Solvatochromic Shifts of 4-Nitrophenol upon Hydrogen Bonding to Nitriles

6 Solvatochromic Shifts of 4-Nitrophenol upon Hydrogen Bonding to Nitriles 

The longest wavelength absorption band of the UV spectrum of 4-nitrophenol is at 263.3 nm (37 980 ) in the gas phase. This band is attributed to a tt tt transition with 

4v(OH - OMe) is determined for three nitriles chloroacetonitrile, acetonitrile and dimethylcyanamide. The results are analysed in terms of substituent effects on the basicity of the nitrile group and compared with other hydrogen-bond basicity scales, in order to test the significance of electronic spectral shifts as basicity parameters. 

---