A theoretical analysis based on arsenic adapted vibrational computational tools, i.e. DFT/Binning VTZP anharmonic potential and the use of a variational method allow us to predict the gas phase spectra of the two simplest multiples bonded carbon-arsenic systems (H2C=AsH and HC=As) in the mid infrared region up to 4500 cm(-1). Several weak and very weak bands corresponding to overtones are enlightened in addition to the fundamental bands in order to accurately assign future IR spectra, but also to propose an efficient method for the prediction of experimental data of organoarsenic compounds. (C) 2010 Elsevier B.V. All rights reserved.