Analysis of the Coriolis interaction between ν6 and ν4 bands of ethylene-cis-d2(cis-C2H2D2) by high-resolution FTIR spectroscopy

► The spectrum of ν6 band of cis-C2H2D2 was recorded in the 990-1100 cm−1 region. ► Rovibrational constants for v6 = 1 state and ν6 band centre were improved. ► 609 Infrared lines were fitted by Watson A-reduced Hamiltonian (Ir representation). ► Second-order a-type Coriolis coupling constant between ν6 and ν4 was obtained.