Patent ID: 8545809

Claim:
A bifunctional chelating agent comprising a compound of the structure wherein R 1 and R 2 are independently selected from the group consisting of —CH 2 —COOH —CH 2 —CH 2 —OH —CH(CH 3 )—COOH —CH(C 6 H 5 )—COOH and R 3 is selected from the group consisting of: wherein M is a metal selected from the group consisting of Gd Fe, Cu, Al, Ga, In, Tl, Lu, La, Sm, Ta, Si, Ge, Sn, Co, Cr, Mn, Ti, V, Sc, Y, Tc, Zr, Mo, W, Ru, Rh, Ir and Ni and X is a coordinating species selected from the group consisting OH, Cl, Br, F, I, NO 3 , O 2 − , CH 3 , CN, ClO 4 , H 2 O, BF 4 , SCN, N 3 , RCOO, CF 3 COO, CH 3 COO, HCO 3 , RSH and ROH, wherein n=1-9 and wherein R═F, CH2F, CHF2, CH3 or OCF3.