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Polymorphism of the dinuclear Co III –Schiff base complex [Co 2 ( o ‐van‐en) 3 ]·4CH 3 CN ( o ‐van‐en is a salen‐type ligand)
Author(s) -
Vráblová Anna,
Černák Juraj,
Falvello Larry R.,
Tomás Milagros
Publication year - 2019
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229619003115
Subject(s) - ethylenediamine , chemistry , acetonitrile , crystallography , monoclinic crystal system , octahedron , triclinic crystal system , schiff base , molecule , ligand (biochemistry) , crystal structure , intermolecular force , hydrogen bond , stereochemistry , inorganic chemistry , organic chemistry , biochemistry , receptor
Reactions of Co(OH) 2 with the Schiff base bis(2‐hydroxy‐3‐methoxybenzylidene)ethylenediamine, denoted H 2 ( o ‐van‐en), under different conditions yielded the previously reported complex aqua[bis(3‐methoxy‐2‐oxidobenzylidene)ethylenediamine]cobalt(II), [Co(C 18 H 18 N 2 O 4 )(H 2 O)], 1 , under anaerobic conditions and two polymorphs of [μ‐bis(3‐methoxy‐2‐oxidobenzylidene)ethylenediamine]bis{[bis(3‐methoxy‐2‐oxidobenzylidene)ethylenediamine]cobalt(III)} acetonitrile tetrasolvate, [Co 2 (C 18 H 18 N 2 O 4 ) 3 ]·4CH 3 CN, i.e. monoclinic 2 and triclinic 3 , in the presence of air. Both novel polymorphs were chemically and spectroscopically characterized. Their crystal structures are built up of centrosymmetric dinuclear [Co 2 ( o ‐van‐en) 3 ] complex molecules, in which each Co III atom is coordinated by one tetradentate dianionic o ‐van‐en ligand in an uncommon bent fashion. The pseudo‐octahedral coordination of the Co III atom is completed by one phenolate O and one amidic N atom of the same arm of the bridging o ‐van‐en ligand. In addition, the asymmetric units of both polymorphs contain two acetonitrile solvent molecules. The polymorphs differ in the packing orders of the dinuclear [Co 2 ( o ‐van‐en) 3 ] complex molecules, i.e. alternating ABABAB in 2 and AAA in 3 . In addition, differences in the conformations, the positions of the acetonitrile solvent molecules and the pattern of intermolecular interactions were observed. Hirshfeld surface analysis permits a qualitative inspection of the differences in the intermolecular space in the two polymorphs. A knowledge‐based study employing Full Interaction Maps was used to elucidate possible reasons for the polymorphism.