A re-examination of the crystal and molecular structure of azulene as is present in LADWEW = tris(1,2,4,5-tetrafluoro-3,6-diiodobenzene) bis(azulene), 2(C10H8), 3(C6F4I2) - a conglomerate in P1

Abstract

In need of information on the precise structural data of the monomer of azulene, we were long frustrated by our inability to characterize it thus because the known specimens always contained its extremely stable head-to-tail dimer. Recently, a claim was made of having prepared such a monomeric species in the case of (tris(1,2,4,5-tetrafluoro-3,6-diiodobenzene)bis(azulene), whose REFCODE = LADWEW), which the authors used to “demonstrate how a highly robust C-I⋯π motif permits the systematic exchange of original co-crystal components with azobenzene and azulene, resulting in optically interesting dichroic or pleochroic materials.” We demonstrate that the structural data used in the theoretical treatment of the title compound were derived from an improper crystallographic analysis. The hkl values provided in the original report were used to obtain the correct structural solution in P1, (Z’ = 1) as opposed to the original centrosymmetric P-1, (Z’ = 0.5) interpretation. These new data have been deposited with the CCDC #2403565.