B3LYP/6-311++G(d,p) calculations were used in order to model the geometries of the  C₂H₆N⁺···nBeH₂  bimolecular (n = 1)  and  C₂H₆N⁺···nMgH₂  trimolecular (n = 2) dihydrogen-bonded complexes. Our theoretical proposal is to demonstrate that the C₂H₆N⁺ cationic ring can be useful to interact with one and two earth alkaline compounds such as BeH₂ and MgH₂. Being by analysis of structural parameters and measurement of the dihydrogen bond energy strengths, we would like to mention that although the protonated nitrogen is highly positive, it is by the hydrogen atoms that BeH₂ and MgH₂ interact and therefore the dihydrogen-bonded complexes are formed, being then bimolecular (n = 1) or trimolecular (n = 2) ones. Moreover, the interpretation of the infrared spectrum indicates the existence of red-shifts and blue-shifts related to NH bonds of the C₂H₆N⁺ cationic rings. These two chemical shift types also have been verified on BeH₂ and MgH₂, what lead us to observe that red-shifts and blue-shifts arise in different chemical regions, the first related to the  formation  of  the (H···H)  dihydrogen-bonds,  while  the  second  is  associated  to peripherical centers,  such  as  NH,  BeH  and  Mg  bond not  directly  involved  with  the intermolecular charge transfer.