Isostructural Inorganic–Organic Piperazine-1,4-diium Chlorido- and Bromidoantimonate(III) Monohydrates: Octahedral Distortions and Hydrogen Bonds

NH2(CH3)2CuCl3 Organic-Inorganic Hybrid Perovskite: Consideration to Crystal Structure, Thermodynamics, and Structural Molecular Dynamics

The crystal structure of NH2(CH3)2CuCl3, an organic-inorganic hybrid perovskite, undergoes a phase transition from triclinic to monoclinic at the phase transition temperature T C of 287 K. We investigated the temperature dependencies of NMR chemical shifts and spin-lattice relaxation time T 1ρ to gain insights into the structural geometry and molecular dynamics during the transition from phase II to phase I at high temperatures. Analysis of the 1H and 13C NMR chemical shifts of the cation revealed a continuous change in the surrounding structural geometry with temperature, without any anomalous changes around T C. The sudden decrease in T 1ρ values from low to high temperatures indicated a significant variation in proton and carbon dynamics at T C, arising from the slowing motion of molecular dynamics across the phase transition. The activation energies E a obtained from the temperature dependence of T 1ρ for 1H and 13C were larger in phase I than in phase II. This suggests that molecular motions in phase II exhibit a higher degree of freedom compared to those in phase I, where they are more constrained. These findings on NH2(CH3)2CuCl3 are presented to enhance its potential applications by elucidating the crystal configuration and structural molecular dynamics of ABX3 type compound.

Piperazine-1,4-diol (PipzDiol): synthesis, stereodynamics and assembly of supramolecular hydrogen-bonded 2D networks

The manuscript describes a novel small building block, 1,4-piperazinediol (PipzDiol), which has an extended H-bond donor structure compared to piperazine.

Using a Porphyrin Diacid Cation to Stabilize a Square-Pyramidal BiX5 (X = Br, Cl/Br) Unit

Main-group halogenido metalates are a diverse class of compounds with an intricate structural chemistry and a wide range of applications. Here, we present an unprecedented anion motif in the structural chemistry of halogenido bismuthates, a square-pyramidal BiX₅ unit. We show how the porphyrin diacid used as our compounds' counterion is templating the formation of this new motif, suggesting that other strong anion receptors may be able to stabilize unique metalate anions in future work.