6631-16-9Relevant articles and documents
Synthesis and optical properties of a library of multi-colored isomeric aryldibenzopyrylium halochromic cations
Meyer, Samantha M.,Charlesworth-Seiler, Eva M.,Patrow, Joel G.,Kitzrow, Jonathan P.,Gerlach, Deidra L.,Reinheimer, Eric W.,Dahl, Bart J.
, (2020)
This report describes the synthesis of five new colorful 6-aryldibenzo[b,d]pyrylium cation salts, a largely unexplored structural unit. These rare compounds are benzannulated structural derivatives of the well-known flavylium cations found widespread in natural pigments. These new dyes are directly compared to three previously synthesized 6-aryldibenzo[b,d]pyrylium cation salts as well as eight colorful isomeric 9-aryldibenzo[b,e]pyrylium cation, or 9-arylxanthylium, salts. The 9-arylxanthylium unit is commonly found in the biologically important rhodamine and rosamine dyes, yet six of the analogs presented in this study were either previously unreported or not isolated. The visual and spectroscopic properties of all 16 compounds were analyzed as a function of the structural differences between the compounds. All compounds displayed reversible halochromism in organic solution, displaying bright colors under acidic conditions and becoming colorless under basic conditions.
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.
, (2020/06/09)
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.
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 (2017/09/25)
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.
