Copper complex emission spectra

The complete description of the different radiations that comprise the Ka emission is complex. In the case of copper, for example, at least 6 different peaks are observed [DEU 95 DEU 96 DIA 00], However, the K emission spectrum can be considered in a first approximation to be comprised of 2 main peaks, Kai and Kc(2. These two contributions cannot be separated by an absorption filter, which is why the resulting beam remains bichromatic. The two peaks can only be separated with the use of a monochromator crystal, under certain conditions. 

In a series of papers, Ford and co-workers described the photophysical and photochemical properties of these luminescent clusters in detail [46-58]. In addition to complexes 4a and 4b, time-resolved emission spectra of the tetranu-clear copper(I) iodide clusters [Qi4l4(L)4] with a series of substituted pyridines [L = 4-tert-butylpyridine (4c), 4-benzylpyridine (4d), pyridine-dj (4e), 4-phe-nylpyridine (4f), 3-chloropyridine (4g), piperidine (4h), P"Bu3 (4i)] have also been studied [49]. The photophysical data are summarized in Table 1. In general, in toluene solution at 294 K, the complexes revealed a low-energy emission at 678-698 nm and a weaker, higher energy emission at 473-537 nm. The emission spectrum of 4a in toluene at 294 K is shown in Fig. 2... 

The spectroscopic and photophysical properties of a hexanuclear copper(I) complex [(CuPPh3)sL2] (16) (H3L = trithiocyanuric acid) have also been reported by Che and co-workers [89]. The UV-Vis absorption spectrum of the complex in CH2CI2 shows a broad absorption band at 355 nm (e = 2.03 X 10 dm moL cm ) with weaker absorption tails extending to 500 nm. The emission of the complex occurs at 562 nm in the solid state and 580 nm in CH2CI2 solution. The origin of the luminescence has been suggested to be associated with MLCT [Cu -> 7C (L)] and/or intraligand [tc tc (L)] transitions of the stacked triazine moieties. 

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