by the US Department of Energy, Office of Sciences, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences, and performed in EMSL, a national scientific user facility sponsored by the Department of Energy’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is a multiprogram national laboratory operated for the DOE by Battelle.

Chen, Long↗
NASA NTRS1987

A cure-rate model for the Shuttle filament-wound case

An epoxy and carbon fiber composite has been used to produce a light-weight rocket case for the Space Shuttle. A kinetic model is developed which can predict the extent of epoxy conversion during the winding and curing of the case. The model accounts for both chemical and physical kinetics. In the model, chemical kinetics occur exclusively up to the time the transition temperature equals the reaction temperature. At this point the resin begins to solidify and the rate of this process limits the rate of epoxy conversion. A comparison of predicted and actual epoxy conversion is presented for isothermal and temperature programmed cure schedules.

Cagliostro, D. E.↗
DOE OSTI2022

Olefin methylation over iron zeolites and the methanol to hydrocarbons reaction

The effect of olefin addition to a stream of dimethyl ether on the methanol homologation reaction is investigated using iron-substituted zeolites Fe-beta and Fe-ZSM-5. The reaction was investigated using plug-flow microreactors in the temperature range of 240–400 °C, at a total pressure of 0.239 MPa and a WHSV of 6.12 (g DME/ gcat -hr). For Fe-beta (Si/Fe= 9.2) catalysts, isobutene co-feeding almost doubles dimethyl ether (DME) consumption rate and shifts selectivity towards larger olefins with carbon numbers from 5 to 7. Addition of isobutene above 6.3%, however, resulted in a reduction of DME consumption rates, an effect assigned to the replacement of surface methoxy groups for adsorbed olefins in the zeolite pores. Below a temperature of 340 °C hydride-transfer rates are negligible; reaction rates are stable for over 5.5 h and the products consist almost exclusively of olefins and a small amount of methane. Above 360 °C the onset of catalytic hydride transfer processes is observed leading to fast catalyst deactivation rates and an increase in the concentration of aromatic species. Iron ZSM-5 (Si/Fe = 21.4) catalysts under similar reaction conditions consumes methanol faster than Fe-beta at approximately three times the TOF (on a per iron basis). The Fe-ZSM-5 catalyst was selective to a distribution of products (C5 to C8) as compared to Fe-beta which was selective to primarily C5 and C7. Co-feeding larger olefins (2-methyl-2-butene, 2,3-dimethyl-2-butene, 2,3,3-trimethyl-1-butene, and 2,4,4-trimethyl-2-pentene) at a 3.9% olefin concentration over Fe-beta changed selectivity towards cracking products (C4 compounds such as isobutene). As the size of the olefin increases, a reduction of DME consumption rate is also observed. Here these results show that co-feeding olefins with DME over Fe-zeolites is a promising route to increase methylation rates at relatively low temperatures producing larger branched olefins and that the product distribution is highly dependent on the zeolite pore size and structure of the olefin.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Exclusive $J/ψ$ photoproduction on nuclei

Motivated by the recent experimental developments, the Pom-CQM model of the γ+N → J/ψ+N reaction of Lee et al. [Eur. Phys. J. A. 58, 252 (2022)] and Sakinah et al. [Phys. Rev. C. 109, 065204 (2024)] has been applied to predict the exclusive J/ψ photo-production on nuclei (A). Within the multiple scattering theory, the calculations have been performed by including the impulse amplitude $T^{\textrm{IMP}}_{J/ψA,γA}$ and the J/ψ-nucleus final state interaction (FSI) amplitude $T^{\textrm{FSI}}_{J/ψA,γA}$. For the deuteron target, $T^{\textrm{IMP}}_{J/ψd,γd}$ is calculated exactly using the wave function generated from the realistic nucleon-nucleon potentials. Here, it is found that, near the threshold region, the J/ψ photoproduction cross sections depend sensitively on the d-state of the deuteron wave function. The FSI amplitude $T^{\textrm{FSI}}_{J/ψA,γA}$ is calculated using the first-order optical potential constructed from the J/ψ-N scattering amplitude generated from the employed Pom-CQM model. It turns out that the FSI has significant effects in the large momentum-transfer region. By using the conventional fixed scatter approximation (FSA) and the nuclear form factors from the variational Monte-Carlo (VMC) calculations of Lonardoni et al. [Phys. Rev.C. 96, 024326 (2017)], the cross sections of the J/ψ photo-production on 4 He, 16 O, and 40 Ca are also predicted for future experimental investigations at JLab and EIC.

Kim, Sang-Ho [Soongsil University, Seoul (Korea, R↗
DOE OSTI2025

Growth-induced Donnan exclusion influences swelling kinetics in highly charged dynamic polymerization hydrogels

Polymeric gels crosslinked by DNA sequences can exploit DNA strand-displacement reactions to promote swelling through dynamic polymerization. The degree of swelling and the rate of swelling must be directly tunable to achieve the promise of programmable soft matter. Though the kinetics of the strand-displacement reaction provide insertion rates up to 10 4 /Molar/second as measured in bulk solution, DNA hydrogel swelling can take upwards of 30 h to complete. Computational modeling of the reaction-induced swelling of these gels with our recently-developed reactive electrochemomechanical theory (Zimmerman et al., 2024) suggests that their extraordinarily slow swelling is partly due to a scaling mismatch between the addition of charge and the addition of fluid volume, leading to a large transient increase in the fixed charge density. The significant increase in the gel’s fixed charge density, due to the binding of negatively charged DNA, sharply restricts the concentration of mobile hairpins through the phenomenon of Donnan charge exclusion, an effect commonly exploited in nanofiltration applications using polymeric membranes. The scaling problem is overcome when the mean additional swelling provided to the hydrogel by addition of a crosslink is above a critical value, thus the swelling outpaces the charge accumulation, leading the fixed charge density to drop and significantly accelerating the swelling process. This study shows that Donnan exclusion can explain the kinetics of DNA hydrogel swelling, and studies ways to modulate the reaction speed by either modifying the salt concentration or increasing or decreasing the number of base pairs in each DNA sequence.

42 ENGINEERING↗
DOE OSTI2025

Photon–photon chemical thermodynamics of frequency conversion processes in highly multimode systems

Abstract Frequency generation in highly multimode nonlinear optical systems is inherently a complex process, giving rise to an exceedingly convoluted landscape of evolution dynamics. While predicting and controlling the global conversion efficiencies in such nonlinear environments has long been considered impossible, here, we formally address this challenge even in scenarios involving a very large number of spatial modes. By utilizing fundamental notions from optical statistical mechanics, we develop a universal theoretical framework that effectively treats all frequency components as chemical reactants/products, capable of undergoing optical thermodynamic reactions facilitated by a variety of multi-wave mixing effects. These photon–photon reactions are governed by conservation laws that directly determine the optical temperatures and chemical potentials of the ensued chemical equilibria for each frequency species. In this context, we develop a comprehensive stoichiometric model and formally derive an expression that relates the chemical potentials to the optical stoichiometric coefficients, in a manner akin to atomic/molecular chemical reactions. This advancement unlocks new predictive capabilities that can facilitate the optimization of frequency generation in highly multimode photonic arrangements, surpassing the limitations of conventional schemes that rely exclusively on nonlinear optical dynamics. Notably, we identify a universal regime of Rayleigh–Jeans thermalization where an optical reaction at near-zero optical temperatures can promote the complete and entropically irreversible conversion of light to the fundamental mode at a target frequency. Our theoretical results are corroborated by numerical simulations in settings where second-harmonic generation, sum-frequency generation and four-wave mixing processes can manifest.

Optics↗
DOE OSTI2023

Armor for Steel: Facile Synthesis of Hexagonal Boron Nitride Films on Various Substrates

Abstract While hexagonal boron nitride (hBN) has been widely used as a buffer or encapsulation layer for emerging electronic devices, interest in utilizing it for large‐area chemical barrier coating has somewhat faded. A chemical vapor deposition process is reported here for the conformal growth of hBN on large surfaces of various alloys and steels, regardless of their complex shapes. In contrast to the previously reported very limited protection by hBN against corrosion and oxidation, protection of steels against 10% HCl and oxidation resistance at 850 °C in air is demonstrated. Furthermore, an order of magnitude reduction in the friction coefficient of the hBN coated steels is shown. The growth mechanism is revealed in experiments on thin metal films, where the tunable growth of single‐crystal hBN with a selected number of layers is demonstrated. The key distinction of the process is the use of N 2 gas, which gets activated exclusively on the catalyst's surface and eliminates adverse gas‐phase reactions. This rate‐limiting step allowed independent control of activated nitrogen along with boron coming from a solid source (like elemental boron). Using abundant and benign precursors, this approach can be readily adopted for large‐scale hBN synthesis in applications where cost, production volume, and process safety are essential.

2D materials↗
DOE OSTI2024

Morphology‐controlled synthesis of multi‐metal‐based spinel oxide nanocatalysts and their performance for oxygen reduction

Abstract We present a one‐pot colloidal synthesis method for producing monodisperse multi‐metal (Co, Mn, and Fe) spinel nanocrystals (NCs), including nanocubes, nano‐octahedra, and concave nanocubes. This study explores the mechanism of morphology control, showcasing the pivotal roles of metal precursors and capping ligands in determining the exposed crystal planes on the NC surface. The cubic spinel NCs, terminated with exclusive {100}‐facets, demonstrate superior electrocatalytic activity for the oxygen reduction reaction (ORR) in alkaline media compared to their octahedral and concave cubic counterparts. Specifically, at 0.85 V, (CoMn)Fe 2 O 4 spinel oxide nanocubes achieve a high mass activity of 23.9 A/g and exhibit excellent stability, highlighting the promising ORR performance associated with {100}‐facets of multi‐metal spinel oxides over other low‐index and high‐index facets. Motivated by exploring the correlation between ORR performance and surface atom arrangement (active sites), surface element composition, as well as other factors, this study introduces a prospective approach for shape‐controlled synthesis of advanced spinel oxide NCs. It underscores the significance of catalyst shape control and suggests potential applications as nonprecious metal ORR electrocatalysts.

Li, Can↗
DOE OSTI2023

Measurement of the cross section of $$ {e}^{+}{e}^{-}\to {\Xi}^{-}{\overline{\Xi}}^{+} $$ at center-of-mass energies between 3.510 and 4.843 GeV

Abstract Usinge + e − collision data corresponding to a total integrated luminosity of 12.9 fb −1 collected with the BESIII detector at the BEPCII collider, the exclusive Born cross sections and the effective form factors of the reaction$$ {e}^{+}{e}^{-}\to {\Xi}^{-}{\overline{\Xi}}^{+} $$ e + e − → Ξ − Ξ ¯ + are measured via the single baryon-tag method at 23 center-of-mass energies between 3.510 and 4.843 GeV. Evidence for the decay$$ \psi (3770)\to {\Xi}^{-}{\overline{\Xi}}^{+} $$ ψ 3770 → Ξ − Ξ ¯ + is observed with a significance of 4.5σby analyzing the measured cross sections together with earlier BESIII results. For the other charmonium(-like) statesψ(4040),ψ(4160),Y(4230),Y(4360),ψ(4415), andY(4660), no significant signal of their decay to$$ {\Xi}^{-}{\overline{\Xi}}^{+} $$ Ξ − Ξ ¯ + is found. For these states, upper limits of the products of the branching fraction and the electronic partial width at the 90% confidence level are provided.

Physics↗
NASA NTRS1985

Propagation of detonations in hydrazine vapor

In the range of greater hydrazine vapor pressure, detonation speed depends exclusively on the extent of the ammonia decomposition in the second reaction stage. As vapor pressure decreases, the ammonia disintegration speed becomes increasingly slower and the reaction reached in the reaction zone increasingly decreases until finally, in the vapor pressure range between 53 and 16 Torr, the contribution of the second stage to detonation propagation disappears, and only the first stage remains active. Since the disintegration speed of the hydrazine in this pressure range has decreased markedly as well, no level, but rather only spinning, detonations occur. Temporary separations of the impact front and the reaction zone in the process lead to fluctuations of the detonation speed.

Heinrich, H. J.↗
DOE OSTI2023

Co 2 Mo 6 S 8 Catalyzes Nearly Exclusive Electrochemical Nitrate Conversion to Ammonia with Enzyme-like Activity

Electrocatalytic nitrate to ammonia conversion is a key reaction for energy and environmental sustainability. This reaction involves complex multi electron and proton transfer steps, and is impeded by the lack of catalyst for promoting both reactivity and ammonia selectivity. Here, we demonstrate active motifs based on the Chevrel phase Co 2 Mo 6 S 8 exhibit an enzyme-like high turnover frequency of ~95.1 s –1 for nitrate electroreduction to ammonia. We reveal strong synergy of multiple binding sites on this catalyst, such that the ligand effect of Co steers H ad* toward hydrogenation other than hydrogen evolution, the ensemble effect of Co, and the spatial confinement effect that promote the full hydrogenation of NO x to ammonia without N–N coupling. The catalyst exhibits almost exclusive ammonia conversion with a Faradaic efficiency of 97.1% and ammonia yielding rate of 115.5 mmol·g cat –1 ·h –1 in neutral electrolytes. The high activity was also confirmed in electrolytes with dilute nitrate and high chloride concentrations.

36 MATERIALS SCIENCE↗
NASA NTRS1994

Emergence of a replicating species from an in vitro RNA evolution reaction

The technique of self-sustained sequence replication allows isothermal amplification of DNA and RNA molecules in vitro. This method relies on the activities of a reverse transcriptase and a DNA-dependent RNA polymerase to amplify specific nucleic acid sequences. We have modified this protocol to allow selective amplification of RNAs that catalyze a particular chemical reaction. During an in vitro RNA evolution experiment employing this modified system, a unique class of "selfish" RNAs emerged and replicated to the exclusion of the intended RNAs. Members of this class of selfish molecules, termed RNA Z, amplify efficiently despite their inability to catalyze the target chemical reaction. Their amplification requires the action of both reverse transcriptase and RNA polymerase and involves the synthesis of both DNA and RNA replication intermediates. The proposed amplification mechanism for RNA Z involves the formation of a DNA hairpin that functions as a template for transcription by RNA polymerase. This arrangement links the two strands of the DNA, resulting in the production of RNA transcripts that contain an embedded RNA polymerase promoter sequence.

Non-NASA Center↗
DOE OSTI2021

Competitive Exclusion and Metabolic Dependency among Microorganisms Structure the Cellulose Economy of an Agricultural Soil

Microorganisms that degrade cellulose utilize extracellular reactions that yield free by-products which can promote interactions with noncellulolytic organisms. We hypothesized that these interactions determine the ecological and physiological traits governing the fate of cellulosic carbon (C) in soil. We performed comparative genomics with genome bins from a shotgun metagenomic-stable isotope probing experiment to characterize the attributes of cellulolytic and noncellulolytic taxa accessing 13 C from cellulose. We hypothesized that cellulolytic taxa would exhibit competitive traits that limit access, while noncellulolytic taxa would display greater metabolic dependency, such as signatures of adaptive gene loss. We tested our hypotheses by evaluating genomic traits indicative of competitive exclusion or metabolic dependency, such as antibiotic production, growth rate, surface attachment, biomass degrading potential, and auxotrophy. The most 13 C-enriched taxa were cellulolytic Cellvibrio (Gammaproteobacteria) and Chaetomium (Ascomycota), which exhibited a strategy of self-sufficiency (prototrophy), rapid growth, and competitive exclusion via antibiotic production. Auxotrophy was more prevalent in cellulolytic Actinobacteria than in cellulolytic Proteobacteria, demonstrating differences in dependency among cellulose degraders. Noncellulolytic taxa that accessed 13 C from cellulose (Planctomycetales, Verrucomicrobia, and Vampirovibrionales) were also more dependent, as indicated by patterns of auxotrophy and 13 C labeling (i.e., partial labeling or labeling at later stages). Major 13 C-labeled cellulolytic microbes (e.g., Sorangium, Actinomycetales, Rhizobiales, and Caulobacteraceae) possessed adaptations for surface colonization (e.g., gliding motility, hyphae, attachment structures) signifying the importance of surface ecology in decomposing particulate organic matter. Our results demonstrated that access to cellulosic C was accompanied by ecological trade-offs characterized by differing degrees of metabolic dependency and competitive exclusion.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Quantifying uncertainties due to irreducible three-body forces in deuteron-nucleus reactions

Deuteron-induced nuclear reactions are an essential tool for probing the structure of nuclei as well as astrophysical information such as (n, γ) cross sections. The deuteron-nucleus system is typically described within a Faddeev three-body model consisting of a neutron (n), a proton (p), and the target nucleus (A) interacting through pairwise phenomenological potentials. While Faddeev techniques enable the exact description of the three-body dynamics, their predictive power is limited in part by the omission of irreducible neutron-proton-nucleus three-body force (n–p–A 3BF). Here, our goal is to quantify systematic uncertainties stemming from the reduction of deuteron-nucleus (d + A) dynamics to a picture of three pointlike nuclear clusters interacting via pairwise nucleon-nucleus forces, using as testing grounds d + α scattering and the 6 Li ground state. We particularly focus on quantifying uncertainties arising from the full antisymmetrization of the (A + 2)-body system with the target nucleus fixed in its ground state. We adopt the ab initio no-core shell model coupled with the resonating group method (NCSM/RGM) to compute microscopic n–α and p–α interactions, and use them in a three-body description of the d + α system by means of momentum-space Faddeev-type equations. Simultaneously, we also carry out ab initio calculations of d + α scattering and 6 Li ground state by means of six-body NCSM/RGM calculations to serve as a benchmark for the three-body model predictions given by the Faddeev calculations. By comparing the Faddeev and NCSM/RGM results, we show that the irreducible n–p–α 3BF has a non-negligible effect on bound state and scattering observables alike. Specifically, the Faddeev approach yields a 6 Li ground state that is approximately 600 keV shallower than the one obtained with the NCSM/RGM. Additionally, the Faddeev calculations for d + α scattering yield a 3 + resonance that is located approximately 400 keV higher in energy compared to the NCSM/RGM result. The shape of the d + α angular distributions computed using the two approaches also differ, owing to the discrepancy in the predictions of the 3 + resonance energy. The Faddeev three-body model predictions for d + α scattering and 6 Li using microscopic n–α and p–α potentials differ from those computed microscopically with the NCSM/RGM. These discrepancies are due to the n–p–α 3BF, which arises from two-nucleon exchange terms in the microscopic d–α interaction and are not accounted for in the three-body model Faddeev calculations. This study lays the foundation for future parametrizations of the 3BF due to Pauli exclusion principle effects in improved three-body calculations of deuteron-induced reactions.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS1996

Synthesis of RNA oligomers on heterogeneous templates

The concept of an RNA world in the chemical origin of life is appealing, as nucleic acids are capable of both information storage and acting as templates that catalyse the synthesis of complementary molecules. Template-directed synthesis has been demonstrated for homogeneous oligonucleotides that, like natural nucleic acids, have 3',5' linkages between the nucleotide monomers. But it seems likely that prebiotic routes to RNA-like molecules would have produced heterogeneous molecules with various kinds of phosphodiester linkages and both linear and cyclic nucleotide chains. Here we show that such heterogeneity need be no obstacle to the templating of complementary molecules. Specifically, we show that heterogeneous oligocytidylates, formed by the montmorillonite clay-catalysed condensation of actuated monomers, can serve as templates for the synthesis of oligoguanylates. Furthermore, we show that oligocytidylates that are exclusively 2',5'-linked can also direct synthesis of oligoguanylates. Such heterogeneous templating reactions could have increased the diversity of the pool of protonucleic acids from which life ultimately emerged.

Non-NASA Center↗