TY - JOUR A1 - Scholz, Norman A1 - Jadhav, A. A1 - Shreykar, M. A1 - Behnke, Thomas A1 - Nirmalananthan-Budau, Nithiya A1 - Resch-Genger, Ute A1 - Sekar, N. T1 - Coumarin-rhodamine hybrids-novel probes for the optical measurements of viscosity and polarity JF - Journal of Fluorescence N2 - A comprehensive systematic study of Absorption and fluorescence properties in solvents of varying viscosity and polarity of three novel and red-emitting coumarin-rhodamine hybrid derivatives with differences in the rigidity of their substituents is presented. This includes ethanol-polyethylene glycol, toluene-polyethylene glycol, and tolueneparaffin mixtures. Moreover, protonation-induced effects on the spectroscopic properties are studied. A viscosity-induced emission enhancement was observed for all coumarin-rhodamine hybrid derivatives. MCR2 bearing a julolidine donor showed the expected low sensitivity to viscosity whereas MCR3 with its freely rotatable diphenylamino Substituent revealed a particularly pronounced sensitivity to this parameter. Moreover, MCR2 shows an enhancement in Emission in the open, i.e., protonated form in conjunction with a largely Stokes shift fluorescence in the deep red spectral region. This enables the application of these dyes as viscosity sensors and as far red emitting pH-sensitive probes. KW - Fluorescence KW - Dye KW - Quantum yield KW - Viscosity KW - Polarity KW - Environment KW - Probe KW - Coumarin KW - Rhodamine KW - Synthesis PY - 2017 DO - https://doi.org/10.1007/s10895-017-2165-4 SN - 1573-4994 SN - 1053-0509 N1 - Geburtsname von Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. - Birth name of Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. VL - 27 IS - 6 SP - 1949 EP - 1956 PB - CrossMark AN - OPUS4-42584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -