Table 2.

Absorption wavelengths (${\lambda }_{\mathit{max}}$), excitation energy (E_x) and oscillator strength ($f_{\mathit{os}}$) of DTPR and DTPD1-DTPD6.

Compounds	$\lambda$(nm)DFT	$\lambda$(nm) Exp	Ex (eV)	fos	MO contributions
DTPR	585.490	532	2.118	3.182	H-1 → L + 1(11%), H → L(80%)
DTPD1	656.900	-	1.887	3.284	H-1 → L + 1(12%), H → L(79%)
DTPD2	709.693	-	1.747	2.812	H-1 → L + 1(11%), H → L(80%)
DTPD3	665.397	-	1.863	3.350	H-1 → L + 1(12%), H → L(80%)
DTPD4	675.217	-	1.836	3.229	H-1 → L + 1(12%), H → L(81%)
DTPD5	598.462	-	2.072	3.153	H → L(74%), H → L + 1 (5%)
DTPD6	606.899	-	2.043	3.064	H → L(73%), H → L + 1 (6%)