2) are carried out in progressively more dilute mixtures of HBA (hydrogen bond acceptor) solvents in non-HBA cosolvents. VF50 values of Me2S0 (volume fractions of MezSO in the cosolvents at which the hydrogen bonded complex with 1 is approximately half dissociated) are shown to increase in magnitude with increasing polarity of the cosolvent. A linear relationship between log VFbO values for the Me2SO:1:Me2S0 complex and formation constants reported earlier for the 4-fluorophen01:Me~SO hydrogen bonded complex in the same cosolvents is demonstrated. Self-associating alcohol solvents show nontypical dilution behavior. Dissociation of the (ROH), complexes simultaneously with the l:(ROH), complexes causes -AAv( 1-2) values (enhanced bathochromic shifts attributable to hydrogen bonding) to fall off more rapidly on dilution into non-HBA cosolvents. A comparison of dilution behavior provides strong evidence that the (MeOH), self-association equilibrium constant is significantly higher than that for (t-BuOH),.

Midinfrared (2.5–25 μm) reflectance spectra of minerals are often used to predict emittance qualitatively. These spectra display weak overtone and combination tone bands, which may be as diagnostic of composition as the strong fundamental molecular vibration bands usually considered for remote sensing applications, but which have been widely ignored. However, unlike the strong bands, the contrast of weak bands relative to the continuum in the midinfrared usually does not decrease with decreasing particle size, but typically increases. To illustrate this behavior, transmittance and reflectance spectra of calcite and quartz are presented for the wavelength range from 4000 to 400 cm−1 (2.5–25 μm). It is the purpose of this paper to point out that these weak bands are potentially useful for compositional remote sensing of particulate planetary surfaces; this will require completion of supporting laboratory studies to document the occurrence of weak bands.

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AS POINTED out in a previous paper (12), the discovery of f\ Adams and Holmes (1) in 1935 that synthetic resins exhibited ion-exchange adsorption has refocused the