The ν₃ vibration–rotation band of DCP and the equilibrium structure of methinophosphide

Abstract

The ν 3 band of D 12 CP(C—P stretching) has been recorded at a resolution of about 0.03 cm −1 . The band centre, ν 0 , is found to be at 1231.4025(6) cm −1 , whereas a force constant calculation had previously given a value of 1216 cm −1 . The rotational constant B 3 is determined and this allows the calculation of B e since the constants B 1 and B 2 are already known. Finally, the equilibrium moment of inertia, I e , of the D 12 CP molecule is calculated. Since I e for the H 12 CP molecule is also known, the equilibrium internuclear distances of methinophosphide may be calculated. One obtains: r e (C—H) 1.0666(2) Å, and r e (C≡P) 1.54020(3) Å.