Crystal structure, vibrational spectroscopy and optical properties of a one-dimensional organic-inorganic hybrid perovskite of [NH3CH2CH(NH3)CH2]BiCl5

Exploring the potential applications of lead-free organic-inorganic perovskite type [NH3(CH2)nNH3]MCl4 (n = 2, 3, 4, 5, and 6; M = Mn, Co, Cu, Zn, and Cd) crystals

The organic-inorganic hybrid perovskite compounds have been extensively studied since the dawn of a new era in the field of photovoltaic applications. Up to now, perovskites have proven to be the most promising in terms of power conversion efficiency; however, their main disadvantages for use in solar cells are toxicity and chemical instability. Therefore, it is essential to develop a hybrid perovskite that can be replaced with lead-free materials. This review focuses on the possibility of applying lead-free organic-inorganic perovskite types [NH3(CH2)nNH3]MCl4 (n = 2, 3, 4, 5, and 6; M = Mn, Co, Cu, Zn, and Cd) crystals. We are seeking organic-inorganic hybrid perovskite materials with very high temperature stability or without phase transition temperature, and thermal stability. Thus, by considering the characteristics according to the methylene lengths and the various transition metals, we aim to identify improved materials meeting the criteria mentioned above. Consequently, the physicochemical properties of organic-inorganic hybrid perovskite [NH3(CH2)nNH3]MCl4 regarding the effects of various transition metal ions of the anion and the methylene lengths of the cation are expected to promote the development and application of lead-free hybrid perovskite solar cells.

Processing on crystal growth, structure, thermal property, and nuclear magnetic resonance of organic-inorganic hybrid perovskite type [NH3(CH2)6NH3]ZnCl4 crystal

Organic-inorganic hybrid compounds have recently gained significant attention in recent years due to their diverse applications. Herein, [NH3(CH2)6NH3]ZnCl4 crystals were grown, and their triclinic structure, phase transition temperature (TC = 408 K), and high thermal stability (Td = 584 K) was determined using X-ray diffraction (XRD), differential scanning calorimetry, and thermogravimetry measurements. By analyzing the chemical in response to temperature changes, we observed that the coordination geometry around 1H and 13C were highly symmetric below TC, whereas their symmetry was lowered above TC. The change of N-H⋯Cl hydrogen bond from XRD results and the change of 14N NMR chemical shifts was due to the changes to the coordination geometry of Cl- around Zn2+ in the ZnCl4 anion. The activation energy of 1H was three times greater than that of 13C, and this result indicates that the energy transfer of 13C was easier than those of 1H. We compared the results for [NH3(CH2)nNH3]ZnCl4 (n = 6) studied here with those for n = 2, 3, 4, and 5 obtained from previous studies. The characteristics of the length of CH2 in the methylene chain are expected to be used for potential applications in the near future.

Investigation of the structure, phase transitions, molecular dynamics, and ferroelasticity of organic-inorganic hybrid NH(CH3)3CdCl3 crystals

Understanding the physical and chemical properties of the organic-inorganic hybrid NH(CH₃)₃CdCl₃ is essential for its application. Considering its importance, a single crystal of NH(CH₃)₃CdCl₃ was grown with an orthorhombic structure at 300 K. The phase transition temperatures were determined to be 345 (T_C3), 376 (T_C2), and 452 K (T_C1) (phases IV, III, II, and I, respectively, starting from a low temperature). The partial decomposition temperature was 522 K (T_d). Furthermore, the NMR chemical shifts of the ¹H, ¹³C, and ¹¹³Cd atoms of the cation and anion varied with increasing temperature. Consequently, a significant change in the coordination geometry of Cl around Cd in CdCl₆ and a change in the coordination geometry of H in NH was associated with changes in the N-H⋯Cl hydrogen bond near the phase transition temperature. The ¹³C activation energy E_a obtained from the spin-lattice relaxation time was smaller than that of ¹H E_a, suggesting that energy transfer around ¹³C is easier. Additionally, a comparison of the twin domain walls measured via optical polarizing microscopy and Sapriel's theory indicated that the crystal structure in phase III was more likely to be orthorhombic than hexagonal.

Investigating the physicochemical properties, structural attributes, and molecular dynamics of organic-inorganic hybrid [NH3(CH2)2NH3]2CdBr4·2Br crystals

An in-depth understanding of the physicochemical properties of the organic-inorganic hybrid [NH₃(CH₂)₂NH₃]₂CdBr₆ whose structure corresponds to the formulation [NH₃(CH₂)₂NH₃]₂CdBr₄· 2Br is essential for its application in batteries, supercapacitors, and fuel cells. Therefore, this study aimed to determine the crystal structure, phase transition, structural geometry, and molecular dynamics of these complexes. Considering its importance, a single crystal of [NH₃(CH₂)₂NH₃]₂CdBr₆ was grown; the crystal structure was found to be monoclinic. The phase transition temperatures were determined to be 443, 487, 517, and 529 K, and the crystal was thermally stable up to 580 K. Furthermore, the ¹H, ¹³C, ¹⁴N, and ¹¹³Cd NMR chemical shifts caused by the local field surrounding the resonating nucleus of the cation and anion varied with increasing temperature, along with the surrounding environments of their atoms. In addition, ¹H spin-lattice relaxation time T_1ρ and ¹³C T_1ρ, which represent the energy transfer around the ¹H and ¹³C atoms of the cation, respectively, varied significantly with temperature. Consequently, changes in the coordination geometry of Br around Cd in the CdBr₆ anion and the coordination environment around N (in the cation) were associated with changes in the N-H···Br hydrogen bond. The structural geometry revealed critical information regarding their basic mechanism of organic-inorganic hybrid compounds.

Growth, structure, phase transition, thermal properties, and structural dynamics of organic-inorganic hybrid [NH3(CH2)5NH3]ZnCl4 crystal

In this study, the physicochemical properties of [NH₃(CH₂)₅NH₃]ZnCl₄ crystals were investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, and nuclear magnetic resonance (NMR). The crystals at 300 K had a monoclinic structure with C2/c space group and lattice constants are a = 21.4175 Å, b = 7.3574 Å, c = 19.1079 Å, β = 120.5190°, and Z = 8. Three endothermic peaks at 256, 390, and 481 K were observed in the DSC curve. From the single-crystal XRD patterns, powder XRD patterns, and optical microscopy results based on the temperature change, the phase transition and melting temperatures were determined to be 390 and 481 K, respectively. NMR studies indicated no change in ¹H chemical shifts, but a change in the chemical shifts for C2, located between C1 and C3 of the cation at 340 K. Increase in molecular motion caused an increase in the spin-lattice relaxation time, T_1ρ, at low spinning rates, under magic-angle spinning rate conditions. This crystal showed a minor change in the N-H···Cl hydrogen bond, related to the coordination geometry of the ZnCl₄ anion.

Phase transition, thermal stability, and molecular dynamics of organic-inorganic hybrid perovskite [NH3(CH2)6NH3]CuCl4 crystals

Organic-inorganic hybrid perovskites have various potential applications in fuel cells and solar cells. In this regard, the physicochemical properties of an organic-inorganic [NH3(CH2)6NH3]CuCl4 crystal was conducted. The crystals had a monoclinic structure with space group P21/n and lattice constants a = 7.2224 Å, b = 7.6112 Å, c = 23.3315 Å, β = 91.930°, and Z = 4 at 300 K, and the phase transition temperature (T C) was determined to be 363 K by X-ray diffraction and differential scanning calorimetry experiments. From the nuclear magnetic resonance experimental results, the changes in the 1H chemical shifts in NH3 and the influence of C1 located close to NH3 in the [NH3(CH2)6NH3] cation near T C are determined to be large, which implies that the structural change of CuCl4 linked to N-H⋯Cl is large. The 1H spin-lattice relaxation time (T 1ρ) in NH3 is shorter than that of CH2, and the 13C T 1ρ values for C1 close to NH3 are shorter than those of C2 and C3 due to the influence of the paramagnetic Cu2+ ion in square planar geometry CuCl4. The structural mechanism for the phase transition was the change in the N-H⋯Cl hydrogen bond and was associated with the structural dynamics of the CuCl4 anion.

Recent advances on structural, thermal, vibrational, optical, phase transitions, and catalysis properties of alkylenediammonium halogenometallate materials (Metal: Bi, Sb, Halogen: Cl, Br, I)

This paper aims to review recent advances on synthesis, crystal structures, thermal, spectroscopic, phase transitions, optical, dielectric, and catalysis properties of hydrate and anhydrous alkylenediammonium halogenometallates materials (Metal: Bi, Sb, Halogen: Cl, Br, I). These hybrid materials present rich structural diversities based on octahedra forming infinite zero dimensional, 1-dimensional chains, 2-dimensional layers, discrete bioctahedra, and discrete tetramer units. The effect, contribution and importance of hydrogen bonding N–H … X (X: Cl, Br, I) are reviewed in terms of solid state relationship. Particularly, a comparative study is made on hydrate and anyhdrous aliphatic chlorobismuthates with alkylenediammonium +NH3(CH2) n NH3 + based on structural data and V/Z variation with (CH2) n chains (n = 2–8, 12), and variation of BiCl6 3− Raman frequencies modes versus (CH2) n chains (n = 3–8). Hydrate salts with (n = 3, 12) consist of isolated BiCl6 3− anions and two water molecules, against others ones with isolated anionic chains [BiCl5 2−] n or Bi2Cl10 4− dimers, formed by distorted octahedra BiCl6 3− sharing corners, vices or edges. The reviewed optical and electronic band gaps suggested interesting compounds with band gaps (1.85–2.4 eV), as suitable materials in optoelectronic properties, photoactive layer in solution-processed photovoltaics, and bio-imaging or photovoltaic applications. It was concluded that iodobismuthate salts have generally the lowest bands gap, compared to that of bromo and chlorobismuthate slats. Catalysis proprieties are reviewed n fast (RhB) degradation under dark conditions for (C4N2H7)4Bi2Cl10, (C5H9N2)BiI4, and {(H-BPA)4·[(BiI6)I13]·2I3} n , and in organic salts synthesis under solvent-free conditions. Herein NH3(CH2) n NH3BiCl5 (n = 5–7) salts were used as highly efficient catalysts, which is a novel tendency in chlorobismuthate researchs in the green chemistry field.