Source of materialZn(CH 3 COO)2 · 4H 2 0 (0.122 g, 0.5 mmol) and NH4SCN (0.192 g, 1 mmol) were refluxed in anhydrous methanol (10 mL) for 50 min and then was added 20 mL methanol solution of freshly distilled salicylaldehyde and ethylenediamine. The mixture was stirred for 3 h, then was added 10 mL methanol solution of 4,4'-bipyridine, further stirred for 2 h and then filtered. Hie resulting clear solution was diffused with diethyl ether vapor at room temperature for two weeks. Block-shaped yellow crystals were formed, collected by filtration and dried in air (yield 0.423 g, 48 %). Elemental analysis -found: C, 59.82 %; H, 4.67 %; N, 9.60 %; calc. for C44H44N 6 06Zn 2 : C, 59.75 %; H, 4.98 %; N, 9.51 %.
Experimental detailsWhile the hydroxyl Η atom was refined, the other Η atoms were added geometrically.
DiscussionThe chemistry of metal complexes with multi-dentate ligands such as salicylaldehyde Schiff bases has gained much interest because of their use as models in biological systems and organic reactions, catalysis and making desirable the widest range of ways to modify liquid crystal compounds, nano-devices and machines [1][2][3][4]. Zinc is an essential element for human, which plays a central, if still only dimly understood, role in a number of healing processes probably acting as a convenient source of bioactive Zn 2+ (aq). 4,4'-bipyridine is an excellent rodlike bifunctional ligand and has been extensively employed as the rigid organic building block for the construction of infinite ID, 2D, 3D coordination polymeric frameworks [5][6][7]. The study of zinc(II) complex involving an aromatic Schiff base as the primary ligand, 4,4'-bipyridine as the secondary ligand acting as a bridging mode can serve as useful models for gaining a better understanding of enzyme-metal ion-substrate complexes that play an important role in metalloenzyme-catalyzed biochemical reactions. The crystal structure of the complex is found to contain two discrete crystallographically independent dinuclear centrosymmetric zinc(II) complex units bridged through the 4,4'-bipyridine with a Zn-Zn separation of 11.28 Ä (figure, top). Each Zn(ll) ion is fivecoordinated by three nitrogen and two oxygen atoms, forming a distorted square pyramid with the terminal nitrogen atom from 4,4'-bipyridine located at the apical position. Two nitrogen atoms are from the deprotonated ethylenediamine part, and two oxygen atoms from the salicylaldehyde hydroxyl group, which lead to one Unauthenticated Download Date | 5/12/18 4:43 AM