Paramagnetic complex

In this section, compounds of d-block transition elements will be considered first and then those of the lanthanide and actinide elements. Papers concerning the use of paramagnetic complexes as shift or relaxation reagents are usually omitted. 

Five reviews have appeared Probing spin densities by use of NMR spectroscopy , Paramagnetic NMR relaxation enhancement. Recent advances in theory , Roles of solvation in variability of ligand field and stereochemistry for transition metal complexes as revealed by UV-vis, CD and/or paramagnetic NMR spectroscopy , which contains and Co NMR data, Selected NMR techniques for the determination of absolute configuration , and Similarities and differences between the isoelectronic Gd and Eu complexes with regard to MRI contrast agent applications .  

The development of NMR instrumentation to achieve excitation of large band-widths in high resolution spectra at high field has been described and applied to paramagnetic model complexes.  

Five reviews have appeared Nuclear magnetic resonance of paramagnetic compounds , Advances in single- and multi-dimensional NMR spectroscopy of paramagnetic metal complexes , NMR and spin relaxation in dimers , Liquid-liquid extraction and NMR , which contains the use of lanthanide and actinide ions to determine distances, and Lanthanide(III) chelates for NMR biomedical applications .  

A number of broadly based papers on paramagnetic compounds have been published. A theoretical model of NMR line-breadth of strong paramagnetic ions 

Albeck, H. Weitman, B. Sredni, and M. Albeck, Inorg. Chem., 1998,37, 1704. 

Idalia Rangel Salas and A. Ariza Castolo, Educ. Quim., 1997, 8, 231 Chem. Abstr., 

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Nuclear Magnetic Resonance (Other Paramagnetic Complexes)... 

The number of unpaired electrons in a paramagnetic complex can be determined with a Gouy balance. 

The shifts produced by the addition of a paramagnetic complex have been used in the assignment of the aromatic protons in (83). ... 

Lutidylphenylketone thiosemicarbazone, 38, and nickel(II) chloride, bromide, or iodide yield [Ni(38-H)2]A2 with NNS coordination based on infrared spectra [187]. All three complexes are electrolytes and the cations are dimeric with sulfur atoms acting as bridges interdimer interactions via sulfur are present. The electronic spectra suggest a nickel(Il) stereochemistry other than tetrahedral or octahedral for these paramagnetic complexes. 

More recently [147], five-coordinate, paramagnetic complexes of stoichiometry [NiLAj] (A = Cl, Br, I, NO3, NCS, and NCSe) have been prepared from both 2-formylquinoline and 1-formylisoquinoline thiosemicarbazone, 20 and 21, respectively. Bonding of the neutral ligands is considered to be NNS. 

In the case of paramagnetic complexes their experimental magnetic parameters are determined by computer simulation of the powder spectra [59], Together with the corresponding calculated values, obtained using a relativistic spin-unrestricted ZORA approach, they all are collected in Table 2.8. 

Thus, for paramagnetic complexes the reactivity patterns promoted either by the metal center or by the ligand (equivalent to an inner- vs. an outer-sphere pathway), are essentially triggered by the spin density distribution. 

Both the retention time of the paramagnetic complex in the vasculature and the relaxivity increase resulting from the slower rotation of the macromolecular adduct will depend on the... 

The effect of the hydrophobicity of the paramagnetic complex on the affinity towards serum albumin has been studied by comparing the K l values for a series of Gd111 complexes bearing an... 

Electroactive Paramagnetic Complexes as Molecular Bricks for tt-d Conducting Magnets... 

Fig. 4 Representation of the supramolecular arrangement of electroactive paramagnetic complexes emphasizing the n—d interactions through a chemical bridge between electronic spins of TTFs (or BEDT-TTFs) and d spins of transition metal ions and the polarization effects on the magnetic moment alignments of each complex...

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