Synthesis, spectroscopy and redox chemistry of bis(N-aryl-3,5-di-tert-butylsalicylaldiminato)-copper(II) complexes
Küçük Resim Yok
Tarih
2004
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
TAYLOR & FRANCIS LTD
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
A series of new bis(N-aryl-3,5-di-tert-butylsalicylaldiminato)copper(II) complexes (I), prepared from 3,5-di-tert-butylsalicylaldehyde and mono-substituted anilines, X-C6H4NH2 (X = H, o-F, Cl, Br, CH3, CH3O; p-F, Cl, Br, CH3, CH3O, t-Bu and 5,6-benzo), and their spectroscopic properties as well as electrochemistry and reactivity toward PPh3 are described. Comparison of g(parallel to) (2.223-2.249), A(parallel to) (150-170 G) tensors and the axial symmetry parameter, g(parallel to)/A(parallel to), (140-155 cm) of I with those of model Cu(II) complexes reveals that the coordination site is distorted from square planar toward tetrahedral geometry. The di-tert-butyl groups on the salicylaldehyde moiety unlike those introduced on the aniline rings do not facilitate reactivity toward PPh3. Electrochemical studies of I in acetonitrile solutions reveal highly irreversible behavior, due to chemical or stereochemical changes subsequent to electron transfer. In the oxidation of some complexes with (NH4)(2)Ce(NO3)(6) in acetonitrile at 300 K, along with decreasing ESR signals of Cu(II), the appearance of coordinated phenoxyl radical signals centered at g = 2.004 were detected. The CV studies on acetonitrile solutions of I revealed well-resolved quasi-reversible redox waves at E-1/2(1) = 0.61-0.99 V and E-1/2(1) = 1.09-1.23 V (vs. Ag/AgCl) attributable to ligand-centered oxidation processes to yield corresponding coordinated phenoxyl radical species such as Cu(II)(phenoxyl)(phenolate) and Cu(II)(phenoxyl)(2).
Açıklama
Anahtar Kelimeler
bis(N-aryl-3,5-di-tert butylsalicylaldiminato)copper(II) complexes, optical and ESR spectra, redox reactivity, cyclic voltammetry
Kaynak
JOURNAL OF COORDINATION CHEMISTRY
WoS Q Değeri
Q3
Scopus Q Değeri
Q3
Cilt
57
Sayı
7
