Neutral technetium 99-m complexes useful as radiodiagnostic agents

A neutral radiodiagnostic agent comprising a complex of (1) Tc-99m, (ii) a complexing ion selected from Cl, Br, I and SCN, (iii) SO.sub.2 and (iv) a mono- or polydentate organic ligand having a formula selected from:

• ##STR7## wherein:
• R, R', R", R'", R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.21, R.sup.22 and R.sup.23 are each independently selected from hydrogen;
• or substituted or unsubstituted alkyl, alkylene, aryl, alkylaryl, arylalkyl, monocycloalkyl, polycycloalkyl, heterocyclic and carbocyclic group, and R plus R' in formula (A) may be taken together to form a cyclic compound;
• A, A', A", A.sup.1, A.sup.2, A.sup.3, A.sup.4, A.sup.5 and A.sup.6 are independently selected donor atoms, each having a free electron pair available for accepting a proton to provide a charged ligand and having the capability of complexing with Tc-99m to form a neutral complex;
• B is an atom selected from the group of donor atoms having a pair of electrons for complexing with Tc-99m or Tc-99, boron or from the elements listed in Group IVA of the periodic table;
• Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4, Y.sup.5 and Y.sup.6 are independently selected from hydrogen;
• or substituted or unsubstituted alkyl, alkylene, aryl, alkylaryl, arylalkyl, monocycloalkyl, polycycloalkyl, heterocyclic and carbocyclic groups;
• X and X' are saturated or unsaturated alkyl groups;
• Z is an anion;
• i is an integer from 1 to 6, j, j' and j;
• are each independently 0 or 1;
• k.sup.1, k.sup.2, k.sup.3, k.sup.4, k.sup.5 and k.sup.6 are each independently 0 or 1;
• n, n' and n" are each independently the integer 1 or 2;
• n.sub.1, n.sub.2, n.sub.3, n.sub.4, n.sub.5, n.sub.6 are independently 0 or 1;
• n.sub.7 and n.sub.8 are each an integer from 1 to 6;
• n.sub.9, n.sub.10 and n.sub.12 are each an integer from 1 to 3;
• m is 0 or 1;
• r', r" and r'" are independently 0 or 1;
• and t and t' are independently 0 or 1.