Menu

Solid state NMR spectroscopy

Researcher: Xenia Filip

Keywords: nuclear magnetic resonance, NMR, solid states, structure

Description

Solid State Nuclear Magnetic Resonance Spectroscopy (ss-NMR) is an analytical technique for characterization of organic or inorganic materials, the signal being generated by atomic species with non-zero nuclear magnetic moment.

The nuclei most frequently studied inthe case of organic compounds are 13C, 15N, 1H, 2H, 19F, 23Na, 31P, 17O, and in the case of inorganic materials 6,7Li, 11B, 29Si, 27Al, 31P, 33S.

The information extracted from ss-NMR spectra is used for local structural characterization at the  atomic-scale and for studying molecular dynamics over a time scale extending across more than ten orders of magnitude (between 10-10 –  1 s).

An important advantage of ss-NMR spectroscopy is its versatility, as there are a very large number of different experimental conditions that can be applied in current practice to extract the desired information, namely:

  • Primary information such as chemical structure/identification of structural groups is extracted from simple 1D ss-NMR spectra – these do not require special efforts to calibrate the pulse sequences used; depending on the complexity of the system being investigated, the interpretation of the results may be immediate  or may require combining with molecular modeling
  • To obtain more complex information such as the connectivities between structural units or local spatial parameters (such as interatomic distances, torsion angles, etc.) it is necessary to record 2D/3D correlation ss-NMR spectra between the nuclear species of interest. For this purpose, a very wide variety of experimental methods (pulse sequences) have been developed, optimized to obtain the desired parameters with the highest possible selectivity and accuracy. With a few exceptions, recording correlation ss-NMR spectra requires isotopic labeling of the positions of interest.

 Applications

Areas of application: research and development, process/product optimization in industry, quality control (detection of impurities, stability under different environmental conditions, etc.).

Systems:

  1. organic and inorganic crystalline compounds (pharmaceutically active compounds, natural active compounds from extracts, (bio)molecular systems that can be crystallized, metal-organic structures, minerals)
  2. amorphous materials (polymers, biopolymers and polymer composites, graphene and graphene-based composites, glass, ceramics and their composites
  3. nanosystems (decorated and/or functionalized nanoparticles, nanostructured hybrid materials, etc.)

Industries: pharmaceuticals industry, dietary supplements industry, medical devices, chemical industry, environment/pollution control, agro-food industry, health – nanomedicine

 Infrastructure

The NMR spectroscopy laboratory is equipped with a Bruker Avance III 500 MHz spectrometer, dedicated to solid-state applications. It features a wide bore cryo-magnet, three radio frequency channels and is equipped with three probe heads, covering almost the entire range of high resolution ss-NMR spectroscopy applications:

(i) a CP-MAS probe with two channels, a 4 mm rotor and maximum sample spinning frequency of 15 kHz;

(ii) a CP-MAS probe with three channels, a 2.5 mm rotor and a maximum sample spinning frequency of 35 kHz;

(iii) an ultra-fast MAS probe with two channels, a 1.3 mm rotor and a maximum sample spinning frequency of 65 kHz.

Advantages

 INCDTIM offers R&D services based on ss-NMR spectroscopy, used either independently or in combination with other complementary analytical techniques, covering nearly the entire range of practical applications

 Before entering into a contractual relationship we provide consulting to define the client’s/partner’s needs and, if necessary, we perform preliminary tests free of charge

 Our existing equipment allow us to address most of the ss-NMR methods used in current practice, many of which are already implemented in our laboratory

 We have specialized staff trained at prestigious research centers abroad, capable of covering all stages of a contractual collaboration with the highest level of professionalism: defining the problem to be adressed, designing the experiment, collecting data, interpreting results and correlating them with other complementary information, if necessary

Upon request, we also offer the possibility of  isotopic labeling with 13C, 15N and 2H

Estimated costs

The total cost of R&D services based on ss-NMR spectroscopy consists of two components:

spectrometer usage time, which includes consumables and wear: 50 lei/hour

labor, which includes personnel and indirect costs associated with sample preparation operations, analysis and interpretation of results, preparation of the analysis/research report: negotiable, depending on the complexity of the study.