The coordination chemistry of three new quinoline pendant arm derivatives of [9]aneN3 (L1, L2) and [9]aneN2S (L3) towards CuII, ZnII, CdII, HgII and PbII has been investigated both in solution and in the solid state. The protonation constants for L1-L3 and stability constants with the aforementioned metal ions have been determined potentiometrically in 0.10 M NMe4Cl MeCN/H2O (1:1 v/v) solution at 298.1±0.1 K; the measured values show that CuII has the highest affinity for all three ligands, followed by ZnII, HgII, PbII and CdII. For each metal ion considered, 1:1 complexes with L1-L3 have also been isolated in the solid state and [Cu(L1)](BF4)2 (1), [Zn(L1)](BF4)2 (2), [Cd(L1)](ClO4)2 (3), [Hg(L1)](NO3)2 (4), [Pb(L1)](ClO4)2•MeCN (5), [Zn2Cl2(L2)2](BF4)2•½MeNO2•H2O (6), [Cu(L3)](ClO4)2 (7), [Zn(L3)(NO3)]NO3 (8), [Cd(L3)(NO3)0.82Cl0.18]NO3 (9), and [Hg(L3)](ClO4)2•MeCN (10) have also been characterized by X-ray crystallography. The optical response of L1-L3 to the presence of the above mentioned metal ions has been investigated in MeCN/H2O (1:1 v/v) and H2O solutions. All three ligands show a stronger “OFF-ON” CHEF (chelation enhancement of fluorescence) effect in the ZnII complexes than in the CdII complexes in both media. The results have been examined by considering the ratio Irel(ZnII)/Irel(CdII), within the emerging idea that the relative strength of the CHEF effect for the small ZnII ion as compared to larger CdII ion might be determined by steric crowding in the corresponding complexes with quinoline-based fluorescent chemosensors.

Synthesis and coordination properties of quinoline pendant arm derivatives of [9]aneN3 and [9]aneN2S as fluorescent Zinc sensors

ARAGONI, MARIA CARLA;ARCA, MASSIMILIANO;CALTAGIRONE, CLAUDIA;ISAIA, FRANCESCO;LIPPOLIS, VITO;
2009-01-01

Abstract

The coordination chemistry of three new quinoline pendant arm derivatives of [9]aneN3 (L1, L2) and [9]aneN2S (L3) towards CuII, ZnII, CdII, HgII and PbII has been investigated both in solution and in the solid state. The protonation constants for L1-L3 and stability constants with the aforementioned metal ions have been determined potentiometrically in 0.10 M NMe4Cl MeCN/H2O (1:1 v/v) solution at 298.1±0.1 K; the measured values show that CuII has the highest affinity for all three ligands, followed by ZnII, HgII, PbII and CdII. For each metal ion considered, 1:1 complexes with L1-L3 have also been isolated in the solid state and [Cu(L1)](BF4)2 (1), [Zn(L1)](BF4)2 (2), [Cd(L1)](ClO4)2 (3), [Hg(L1)](NO3)2 (4), [Pb(L1)](ClO4)2•MeCN (5), [Zn2Cl2(L2)2](BF4)2•½MeNO2•H2O (6), [Cu(L3)](ClO4)2 (7), [Zn(L3)(NO3)]NO3 (8), [Cd(L3)(NO3)0.82Cl0.18]NO3 (9), and [Hg(L3)](ClO4)2•MeCN (10) have also been characterized by X-ray crystallography. The optical response of L1-L3 to the presence of the above mentioned metal ions has been investigated in MeCN/H2O (1:1 v/v) and H2O solutions. All three ligands show a stronger “OFF-ON” CHEF (chelation enhancement of fluorescence) effect in the ZnII complexes than in the CdII complexes in both media. The results have been examined by considering the ratio Irel(ZnII)/Irel(CdII), within the emerging idea that the relative strength of the CHEF effect for the small ZnII ion as compared to larger CdII ion might be determined by steric crowding in the corresponding complexes with quinoline-based fluorescent chemosensors.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11584/94583
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 68
  • ???jsp.display-item.citation.isi??? 67
social impact