The importance of deformation on the strength of beryllium bonds

Study of Beryllium, Magnesium, and Spodium Bonds to Carbenes and Carbodiphosphoranes

“…The current situation with this nomenclature has recently been well captured by Alkorta, Elguero, and Frontera in a review article in Crystals [ 1 ]. Thus, in addition to hydrogen bonds [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ], which have been well established for a hundred years, we also now have alkali bonds [ 17 , 18 , 19 , 20 , 21 , 22 ], alkaline earth metal bonds [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ], triel bonds [ 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ], tetrel bonds [ 47 , 48 , 49 , 50 , 51 , 52 ,…”

“…Apart from the obvious hydrogen bonds, the remaining terms refer consecutively to the interaction in which a Lewis acid is an element of groups 1–2 and then 13–18 of the periodic table. In circulation, there also exist names that refer to individual elements of group 1 or 2, namely lithium bonds [ 17 , 18 , 19 , 20 ] and sodium bonds [ 21 , 22 ] in the former case and beryllium bonds [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ], magnesium bonds [ 23 , 29 , 30 , 31 , 32 , 33 ], and calcium bonds [ 34 ] in the latter. Interactions involving various transition metals have not been called so willingly; however, in the case of interactions in which the Lewis acid center is a metal from groups 10 or 11, the term regium bonds [ 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 ] is relatively common.…”

A computational study of model beryllium-bonded complexes of oxirane and F-substituted oxiranes with BeX2 (X=H, Cl)

“…This also resulted in a substantial lengthening of the Be X bonds and red-shifting of the X Be X antisymmetric stretching frequencies: it was also noted that the symmetric X Be X stretch was significantly blue-shifted [11]. Other more recent studies have found similar strong assocations of this bond angle with the intermolecular interaction energy [19,20].…”

Some Interesting Features of Non-Covalent Interactions

“…This situation is not only found in boron complexes, but is also reproduced when dealing with beryllium bonds. 25 Again surprisingly in the NH 3 :BeH 2-n F n complexes the interaction energy does not increase steadily with the number of fluorine substituents (See Figure 3a) because the value calculated for the NH 3 :BeHF complex is smaller than the one calculated for the unsubstituted parent compound. If the LUMO of the three Lewis acids, namely BeH 2 , BeHF and BeF 2 in their equilibrium conformations is taken as a measure of their intrinsic capacity as electron acceptors (See Figure 3b) one should conclude that the Lewis acidity of BeH 2 and BeF 2 should be practically equal, whereas that of BeHF should be much smaller than the other two, what is in clear contrast with the calculated dissociation energies.…”