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 (CHNHNH, MHy), [CHNHNH]CdCl (MHyCdCl), and [CHNHNH]CuCl (MHyCuCl), are reported. In contrast to previously reported MHyCl ( = Mn, Ni, and Co) analogues, neither compound undergoes phase transitions. The MHyCuCl has a crystal structure familiar to previous crystals composed of edge-shared 1D chains of the [CuClN] octahedra. MHyCuCl crystallizes in monoclinic 2/ symmetry with MHy cations directly linked to the Cu ions. The MHyCdCl analogue crystallizes in lower triclinic symmetry with zig-zag chains of the edge-shared [CdCl] 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 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 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 and Cd analogues are 2.62 and 5.57 eV, respectively. Magnetic tests indicated that MHyCuCl has smeared antiferromagnetic ordering at 4.8 K.