A LARGE-SCALE VIBRATION CORRELATION DIAGRAM FOR MATRIX-ISOLATED AND SOLUTION HYDROGEN-BONDED COMPLEXES BETWEEN WATER AND DIFFERENT BASES

A large scale correlation diagram is established relating corrected relative frequency shifts of the stretching mode for the bonded OH group in H-bonded base...H2O complexes, observed in low-temperature matrices or in solution, and proton affinity values of the complexed bases. This correlation diagram is discussed in terms of charge-transfer contributions to the H-bond interactions pi...H2O, O...H2O, S...H2O and N...H2O. Examples are provided of how the separate correlations may be used to interpret the complex spectral patterns often exhibited by tautomeric base...H2O systems, or to obtain a first, crude estimation of proton affinities for some basic groups in polyfunctional bases.