Multinuclear NIR luminescent 1,4-BDC bridged Schiff-base complexes of Nd(III)

Solvent and reaction stoichiometry dictate the products isolated from reactions of the dinuclear precursor complex [ZnNdL(H2O)(NO3)(3)] (H2L=N,N'-bis(3-methoxy-salicylidene)ethylene-1,2-diamine) with the anionic multidentate linker 1,4-benzenedicarboxylate (1,4-BDC). With a 2:1 molar ratio of ZnNd:Na(2)1,4-BDC in CH3CN-EtOH the tetranuclear complex [Zn2Nd2L2(1,4-BDC)(NO3)(4)(EtOH)(2)] center dot 2MeCN (1) is produced while hexanuclear [Zn4Nd2L4(1,4-BDC)(2)] center dot (NO3)(2) center dot 2Et(2)O center dot 4H(2)O (2) can be isolated from a DMF-EtOH mixture. A 4:1 mole ratio in DMF-EtOH gave the unusual polynuclear complex [Zn4Nd2L4(1,4-BDC)(2)] center dot [ZnNdL(NO3)(3)(OAc)](2) (3). The NIR photophysical properties of the new compounds are reported. (C) 2008 Elsevier Ltd. All rights reserved.