Synthesis, Redox, and Amphiphilic Properties of Responsive Salycilaldimine-Copper(II) Soft Materials
2008; American Chemical Society; Volume: 47; Issue: 8 Linguagem: Inglês
10.1021/ic702233n
ISSN1520-510X
AutoresS.S. Hindo, R. Shakya, N. S. Rannulu, M. ALLARD, Mary Jane Heeg, M. T. Rodgers, Sandro R. P. da Rocha, Cláudio N. Verani,
Tópico(s)Magnetism in coordination complexes
ResumoHydrolysis of the asymmetric pyridine- and phenol-containing ligand HL1 (2-hydroxy-4-6-di-tert-butylbenzyl-2-pyridylmethyl)imine) led to the use of bis-(3,5-di-tert-butyl-2-phenolato-benzaldehyde)copper(II), [CuII(LSAL)2] (1) as a precursor for bis-(2,4-di-tert-butyl-6-octadecyliminomethyl-phenolato)copper(II), [CuII(L2)2] (3), bis-(2,4-di-tert-butyl-6-octadecyl aminomethyl-phenolato)copper(II), [CuII(L2A)2] (3′), and bis-(2,4-di-tert-butyl-6-[(3,4,5-tris-dodecyloxy-phenylimino)-methyl]-phenolato)copper(II), [CuII(L3)2] (4). These complexes exhibit hydrophilic copper-containing head groups, hydrophobic alkyl and alkoxo tails, and present potential as precursors for redox-responsive Langmuir–Blodgett films. All systems were characterized by means of elemental, spectrometric, spectroscopic, and electrochemical techniques, and their amphiphilic properties were probed by means of compression isotherms and Brewster angle microscopy. Good redox activity was observed for 3 with two phenoxyl radical processes between 0.5 and 0.8 V vs Fc+/Fc, but this complex lacks amphiphilic behavior. To attain good balance between redox response and amphiphilicity, increased core flexibility in 3′ and incorporation of alkoxy chains in 4 were attempted. Film formation with collapse at 14 mN·m−1 was observed for the alkoxy-derivative but redox-response was seriously compromised. Core flexibility improved Langmuir film formation with a higher formal collapse and showed excellent cyclability of the ligand-based processes.
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