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Weak intermolecular hydrogen and halogen interactions in an isomorphous halogen series of pseudoterpyridine Zn II complexes
Author(s) -
Dumitru Florina,
Legrand YvesMarie,
Barboiu Mihail,
van der Lee Arie
Publication year - 2013
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
eISSN - 2052-5206
pISSN - 2052-5192
DOI - 10.1107/s2052519212050439
Subject(s) - isostructural , chemistry , halogen , hydrogen bond , homoleptic , halogen bond , crystallography , crystal structure , cationic polymerization , stereochemistry , trifluoromethanesulfonate , molecule , catalysis , metal , alkyl , organic chemistry
The synthesis and characterization of a series of halogen‐substituted pseudoterpyridine Zn II homoleptic mononuclear complexes, based on ligands L 11 – L 44 [2,6‐pyridinedicarboxaldehydebis( p ‐ R ‐phenylimines), R = F, Cl, Br, I] are reported. Neither of the structures contain relatively strong classical hydrogen bonds (OH...O, NH...O, OH...N, NH...N) and the structure packing is thus determined by a subtle interplay of weaker interactions. Isostructurality of the four halogen analogues is very rare, and in this study —Br, —Cl and —F are found to be isostructural in different degrees, whereas —I is not. Interestingly, although it is closely isostructural to the —Cl and —Br compounds, the F analogue is shown not to form F...O bonds, while the Cl and the Br analogues do form Hal...O bonds. This raises an important question on the role of Hal...O bonds in the structuration of the crystal packing, particularly the stabilization effect. Similarly, while the CH...Hal interaction seems to give one‐dimensional cohesion in the —Cl and —Br analogues, this feature is absent in the —F analogue, despite its close isostructurality. CH...O interactions appear to dominate to a first degree the cohesion between the anionic trifluoromethanesulfonate network and the cationic Zn‐pyridinedicarboxaldehydebis( p ‐ R ‐phenylimines) network. The analysis of these interactions is corroborated by reduced density gradient calculations based on promolecular densities.