Generation and IR spectra of ionic and molecular complexes of aluminum chloride with tert- and sec-butyl chlorides

Abstract

Sec butyl and tert butyl cations were first stabilized upon cocondensation of aluminum chloride and haloalkanes (2 chlorobutane and 2 chloro 2 methylpropane, respectively) and their IR spectra and thermal stability investigated. Aluminum chloride anions participating in stabilization of carbenium ions were revealed. Ionic complexes and both 1:1 and 2:1 molecular complexes of reagents were detected and their IR spectra studied. Quantum chemical calcula tions at the PBE level of density functional theory with inclusion of electron correlation were employed to optimize the geometric parameters and to determine the vibrational frequencies of aluminum chloride, butyl chlorides, and their complexes of various compositions. The struc tures of the associates observed were determined on the basis of comparison of the experimental and calculated vibrational spectra.

Reactions of 2-chlorobutane with polynuclear bimetallic aluminum and cobalt chloride complexes: low-temperature synthesis and structure of adducts

“…Figure 5, 1 shows the IR spectrum of the corresponding ionic com plex s Bu + [Al 3 Cl 10 ] -, which has been studied by us in details earlier. 13 Very close spectrum has been obtained for s Bu + in the SbF 5 matrix as well. 14 The spectrum of the triple co condensate 2 ClBu•CoCl 2 •AlCl 3 (ratio of reagents ~1 : 1 : 1) recorded after heating to 150 К is also shown in Fig.…”

“…Note that the IR spectra of complexes 1 and 2 are close enough as well. 13 However, in the low frequency region of the spectrum (700-400 cm -1 ) where metal-chlorine stretching vibra tions are found (Fig. 2), considerable differences in the binary (Fig.…”

“…13, the reaction of Al 2 Cl 6 with 2 ClBu at 80 K mainly leads to molecular complexes 2 ClBu•AlCl 3 (1). When aluminum chloride is in excess amount, the 1 : 2 complexes 2 ClBu•Al 2 Cl 6 (2) are also formed along with complexes 1.…”

“…This approach has been applied by us earlier for the detection and identification of aluminum chloride complexes with cobalt halides 11,12 and alkyl halides. 13 As a result, a possibility of stabilization of a secondary butyl cation in the reaction of 2 chlorobutane and aluminum chloride has been shown for the first time. Earlier, ion pairs involving this cation have been registered only in the presence of the strongest Lewis acids, for example, in the SbF 5 matrix (see Ref.…”

Liquid-phase isobutane alkylation with butenes over aluminum chloride complexes synthesized in situ from activated aluminum and tert-butyl chloride

“…Thus, we believe that the observed direc tion of isobutane alkylation with butenes is due to the Observed absorption bands in the ATR-FT-IR spectra of the aluminum chloride complexes and the correspond ing data from the literature[13,14] The article is based on the materials of the Russian Congress on Catalysis, Moscow, October 3-7, 2011.…”