Temperature-dependent self-assembly of near-infrared (NIR) luminescent Zn2Ln and Zn2Ln3 (Ln = Nd, Yb or Er) complexes from the flexible Salen-type Schiff-base ligand

Tiezheng Miao, Zhao Zhang, Weixu Feng, Peiyang Su, Heini Feng, Xingqiang Lü*, Daidi Fan, Rick W K WONG, Richard A. Jones, Chengyong Su

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Through the self-assembly of the precursor [Zn(L)(MeCN)] (H2L = N,N′-bis(3-methoxy-salicylidene)cyclohexane-1,2-diamine) with LnCl 3·6H2O (Ln = La, Nd, Yb, Er or Gd) and NaN 3 in alcohol-containing solutions, two series of mixed anions-induced Zn2Ln-arrayed complexes [Zn2(L)2(MeOH) ClLn(N3)]·Cl (Ln = La, 1; Ln = Nd, 2; Ln = Yb, 3; Ln = Er, 4 or Ln = Gd, 5) and Zn2Ln3-arrayed complexes [Zn 2(L)3Cl22-OH) (μ3-OH)2Ln3(N3)2] (Ln = La, 6; Ln = Nd, 7; Ln = Yb, 8; Ln = Er, 9 or Ln = Gd, 10) are obtained at room temperature or under reflux, respectively. In contrast to Zn 2Ln-arrayed complexes with the two Zn2+ ions in the inner cis-N2O2 cores and one Ln3+ ion in the outer O2O2 moieties, the demetalation of partial precursors leads to the selective exchange of Zn2+ centers for the Ln 3+ ions for the formation of novel heterometallic Zn 2Ln3-arrayed complexes with the Ln3+ ions in both the inner cis-N2O2 core and the outer O 2O2 moieties of the ligands. The result of their photophysical properties shows that the characteristic near-infrared (NIR) luminescence of Nd3+ or Yb3+ ion has been sensitized from the excited state (both 1LC and 3LC) of the ligand H 2L, while relatively lower quantum yields for Zn2Ln 3-arrayed complexes than those for Zn2Ln-arrayed complexes, correspondingly, should be due to the luminescent quenching with the involvement of OH- oscillators around the Ln3+ ions.

Original languageEnglish
Pages (from-to)205-214
Number of pages10
JournalSpectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
Publication statusPublished - 11 Nov 2014

Scopus Subject Areas

  • Analytical Chemistry
  • Atomic and Molecular Physics, and Optics
  • Instrumentation
  • Spectroscopy

User-Defined Keywords

  • Mixed anions
  • Sensitization of NIR luminescence
  • Temperature dependence for demetalation


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