Temperature-induced mobility in octacalcium phosphate impacts crystal symmetry: water dynamics studied by NMR crystallography.

Octacalcium phosphate (OCP, Ca(PO)(HPO)·5HO) is a notable calcium phosphate due to its biocompatibility, making it a widely studied material for bone substitution. It is known to be a precursor of bone mineral, but its role in biomineralisation remains unclear. While the structure of OCP has been the subject of thorough investigations (including using Rietveld refinements of X-ray diffraction data, and NMR crystallography studies), important questions regarding the symmetry and H-bonding network in the material remain.

High-Resolution O Solid-State NMR as a Unique Probe for Investigating Oxalate Binding Modes in Materials: The Case Study of Calcium Oxalate Biominerals.

Oxalate ligands are found in many classes of materials, including energy storage materials and biominerals. Determining their local environments at the atomic scale is thus paramount to establishing the structure and properties of numerous phases. Here, we show that high-resolution O solid-state NMR is a valuable asset for investigating the structure of crystalline oxalate systems.

Probing oxygen exchange between UiO-66(Zr) MOF and water using O solid-state NMR.

The Zr-based Metal Organic Framework (MOF) UiO-66(Zr) is widely employed owing to its good thermal and chemical stabilities. Although the long-range structure of this MOF is preserved in the presence of water during several days, little is known about the formation of defects, which cannot be detected using diffraction techniques. We apply here O solid-state NMR spectroscopy at 18.

Induction-heated ball-milling: a promising asset for mechanochemical reactions.

While ball-milling is becoming one of the common tools used by synthetic chemists, an increasing number of studies highlight that it is possible to further expand the nature and number of products which can be synthesized, by heating the reaction media during mechanochemical reactions. Hence, developing set-ups enabling heating and milling to be combined is an important target, which has been looked into in both academic and industrial laboratories. Here, we report a new approach for heating up reaction media during ball-milling reactions, using induction heating (referred to as i-BM).

Coordinatively Cross-Linked Binders for Silicon-Based Electrodes for Li-Ion Batteries: Beneficial Impact on Mechanical Properties and Electrochemical Performance.

A simple and versatile preparation of Zn(II)-poly(carboxylates) reticulated binders by the addition of Zn(II) precursors (ZnSO, ZnO, or Zn(NO)) into a preoptimized poly(carboxylic acids) binder solution is proposed. These binders lead systematically to a significantly improved electrochemical performance when used for the formulation of silicon-based negative electrodes. The formation of carboxylate-Zn(II) coordination bonds formation is investigated by rheology and FTIR and NMR spectroscopies.

Fast and Cost-Efficient O-Isotopic Labeling of Carboxylic Groups in Biomolecules: From Free Amino Acids to Peptide Chains.

O NMR spectroscopy is a powerful technique, which can provide unique information regarding the structure and reactivity of biomolecules. However, the low natural abundance of O (0.04 %) generally requires working with enriched samples, which are not easily accessible.

Correction to "First Direct Insight into the Local Environment and Dynamics of Water Molecules in the Whewellite Mineral Phase: Mechanochemical Isotopic Enrichment and High-Resolution O and H NMR Analyses".

[This corrects the article DOI: 10.1021/acs.jpcc.

O solid state NMR as a valuable tool for deciphering reaction mechanisms in mechanochemistry: the case study on the O-enrichment of hydrated Ca-pyrophosphate biominerals.

The possibility of enriching in O the water molecules within hydrated biominerals belonging to the Ca-pyrophosphate family was investigated, using liquid assisted grinding (LAG) in the presence of O-labelled water. Two phases with different hydration levels, namely triclinic calcium pyrophosphate dihydrate (CaPO·2HO, denoted -CPPD) and monoclinic calcium pyrophosphate tetrahydrate (CaPO·4HO, denoted -CPPT β) were enriched in O using a "post-enrichment" strategy, in which the non-labelled precursors were ground under gentle milling conditions in the presence of stoichiometric quantities of O-enriched water (introduced here in very small volumes ∼10 μL). Using high-resolution O solid-state NMR (ssNMR) analyses at multiple magnetic fields, and dynamic nuclear polarisation (DNP)-enhanced O NMR, it was possible to show that the labelled water molecules are mainly located at the core of the crystal structures, but that they can enter the lattice in different ways, namely by dissolution/recrystallisation or by diffusion.

acoustic analysis: a valuable method for investigating reaction mechanisms in mechanochemistry.

We present a new approach for following reactions taking place in mechanochemistry, relying on the analysis of the evolution of the sound during milling. We show that differences in sound can be directly correlated to (physico)chemical changes in the reactor, making this technique highly attractive and complementary to others for monitoring mechanochemical reactions. Most notably, it can provide unique information on the actual movements of the beads within the milling jars, which opens new avenues for helping rationalize mechanochemical processes.

From Raman Mechanochemistry to "NMR Crystallography": Understanding the Structures and Interconversion of Zn-Terephthalate Networks Using Selective O-Labeling.

The description of the formation, structure, and reactivity of coordination networks and metal-organic frameworks (MOFs) remains a real challenge in a number of cases. This is notably true for compounds composed of Zn ions and terephthalate ligands (benzene-1,4-dicarboxylate, BDC) because of the difficulties in isolating them as pure phases and/or because of the presence of structural defects. Here, using mechanochemistry in combination with Raman spectroscopy, the observation of the formation of various zinc terephthalate compounds was rendered possible, allowing the distinction and isolation of three intermediates during the ball-milling synthesis of Zn(OH)(BDC).

Stacking Versatility in Alkali-Mixed Honeycomb Layered NaKNiTeO.

The reaction between P2-type honeycomb layered oxides NaNiTeO and KNiTeO enables the formation of NaKNiTeO. The compound is characterized by X-ray diffraction and Na solid-state nuclear magnetic resonance spectroscopy, and the structure is discussed through density functional theory calculations. In addition to the honeycomb Ni/Te cationic ordering, NaKNiTeO exhibits a unique example of alternation of sodium and potassium layers instead of a random alkali-mixed occupancy.

A novel multinuclear solid-state NMR approach for the characterization of kidney stones.

The spectroscopic study of pathological calcifications (including kidney stones) is extremely rich and helps to improve the understanding of the physical and chemical processes associated with their formation. While Fourier transform infrared (FTIR) imaging and optical/electron microscopies are routine techniques in hospitals, there has been a dearth of solid-state NMR studies introduced into this area of medical research, probably due to the scarcity of this analytical technique in hospital facilities. This work introduces effective multinuclear and multidimensional solid-state NMR methodologies to study the complex chemical and structural properties characterizing kidney stone composition.

Long-term performances of polylactide/iron oxide nanoparticles core-shell fibrous nanocomposites as MRI-visible magneto-scaffolds.

There is a growing interest in magnetic nanocomposites in biomaterials science. In particular, nanocomposites that combine poly(lactide) (PLA) nanofibers and superparamagnetic iron oxide nanoparticles (SPIONs), which can be obtained by either electrospinning of a SPION suspension in PLA or by precipitating SPIONs at the surface of PLA, are well documented in the literature. However, these two classical processes yield nanocomposites with altered materials properties, and their long-term fate and performances have in most cases only been evaluated over short periods of time.

Cost-efficient and user-friendly O/O labeling procedures of fatty acids using mechanochemistry.

Two mechanochemical procedures for 17O/18O-isotope labeling of fatty acids are reported: a carboxylic acid activation/hydrolysis approach and a saponification approach. The latter route allowed first-time enrichment of important polyunsaturated fatty acids (PUFAs) including docosahexaenoic acid (DHA). Overall, a total of 9 pure labeled products were isolated in high yields (≥80%) and with high enrichment levels (≥37% average labeling of C=O and C-OH carboxylic oxygen atoms), under mild conditions, and in short time ( View Article and Find Full Text PDF

Labeling and Probing the Silica Surface Using Mechanochemistry and O NMR Spectroscopy*.

In recent years, there has been increasing interest in developing cost-efficient, fast, and user-friendly O enrichment protocols to help to understand the structure and reactivity of materials by using O NMR spectroscopy. Here, we show for the first time how ball milling (BM) can be used to selectively and efficiently enrich the surface of fumed silica, which is widely used at industrial scale. Short milling times (up to 15 min) allowed modulation of the enrichment level (up to ca.

A Ca nuclear magnetic resonance perspective on octacalcium phosphate and its hybrid derivatives.

Ca nuclear magnetic resonance (NMR) spectroscopy has been extensively applied to the detailed study of octacalcium phosphate (OCP), Ca (HPO ) (PO ) .5H O, and hybrid derivatives involving intercalated metabolic acids (viz., citrate, succinate, formate, and adipate).

Looking into the dynamics of molecular crystals of ibuprofen and terephthalic acid using O and H nuclear magnetic resonance analyses.

Oxygen-17 and deuterium are two quadrupolar nuclei that are of interest for studying the structure and dynamics of materials by solid-state nuclear magnetic resonance (NMR). Here, O and H NMR analyses of crystalline ibuprofen and terephthalic acid are reported. First, improved O-labelling protocols of these molecules are described using mechanochemistry.

Unveiling the Structure and Reactivity of Fatty-Acid Based (Nano)materials Thanks to Efficient and Scalable O and O-Isotopic Labeling Schemes.

Fatty acids are ubiquitous in biological systems and widely used in materials science, including for the formulation of drugs and the surface-functionalization of nanoparticles. However, important questions regarding the structure and reactivity of these molecules are still to be elucidated, including their mode of binding to certain metal cations or materials surfaces. In this context, we have developed novel, efficient, user-friendly, and cost-effective synthetic protocols based on ball-milling, for the O and O isotopic labeling of two key fatty acids which are widely used in (nano)materials science, namely stearic and oleic acid.

Recent directions in the solid-state NMR study of synthetic and natural calcium phosphates.

Materials containing a calcium phosphate component have been the subject of much interest to NMR spectroscopists, especially in view of understanding the structure and properties of mineralized tissues like bone and teeth, and of developing synthetic biomaterials for bone regeneration. Here, we present a selection of recent developments in their structural characterization using advanced solid state NMR experiments, highlighting the level of insight which can now be accessed.