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Isomorphism and mixed crystals in 2‐ R ‐naphthalenes: evidence of structural subfamilies and prediction of metastable forms
Author(s) -
Haget Y.,
Chanh N. B.,
Meresse A.,
Bonpunt L.,
Michaud F.,
Negrier P.,
CuevasDiarte M. A.,
Oonk H. A. J.
Publication year - 1999
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889899002423
Subject(s) - naphthalene , metastability , subfamily , crystallography , isomorphism (crystallography) , chemistry , isothermal process , phase (matter) , substructure , type (biology) , stereochemistry , thermodynamics , crystal structure , physics , organic chemistry , ecology , biochemistry , structural engineering , biology , engineering , gene
Solid–liquid binary phase diagrams and isothermal unit‐cell parameters as a function of composition are given for the high‐temperature form ( P 2 1 / a , Z = 2) mixed crystals generated by 2‐fluoronaphthalene, naphthalene and 2‐naphthol with four other β derivatives of naphthalene. The study leads to the distinction between two high‐temperature forms (or types of packing). The first one (type 1) is taken by five 2‐ R ‐naphthalenes ( R = F, Cl, Br, SH, CH 3 ; the first subfamily), the second one (type 2) by naphthalene itself and 2‐naphthol ( R = H, OH; the second subfamily). The crystallographic data also allow an estimation of unit‐cell parameters for the metastable forms of naphthalene (type 1, a = 8.0, b = 5.95, c = 8.6 Å, β = 116°) and 2‐fluoronaphthalene (type 2, a = 8.336, b = 5.915, c = 9.000 Å, β = 122.23°), supporting an interpretation, in terms of crossed isodimorphism, of the observed two‐phase regions in systems in which the components do not belong to the same subfamily.