42528-40-5Relevant academic research and scientific papers
An investigation of the complexation of host N,N′-bis(9-phenyl-9-thioxanthenyl)ethylenediamine with dihaloalkane guests
Barton, Benita,de Jager, Lize,Hosten, Eric C.
, p. 105 - 116 (2017)
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.
Synthesis and assessment of compounds trans-N,N′-bis(9-phenyl-9-xanthenyl)cyclohexane-1,4-diamine and trans-N,N′-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,4-diamine as hosts for potential xylene and ethylbenzene guests
Barton, Benita,Jooste, Daniel V.,Hosten, Eric C.
, p. 333 - 346 (2019)
In this work, two novel compounds, trans-N,N′-bis(9-phenyl-9-xanthenyl)cyclohexane-1,4-diamine 1 and trans-N,N′-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,4-diamine 2, were designed and successfully synthesized in our laboratories, and assessed for their host potential in the presence of potential xylene (Xy) isomer and ethylbenzene (EB) guests. Host 1 successfully formed complexes with all four of o-Xy, m-Xy, p-Xy and EB, while 2 only clathrated p-Xy and EB. Equimolar guest/guest competition experiments showed that hosts 1 and 2 possess very similar selectivities for these guests [p-Xy (73.9%) > EB (13.0%) > m-Xy (8.1%) > o-Xy (5.0%) and p-Xy (71.3%) > EB (20.2%) > m-Xy (6.0%) > o-Xy (2.5%) for 1 and 2, respectively]. Single crystal diffraction analyses revealed striking geometry changes for the sulfur host analogue: while the tricyclic fused ring system of the oxygen host remained planar when guest was absent or present, this fused system of the sulfur analogue experienced a dramatic geometry change from buckled (in the absence of guest) to planar (in guest presence). This observation explained the selectivity similarities of both hosts in the presence of these guests. Additionally, the relative thermal stabilities of the four complexes with host 1 were assessed by employing thermal analyses, and the results of these correlated exactly with the selectivity order, since the onset temperature of the guest release processes (Ton) was in the order p-Xy (88.0?°C) > EB (70.9?°C) > m-Xy (59.7?°C) > o-Xy (46.2?°C). Ton values also explained the significant preference of host 2 for p-Xy (115.5?°C) relative to EB (76.6?°C), respectively.
trans-N,N′-Bis(9-phenyl-9-xanthenyl)cyclohexane-1,2-diamine and its thioxanthenyl derivative as potential host compounds for the separation of anilines through host?guest chemistry principles
Barton, Benita,Hosten, Eric C.,Jooste, Daniel V.
, (2020)
In this work, we investigate the potential of separating mixtures of the guest solvents aniline (ANI), N-methylaniline (NMA) and N,N-dimethylaniline (DMA) by means of host?guest chemistry principles employing two novel host compounds, namely trans-N,N′-bis(9-phenyl-9-xanthenyl)cyclohexane-1,2-diamine (1,2-DAX) and trans-N,N′-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,2-diamine (1,2-DAT). These aniline solvents may exist in such mixtures since NMA and DMA are often prepared from ANI by alkylation methods, and reaction yields are seldom quantitative. Owing to their similar boiling points, ranging from 184 to 196 oC, the more usual distillation techniques for their separation are challenging. After recrystallization experiments of the two host compounds from various combinations of these anilines, it was revealed that host?guest chemistry certainly has the potential to serve as an alternative separation strategy for such mixtures. Equimolar ANI/DMA solutions proved most successful, where both 1,2-DAX and 1,2-DAT showed near-quantitative selectivity for DMA (90%). Both single crystal diffraction and thermal analyses were employed in order to understand the preferential behaviour displayed by each host compound.
Host proficiency of N,N′-bis(9-phenyl-9-thioxanthenyl)ethylenediamine for pyridine and the methylpyridine guests–a competition study
Barton, Benita,de Jager, Lize,Hosten, Eric C.
, p. 61 - 71 (2018)
N,N′-Bis(9-phenyl-9-thioxanthenyl)ethylenediamine proved to be an extremely efficient host compound for pyridine and the isomeric methylpyridines. Furthermore, this host displayed selective behaviour during equimolar guest competitions, consistently favouring 3-methylpyridine in binary, ternary and quaternary experiments. Selectivity orders were 3-methylpyridine >> 4-methylpyridine?>?2-methylpyridine, and 3-methylpyridine?>?pyridine?>?4-methylpyridine?>?2-methylpyridine, for equimolar ternary and quaternary solutions, respectively. When guest concentrations in binary competitions were varied, 3-methylpyridine remained the favoured guest, even at low 3-methylpyridine concentrations. Single crystal X-ray diffraction showed that all four complexes were isostructural (monoclinic, P21/n) while guests occupy discrete cavities in the crystal. Only 3-methylpyridine experiences (guest methyl)C–H???π(host) and (guest methyl)C–H???H–Ar(host) interactions, explaining the observed affinity of the host for this guest. DSC analyses provided further affirmation for the host preference: endotherm peak temperatures for the guest release processes correlated directly with the selectivity order for the three methylpyridine isomers.
9-Phenylxanthen-9-ylium and 9-phenylthioxanthen-9-ylium ions: Comparison of o- and p-substitutions in the 9-phenyl group by cyclic voltammetry and visible spectra
Erabi, Tatsuo,Asahara, Masahiro,Miyamoto, Masahumi,Goto, Keisuke,Wada, Masanori
, p. 1325 - 1332 (2007/10/03)
9-Arylxanthen-9-ylium (3a-i) and 9-arylthioxanthen-9-ylium (4a,b,e-i) perchlorates [aryl = 2,4,6-(MeO)3C6H2 (a), 2,6-(MeO)2C6H3 (b), 2-MeOC6H4 (c), 4-MeOC6H4 (d), 3-Br-2,6-(MeO)2C6H2 (e), 2,4,6-Me3C6H2 (f), 2-MeC6H4 (g), 4-MeC6H4 (h), C6H5 (i)] were prepared by the reactions of 9-arylxanthen-9-ols or 9-arylthioxanthen-9-ols with perchloric acid. Their LUMO and HOMO levels were estimated from the redox potential (E0) in cyclic voltammetry and λmax in the UV-visible spectra measured for a 1,2-dichloroethane solution, and were compared with those of 9-aryl-1,8-dimethoxyxanthen-9-ylium ions (8b,i). We found that 1) both the LUMO and HOMO levels varied almost in the same order of substituent on the 9-phenyl group; 2) the MeO-group on the 9-phenyl group was more effective to raise both the HOMO and LUMO levels than the Me-group; 3) the HOMO levels of 3 and 4 were more sensitive than the LUMO levels to the change in the 9-aryl group; 4) p-substitution by MeO- or Me-groups was more effective to raise the HOMO and LUMO levels than o-substitution; 5) the presence of two o-MeO groups was more effective to raise the HOMO and LUMO levels than one o-MeO group; 6) a m-bromination of 9-aryl group in 3b or 4b greatly lowered both LUMO and HOMO levels, as observed for 3e or 4e; 7) both the HOMO and LUMO levels of 8b and 8i were higher than those of 3b and 3i, respectively; 8) the LUMO level of 3b was higher than that of 8i, the isomer.
