TY - JOUR
T1 - Synthesis and NMR studies of new DOTP-like lanthanide(III) complexes containing a hydrophobic substituent on one phosphonate side arm
AU - Li, X.
AU - Zhang, S.
AU - Zhao, P.
AU - Kovacs, Z.
AU - Sherry, A. D.
PY - 2001/12/17
Y1 - 2001/12/17
N2 - Three derivatives of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methylene phosphonic acid) (DOTP) containing a hydrophobic substituent on one side chain were prepared and their lanthanide complexes examined by NMR. The new ligands include 1-(1-octyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane (C8-DOTP),1-(1 -undecyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane (C11-DOTP), and 1-(1-4-nitro-phenyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane (NO2-Ph-DOTP). 1H NMR spectra of the ytterbium(III) complexes were assigned by using a combination of COSY spectroscopy and a fitting procedure that matches experimental NMR hyperfine shifts with those estimated from a MMX-derived structure. The analysis showed that a single isomer is present in solution and that the bulky hydrophobic substituent occupies the less sterically demanding H6 equatorial position in the YbL5- complexes. Although the YbL5- complexes have lower symmetry due to the added substituent, the average 1H hyperfine shifts are 5-10% larger in these complexes compared to YbDOTP5-. This was magnified further in the hyperfine 23Na NMR shifts of ion-paired sodium ions where the extracellular Na+ signal in perfused rat hearts displayed a 28% larger hyperfine shift in the presence of Tm(C11-DOTP)5- than with an equivalent amount of TmDOTP5-.
AB - Three derivatives of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methylene phosphonic acid) (DOTP) containing a hydrophobic substituent on one side chain were prepared and their lanthanide complexes examined by NMR. The new ligands include 1-(1-octyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane (C8-DOTP),1-(1 -undecyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane (C11-DOTP), and 1-(1-4-nitro-phenyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane (NO2-Ph-DOTP). 1H NMR spectra of the ytterbium(III) complexes were assigned by using a combination of COSY spectroscopy and a fitting procedure that matches experimental NMR hyperfine shifts with those estimated from a MMX-derived structure. The analysis showed that a single isomer is present in solution and that the bulky hydrophobic substituent occupies the less sterically demanding H6 equatorial position in the YbL5- complexes. Although the YbL5- complexes have lower symmetry due to the added substituent, the average 1H hyperfine shifts are 5-10% larger in these complexes compared to YbDOTP5-. This was magnified further in the hyperfine 23Na NMR shifts of ion-paired sodium ions where the extracellular Na+ signal in perfused rat hearts displayed a 28% larger hyperfine shift in the presence of Tm(C11-DOTP)5- than with an equivalent amount of TmDOTP5-.
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U2 - 10.1021/ic010291s
DO - 10.1021/ic010291s
M3 - Article
C2 - 11735465
AN - SCOPUS:0035905041
SN - 0020-1669
VL - 40
SP - 6572
EP - 6579
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 26
ER -