Boronic acid adducts of metal dioxime complexes useful in labelling proteins and other amine-containing compounds

Boronic acid adducts of Metal dioxime complexes having the formula

• MX(Y).sub.3 Z I
• wherein:
• M is an isotope of technetium or rhenium,
• X is an anion,
• Y is a vicinal dioxime having the formula ##STR12## or a pharmaceutically acceptable salt thereof, and R.sub.1 and R.sub.2 are each independently hydrogen, halogen, alkyl, aryl or a 5 or 6-membered nitrogen, sulfur or oxygen containing heterocycle, or together R.sub.1 and R.sub.2 are --(CR.sub.8 R.sub.9).sub.n -- wherein n is 3, 4, 5 or 6 and R.sub.8 and R.sub.9 are each independently hydrogen or alkyl;
• and
• Z is a boron derivative having the formula ##STR13## wherein P is zero or an integer from one to six, R.sub.3 is NCS, and R.sub.4 is hydrogen, or a water solubilizing functionality selected from the group consisting of COOH, carboxyalkyl, hydroxyalkyl, SO.sub.3 H, alkyl-sulfonate, sulphonamide, or hydroxyl, or a pharmaceutically acceptable salt thereof.