1. Octadecanuclear gear wheels by self-assembly of self-assembled 'double saddle'-type coordination entities: molecular 'rangoli'
- Author
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Dillip Kumar Chand, Rajamony Jagan, and Hareesha Dasary
- Subjects
Palladium compounds ,Stacking ,Molecular rings ,Ethylenediamine ,Crystal structure ,Ligands ,Ring (chemistry) ,Catalysis ,Tetramethylethylenediamine ,chemistry.chemical_compound ,Bipyridine ,Pi interactions ,Urea ,Pi interaction ,Tridentate ligands ,Organic Chemistry ,1 ,10-phenanthroline ,General Chemistry ,Self assembly ,Molecular spectroscopy ,Stacking interaction ,Crystallography ,chemistry ,Synthesis (chemical) ,Ethylenediamine (en) ,Self-assembly ,Trinuclear complex ,Palladium - Abstract
A series of self-assembled "double saddle"-type trinuclear complexes of [Pd3L?3L3] formulation have been synthesized by complexation of a series of cis-protected palladium(II) components with a slightly divergent "Eshaped" non-chelating tridentate ligand, 1,1?-(pyridine-3,5-diyl)bis(3-(pyridin-3-yl)urea (L). The cis-protecting agents L? employed in the study are ethylenediamine (en), tetramethylethylenediamine (tmeda), 2,2?-bipyridine (bpy), and 1,10-phenanthroline (phen), for 1, 2, 3, and 4, respectively. The crystal structures of [Pd3(tmeda)3(L)2](NO3)6 (2), [Pd3(bpy)3(L)3](NO3)3 (3), and [Pd3(phen)3(L)2](NO3 )6 (4) unequivocally support the new architecture. Two of the "double saddle"-type complexes (3 and 4) are suitably crafted with p surfaces at the strategically located cis-protecting sites to facilitate intermolecular p-p interactions in the solid state. As a consequence, six units of the 3 (or 4 ) are assembled, by means of six-pairs of p-p stacking interactions, in a circular geometry to form an octadecanuclear molecular ring of [(Pd3L?3L3)3] composition. The overall arrangement of the rings in the crystal packing is equated with the traditional Indian art form rangoli. � 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
- Published
- 2014