We introduce a new family of highly efficient polarizing agents for dynamic nuclear polarization (DNP)-enhanced magnetic resonance (NMR) applications, composed asymmetric bis-nitroxides, in which piperidine-based radical and pyrrolinoxyl or proxyl are linked together. The design the AsymPol was guided by use advanced simulations that allow computation impact structure on DNP efficiency. These suggested relatively short linker with intention to generate sizable intramolecular electron dipolar...

Reaching a historic high of 36.3 gigatonnes in 2021, global CO2 emissions from fossil fuel combustion continue to increase at an alarming rate. removal technologies are part the solution tackle this crucial environmental challenge. Thus, development porous materials for storage and capture gas molecules (in particular, carbon storage) has attracted great interest both academic industrial communities due its potential mitigating atmospheric concentrations. Atomic-scale studies essential...

This study delves into the potential advantage of utilizing crab shells as sustainable solid adsorbents for CO

Adsorption isotherms obtained through volumetric measurements are widely used to estimate the gas adsorption performance of porous materials. Nonetheless, there is always ambiguity regarding contributions chemi- and physisorption processes overall retained volume. In this work, we propose, for first time, use solid-state NMR (ssNMR) generate CO2 adsorbed onto an amine-modified silica sorbent. This method enables separation six individual physisorbed components, a feat only possible using...

Metal-organic frameworks (MOFs) are promising porous materials for CO2 adsorption due to their high surface area, tunable properties, and selective capabilities. The recently reported Calgary Framework 20 (CALF-20) MOF has very appealing capture properties: uptake capacity; low regeneration energy; durability (>450 000 cycles) under steam wet acid gases; simple scalable synthesis. This study investigates the microwave (MW)-assisted synthesis of CALF-20, which reduces reaction time 12-fold...

The 13C chemical shifts of the primary visual photointermediate bathorhodopsin have been observed by performing double-quantum magic-angle-spinning NMR at low temperature in presence illumination. Strong isomerization upon conversion rhodopsin into bathorhodopsin.

Yeast cell walls undergo modifications during the brewing process, leading to a remodelling of their architecture. One significant change is increased insolubility wall glycogen pool, likely due formation covalent bonds between and polysaccharides. To verify this hypothesis, we extracted brewer's spent yeast with 4 M KOH, obtaining an insoluble glucan fraction (AE.4 M) primarily composed (α1 → 4)- (1 3)-linked Glc residues. Dynamic nuclear polarization solid-state NMR AE.4 revealed distinct...

Sel-DNP allows selective recovery of high-resolution information from protein binding sites by DNP-enhanced NMR.

The OX63 radical forms supramolecular capsules hosting tetraalkylammonium cations. Extensive self-association is also observed under standard dynamic nuclear polarization conditions.

Abstract Nanoscale flows of liquids can be revealed in various biological processes and underlie a wide range nanofluidic applications. Though the integral characteristics these systems, such as permeability effective diffusion coefficient, measured experiments, behaviour within nanochannels is still matter speculation. Herein, we used combination quadrupolar solid-state NMR spectroscopy, computer simulation, dynamic vapour sorption measurements to analyse water inside peptide nanochannels....

Dynamic nuclear polarization (DNP) has become an attractive technique to boost the sensitivity of NMR experiments. In case ex situ polarizations two-dimensional (2D) spectra are limited by short lifetime after dissolution and sample transfer a high field magnet. This limitation can be overcome various approaches. Here we show how use 13C-labelled acetyl tags help obtain 2D-HMQC for many small molecules, owing Overhauser enhancement between 13C spins originating from long-lived carbonyl...

Despite its broad applicability NMR has always been limited by inherently low sensitivity. Hyperpolarization methods have the potential to overcome this limitation and, in case of ex situ dynamic nuclear polarization (DNP), large enhancement factors achieved. Although many other described past, including chemically and parahydrogen-induced optical pumping, DNP recently most popular. Here we present an additional mechanism arising from quantum rotor effects methyl groups, which generates...

Spherical nanoparticles and fibres observable by cryo-electron microscopy are spontaneously formed the Finland trityl radical at concentrations above 15 mM. These species represent a new class of paramagnetic, metal-free, nanoscale supramolecular materials. Self-association was observed under variety experimental conditions, including aqueous solution room temperature, low temperature frozen glasses gas phase. Oligomers least 5 radicals were detected ion-mobility mass spectrometry. Magnetic...

Although recent advances in dynamic nuclear polarization techniques have boosted the otherwise low sensitivity of NMR spectroscopy, efficiency hyperpolarization process depends on composition matrix, particular contact between radical and target molecule capability matrix to transfer through spin diffusion. A concept for optimal design is presented, applied obtain two-dimensional heterocorrelated spectra small drug-like molecules 1−2 min after 90 hyperpolarization.

Herein, we report the synthesis and study of a novel mixed biradical with BDPA TEMPO radical units that are covalently bound by an ester group (BDPAesterTEMPO) as polarizing agent for fast dissolution DNP. The exhibits extremely high DNP NMR enhancement >50 000 times, which constitutes one largest signal enhancements observed so far, to best our knowledge.

Although spectroscopic investigation of surface chemisorbed CO2 species has been the focus most studies, identifying different domains weakly interacting (physisorbed) molecules in confined spaces is less trivial as they are often indistinguishable resorting to (isotropic) NMR chemical shift or vibrational band analyses. Herein, we undertake for first time a thorough solid-state analysis physisorbed prior and after amine-functionalization silica surfaces; combining 13C anisotropy (CSA)...

The synthesis and characterization of a novel trityl-TEMPO biradical the investigation its properties as Dynamic Nuclear Polarization (DNP) polarizing agent are reported. Comparison with structurally related monoradical (PTM–TEMPE) or mixtures two components reveals that has much higher polarization efficiency faster buildup. This offers possibility recycling further contributing to agent.

Previous studies on CO

Chitooligosaccharides have been suggested as cholesterol reducing ingredients mostly due to their ability sequestrate bile salts. The nature of the chitooligosaccharides-bile salts binding is usually linked with ionic interaction. However, at physiological intestinal pH range (6.4 7.4) and considering chitooligosaccharides pKa, they should be uncharged. This highlights that other type interaction might relevance. In this work, aqueous solutions an average degree polymerization 10 90 %...

Long‐lived states (LLS) are relaxation‐favored spin population distributions of J ‐coupled magnetic nuclei. LLS were measured, along with classical 1 H and 15 N relaxation rate constants, in amino acids the N‐terminal Unique domain c‐Src kinase, which is disordered vitro under physiological conditions. The rates can probe motions interactions biomolecules. aliphatic protons glycines, lifetimes approximately four times longer than their spin–lattice times, reported for first time an...