The bands in the visible region at 602 nm (Cu(II) complex) also indicated that the imino nitrogen
was involved in coordination to the metal ion .
As we are developing a chemosensor for TNP, the main motivation behind the synthesis of compound A is that it was expected to become a nonfluorescent moiety as photoinduced electron transfer (PET) process can take place due to presence of imino nitrogen
The introduction of methyl substituents in meta position to the imino nitrogen atoms increased the activities of the complex 41 compared to the unsubstituted complex 40.
The position of the methyl group relative to the imino nitrogen influences the catalytic activity of the 1,2-bis-benzoxazolyl benzene (41, 42), 1,2-bisbenzoxazolyl-4-methylbenzene (44, 45), 1,2-bisbenzoxazolyl-4-chlorobenzene (47, 48), 1,2-bis benzoxazolyl-4-bromobenzene (50, 51) and 2,6-bis benzoxazolyl pyridine (66, 67) vanadium complexes, the methyl group in para position to the imino nitrogen (42, 45, 48, 51 and 67) increases the electron density on the metal atom and hence this is leading to a weaker interaction between the metal centre and the [pi]-electrons of ethylene resulting in a lower activity , (Figure 11).
The ABCB1-dependent ATPase activity stimulated by nitensidine A was greatly reduced by substituting sulfur (S) or oxygen (0) for the imino nitrogen atom (N) in nitensidine A.
To gain more insight into which structural features of nitensidine A contribute to its ability to serve as a substrate for ABCB1, the role of the imino nitrogen atom was examined with a focus on its biological activities.
The role of the imino nitrogen atom was also examined with a focus on its chemical features to gain more insight into which structural features of nitensidine A contribute to its ability to behave as a substrate for ABCB1.
The substitution in the imino nitrogen atom has been shown to change the optimal conformation of each analog.
Monodentate Schiff bases are not known to form stable complexes, probably due to the insufficient basic strength of imino nitrogen
of the C = N group.
The bands in the visible region at 602nm (L-1 Cu(II) complex), 560nm (L-2 Cu(II) Complex) and 648nm (L-3 Cu(II) complex) indicate that the imino nitrogen
was involved in coordination to the metal ion suggesting the square planar geometry of the complexes.
Monodentate Schiff's bases are less known to form stable complexes, probably due to the insufficient basic strength of the imino nitrogen
of the C=N group.
The imino protons in the ligands were 0.47-1.75 ppm less shifted than amino protons after complexation; this demonstrates the absence of direct coordination of imino nitrogen
with Pd(II) .