Further study of the microwave spectrum of chlorine lsocyanate: The substitution structure and nuclear quadrupole coupling
The microwave spectra of three further isotopic species of chlorine isocyanate ( 35Cl 15N 12C 16O, 37Cl 15N 12C 16O, 35Cl 14N 13C 16O) have been measured. From them we have obtained rotational constants, centrifugal distortion constants, and nuclear quadrupole coupling constants. The data are combined with earlier data ( 1) to confirm the planarity of the molecule, and to give a full substitution structure as follows: r (ClN) = 1.705 ± 0.005 Å; r (NC) = 1.226 ± 0.005 Å; r (CO) = 1.162 ± 0.005 Å; < (ClNC) = 118°50' ± 30'; < (NCO) = 170°52' ± 30', with Cl and O trans. We have also calculated the chlorine and nitrogen quadrupole coupling constants using the SCF-MO-CNDO method, and have obtained good agreement with the measured values. Evidence for in-plane π-bonding at nitrogen has been obtained.