The first tellurium-containing analogues of the rosamine and rhodamine dyes were prepared by theaddition of Grignard or organolithium reagents to telluroxanthone precursors. The 125Te spectra of boththe dyes and the telluroxanthone precursors are reported. One derivative was characterized by X-raycrystallography and was found to have a nearly planar telluroxanthylium core with a 9-aryl substituentheld nearly orthogonal to the core. Density functional theory (DFT) and time-dependent DFT (TDDFT)calculations were performed to analyze the trends for the excitation wavelengths observed experimentally.The computations indicated that participation of the heteroatom lone pair orbitals is responsible for thistrend.
Tellurium-containing analogues of the rosamine and rhodamine dyes were prepared and characterized by X-ray crystallography, 125Te NMR, and density functional theory (DFT) and time-dependent DFT (TDDFT) calculations.