Synthesis, experimental and theoretical study of novel 2-haloalkyl (-CF2H, -CCl2H, -CF2CF3)-, 3-bromo and bromomethyl substituted chromones

Abstract:

A set of seven new chromones with 2-haloalkyl (-CF<inf>2</inf>H, -CCl<inf>2</inf>H, -CF<inf>2</inf>CF<inf>3</inf>) and 3-bromo and bromomethyl substituents were synthesized. The novel compounds were studied by DFT calculations and characterized by vibrational spectroscopy (IR and Raman) in solid state, and NMR (¹H, ¹³C and ¹⁹F) and UV–vis spectroscopy in solution. The crystal structure of 3-dibromomethyl-2-difluoromethyl chromone was determined by X-ray diffraction. Due to extended π-bond delocalization, the organic framework is planar and lies on a crystallographic m-mirror plane. The intermolecular non-covalent interactions of 3-dibromomethyl-2-difluoromethyl chromone, as π⋯π stacking arrangements, F⋯H hydrogen bonds and O⋯Br contacts were evaluated by Hirshfeld surfaces analysis. These intermolecular contacts, which affect the absorption bands location of the involved groups, were also detected in the vibrational spectra.

Año de publicación:

2021

Keywords:

• structural X-ray diffraction
• Spectroscopic properties
• Hirshfeld surface analysis
• Halogen bonds
• Quantum chemical calculations
• 2-haloalkyl chromones

Fuente:

scopus