Infrared laser jet spectroscopy of the nu(11) fundamental band of Fe(CO)(5)

The rotationally resolved spectrum of the nu(11) (E') fundamental band of F e(CO)(5) at 649 cm(-1) has been measured in a supersonic jet using infrared diode laser absorption spectroscopy. Adopting a ground state A rotational constant of 0.030 75 cm(-1), calculated from the electron diffraction struc ture, the following rotational constants were determined: A(11) = 0.030 71( 3) cm(-1), B-0 = 0.026 82(11) cm(-1) and B-11 = 0.026 83(10) cm(-1). The B rotational constants are in close agreement with recent ab initio calculati ons. The band origin is 649.078 9(22) cm(-1) and the Coriolis coupling cons tant zeta(11) = +0.838 8(10).