Flexible cofacial binuclear metal complexes derived from α,α-bis(salicylimino)-m-xylene
The tetradentate Schiff-base ligand SIXH2 (α,α-bis(salicylimino)-m-xylene), prepared from salicylaldehyde and m-xylylenediamine, forms cofacial binuclear complexes with Pd and Cu. Of the two isomers possible (trans-syn and trans-anti) for M2(SIX) 2, these complexes crystallize exclusively as the trans-anti isomer. In ansolvous Pd2(SIX)2, the metal-containing planes are approximately parallel, with Pd ⋯ Pd 4.416(1) Å. Pd 2(SIX)2 also forms a crystalline solvate, in which the molecules adopt a more open conformation with longer metal-metal distances (5.109(1) and 5.112(1) Å). The M ⋯ M distance is significantly longer in Cu2(SIX)2 (6.653(1) Å), because of conformational changes in the m-xylylene moieties and substantial tetrahedral distortion about Cu.
Publication Source (Journal or Book title)
Maverick, A., Laxman, R., Hawkins, M., Martone, D., & Fronczek, F. (2005). Flexible cofacial binuclear metal complexes derived from α,α-bis(salicylimino)-m-xylene. Dalton Transactions (1), 200-206. https://doi.org/10.1039/b412666a