Publications de Shima Karimi | EPFL Graph Search

Water Exchange on [Ln(DO3A)(H2O)2] and [Ln(DTTA–Me)(H2O)2]− Studied by Variable Temperature, Pressure, and Magnetic Field NMR

Water exchange kinetics of [Ln(L)(H2O)2]x complexes (Ln = Pr, Nd, Dy, Tm, and Yb; L = DO3A and DTTA–Me) were studied by 17O NMR spectroscopy as a function of temperature, pressure, and frequency and by 1H nuclear magnetic relaxation dispersion. Water excha ...

American Chemical Society2016

Evaluation of Water Exchange Kinetics on [Ln(AAZTAPh–NO2)(H2O)q]x Complexes Using Proton Nuclear Magnetic Resonance

Lothar Helm, Shima Karimi

Water exchange kinetics on [Ln(AAZTAPh–NO2)(H2O)q]− (Ln = Gd3+, Dy3+, or Tm3+) were determined by 1H nuclear magnetic resonance (NMR) measurements. The number of inner-sphere water molecules was found to change from two to one when going from Dy3+ to Tm3+. ...

American Chemical Society2016

Complexation of [Gd(DTTA–Me)(H2O)2]− by Fluoride and Its Consequences to Water Exchange

Lothar Helm, Loïck Moriggi, Shima Karimi, Gail Ruth Hunter

The displacement of water molecule(s) from the inner coordination sphere of [Gd(DTTA–Me)(H2O)2]− (DTTA = ethylenetriamine-N,N,N″,N″-tetraacetate) by fluoride has been studied by multinuclear NMR relaxation (1H, 17O, 19F) and DFT calculations. Fluoride anio ...

American Chemical Society2016

Water exchange studies of lanthanide complexes and aqua ions

Shima Karimi

Complexes of lanthanide (III) ions have been used in structural studies of biomolecules and as contrast agents (CA). Clinically approved CAs have only one water molecule in their first coordination sphere. Structure and water exchange rate of these complex ...

EPFL2016

PEGylated DOTA-AHA-Based Gd-III Chelates: A Relaxometric Study

Lothar Helm, Shima Karimi

Three PEGylated derivatives of 6-amino-2-[4,7,10-tris(carboxymethyl)-1,4,7,10-tetrazacyclododec-1-yl]hexanoic acid (DOTA-AHA) with different molecular weights were prepared and characterized. Their Gd-III chelates were studied in aqueous solution through v ...

Wiley-Blackwell2015

Dinuclear DOTA-Based Gd-III Chelates - Revisiting a Straightforward Strategy for Relaxivity Improvement

Lothar Helm, Shima Karimi

The need for magnetic resonance imaging (MRI) contrast agents with improved relaxivity maintains the development of new Gd-III chelates as an intensive and demanding field of research. In this work, we introduce the new dimeric chelators bis{1,4,7,10-tetra ...

Wiley-Blackwell2015

Gd(DOTAlaP): Exploring the Boundaries of Fast Water Exchange in Gadolinium-Based Magnetic Resonance Imaging Contrast Agents

Lothar Helm, Shima Karimi

Here, we describe the synthesis of the single amino acid chelator DOTAlaP and four of its derivatives. The corresponding gadolinium(III) complexes were investigated for their kinetic inertness, relaxometric properties at a range of fields and temperatures, ...

American Chemical Society2014