Lamberto, Massimiliano et al. published their research in Tetrahedron Letters in 2005 | CAS: 313648-56-5

Dimethyl 5-ethynylisophthalate (cas: 313648-56-5) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Product Details of 313648-56-5

Synthesis of novel rigid-rod and tripodal azulene chromophores was written by Lamberto, Massimiliano;Pagba, Cynthia;Piotrowiak, Piotr;Galoppini, Elena. And the article was included in Tetrahedron Letters in 2005.Product Details of 313648-56-5 This article mentions the following:

Two novel azulene chromophores and were synthesized to study dynamics of ultrafast electron injection at the interface of TiO2 semiconductor nanoparticles. Fluorescence quenching was observed upon binding. In the experiment, the researchers used many compounds, for example, Dimethyl 5-ethynylisophthalate (cas: 313648-56-5Product Details of 313648-56-5).

Dimethyl 5-ethynylisophthalate (cas: 313648-56-5) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Product Details of 313648-56-5

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics