Solvent effects on infrared frequencies-IV. The effect of acetone on the C-D bands of some deuterated haloforms
1963; Elsevier BV; Volume: 19; Issue: 3 Linguagem: Inglês
10.1016/0371-1951(63)80126-5
ISSN1873-3816
Autores Tópico(s)Solid-state spectroscopy and crystallography
ResumoThe effect of acetone on the C-D bands of CDCl3, CDCl2Br and CDBr3 has been studied in mixed solutions of n-hexane and acetone. The use of an inert solvent is necessary in order to reduce the effects of self-association and higher-order complexes. The changes in absorptivity have been interpreted in terms of 1:1 acetone-haloform complexes. Equilibrium formation constants of 0.90 ± 0.05, 0.80 ± 0.05 and 0.45 ± 0.05 1. mole−1 have been determined for the CDCl3−, CDCl2Br− and CDBr3−acetone complexes, respectively. By studying the C-D band intensities as a function of temperature it has been possible to calculate heats of formation which have values of −3.5 ± 0.2, −3.3 ± 0.2 and −2.7 ± 0.2 kcalmole, respectively. Finally, the observed intensity differences of C-D bands in the free haloform-d and the complex have been discussed in terms of a charge-transfer model.
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