Synthesis, reactivity and X-ray molecular structure of the activated ester complex [(η5-C5H4COONS)Co(CO)2](NS ; N-succinimidyl)

Abstract The title compound [( η 5 -C 5 H 4 COONS)Co(CO) 2 ] ( 2 ) was prepared in high yield (91%) by treatment of the organometallic carboxylic acid [( η 5 -C 5 H 4 COOH)Co(CO) 2 ] ( 1 ) with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide. The activated ester complex 2 was identified by spectroscopic methods, in addition its X-ray structure was determined. Compound 2 crystallizes in the triclinic space group P 1 with a = 6.1880(8), b = 9.722(1), c = 10.869(1) A, α = 83.37(1), β = 83.91(1) and γ = 86.30(1)°, V = 645(1) A3 and Z = 2. The stability of the above species 2 and its reactivity as labelling agent for amines and amino-esters are investigated and discussed.