Properties, Solution State Behavior, and Crystal Structures of Chelates of DOTMA
- 5 August 2011
- journal article
- research article
- Published by American Chemical Society (ACS) in Inorganic Chemistry
- Vol. 50 (17), 7955-7965
- https://doi.org/10.1021/ic2012827
Abstract
The chemistry of polyamino carboxylates and their use as ligands for Ln3+ ions is of considerable interest from the point of view of the development of new imaging agents. Of particular interest is the chemistry of the macrocyclic ligand 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and its derivatives. Herein we report that the tetramethylated DOTA derivative, DOTMA, possess several properties that, from an imaging agent development point of view, are more advantageous than those of the parent DOTA. In particular, the Ln3+ chelates of DOTMA exhibit a marked preference for the monocapped twisted square antiprismatic coordination isomer which imparts more rapid water exchange kinetics on the chelates; τM298 was determined to be 85 ns for GdDOTMA. Differential analysis of the 17O R2ρ temperature profiles of both GdDOTA and GdDOTMA afforded the τM298 values for the square (SAP) and twisted square antiprismatic (TSAP) isomers of each chelate that were almost identical: 365 ns (SAP) and 52 ns (TSAP). The origin of this accelerated water exchange in the TSAP isomer appears to be the slightly longer Gd–OH2 bond distance (2.50 Å) that is observed in the crystal structure of GdDOTMA which crystallizes in the P2 space group as a TSAP isomer. The Ln3+ chelates of DOTMA also exhibit high thermodynamic stabilities ranging from log KML = 20.5 for CeDOTMA, 23.5 for EuDOTMA and YbDOTMA comparable to, but a shade lower than, those of DOTA.Keywords
This publication has 53 references indexed in Scilit:
- Analysis of the Conformational Behavior and Stability of the SAP and TSAP Isomers of Lanthanide(III) NB-DOTA-Type ChelatesInorganic Chemistry, 2011
- Solid State and Solution Dynamics of Pyridine Based Tetraaza-Macrocyclic Lanthanide Chelates Possessing Phosphonate Ligating Functionality (Ln-PCTMB): Effect on Relaxometry and Optical PropertiesInorganic Chemistry, 2009
- Towards the Rational Design of MRI Contrast Agents: Electron Spin Relaxation Is Largely Unaffected by the Coordination Geometry of Gadolinium(III)–DOTA‐Type ComplexesChemistry – A European Journal, 2008
- Potentiometric and Relaxometric Properties of a Gadolinium-Based MRI Contrast Agent for Sensing Tissue pHInorganic Chemistry, 2007
- Structural and Chiroptical Properties of the Two Coordination Isomers of YbDOTA-Type ComplexesInorganic Chemistry, 2005
- Solution Dynamics and Stability of Lanthanide(III) (S)-2-(p-Nitrobenzyl)DOTA ComplexesInorganic Chemistry, 2004
- Structure and dynamics of all of the stereoisomers of europium complexes of tetra(carboxyethyl) derivatives of dota: ring inversion is decoupled from cooperative arm rotation in the RRRR and RRRS isomersChemical Communications, 1998
- Structural and Dynamic Parameters Obtained from 17O NMR, EPR, and NMRD Studies of Monomeric and Dimeric Gd3+ Complexes of Interest in Magnetic Resonance Imaging: An Integrated and Theoretically Self-Consistent Approach1Journal of the American Chemical Society, 1996
- An empirical correction for absorption anisotropyActa Crystallographica Section A Foundations of Crystallography, 1995
- Komplexbildung mit Tetraazacycloalkan‐N,N′,N″,N‴‐tetraessigsäuren in Abhängigkeit von der RinggrößeAngewandte Chemie, 1976