Kt. Potts et al., Multimetallic, double-stranded helical complexes derived from hexa(n-propylthio)novipyridine: synthesis, structure and redox properties, INORG CHIM, 288(2), 1999, pp. 189-199
4 ',4 ",4 '",4 ""',4 """,4 """'-Hexan(n-propylthio)-2,2 ';6 ',2 ":6 ",2 "':
6 "',2 "":6 "",2 ""':6 ""',2 """:6 """,2 """':6 """',2 """"-novipyridine (L
), a new nonadentate;ate ligand, reacts with cuprous tetrakis(acetonitrile)
hexafluoro-phosphate in oxygen-free methanol at room temperature to yield
the black, crystalline cuprous complex [L2Cu1/5][PF6](5). In the presence o
f air the corresponding mixed-valence complex [(L2CuCu1)-Cu-11/3][PF6](5) i
s obtained. Reaction with Cu-II and Co-II ions resulted in the formation of
the corresponding trimetallic complexes [L2M3II][PF6](6). Molecular compos
itions were established from partial elemental analysis, FAB mass spectral
data, and from electrochemical and electronic spectral data. [L2Cu1/5 ](5+)
contains the most cuprous ions assembled in a oligopyridine complex to dat
e and these complexes, analogous to others in this series, were assigned do
uble-stranded helical structures. An intramolecular diastereotopic effect i
n the H-1 NMR spectrum of the diamagnetic pentacuprous complex showed its c
hiral nature and its stability in solution. Electrochemical studies of thes
e complexes showed appreciable metal-metal interactions, and redox-induced
transformations among the copper helicates were established spectroelectroc
hemically. (C) 1999 Elsevier Science S.A. All rights reserved.