title: Stabilization of D5h and C2v valence tautomers of the croconate dianion.
abstract: The non-benzenoid aromatic D(5h) and enediolate C(2v) form of C5O5(2-) have been stabilized by hydrogen bonding with urea and 1,3-dimethylurea, respectively, in the host lattices of two novel crystalline inclusion compounds.
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, P. R. China.
authors.forename: Chi-Keung
authors.initials: CK
authors.lastname: Lam
authors.forename: Mei-Fun
authors.initials: MF
authors.lastname: Cheng
authors.forename: Chi-Lun
authors.initials: CL
authors.lastname: Li
authors.forename: Jie-Peng
authors.initials: JP
authors.lastname: Zhang
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Chen
authors.forename: Wai-Kee
authors.initials: WK
authors.lastname: Li
authors.forename: Thomas C W
authors.initials: TC
authors.lastname: Mak