Pulsed NMR Research Articles

A comparative study between three different methods of hydrogel network characterization: effect of composition on the crosslinking properties using sol–gel, rheological and mechanical analyses

Previously, different techniques were used to identify the crosslinking density of hydrogels. In this study, we aimed to compare three different methods of network structure determination: using sol–gel analyses, rheological and mechanical experiments. To do this, we synthesized a polyvinylpyrrolidone (PVP) hydrogel using gamma-ray crosslinking. The effect of dose, PVP, polyethylene glycol (PEG) and agar content on network properties and mesh size were investigated. It was found that rheological experiment gives more precise results. Determined network parameters such as molecular weight between crosslinks \(\left( {\overline{{M_{\text{c}} }} } \right)\), crosslinking density (v e) and mesh size (ξ), were used to determine the impact of composition on physicochemical properties. It was found that increasing dose and PVP content leads to an increase in the crosslinking density and a decrease in pore size. However, increasing agar and PEG molar ratio leads to a decrease in the crosslinking density. Regarding elastic behavior, it was found that agar increases viscous modulus and acts as a crosslinking inhibitor but PEG decreases it and acts as a plasticizer. These results were confirmed by determining the state of water in hydrogel network using pulse NMR. SEM images confirmed also calculated network parameters.

Formula omitted] gradient coherence selection using a tapered stripline

Pulsed-field gradients are common in modern liquid state NMR pulse sequences. They are often used instead of phase cycles for the selection of coherence pathways, thereby decreasing the time required for the NMR experiment. Soft off-resonance pulses with a B1 gradient result in a spatial encoding similar to that created by pulsed-field (B0) gradients. In this manuscript we show that pulse sequences with pulsed-field gradients can easily be converted to one which uses off-resonance B1 field gradient (OFFBEAT) pulses. The advantage of B1 gradient pulses for coherence selection is that the chemical shift evolution during the pulses is (partially) suppressed. Therefore no refocusing echos are required to correct for evolution during the gradient pulses. A tapered stripline is shown to be a convenient tool for creating a well-defined gradient in the B1 field strength. B1 gradient coherence selection using a tapered stripline is a simple and cheap alternative to B0 pulsed-field gradients.

Crude Oil Adsorbates on Calcite and Quartz Surfaces Investigated by NMR Spectroscopy

The complexity of crude oils may contribute to alteration of petroleum reservoir wetting states in ways that cannot be mimicked by model oils. Subsequent to a wet aging procedure, the molecular arrangements of crude oil adsorbates and water on calcite and quartz surfaces were investigated by various 1H NMR techniques. Solid state magic angle spinning (MAS) magnitude mode, 1H–1H double-quantum single-quantum (DQSQ), and 1H single pulse NMR spectra were used to directly observe molecules on both surfaces. T1 and T2 relaxation time measurements were used to determine molecular surface arrangement. Liquid state 1H NMR was used to investigate possible differences in the crude oil caused by the aging procedure. 1H DQSQ spectra were found most valuable in assignment of the quartz surface where the resonances from the entire adsorbate were relatively well resolved. In addition to adsorbate molecular positioning, this study also provides quantitative measurements of water present at both surfaces subsequent to wet...

In Situ NMR Imaging of Ion Transport in Li-Ion Batteries

The operation of battery management systems requires that the transient conditions experienced by a battery in electrified vehicle applications can be accurately described through battery modeling. Reliable data on the transport properties of electrolyte solutions, as functions of both salt concentration and temperature, are a prerequisite for such a task. The accurate characterization of the transport parameters is a complex problem, because the values of ionic diffusion coefficients in an electrolyte solution depend strongly on the salt concentration. At the same time, the salt concentration inside a battery is neither stationary nor homogeneous, during battery operation at high charge/discharge rates. It is, rather, a function of current density, time and distance from the electrodes. Recently, MRI was used for in operando characterization of materials used in Li-ion batteries. The main advantage of MRI over commonly used methods, such as NMR and electrochemical techniques, is its ability to provide spatially resolved details regarding the chemical and dynamic features of solution species. Therefore, such data enable a more accurate representation of the processes occurring in an electrolyte solution under an applied electrical potential, instead of values averaged over the entire volume of a sample cell. Using in situ MRI, we have unambiguously mapped the large concentration polarization experienced by an electrolyte solutions during battery operation.1 The concentration gradient created in the electrolyte solution of the cell under galvanostatic conditions will increase until a steady-state (time invariant) condition is achieved, when the diffusion flux compensates for the migration flux of the ions. Our results confirm that the concentration gradient developed under such conditions is proportional to the applied current (Fig. 1b) as described by the diffusion-migration equation (Eqn. 1), where i is the current density and F is the Faraday constant.2 We have shown previously that, while the degree of ion pairing is quite high (up to 67%) in electrolyte solutions under normal operating conditions, it is almost constant during a steady-state NMR gradient measurements (with salt concentrations varying from 0.8 to 1.2 M).3 Therefore, one can use averaged diffusion coefficients of charged and neutral species measured by pulsed field gradient NMR (PFG-NMR) in Eqn. 1. Also the total salt concentration, obtained directly by MRI should be used, instead of concentration of free ions.2 The inverse modeling of evolution of salt concentration profiles measured by in situ MRI under applied electric current also supported this conclusion.4 Therefore, by combining the PFG-NMR and the in situ MRI techniques into one experiment, one can simultaneously determine the distribution of salt concentration and the salt diffusivity in the electrolyte solution during a galvanostatic experiment (Fig. 2). It can be readily seen that the diffusion coefficient has a significant dependence on the salt concentration, with the values of D measured at opposite ends of the cell varying by more than 60%. Such changes obviously must be taken into account in order to provide an accurate description of mass-transport. The Li+ transference number (t+ ) can then be obtained by means of Eqn.(1). A slight decrease in t+ with concentration was observed, which can be explained by an increase in ion association. However, with the exception of data point at the lowest concentration, all of values of the Li+ transference numbers thus obtained fall within the experimental error and t += 0.31 ± 0.03. The formed concentration gradient affects not only the mass transport in electrolyte solution, but also the electrode lithiation. The electrolyte depletion prevents the active material in the solid from being lithiated in regions where electrolyte has been depleted. Furthermore, when the electrolyte concentration approaches zero, its conductivity drops, significantly hampering the process. The current tends to flow into the particles nearest the separator until they are completely lithiated, causing the intercalation reaction to occur preferentially at the front of the electrode. Implementation of pure phase-encoding MRI methods allows us to visualize non-uniform lithiation of the graphite electrode during cycling of Li-ion cell (Fig. 1c), leading to the next level of battery performance characterization.

NOAH: NMR Supersequences for Small Molecule Analysis and Structure Elucidation.

Nested NMR experiments combining up to five conventional NMR pulse sequences into one supersequence are introduced. The core 2D NMR techniques routinely employed in small molecule NMR spectroscopy, such as HSQC, HMQC, HMBC, COSY, NOESY, TOCSY, and similar, can be recorded in a single measurement. In this way the data collection time may be dramatically reduced and sample throughput increased for basic NMR applications, such as structure elucidation and verification in synthetic, medicinal, and natural product chemistry.

NOAH: NMR Supersequences for Small Molecule Analysis and Structure Elucidation

AbstractNested NMR experiments combining up to five conventional NMR pulse sequences into one supersequence are introduced. The core 2D NMR techniques routinely employed in small molecule NMR spectroscopy, such as HSQC, HMQC, HMBC, COSY, NOESY, TOCSY, and similar, can be recorded in a single measurement. In this way the data collection time may be dramatically reduced and sample throughput increased for basic NMR applications, such as structure elucidation and verification in synthetic, medicinal, and natural product chemistry.

Low-field rheo-NMR: A novel combination of NMR relaxometry with high end shear rheology

Time-domain NMR is a well known tool for assessing the molecular dynamics in soft matter by measuring the excitation and subsequent decay of 1H nuclear magnetization. It is widely used, e.g., to quantify the composition of heterogeneous soft matter systems like semicrystalline polymers or emulsions. Further applications, known from academic research and industrial application, include measuring the moisture content in solids, the residual magnetic dipolar coupling for quantifying molecular motion in crosslinked systems, or diffusometry. We report the integration of a permanent magnet based pulsed NMR spectrometer into a modern, commercially available high-end shear rheometer. The setup allows for the first time to simultaneously conduct time-domain 1H NMR and steady shear or dynamic rheological measurements on one sample and to directly correlate the results from both, without concerns about differences in the sample history or temperature calibration. Moreover, the new in-situ combination allows the full usage of the rheometer to apply nonlinear deformation, under steady shear or large amplitude oscillatory shear, and directly measure the effect on the time evolution of the sample properties. This publication introduces the technical setup of this novel instrument combination and describes the shear induced crystallization of polyolefins to demonstrate its capabilities. Further potential applications are outlined.

Properties of High Na-Ion Content N-Propyl-N-Methylpyrrolidinium Bis(Fluorosulfonyl)Imide -Ethylene Carbonate Electrolytes

Sodium-based batteries have emerged as promising alternatives to Li-based batteries for future safe, high energy-density energy storage. They are expected to be cheaper, due to the greater abundance of Na and likely reduction in raw material costs. In this study, we investigate the properties of superconcentrated sodium bis(fluorosulfonyl)amide (NaFSI) mixtures with the ionic liquid (IL) methylpropylpyrrolinium (C3mpyr) FSI in the presence of ethylene carbonate (EC) in the liquid and gel states. Ionic conductivity and thermal stability are evaluated through electrochemical impedance spectroscopy (EIS) and differential scanning calorimetry (DSC), respectively. NaFSI is soluble in the IL up to 55 mol% Na; adding EC (30wt.%) to the IL almost doubles the ionic conductivity at ambient temperature. The temperature dependence of conductivity is well described by the Vogel-Tamman-Fulcher equation. NMR spectroscopy and Pulse Field Gradient NMR diffusion were employed to investigate transport in these electrolyte systems, while the chemical interactions were also studied using ATR-FTIR. Stable plasticized gel electrolytes were observed, even at 30wt. % EC; the formation of the gel does not significantly affect the liquid-like ion dynamics in these materials, as shown by DSC and FTIR analysis. The Na+ transference number of Na0.55[C3mpyr]0.45[FSI]+30wt.% EC was up to 0.32, and deposition and dissolution of sodium metal were observed in cyclic voltammetry around 0V vs. Na/Na+. Moreover, the suitability of the prepared electrolyte is preliminarily verified in half-cells at room temperature using Na3V2(PO4)3 as a cathode. The cells delivered capacity of 52.4 mAhg−1 at C/20.

The Effect of Foreign Fats on the Physical Properties of Anhydrous Milk Fat

Butter and anhydrous milk fat are considered valuable raw materials, therefore it is important to detect the presence of foreign fats and declare their purity. In this study, the authors compared the physical properties of pure anhydrous milk fat and its contaminated forms which were binary blends made with lard and palm fat. Tests with pulsed NMR and DSC were carried out ignoring any solvents or chemicals to observe melting and crystallization processes. Based on the results, small amounts (5-10 V/V %) of lard or palm fat can modify milk fat’s behavior in perceptible extent. Despite of this, a completely unknown fat cannot be identified by these methods only. However, with multiple replications and using statistical methods pNMR and DSC can be utilized for quality control purposes.

Inhibition of Proliferation of Vascular Smooth Muscle Cells by Cucurbitanes from Momordica charantia.

The cucurbitaceous plant Momordica charantia L., named "bitter melon", inhabits Asia, Africa, and South America and has been used as a traditional medicine. The atypical proliferation of vascular smooth muscle cells (VSMCs) plays an important role in triggering the pathogenesis of cardiovascular diseases. Platelet-derived growth factor (PDGF) is regarded as the most powerful growth factor in promoting the intimal accumulation of VSMCs. The current study features the identification of six new cucurbitane-type triterpenoids (1-6) from the fruits of M. charantia, utilizing diverse chromatographic and spectroscopic techniques. In particular, the 2D structure of 1 was confirmed utilizing the long-range HSQMBC NMR pulse, capable of measuring heteronuclear long-range correlations (4-6JCH). The cucurbitanes were also assessed for their inhibitory activity against PDGF-induced VSMC proliferation. This current study may constitute a basis for developing those chemotypes into sensible pharmacophores alleviating cardiovascular disorders.

The structural parameters of rigid matrix of saccharide-based gel described by short and long diffusion regime analysis

The tortuosity–porosity relation and internal structure diameters in a selected organogel are studied. The diffusion coefficient measured by pulsed field gradient NMR at short and long observation times can be used to estimate the tortuosity and the pore surface-to-volume (S/Vpore) ratio of a porous material (Latour et al. in J Magn Res A 112:83–91, 1995; Mair et al. in Magn Res Imaging 19:345–351, 2001; Mitra et al. in Phys Rev B 47(14):8565–8574, 1993; Valiullin and Skirda in J Chem Phys 114:452–458, 2001). The value of S/Vpore allows to calculate the average pore and barrier diameters. In the experiment, the time-dependent diffusion coefficient of toluene in a low molecular weight gelator methyl-4,6-O-(p-nitrobenzylidene)-α-d-glucopyranoside (Gluco-NO2) matrix was measured. The results revealed the relation between the diffusion coefficient of toluene and the concentration of gelator Gluco-NO2 in the system. With increasing Gluco-NO2 compound in the sample, the diffusion coefficient of toluene decreases. On the basis of the diffusion coefficient behaviour as a function of time and gelator concentration, the fibrous structure of the gel matrix was identified and the structural parameters of the system were investigated.

Solid-State NMR Spectroscopy Proves the Presence of Penta-coordinated Sc Sites in MIL-100(Sc).

Advanced solid-state NMR methods and first-principles calculations demonstrate for the first time the formation of penta-coordinated scandium sites. These coordinatively unsaturated sites were shown during the thermal activation of scandium-based metal-organic frameworks (MOFs). A 45 Sc NMR experiment allows their specific observation in activated Sc3 BTB2 (H3 BTB=1,3,5-tris(4-carboxyphenyl)benzene) and MIL-100(Sc) MOFs. The assignment of the ScO5 groups is supported by the DFT calculations of NMR parameters. The presence of ScO5 Lewis acid sites in MIL-100(Sc) explains furthermore its catalytic activity. The first NMR experiment to probe 13 C-45 Sc distances is also introduced. This advanced solid-state NMR pulse sequence allows the demonstration of the shrinkage of the MIL-100(Sc) network when the activation temperature is raised.

Measurement of 15N longitudinal relaxation rates in 15NH4+ spin systems to characterise rotational correlation times and chemical exchange

Many chemical and biological processes rely on the movement of monovalent cations and an understanding of such processes can therefore only be achieved by characterising the dynamics of the involved ions. It has recently been shown that 15N-ammonium can be used as a proxy for potassium to probe potassium binding in bio-molecules such as DNA quadruplexes and enzymes. Moreover, equations have been derived to describe the time-evolution of 15N-based spin density operator elements of 15NH4+ spin systems. Herein NMR pulse sequences are derived to select specific spin density matrix elements of the 15NH4+ spin system and to measure their longitudinal relaxation in order to characterise the rotational correlation time of the 15NH4+ ion as well as report on chemical exchange events of the 15NH4+ ion. Applications to 15NH4+ in acidic aqueous solutions are used to cross-validate the developed pulse sequence while measurements of spin-relaxation rates of 15NH4+ bound to a 41kDa domain of the bacterial Hsp70 homologue DnaK are presented to show the general applicability of the derived pulse sequence. The rotational correlation time obtained for 15N-ammonium bound to DnaK is similar to the correlation time that describes the rotation about the threefold axis of a methyl group. The methodology presented here provides, together with the previous theoretical framework, an important step towards characterising the motional properties of cations in macromolecular systems.

Strongly Bound Sodium Dodecyl Sulfate Surrounding Single-Wall Carbon Nanotubes.

NMR techniques have been widely used to infer molecular structure, including surfactant aggregation. A combination of optical spectroscopy, proton NMR spectroscopy, and pulsed field gradient NMR (PFG NMR) is used to study the adsorption number for sodium dodecyl sulfate (SDS) with single-wall carbon nanotubes (SWCNTs). Distinct transitions in the NMR chemical shift of SDS are observed in the presence of SWCNTs. These transitions demonstrate that micelle formation is delayed by SWCNTs due to the adsorption of SDS on the nanotube surface. Once the nanotube surface is saturated, the free SDS concentration increases until micelle formation is observed. Therefore, the adsorption number of SDS on SWCNTs can be determined by the changes to the apparent critical micelle concentration (CMC). PFG NMR found that SDS remains strongly bound onto the nanotube. Quantitative analysis of the diffusivity of SDS allowed calculation of the adsorption number of strongly bound SDS on SWCNTs. The adsorption numbers from these techniques give the same values within experimental error, indicating that a significant fraction of the SDS interacting with nanotubes remains strongly bound for as long as 0.5 s, which is the maximum diffusion time used in the PFG NMR measurements.

Emerging NMR approaches for characterizing rock heterogeneity

Two 2D-NMR methods were introduced for characterizing the heterogeneity of rock plugs with different lithologies. The first one, so-called eigenmode correlation experiment, allows one to obtain pore length scales correlated to NMR relaxation time, and to intrinsically extract surface relaxivity values from 2D eigenmode correlation maps. The second approach couples the pore length scales with solid-liquid magnetic susceptibility contrast Δχ. NMR results from these two methods are compared and confirmed with independent SEM and micro-CT measurements. It demonstrates that both methods are capable to indicate the heterogeneity degree and do not require sophisticated NMR pulse sequence, which facilitates their implementations in NMR systems on porous rock research.

Automated quantification of metabolites in blood-derived samples by NMR

NMR is widely applied in the field of metabolomics due to the quantitative nature of the technology and the reproducible data generated. However, because of severe spectral crowding, quantifying individual metabolites in body fluids such as serum and plasma remains a challenge. In this study, a method to automatically annotate and quantify a number of small metabolites in human serum and EDTA plasma is introduced. It combines the superior signal-to-noise ratio of the commonly applied CPMG and NOESY1D pulse sequences with the superior resolution of the 2D JRES experiment to construct a model that extracts the metabolite concentrations directly from the 1D spectra without tedious deconvolution. The performance of the method was assessed by comparing the calculated areas of the various glucose peaks with known clinical values, by comparing several peaks of the same metabolite (extracted versus non-extracted), and by comparing areas obtained from various NMR pulse sequences. Additionally, the models were tested on independent datasets. It was found that for many metabolites peaks could be assigned that show a consistent behavior, indicating a precise quantification. The same method should be applicable to other biofluids with a stable composition and pH, such as CSF fluid, cell extracts, and cell media.

Proton-Based Ultrafast Magic Angle Spinning Solid-State NMR Spectroscopy.

Protons are vastly abundant in a wide range of exciting macromolecules and thus can be a powerful probe to investigate the structure and dynamics at atomic resolution using solid-state NMR (ssNMR) spectroscopy. Unfortunately, the high signal sensitivity, afforded by the high natural-abundance and high gyromagnetic ratio of protons, is greatly compromised by severe line broadening due to the very strong 1H-1H dipolar couplings. As a result, protons are rarely used, in spite of the desperate need for enhancing the sensitivity of ssNMR to study a variety of systems that are not amenable for high resolution investigation using other techniques including X-ray crystallography, cryo-electron microscopy, and solution NMR spectroscopy. Thanks to the remarkable improvement in proton spectral resolution afforded by the significant advances in magic-angle-spinning (MAS) probe technology, 1H ssNMR spectroscopy has recently attracted considerable attention in the structural and dynamics studies of various molecular systems. However, it still remains a challenge to obtain narrow 1H spectral lines, especially from proteins, without resorting to deuteration. In this Account, we review recent proton-based ssNMR strategies that have been developed in our laboratory to further improve proton spectral resolution without resorting to chemical deuteration for the purposes of gaining atomistic-level insights into molecular structures of various crystalline solid systems, using small molecules and peptides as illustrative examples. The proton spectral resolution enhancement afforded by the ultrafast MAS frequencies up to 120 kHz is initially discussed, followed by a description of an ensemble of multidimensional NMR pulse sequences, all based on proton detection, that have been developed to obtain in-depth information from dipolar couplings and chemical shift anisotropy (CSA). Simple single channel multidimensional proton NMR experiments could be performed to probe the proximity of protons for structure determination using 1H-1H dipolar couplings and to evaluate the changes in chemical environments as well as the relative orientation to the external magnetic field using proton CSA. Due to the boost in signal sensitivity enabled by proton detection under ultrafast MAS, by virtue of high proton natural abundance and gyromagnetic ratio, proton-detected multidimensional experiments involving low-γ nuclei can now be accomplished within a reasonable time, while the higher dimension also offers additional resolution enhancement. In addition, the application of proton-based ssNMR spectroscopy under ultrafast MAS in various challenging and crystalline systems is also presented. Finally, we briefly discuss the limitations and challenges pertaining to proton-based ssNMR spectroscopy under ultrafast MAS conditions, such as the presence of high-order dipolar couplings, friction-induced sample heating, and limited sample volume. Although there are still a number of challenges that must be circumvented by further developments in radio frequency pulse sequences, MAS probe technology and approaches to prepare NMR-friendly samples, proton-based ssNMR has already gained much popularity in various research domains, especially in proteins where uniform or site-selective deuteration can be relatively easily achieved. In addition, implementation of the recently developed fast data acquisition approaches would also enable further developments in the design and applications of proton-based ultrafast MAS multidimensional ssNMR techniques.

Pengaruh Radiasi Neutron Terhadap Waktu Relaksasi Spin-Kisi (T1) Pada Polimer Polivinil Klorida (Pvc) dengan Spektroskopi Nmr Pulsa

A research measurement of spin-lattice relaxation time (T1) with a pulse NMR spectrometer as well as a test of strength (tensile test and compression test) polymer material PVC (Poly Vinyl Chloride) with tools united-1 test system SFM SFM-30. The study aims to investigate the influence of the neutron fluence on the spin-lattice relaxation time (T1) and to determine the PVC polymer material strength test. On the measurement of the spin-lattice relaxation time (T1) is used method pulse 180o-t-90o and pulse method 90o-t-90o, by means of NMR minispec P.20. Measurement of PVC polymer material strength testing using tools united-1 test system SFM SFM-30. The results showed that the spin-lattice relaxation time (T1) PVC polymer influenced by variations in relaxation times (fluence) neutrons. From the graph of the spin-lattice relaxation time (T1) vs. neutron fluence with the method 90o-t-90o obtained increases and decreases in the value of T1. The value of the spin-lattice relaxation time at the minimum fluence 34.56x1016n/cm2, and the average value of the minimum T1 is (271.1±5.4) for the milli second pulse method 180o-t-90o and the average value The minimum T1 is (263.5±5.3) for the milli second pulse method 90o-t-90o. The value of the spin-lattice relaxation time at the maximum fluence 60.98 x 1016 n/cm2, the average value of the minimum T1 was (481.9±10.1) milli second to the method also 180o-t-90o and the average value of T1 The minimum was (482.5±9.7) for the milli second pulse method 90o-t-90o. Test the strength of the PVC polymer is affected by the neutron fluence. Graph PVC polymer material strength test vs. neutron fluence obtained increases and decreases in the value of the strength of the PVC polymer. Value of the minimum strength of the PVC polymer materials at fluence 34.56 x 1016 n/cm2, the average value of the minimum σ is (9.5± 0.1) MPa for tensile test, and the average value is the minimum σ (38.4±0.1) MPa for compression test. Value of the maximum power of the PVC polymer materials at fluence 60.98x1016n/cm2, the average value of the maximum σ is (43.2±0.9) MPa for tensile test and the average value of the maximum σ is (55.4±1.1) MPa for compression test.

Localisation of alkaline phosphatase in the pore structure of paper

We study the bulk pore structure of bioactive paper impregnated with an enzyme, alkaline phosphatase (ALP), retained with a cationic polyacrylamide (CPAM) with synchrotron small-angle x-ray scattering and examine the translational dynamics of water in the porous material using 1H pulsed field gradient NMR. The aim of this study is to understand the perturbation of enzyme kinetics from the bulk behavior through the localization of the enzyme within the pore structure. We interpret the small-angle x-ray scattering data where the range of length scales examined in the scattering experiment corresponds to the packing of the unitary crystallites, or microfibrils, and aggregates of these cellulosic microfibrils. Pulsed field gradient NMR measurement of H2O diffusion in the pores between these aggregates indicates that some of these pores are strongly connected allowing convective mass transport, while others exhibit strongly restricted diffusion. Diffusion is also strongly anisotropic. We conclude that the CPAM retention polymer and the protein coat interior surfaces inside the pores of a particular size and that there is no major modification of the pore structure of paper by the CPAM or the ALP. The transport properties of this porous matrix are discussed in terms of the mechanisms by which sorption of ALP may perturb enzyme kinetics.

Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors

A comparative study of amine and silver carboxylate adducts [R1COOAg-2(R2NH2)] (R1 = 1, 7, 11; R2 = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, 13C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies (1H and 13C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism.Graphical abstractThe synthesis of a series (bis)alkylamine silver(I) carboxylate complexes in nonpolar solvents were carried out and fully characterized both in the solid and solution. Carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination. The complexes form layered structures which thermally decompose forming nanoparticles stabilized only by aliphatic carboxylates.