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:Na21,4-BDC in CH3CN–EtOH the tetranuclear complex [Zn2Nd2L2(1,4-BDC)(NO3)4(EtOH)2] · 2MeCN (1) is produced while hexanuclear [Zn4Nd2L4(1,4-BDC)2] · (NO3)2 · 2Et2O · 4H2O (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] · [ZnNdL(NO3)3(OAc)]2 (3). The NIR photophysical properties of the new compounds are reported.

Graphical abstractSolvent and reaction stoichiometry dictate the products from reactions [ZnNdL(H2O)(NO3)3] (H2L = N,N′-bis(3-methoxy-salicylidene)ethylene-1,2-diamine) with 1,4-benzenedicarboxylate (1,4-BDC). A 2:1 molar ratio of ZnNd:1,4-BDC in CH3CN–EtOH gave [Zn2Nd2L2(1,4-BDC)(NO3)4(EtOH)2] · 2MeCN (1) while hexanuclear [Zn4Nd2L4(1,4-BDC)2] · (NO3)2 · 2Et2O · 4H2O (2) is formed in a DMF–EtOH mixture. A 4:1 mole ratio in DMF–EtOH gave [Zn4Nd2L4(1,4-BDC)2] · [ZnNdL(NO3)3(OAc)]2 (3).Figure optionsDownload full-size imageDownload as PowerPoint slide