High-resolution infrared spectra in the C-H region of CH2F2: The nu(6) and2 nu(2) bands

High-resolution, infrared absorption spectra of the nu(6) (asymmetric C-H s tretch) and 2(nu 2) (H-C-H symmetric bend overtone) bands of jet-cooled CH2 F2 are reported with a sub-Doppler resolution of similar to 0.002 cm(-1). M ore than 600 transitions were observed in the range of 3002-3036 cm(-1), of which 268 were assigned the nu(6) fundamental and 184 were assigned to the 2(nu 2) overtone. A fit of the nu(6) band to the A-reduced Watson Hamilton ian yielded eight effective constants including nu(0) = 3014.0503(1), A' = 1.62868(4), B' = 0.354165(5), and C' = 0.308852(3) cm(-1). Similarly, the w eaker 2(nu 2) band was fit to seven parameters including nu(0) = 3026.2297( 2), and A' = 1.63396(6), B' = 0.35367(1), and C' = 0.31183(1) cm(-1) Number s in parentheses are two standard deviations in units of the last digit. An omalous values of the A rotational constant and the Delta(K) centrifugal di stortion constant are attributed to an a-axis Coriolis interaction between the 2(nu 2) and nu(6) bands. The relative intensity of the 2(nu 2) band is used to estimate the stretch-bend anharmonic interaction with nu(1). (C) 19 99 Academic Press.