Theoretical study of HBeO

The nature of the chemical bond in BeO0,−, BeOBe+,0,−, and in their hydrogenated products HBeO0,−, BeOH, HBeOH, BeOBeH+,0,−, and HBeOBeH

“…On the other hand, the HBeO isomer in itsX 2 Π state is perfectly linear with no tendency to bend, is strongly bound with respect to either H( 2 S) + BeO(1 3 Π) or HBe(X 2 Σ + ) + O( 3 P), lies above the global BeOH(X 2 A ) minimum by 11 917 (MRCI)/13 057 (RCCSD(T)) cm −1 , and has an isomerization barrier (HBeO/BeOH) of 10 920 cm −1 with respect to the HBeO(X 2 Π) minimum. 22 Finally, the HBeOH system in itsX 1 A (C s ) state exhibits a BeOH angle of 139 • (present work) similar to the one found in BeOH(X 2 A ) and is pretty much bound with dissociation energies ranging from 74 to 149 kcal/mol depending on the reaction path. 8 Let us consider first the HBeO system that was extensively studied by Zaidi et al 22…”

“…22 Finally, the HBeOH system in itsX 1 A (C s ) state exhibits a BeOH angle of 139 • (present work) similar to the one found in BeOH(X 2 A ) and is pretty much bound with dissociation energies ranging from 74 to 149 kcal/mol depending on the reaction path. 8 Let us consider first the HBeO system that was extensively studied by Zaidi et al 22…”

“…It is obvious even from the geometrical features that HBeO(X 2 Π, r e (BeO) = 1.475 Å) (see Scheme 8) is formed from the BeO(1 3 Π, r e = 1.470 Å) state while HBeO(1 2 Σ + , r e (BeO) = 1.415 Å) from the BeO(3 3 Σ + , r e = 1.414 Å) one (see Scheme 9), although the latter state correlates adiabatically to H( 2 S) + BeO(X 1 Σ + ); see also Figure 1 of Ref. 22. Now, let us move to the more mysterious quasilinear BeOH species.…”

Experimental and Theoretical Characterization of the 22A′–12A′ Transition of BeOH/D

“…The highest-energy molecular orbital held closed in this scheme (orbital 5) was predominantly composed of the in-plane O2p y , with small contributions from Be2s, O2s, and H1s. As a point of comparison, previous sa-CASSCF-MRCI calculations yielded excitation energies for the first excited state of 3.92 (adiabatic for the linear geometry) and 3.96 eV (vertical), while the present calculations yielded 3.89 eV (adiabatic).…”

“…The monohydroxides of the alkaline earth metals (MOH, M = Be, Mg, Ca, Sr, Ba) have been the subject of numerous theoretical − and experimental studies. − One of the motivations for this work has been the question of how the M–O bonding changes as a function of the atomic number of the metal. Theoretical studies , indicate that the heavier members of the group, M = Ca, Sr and Ba, have ionic bonds that are formally M + –OH – .…”