title: Synthesis and NMR studies of new DOTP-like lanthanide(III) complexes containing a hydrophobic substituent on one phosphonate side arm.
abstract: 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 (C(8)-DOTP), 1-(1-undecyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane (C(11)-DOTP), and 1-(1-4-nitro-phenyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane (NO(2)-Ph-DOTP). (1)H 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 H(6) equatorial position in the YbL(5)(-) complexes. Although the YbL(5)(-) complexes have lower symmetry due to the added substituent, the average (1)H hyperfine shifts are 5-10% larger in these complexes compared to YbDOTP(5)(-). This was magnified further in the hyperfine (23)Na 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(C(11)-DOTP)(5)(-) than with an equivalent amount of TmDOTP(5)(-).
authors.affiliation: Department of Chemistry, University of Texas at Dallas, Richardson, Texas 75083, USA.
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.forename: P
authors.initials: P
authors.lastname: Zhao
authors.forename: Z
authors.initials: Z
authors.lastname: Kovacs
authors.forename: A D
authors.initials: AD
authors.lastname: Sherry
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006321:Heart / Q000187:drug effects; D006868:Hydrolysis; D066298:In Vitro Techniques; D028581:Lanthanoid Series Elements / Q000138:chemical synthesis* / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008968:Molecular Conformation; D015394:Molecular Structure; D009578:Nitrobenzenes; D063065:Organophosphonates / Q000138:chemical synthesis* / Q000737:chemistry; D009943:Organophosphorus Compounds / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000737:chemistry; D013237:Stereoisomerism; D013932:Thulium / Q000737:chemistry; D015018:Ytterbium / Q000737:chemistry
chemical_list: C444781:1-(1-4-nitro-phenyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane; C444783:1-(1-octyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane; C444782:1-(1-undecyl-methyl-phosphonic acid)-4,7,10-tris(methylene phosphonic acid)-1,4,7,10-tetraazacyclododecane; D028581:Lanthanoid Series Elements; D008024:Ligands; D009578:Nitrobenzenes; D063065:Organophosphonates; D009943:Organophosphorus Compounds; C082084:1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methylenephosphonic acid); D013932:Thulium; D012964:Sodium; D015018:Ytterbium