Lippert plot

Figure 4. Lippert plot for 10 /xM PRODAN in CF3H. The solid points are the experimental data. The dashed line represents the theoretical prediction for PRODAN.

Hk solvent sensitivity of a fluotopiiote can be estimated fiom a Lippert plot This is aplot of -Pjr) vosus the... 

Figure 10.8 Lippert plot, Stokes shift (cm ) versus orientational polarizability (Afl for Pro-dan in solution ( ) and for solid matrices ( ). The solvents were (1) cyclohexane, (2) chloroform, (3) acetone, (4) DMF, (5) acetonitrile.

Evidence for specific solvent-solute interactions can be seen in the Lippert or others solvatochromic plots. One notices that the Stokes shift is generally larger in H-bonding solvents (water, alcohols) than in solvents with less probability to form... 

When Stokes shifts are plotted as a function of the orientation polarizability A f (Lippert s plot, see Section 7.2.2), solvents are distributed in a rather complex manner. A linear relationship is found only in the case of aprotic solvents of relatively low polarity. The very large Stokes shifts observed in protic solvents (methanol, ethanol, water) are related to their ability to form hydrogen bonds. 

Fig. 70 Normalized residual (l-X, ) as a function of the normalized time for a complete conversion (t lx) at 783 K (open symbols), 812 K (+ and x), and 841 K (solid symbols). The equations applied for fitting the data points are included in the plot (see text). (Top) The band at 3060 cm 1 ( and +) representing the aromatic rings. (Bottom) The band at 725 cm 1 (A, A, and x) representing the imide rings. Applied Spectroscopy by T. Lippert [Ref. 281], COPYRIGHT (2001) by SOC FOR APPLIED SPECTROSCOPY, Reproduced with permission of SOC FOR APPLIED SPECTROSCOPY in the format Textbook via Copyright Clearance Center...

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