Rotational transitions of the linear molecule 3-isocyano-2-propynenitrile,
NCCCNC, have been measured in the frequency range from 75 up to 120 GHz and
assigned to the excited vibrational bending states (upsilon(6) upsilon(7)
upsilon(8) upsilon(9)) = (0002), (0003), (0004), (0011), and (0020). The an
alysis of the spectrum extends the spectroscopic data for NCCCNC by adding
various newly determined rotational and rovibrational constants. (C) 2000 E
lsevier Science B.V. All rights reserved.