C-H⋯O interaction and water tunneling in the CHClF2-H2O dimer

► Chirped-pulse and resonant cavity Fourier-transform microwave spectra of CHClF2-H2O. ► Spectra of five isotopologues assigned. ► Both weak C-H⋯O and C-Cl⋯H-O interactions observed. ► Tunneling splittings due to water internal rotation analyzed.