Spectroscopic properties, including equilibrium rotational constants (A e , B e , C e in GHz) and dipole moments (µ in Debye), were calculated at the ωB97XD/def2-TZVP level using ωB97XD-optimized geometries (see Appendix A and Table ). Moments of inertia (I A , I B , I C , in amu Å2 ) were derived from A e , B e , and C e values using the NIST conversion platform NIST (2023). Ground vibrational state rotational constants (A 0 , B 0 , C 0 , in GHz) were also computed at the ωB97XD/def2-TZVP level (Table ).