SYNTHESIS OF THE NEW ORGANOMETALLIC CARBOXYLIC-ACID COMPLEXES [(ETA(5)-C5H4COOH)M(CO)NME](M=MO,N=3 M=FE,N=2) AND THEIR POTENTIAL AS BIOCONJUGATES

The new compounds [(eta5-C5H4COOH)M(CO)nMe] [M = Mo, n = 3 (2); M = Fe , n = 2 (5)] were synthesized in 61 % and 63% yields, respectively, an d treated with N-hydroxysuccinimide to yield the corresponding activat ed ester derivatives [(eta5-C5H4COONS)-M(CO)nMe] [M = Mo, n = 3 (3); M = Fe, n = 2, (6)]. The metal-activated ester complex, [(eta5-C5H5)Mo( CO)3(CH2COONS)] (8) was obtained similarly, the ester unit being bonde d directly to the metal rather than to the pi-bonded cyclopentadienyl. The reactivity and potential of the above species as labelling agents for amino-acids is discussed.