Two new organic–inorganic hybrid materials, based on 1,3-CycloHexaneBis-(Methyl Amine), abbreviated CHBMA, namely (H2CHBMA)ZnCl4·2H2O (CP1) and (H2CHBMA)CdI4·2H2O (CP2), have been synthesized under mild conditions in acidic media and characterized by single-crystal X-ray diffraction, spectroscopic techniques (13C NMR, FTIR, RAMAN) and thermal analysis. The crystal structures of the two compounds were solved by single-crystal X-ray diffraction methods. Both compounds show a 3-dimensional supramolecular structure directed by various interactions between tetrahalidometallate anions (ZnCl42−, CdI42−), water molecule and organic cations (H2CHBMA)2+. For both compounds, the cyclohexane ring of the template cation is in a chair conformation with the methylammonium substituent in the equatorial positions and the two terminal ammonium groups in a cis conformation but with two different orientations (upward for CP1 and downward for CP2) which influences the supramolecular architecture of the two structures. Hirshfeld surface analysis and the associated two-dimensional finger print plots were used to explore and quantify the intermolecular interactions in the crystals.

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Two new organic–inorganic salts of perhalidometallates with protonated organic amine cations have been synthesized and characterized by X-ray diffraction and thermal analysis. (CHBMAH2)ZnBr4·3/2H2O 1 and (CHBMAH2)ZnCl4 4 [(CHBMAH2)2+: 1,3-cyclohexanebis(methylammonium)] were obtained in single-crystal form. The crystal packing in all of the obtained compounds is governed by the formation of various non-covalent intermolecular forces between tetrahalidometallate anions and organic cations, assisted by water molecules in the hydrates. Hirshfeld surface analysis denotes that the most important contributions to the crystal packing are X···H/H···X (X: Cl, Br, I) and H···H interactions. Interestingly, the compound 1,3-cyclohexanebis(methylammonium)tetrachloridozincate (II) dihydrate, (CHBMAH2)ZnCl4·2H2O 2, undergoes thermally-triggered single-crystal-to-single-crystal (SCSC) transformation upon dehydration to produce a supramolecular solid compound, 1,3-cyclohexanebis(methylammonium) tetrachloridozincate (II), (CHBMAH2)ZnCl4 4. The SCSC transformation causes changes in the lattice parameters and a structural rearrangement. Furthermore, the catalytic properties of (CHBMAH2)ZnCl4·2H2O 2 and (CHBMAH2)CdI4·2H2O 3 have been explored in the acetalization process using various uncommon alcohols, beyond methanol or ethanol, for the first time in the literature, with outstanding results, and opening the door to the formation of alternative acetals.