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: 10⁰000⁰0 for ¹⁶O¹²C⁸⁰Se; 10⁰000⁰0 and 11¹001¹0 for ¹⁸O¹²C⁸⁰Se; and 10⁰000⁰0, 11¹001¹0, 10⁰100⁰1, and 10⁰100⁰0 for ¹⁶O¹³C⁸⁰Se. Microwave measurements are given for the J = 4 ← 3, and 3 ← 2 transitions of ¹⁸O¹²C⁸⁰Se and ¹⁶O¹³C⁸⁰Se in the 00⁰0, 01¹0, 02⁰0, 02²0, and 00⁰1 states. Equilibrium rotational constants are given for all three isotopic species and the equilibrium bond distances are determined to be $\text{r}{}_{\mathrm{e}}\text{(CO) = 1.1535 ± 0.0001}\text{A}\text{?}$ and $\text{r}{}_{\mathrm{e}}\text{(CSe) = 1.7098 ± 0.0001}\text{A}\text{?}$.