In the absorption spectrum of 2(Fig. 1), based on
comparison with the spectrum forH(NR), we attribute
the intense band at 614 nm (e= 15,000 M
1
cm
1
) and
the 263, 296 and 340 nm features to metal-perturbed
LC transitions. It is to notice that the solvatochromism
exhibited by the lowest-energy band (kmax= 588 nm in
cyclohexane, 614 nm in dichloromethane, 618 nm in
methanol) is consistent with some degree of CT character for the concerned pp
*
transition (likely involving
filled and empty orbitals localized on different aromatic
rings) [6].