Thermal and optical properties of red luminescent glass forming symmetric and non symmetric styryl-4H-pyran-4-ylidene fragment containing derivatives

Synthesis and Physical Properties of Red Luminescent Glass Forming Pyranylidene and Isophorene Fragment Containing Derivatives

“…The simplest of 2,6-disubstituted-4H-pyran-4-ones is 2,6-dimethyl-4H-pyran-4-one (compound 2 in Fig.2), which is obtained in 86% yield from dehydroacetic acid (compound 1 in Fig.2) by acidic rearrangement with following decarboxylation (see Fig.2) [32][33]. Figure 2.…”

“…If a pyranylidene type compound has two active methyl groups, like compound 25a, (see Fig.10) it will react with one or two aromatic aldehyde molecules producing chromophores 58-66 (see Fig.14). The reaction product will most likely be a mixture of mono-and bis-condensation products, which are difficult to separate and purify [32]. In reaction with two methyl groups bis-styryl derivatives of pyranylidene are obtained (see Fig.14).…”

“…We have synthesized such a compound -4-(bis(2-(trityloxy)ethyl)amino) benzaldehyde [31][32] 75, in Fig.16. …”

“…For obtaining red luminescent glass forming derivatives of pyranylidene, we use three different electron acceptor fragment containing derivatives of pyranylidene (compounds 25a in Fig.17). Malononitrile (in compounds 74a and 75a), indene-1,3-dione (in compounds 74b and 75b) and barbituric acid (in compounds 74c and 75c) are used as electron acceptor fragment carrying compounds [32].…”

“…Such compounds, which can make a solid-state glassy structure prepared from solutions, could facilitate technological processes in the production of many devices in optoelectronics, for example, light emitting devices by low-cost deposition such as wet casting methods and easier light-emitting material synthesis. Some of these red lightemitting compounds have been introduced by us [28][29][30][31][32].…”