Structure of Two Acetylene Derivatives of Salicylic Acid.

Methyl 2-hydroxy-5-[(trimethylsilyl)ethynyl]benzoate and methyl 2-hydroxy-5-ethynylbenzoate have been synthesized, and the crystallographic data on these compounds are reported. Due to their planar molecular structures, both compounds are layered. At the same time, planar molecules do not form a stack packing. In methyl 2-hydroxy-5-ethynylbenzoate, molecules in a layer are bound by hydrogen bonds (including those involving the terminal proton of the ethynyl group). The IR spectra are reported, and the fundamental absorption bands are interpreted for both compounds. The photoluminescence spectrum of methyl 2-hydroxy-5-[(trimethylsilyl)ethynyl]benzoate is also recorded: the emission maxima in the solid state and in chloroform solution are located at ~566 and 500 nm, respectively. [ABSTRACT FROM AUTHOR]