An investigation of the complexation of host N,N'-bis(9-phenyl-9-thioxanthenyl)ethylenediamine with dihaloalkane guests

作者：Barton Benita^*; de Jager Lize; Hosten Eric C

来源：Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2017, 89(1-2): 105-116.

DOI：10.1007/s10847-017-0737-1

• Host-guest chemistry
• Inclusion
• Complexes
• Selectivity
• Alkyl halides
• X-ray crystallography
• Supramolecular chemistry

Two wheel-and-axle host compounds were synthesized and assessed for their host ability. After growing crystals of N,N'-bis(9-phenyl-9-thioxanthenyl)ethylenediamine from various alkyl halide solvents, we discovered that this host is highly proficient for the enclathration of these guest types. However, the novel compound N,N'-bis(9-phenyl-9-xanthenyl)-1,6-hexamethylenediamine, bearing the more flexible axle, showed no inclusion ability whatsoever. Competition experiments where the title host compound was recrystallized from equimolar binary and ternary mixtures of CH2Cl2, CH2Br2 and CH2I2 showed this host to have a selectivity in the order CH2Br2 > CH2I2 > CH2Cl2 for these guests. Varying the molar ratios of guests in these mixtures beyond equimolar revealed that the host remained selective for the bromine derivative whenever it was present, even at low dibromomethane concentrations. Single crystal X-ray diffraction data and, more specifically, host-guest interactions in the crystal, were used to explain the selectivity order; lattice energies were also considered in this context. The relative thermal stabilities of the three complexes, obtained from thermal experiments, showed that the selectivity order and these thermal stabilities are unrelated.

• 出版日期2017-10