Open AccessNew bond-delocalized dianions: The crystal structure of 1,3-bis (dicyanomethylene) croconate salt (C11N4O3K2 2H2O)
Author(s) -
V. L. Himes,
A. D. Mighell,
Camden R. Hubbard,
Alexander J. Fatiadi
Publication year - 1980
Publication title -
journal of research of the national bureau of standards
Language(s) - English
Resource type - Journals
eISSN - 2376-5259
pISSN - 0160-1741
DOI - 10.6028/jres.085.006
Subject(s) - delocalized electron , salt (chemistry) , crystal structure , crystallography , crystal (programming language) , materials science , chemistry , organic chemistry , computer science , programming language
C 11 N 4 O 3 K 2 · 2H 2 O crystallizes in the triclinic space group P 1 ¯ with a = 8.568(2), b = 9.105(4), c = 9.818(4)Å, α = 103.61(3), β = 107.63(3), γ = 101.58(3)°; Z = 2, ρ calc = 1.716, ρ obs = 1.72(2)g cm -3 (flotation). The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.074 for 1989 observed reflections. The five-membered ring is planar and pentagonal. The two = C(CN) 2 groups define separate planes which form angles of 3.36 and 6.30° with the plane of the five-membered ring. The dianions form stacks along the a-axis. In a given stack, there is an alternating sequence of perpendicular distances (3.32, 3.42Å) between the planes defined by the ring atoms.