Microwave and infrared spectra of isotopically substituted carbonyl selenide (OCSe)

Infrared and microwave spectral measurements are given for three isotopically enriched species of carbonyl selenide. The high-resolution infrared measurements (made near 2000 and 2600 cm ^-1) provide constants for the following transitions: 10 ⁰000 ⁰0 for ¹⁶O ¹²C ⁸⁰Se; 10 ⁰000 ⁰0 and 11 ¹001 ¹0 for ¹⁸O ¹²C ⁸⁰Se; and 10 ⁰000 ⁰0, 11 ¹001 ¹0, 10 ⁰100 ⁰1, and 10 ⁰100 ⁰0 for ¹⁶O ¹³C ⁸⁰Se. Microwave measurements are given for the J = 4 ← 3, and 3 ← 2 transitions of ¹⁸O ¹²C ⁸⁰Se and ¹⁶O ¹³C ⁸⁰Se in the 00 ⁰0, 01 ¹0, 02 ⁰0, 02 ²0, and 00 ⁰1 states. Equilibrium rotational constants are given for all three isotopic species and the equilibrium bond distances are determined to be r _e(CO) = 1.1535 ± 0.0001 Å and r _e(CSe) = 1.7098 ± 0.0001 Å.