Self-assembled Transition Metal Coordination Frameworks of ...

C 0pper( II ) complexes
rise to rhombic symmetries. Also, it is inferred that the geometry of the compound
undergoes changes upon dissolution in polar coordinating solvents.
The compounds 11, 12, 18 and 19 having quinolyl substituted ligands have
one similar Cu(H) species as evidenced by the nearly the same g“ values, may be
indicating a weaker N,N,N coordination. The second species in ll and 12 are almost
same and smaller g" values may be due to possible NNS coordination compared to
the possible N, N, O coordination in 18 and 19. The g" values of both Cu(II) species
in compounds 8, 14, 15, and 17 having dipyridyl substituted ligands are different from
the above complexes may support this. I-lowever this observation is ambiguous,
especially without confirming the exact nature of the complexes in solution and in the
absence of any crystal structure to support the coordinations. The simulated spectra of
two different Cu(II) species designated, A and B, in the spectral simulation of selected
copper complexes are shown in Figs. 4.35 to 4.39.
II.‘ w‘
_ ' IlI
;L1
“T _-
. J)’ - "I.
It
n
‘ i" I)’ ‘k
.’____‘\‘ -__ _ I) ___. -'r.\'\‘ _,-J,
. /‘ "-.‘_ __ _-~ '__“‘—. -_ \ '-pi--" J. 1' i_ _.-"._ _,"
Ii 3'
|
ll pi
§ ,1!
B, [mn
2@2702H32QJ3JO310@DK-Il3¢[l3$36J3703HJ
Fig. 4.35. The two simulated spectra of species A (red) and B (magenta) for the
complex 8, with its experimental EPR spectrum (black) (Please see Fig. 4.22 also).
167