Zhang Z, Feng W, Su P, Liu H, Zhang Y, Wang Z, Miao T, Lü X, Fan D, Wong WK, Jones RA. Near-infrared (NIR) luminescent hetero-tetranuclear Zn2Ln2 (Ln = Nd, Yb or Er) complexes self-assembled from the benzimidazole-based HL and two rigid 4,4'-bipyridine ligands with different spacers.
SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013;
116:102-110. [PMID:
23912177 DOI:
10.1016/j.saa.2013.06.122]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 06/20/2013] [Accepted: 06/28/2013] [Indexed: 06/02/2023]
Abstract
Through the self-assembly of the benzimidazole-based ligand HL (HL=2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol) with Zn(OAc)2 · 2H2O, Ln(NO3)3·6H2O (Ln=Nd, Yb, Er or Gd) and 4,4'-bipyridine ligand (bpy, 4,4'-bipyridine or bpe, trans-bis(4-pyridyl)ethylene), two series of Zn2Ln2-arrayed complexes [Zn(2)Ln(2)(L)4(bpy)(NO3)6] (Ln=Nd, 1; Yb, 2; Er, 3 or Gd, 4) and [Zn(2)Ln(2)(L)4(bpe)(NO3)6] (Ln=Nd, 5; Yb, 6; Er, 7 or Gd, 8) were obtained, respectively. The result of their photophysical properties shows that the characteristic near-infrared (NIR) luminescence of Nd(3+), Yb(3+) or Er(3+) ion has been sensitized from the excited state (both (1)LC and (3)LC) of the mixed HL and bipyridyl ligands in both complexes 1-3 and 5-7. Moreover, the change from bpy to bpe bridging for the fine-tuning of whole molecular conjugations, attributing to the different crossings of the two benzimidazole-based L(-) ligands, has the important influence on their NIR luminescent properties.
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