[ closo -B 10 H 8 -10-PhI-1-COOH] - Anion: An Intermediate for Functional Anionic Carboxylate Ligands.

A potentially general intermediate, [ closo -B 10 H 8 -10-PhI-1-COOH] - , for a class of functional anionic carboxylic acids, [ closo -B 10 H 8 -10-X-1-COOH] 2- , was obtained in four steps and 26% overall yield from [ closo -B 10 H 10 ] 2- . It was converted to the pyridinium derivative (X = C 5 H 5 N + ) and subsequently to coordination complexes with (phen) 2 Cu 2+ and (phen) 2 Zn 2+ ions. Both the acid and Zn(II) complex exhibit a cage-to-pyridine charge-transfer band. The availability of such acids opens access to functional metal-ion complexes with compensated charges.