TY - JOUR
T1 - Determination of metal-proton distances and electronic relaxation times in lanthanide complexes by nuclear magnetic resonance spectroscopy
AU - Aime, Silvio
AU - Barbero, Luca
AU - Botta, Mauro
AU - Ermondi, Giuseppe
PY - 1992
Y1 - 1992
N2 - The longitudinal and transverse relaxation times of the proton resonances of three lanthanide(III) complexes of 1,4,7,10-tetraazacyclododecane-N,N′,N″,N′″-tetraacetate have been measured. This allows determination of the metal-proton distances and the electronic relaxation times of the paramagnetic metal ions by exploiting the Curie-spin mechanism contribution to the transverse relaxation rates, once the molecular reorientational time τr is known by an independent experiment. Values of the parameters calculated from data obtained at a single magnetic field (9.4 T) were in good agreement with those found from the evaluation of the magnetic field-induced line broadening of the proton resonances as measured at 2.1, 4.7 and 9.4 T. A chemical exchange contribution to the linewidths is excluded on the basis of experiments performed at different temperatures.
AB - The longitudinal and transverse relaxation times of the proton resonances of three lanthanide(III) complexes of 1,4,7,10-tetraazacyclododecane-N,N′,N″,N′″-tetraacetate have been measured. This allows determination of the metal-proton distances and the electronic relaxation times of the paramagnetic metal ions by exploiting the Curie-spin mechanism contribution to the transverse relaxation rates, once the molecular reorientational time τr is known by an independent experiment. Values of the parameters calculated from data obtained at a single magnetic field (9.4 T) were in good agreement with those found from the evaluation of the magnetic field-induced line broadening of the proton resonances as measured at 2.1, 4.7 and 9.4 T. A chemical exchange contribution to the linewidths is excluded on the basis of experiments performed at different temperatures.
UR - http://www.scopus.com/inward/record.url?scp=9544239303&partnerID=8YFLogxK
U2 - 10.1039/DT9920000225
DO - 10.1039/DT9920000225
M3 - Article
SN - 1472-7773
SP - 225
EP - 228
JO - Journal of the Chemical Society. Dalton Transactions
JF - Journal of the Chemical Society. Dalton Transactions
IS - 2
ER -