Monomeric and polymeric structures of oxovanadium(IV) complexes with Schiff base ligands derived from (R,R)-2,4-pentanediamine - Synthesis and crystal structure
M. Tsuchimoto et al., Monomeric and polymeric structures of oxovanadium(IV) complexes with Schiff base ligands derived from (R,R)-2,4-pentanediamine - Synthesis and crystal structure, POLYHEDRON, 18(23), 1999, pp. 3035-3039
New tetradentate Schiff base-oxovanadium(IV) complexes which have electron
donating or withdrawing groups at the 5-position of the salicylaldehyde moi
eties, [VO{Xsal-(R,R)-2,4-ptn}] (H-2{Xsal-(R,R)-2,4-ptn}: N,N'-di-Xsalicyli
dene-(R,R)-2,4-pentanediamine; X = 5-MeO (methoxy), 5-Br, and 5-NO2) were p
repared. The structures and redox potentials for the V(V)IV(IV) couple of t
he complexes were compared with those of other [VO{Xsal-(R,R)-2,4-ptn}] (X=
3-EtO (ethoxy), 3-MeO, and H). The 5-MeO substituted complex which has elec
tron donating groups at the 5-position of the salicylaldehyde moieties form
s a monomeric structure in the solid state. The 3-EtO substituted complex h
as both monomeric and polymeric structures. On the other hand, the other [V
O{Xsal-(R,R)-2,4-ptn}] (X=H, 3-MeO, 5-Br, 5-NO2) complexes have only polyme
ric structures. X-ray crystal structure analysis of [VO{5-MeOsal-(R,R)-2,4-
ptn}]. CH3OH (1) was carried out. Complex 1 has a monomeric five-coordinate
square-pyramidal structure. The six-membered N-N chelate ring forms a dist
orted flattened boat form with two methyl groups in the axial positions. (C
) 1999 Elsevier Science Ltd. All rights reserved.