Theoretical study on the stability of the complexes A···BX3 [A = CH3NH3+, NH2CHNH2+, NH2CHOH+; B = Sn2+, Pb2+; X = F-, Cl-, Br-, I-].

The interaction of corresponding molecular building blocks of the complexes A···BX3 would provide valuable information to quickly estimate the properties of the solar cell. In this work, the H···X hydrogen bond between the organic cations A+ (CH3NH3+, NH2CHNH2+, NH2CHOH+) and the inorganic anions BX3- (B = Sn2+, Pb2+, X = F-, Cl-, Br-, I-) were studied by theoretical calculation at the B3LYP-D3/ma-def2-TZVP level to investigate the stability of the complexes A···BX3. The strength of H···X hydrogen bond is enhanced in the order of NH2CHNH2+ < CH3NH3+ < NH2CHOH+, Sn2+ < Pb2+, and weakened in the order of F- > Cl- > Br- > I-, indicating that the complexes A···BX3 enhances with the increase of electron donating ability of B and the decrease of electron donating ability of X, and application of the substituent A = NH2CHOH+ may be effective to enhance the stability of perovskite and replace the toxic metal Pb by Sn. Graphical abstract.