Nuclear magnetic resonance spectroscopy multinuclear

The synthesis of the complex is followed by the most important step of characterization of the complex. The composition and the structural features of both the ligand and complex have to be established before embarking on further studies. There exist many methods by which the composition and structural features of the complexes are studied. Some of the methods are (i) elemental analysis, (ii) X-ray crystallography, (iii) UV-Vis absorption spectra, (iv) infrared spectroscopy, (v) Raman spectroscopy, (vi) thermal methods of analysis such as thermogravimetry, differential thermal analysis, (vii) nuclear magnetic resonance spectroscopy (proton, multinuclear), (viii) electrospray mass spectrometry. Depending upon the complexity of the system, some or all the methods are used in the studies of complexes. 

Multinuclear high-resolution nuclear magnetic resonance spectroscopy... 

Includes multinuclear nuclear magnetic resonance spectroscopy, infrared and ultraviolet spectrophotometry, and mass spectrometry... 

Up to about the 1960 s, elemental analysis coupled with absorption spectra and infrared spectra and X-ray crystallography were the primary methods used in the studies of complexes. Later on with the developments in nuclear magnetic resonance (NMR) spectroscopy, especially multinuclear NMR, this technique has been invariably used in the studies of structural features of lanthanide complexes. To illustrate these points some references to literature are herein pointed out. The studies on the rare earth 1,3-diketonates, where 1,3-diketones are acetyl acetone, benzoyl acetone, dibenzoyl methane and 2-thienoyl tri-fluoroacetone totally relied on elemental analysis, UV-Vis and IR spectra to establish the nature of the complexes [89]. The important role played by X-ray crystallography in the elucidation of the structures of lanthanide complexes has been extensively discussed in Chapter 5 and the use of this technique goes as far back as the 1960 s. Nevertheless it continues to play a major role in the studies of lanthanide complexes. 

New complexes of the type [(P-P)Pt(C6F5)(H2O)]+ (P-P = diphosphine) were synthesized according to the route indicated in Fig. 2.1 and were characterized by elemental analysis, multinuclear H, " PI H, and " F H nuclear magnetic resonance (NMR) spectroscopy [27]. The synthetic pathway is very flexible, allowing the preparation of homologous complexes with a wide variety of diphosphine ligands. These are all commercially available except 2g which was prepared following a procedure reported in the literature [34]. 

Azo dyes of the common formula X—N=N—Y represent a very important class of dyestuffs,1 with more than 50% of commercial dyestuffs based on this type of compound. Nuclear magnetic resonance (NMR) spectroscopy, especially in its multinuclear form, is a powerful technique for the characterization of such compounds and also for the description of azo-hydrazone tautomerism, a property which is indivisibly linked with this group of dyes. This chapter reports on high-resolution lH, 13C, 14N, 15N, nO, 19F and 31P NMR spectra of azo dyestuffs measured in solutions. 

This review presents recent developments in the application of nuclear magnetic resonance (NMR) spectroscopy to study ionic liquids. In addition to routine structural characterization of synthesized ionic liquids, availability of multitude of advanced NMR techniques enables researchers to probe the structure and dynamics of these materials. Also most of the ionic liquids contain a host of NMR-active nuclei that are perfectly suitable for multinuclear NMR experiments. This review focuses on the application of NMR techniques, such as pulsed field gradient, relaxometry, nuclear Overhauser effect, electrophoretic NMR, and other novel experiments designed to investigate pure ionic liquids and the interaction of ionic liquids with various salts and solutes. 

R 2 M.H. Levitt, Spin Dynamics Basics of Nuclear Magnetic Resonance , John Wiley Sons, Inc., Chichester, UK, 2001 R 3 K.J.D. MacKenzie and M.E. Smith, Multinuclear Solid-State Nuclear Magnetic Resonance of Inorganic Materials in Pergamon Materials Series, Vol. 6, Pergamon, New York, N.Y., 2002 R 4 I. Noda and Y. Ozaki, Two-Dimensional Correlation Spectroscopy , Wiley, Chichester, UK, 2001... 

Among the techniques more frequently used for elucidating cluster structures are crystallographic studies by both single-crystal X-ray and neutron-diffraction techniques, multinuclear high resolution nuclear magnetic resonance (NMR), and infrared spectroscopy. 

In situ infrared (IR) spectroscopy of the reaction mixture, at a pressure and temperature close to that of the actual catalytic process, indicates [MCCO) ]" (M = Rh or Ir) to be the resting state of the catalyst. However, by varying the conditions under which IR and multinuclear nuclear magnetic resonance (NMR) spectra are recorded, most of the catalj4ic intermediates can be observed. 

Because 53 and 53 are diastereomers, they have slightly different thermodynamic stabilities. In solution, both the isomers can be seen by in situ multinuclear nuclear magnetic resonance (NMR) (see Section 3.2.4), including proton-decoupled Rh, P heteronuclear multiple-quantum correlation (HMQC) 2D NMR spectroscopy. 

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