Patent ID: 8022211

Claim:
A metal complex of a ligand of Formula I: wherein: the metal is a radioactive isotope of either technetium or rhenium; R 4 is —(Z) q —Y; where each Z is independently —CQ 2 -, —CQ═CQ-, —C≡C—, —CQ 2 CO 2 —, —CO 2 CQ 2 -, —NQ-, —NQCO—, —CONQ-, —NQ(C═O)NQ-, —NQ(C═S)NQ-, —SO 2 NQ-, —NQSO 2 —, —CQ 2 OCQ 2 -, —CQ 2 SCQ 2 -, —CQ 2 (NQ)CQ 2 -, a C 4-8 cycloheteroalkylene group, a C 4-8 cycloalkylene group, a C 5-12 arylene group, or a C 3-12 heteroarylene group, an amino acid or a monodisperse polyethyleneglycol (PEG) building block; wherein each Q is independently selected from H, C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, C 1-4 alkoxyalkyl or C 1-4 hydroxyalkyl; q is an integer of value 0 to 10; and Y is H, amino, C 1-10 alkyl, C 3-20 alkylaryl, C 6-14 aryl, C 3-12 heterocycle, C 2-10 alkoxyalkyl, C 1-10 hydroxyalkyl, C 1-10 aminoalkyl, C 1-10 alkoxy, C 1-10 acyloxy, C 6-10 aryloxy, or C 6-10 aroyloxy, or Y is a biological targeting moiety; and wherein not more than three out of a possible five atoms of the ligand are involved in complexation.