Hybrid Chlorides with Methylhydrazinium Cation: [CH 3 NH 2 NH 2 ]CdCl 3 and Jahn-Teller Distorted [CH 3 NH 2 NH 2 ]CuCl 3 .

The synthesis, structural, phonon, optical, and magnetic properties of two hybrid organic-inorganic chlorides with monoprotonated methylhydrazinium cations (CH 3 NH 2 NH 2 + , MHy + ), [CH 3 NH 2 NH 2 ]CdCl 3 (MHyCdCl 3 ), and [CH 3 NH 2 NH 2 ]CuCl 3 (MHyCuCl 3 ), are reported. In contrast to previously reported MHy M II Cl 3 ( M II = Mn 2+ , Ni 2+ , and Co 2+ ) analogues, neither compound undergoes phase transitions. The MHyCuCl 3 has a crystal structure familiar to previous crystals composed of edge-shared 1D chains of the [CuCl 5 N] octahedra. MHyCuCl 3 crystallizes in monoclinic P 2 1 / c symmetry with MHy + cations directly linked to the Cu 2+ ions. The MHyCdCl 3 analogue crystallizes in lower triclinic symmetry with zig-zag chains of the edge-shared [CdCl 6 ] octahedra. The absence of phase transitions is investigated and discussed. It is connected with slightly stronger hydrogen bonding between cations and the copper-chloride chains in MHyCuCl 3 due to the strong Jahn-Teller effect causing the octahedra to elongate, resulting in a better fit of cations in the accessible space between chains. The absence of structural transformation in MHyCdCl 3 is due to intermolecular hydrogen bonding between two neighboring MHy + cations, which has never been reported for MHy + -based hybrid halides. Optical investigations revealed that the bandgaps in Cu 2+ and Cd 2+ analogues are 2.62 and 5.57 eV, respectively. Magnetic tests indicated that MHyCuCl 3 has smeared antiferromagnetic ordering at 4.8 K.