Fluorescent detection of nitroaromatics and 2,3-dimethyl 2,3-dinitrobutane (DMNB) by a zinc complex: (salophen)Zn.
Inorg Chem
; 46(11): 4422-9, 2007 May 28.
Article
em En
| MEDLINE
| ID: mdl-17472370
ABSTRACT
Fluorescent sensors for the detection of chemical explosives are in great demand. It is shown herein that the fluorescence of ZnL* (H2L=N,N'-phenylene-bis-(3,5-di-tert-butylsalicylideneimine)) is quenched in solution by nitroaromatics and 2,3-dimethyl-2,3-dinitrobutane (DMNB), chemical signatures of explosives. The relationship between the structure and fluorescence of ZnL is explored, and crystal structures of three forms of ZnL(base), (base=ethanol, tetrahydrofuran, pyridine) are reported, with the base=ethanol structure exhibiting a four-centered hydrogen bonding array. Solution structures are monitored by 1H NMR and molecular weight determination, revealing a dimeric structure in poor donor solvents which converts to a monomeric structure in the presence of good donor solvents or added Lewis bases to form five-coordinate ZnL(base). Fluorescence wavelengths and quantum yields in solution are nearly insensitive to monomer-dimer interconversion, as well as to the identity of the Lewis base; in contrast, the emission wavelength in the solid state varies for different ZnL(base) due to pi-stacking. Nitroaromatics and DMNB are moderately efficient quenchers of ZnL*, with Stern-Volmer constants KSV=2-49 M-1 in acetonitrile solution.
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Base de dados:
MEDLINE
Assunto principal:
Butanos
/
Salicilatos
/
Compostos de Zinco
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Compostos de Nitrogênio
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article