Structural characterization of a series of aryl selenoacetates

Se-mesityl ethaneselenoate, Se-4-(dimethylamino)phenyl ethaneselenoate, Se-anthracen-9-yl ethaneselenoate, and Se-(4′-cyanobiphenyl-4-yl) ethaneselenoate, potential building blocks for selenium-anchored self-assembled monolayers on metal surfaces, were examined and characterized using single crystal X-ray diffraction, Fourier-transform infrared (FT-IR) spectroscopy, and density functional theory (DFT) calculations. The molecules all adopt similar conformations with the selenoacetate unit being tilted between 61° and 78° with respect to the adjacent arene ring and binding angles of 97–100° at the selenium atom. An interesting feature is that the oxygen atom of the acetyl group always points toward the arene system, a feature correctly reproduced by the DFT calculations. The calculations could also predict the IR spectra of the compounds, making a detailed interpretation possible.

► A series of aryl selenoacetates has been investigated by XRD, DFT and FT-IR. ► Crystal structures of aryl selenoacetates have been measured for the first time. ► Cis-orientation of the carbonyl oxygen regarding the aryl moiety is a common feature for all investigated compounds. ► Torsion angle between the selenoacetate group and the aryl moiety is dominated by the packing effects. ► Strong IR bands at 1702–1722 cm−1 and 565–577 cm−1 are characteristic for the selenoacetate group.