Example of Disulfide Conformational Change in the Solid State: Preparation, Optical Properties, and X-ray Studies of a Cystamine-Based Iodoplombate Hybrid

Organic-Inorganic Hybrid Tin Halide Single Crystals with Sulfhydryl and Hydroxyl Groups: Formation, Optical Properties, and Stability

Lead (Pb)-free halide hybrid materials have received a great deal of attention because of their potential in optoelectronic applications. However, heteroatom-based amine lead-free tin halide hybrid single crystals have not been well investigated yet. Detailed synthetic processes, growth, crystal structures, and stability of (ACH₂CH₂NH₃)₂SnBr₆ (A = OH or SH) and (BCH₂CH₂NH₃)₂SnI₄ (B = I or SH) single crystals were investigated. Interestingly, (IH₃NCH₂CH₂SSCH₂CH₂NH₃)₂HPO₃ exhibited orange-red photoluminescence (PL) at about 620 nm with an average PL lifetime of about 912 ns. (HSCH₂CH₂NH₃)₂SnI₄ single crystals exhibited a PL peak at 620 nm with an average PL lifetime of about 0.607 ns. More importantly, (HSCH₂CH₂NH₃)₂SnI₄ single crystals exhibited reversible red-black color transformations when exposed to a H₃PO₂ solution and an ambient atmosphere, which was attributed to oxidation from Sn²⁺ to Sn⁴⁺, rather than from I^- to I₃^- (I₂). The intriguing characteristics should provide guidance for further optoelectronic applications of these Pb-free halide hybrid materials.

The 2D Halide Perovskite Rulebook: How the Spacer Influences Everything from the Structure to Optoelectronic Device Efficiency

Two-dimensional (2D) halide perovskites have emerged as outstanding semiconducting materials thanks to their superior stability and structural diversity. However, the ever-growing field of optoelectronic device research using 2D perovskites requires systematic understanding of the effects of the spacer on the structure, properties, and device performance. So far, many studies are based on trial-and-error tests of random spacers with limited ability to predict the resulting structure of these synthetic experiments, hindering the discovery of novel 2D materials to be incorporated into high-performance devices. In this review, we provide guidelines on successfully choosing spacers and incorporating them into crystalline materials and optoelectronic devices. We first provide a summary of various synthetic methods to act as a tutorial for groups interested in pursuing synthesis of novel 2D perovskites. Second, we provide our insights on what kind of spacer cations can stabilize 2D perovskites followed by an extensive review of the spacer cations, which have been shown to stabilize 2D perovskites with an emphasis on the effects of the spacer on the structure and optical properties. Next, we provide a similar explanation for the methods used to fabricate films and their desired properties. Like the synthesis section, we will then focus on various spacers that have been used in devices and how they influence the film structure and device performance. With a comprehensive understanding of these effects, a rational selection of novel spacers can be made, accelerating this already exciting field.

Structural Diversity in 2,2'-[Naphthalene-1,8:4,5-bis(dicarboximide)-N,N'-diyl]-bis(ethylammonium) Iodoplumbates

Crystallization from solutions containing 2,2'-[naphthalene-1,8:4,5-bis(dicarboximide)-N,N'-diyl]-bis(ethylammonium) diiodide ((NDIC2)I₂) and PbI₂ has been investigated. Eight different materials are obtained, either by variation of crystallization conditions or by subsequent thermal or solvent-induced transformations. Crystal structures have been determined for five materials. [(NDIC2)₂Pb₅I₁₄(DMF)₂]·4DMF (DMF = N,N-dimethylformamide) (1), [(NDIC2)Pb₄I₁₀]·4DMF (3), [(NDIC2)Pb₂I₆]·4NMP (NMP = N-methyl-2-pyrrolidone) (4), and [(NDIC2)Pb₂I₆]·2H₂O (5) form 1-dimensional (1D) chains consisting of PbI₆ (and, in the case of 1, PbI₅(DMF)) octahedra, either solely face-sharing or a mixture of face-sharing and vertex-sharing. The structure of [(NDIC₂)₃Pb₅I₁₆]·6NMP (2) contains 0D clusters; these consist of three PbI₆ octahedra and two unusually coordinated lead centers that exhibit three relatively short Pb-I bonds, two very long Pb-I contacts, and η²-coordination of an aromatic ring of NDIC2 to the lead. Close contacts between iodide ions and the imide rings of NDIC2 in four of the structures suggest that an iodide-to-NDIC2 charge-transfer interaction may be responsible for the observed red coloration of the materials. The optical and electrical properties of 1 have been studied; its onset of absorption is at 2.0 eV, and its conductivity was measured as 5.4 × 10^-5 ± 1.1 × 10^-5 S m^-1.

Construction of a bicontinuous donor-acceptor hybrid material at the molecular level by inserting inorganic nanowires into porous MOFs

Herein, we report an unprecedented hybrid structure of electron-rich iodoplumbate nanowires precisely inserted into the periodic pores of electron-deficient pyridinium metal-organic frameworks (MOFs). To the best of our knowledge, this is the first example of semiconductive MOFs in situ loaded with inorganic semiconductive nanowires via a simple self-assembly method. Due to the dissimilar semiconductivities between the host and guest components, this hybrid also represents the first bicontinuous donor-acceptor hybrid at the molecular level based on host-guest interactions.

A lead-iodide based single crystal semiconductor: exploring multi-orientation photoconductive behaviour via intervening isopropyl viologen component between the inorganic [Pb2I6]2−n wires

A lead-iodide single crystal semiconductor with multi-orientation photoconductive property and broad spectrum absorption has been designed and constructed by crystal engineering technique.

Assembly of donor–acceptor hybrid heterostructures based on iodoplumbates and viologen coordination polymers

Two D–A hybrid heterostructures have been formed by the insertion of electron-rich iodoplumbates into viologen coordination polymers, which exhibit highly effcient photocatalytic degradation RhB under visible light irradiation.

A simultaneous disulfide bond cleavage, N,S-bialkylation/N-protonation and self-assembly reaction: syntheses, structures and properties of two hybrid iodoargentates with thiazolyl-based heterocycles

Unprecedented multiple in situ reactions were found during preparation of hybrid iodoargentates.

A comparison study of aliphatic and aromatic structure directing agents influencing the crystal and electronic structures, and properties of iodoplumbate hybrids: water induced structure conversion and visible light photocatalytic properties

The introduction of the aliphatic amines en (ethylenediamine), aep (N-(2-aminoethyl)piperazine) and tepa (tetraethylenepentamine), and the aromatic species 2,2'-bipy (2,2'-bipyridine) and dpe (1,2-di(4-pyridyl)ethylene) as structure directing agents (SDAs) into inorganic iodoplumbates affords six hybrids, namely [(Hen)4(H2.5O)2I](PbI6) (1), Cs2n[Pb3I8(en)2]n (2), (H3tepa)n(PbI5)n (3), (H2aep)n(PbI4)n (4), (Et22,2'-bipy)n(Pb2I6)n (5) and (Et2dpe)n(Pb2I6)n (6). 1 contains a discrete octahedral (PbI6)(4-) anion generated under the direction of a novel co-template, [(Hen)4(H2.5O)2I](4+). 2 contains inorganic Cs(+) ions and a novel hybrid anionic layer [Pb3I8(en)2]n(2n-) that has never been encountered in iodoplumbate hybrids. 3 features a zigzag (PbI5)(3-) chain with the charge being compensated by a triprotonated tepa cation. 4 is composed of perovskite sheets of lead(ii) octahedra and aep cations that are generated from tepa via an unprecedented in situ ligand reaction. Both 5 and 6 have (Pb2I6)n(2n-) chains and represent the first example of introducing a 2,2'-bipy or dpe derivative cation in iodoplumbate hybrids, respectively. The comparative study reveals that aliphatic amines and aromatic species contribute differently to the crystal and electronic structures, and the properties of the hybrids. Importantly, 1-4 exhibit interesting water induced structure conversions, while 5 and 6 can be used as heterogeneous photocatalysts for dye wastewater treatment under visible light irradiation.