Psuedosymmetry and pseudomerodry or nonmerohedral twinning for the known structure of diaquabis(quinolin-8-olato-κ2N,O)zinc(II)

Abstract

The structure of the title centrosymmetric compound, [Zn(C9H6NO)2(H2O)2], has already been solved three times [Merritt, Cady & Mundy (1954).Acta Cryst.7, 473–476; Palenik (1964).Acta Cryst.17, 696–700; Chen, Zhang, Shi, Huang, Liang & Zhou (2003).Acta Cryst.E59, m814–m815]. The authors of the two most recent papers state that they attained lowerR1 values than that obtained in the 1954 paper, but they do not mention that Merrittet al.had derived the structural model from a twinned crystal. Also, from a structural point of view, there are strong indications that the most recent report is in fact the isostructural CuIIcomplex already reported by Okabe & Saishu [Acta Cryst.(2001), E57, m251–m252] and not the ZnIIcomplex. The structure of the title compound is reported here based on data obtained from a twinned crystal.