Structural diversity in neodymium bipyrimidine compounds with near infrared luminescence: from mono- and binuclear complexes to metal-organic frameworks

Inorg Chem. 2008 Nov 17;47(22):10398-406. doi: 10.1021/ic800967x. Epub 2008 Oct 11.

Abstract

Treatment of Nd(NO 3) 3 with 2,2'-bipyrimidine (bpm) afforded the mononuclear adduct [Nd(NO 3) 3(bpm)(MeOH) 2] ( 1) after recrystallization from MeOH, while reactions of hydrated NdCl 3 and various beta-diketonates in the presence of bpm gave the binuclear compounds [{Nd(dbm) 3(THF)} 2(mu-bpm)] ( 2) and [{Nd(bta) 3(MeOH)} 2(mu-bpm)].bpm ( 3.bpm) (Hdbm = dibenzoylmethane, Hbta = 4,4,4-trifluoro-1-phenyl-1,3-butanedione) and the one-dimensional coordination polymer [Nd(tta) 3(mu-bpm).MeOH] infinity ( 4.MeOH) (Htta = 2-thenoyltrifluoroacetone). The crystal structures of 2- 4 demonstrate that the bpm molecule can act as a planar bridging ligand between two lanthanide ions as large as Nd (3+). Luminescence measurements revealed that near-IR emission from neodymium can be obtained after excitation of either the bpm or the beta-diketonate ligand, and that an energy transfer occurs from the beta-diketonate group to the bpm molecule.