The vibrat
ional spectra and crystal structures of cesium salts of 3,5-bis(dicyanomethylene)cyclopentane-1,2,4-tr
ionate (
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), known as croconate violet, are described in this work: 1-cesium and potassium croconate violet (CsKCV), 2-cesium croconate violet (Cs
2CV-1), and 3-cesium croconate violet hydrate (Cs
2CV-2). Only CsKCV and Cs
2CV-2 presented single crystals suitable for X-ray diffract
ion analysis; these compounds crystallize in triclinic
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and monoclinic P2
1/a space group, respectively. The stoichiometries of the salts show one water molecule to each M
2C
11N
4O
3 unit, which are involved in hydrogen bonds forming dimmers in CsKCV and an extended structure with one-dimens
ional arrangement (1D) in Cs
2CV-2. Two types of coordinat
ion modes are observed in both salts: monodentate and chelate. Powder diffract
ion data show that Cs
2CV-1 is isostructural to potassium and rubidium croconate violet salts. Vibrat
ional spectra of cesium salts are almost similar, and the biggest differences can be observed in CV ring stretching modes (1600–1400 cm
−1), probably due to small changes in electronic delocalizat
ion over pseudo-
oxocarbon ring. In despite of different crystal packing in these salts, the CV units are almost planar and are displayed in layers, which are separated by cat
ions and water molecules in CsKCV and Cs
2CV-2 crystal structures.