10. Crystal engineering via negatively charged O–H??·?·?·??O– and charge- assisted C–Hδ+??·?·?·??Oδ– hydrogen bonds from the reaction of [Co(η5-C5H5)2][OH] with polycarboxylic acids?§ Dario Braga,Alessandro Angeloni,Emilio Tagliavini,Fabrizia Grepioni J. Chem. Soc. Dalton Trans. 1998 1961