Crystal structure, Hirshfeld surfaces computational study and physicochemical characterization of the hybrid material (C7H10N)2[SnCl6]·H2O

Chloride and Acetonitrile Ruthenium(IV) Complexes: Crystal Architecture, Chemical Characterization, Antibiofilm Activity, and Bioavailability in Biological Systems

Due to the emergence of drug resistance, many antimicrobial medications are becoming less effective, complicating the treatment of infections. Therefore, it is crucial to develop new active agents. This article aims to explore the ruthenium(IV) complexes with the following formulas: (Hdma)2(HL)2[RuIVCl6]·2Cl·2H2O (1), where Hdma is protonated dimethylamine and L is 2-hydroxymethylbenzimidazole, and [RuIVCl4(AN)2]·H2O (2), where AN is acetonitrile. This paper delves into the physicochemical characteristics and crystal structures of these complexes, employing various techniques such as spectroscopy (IR, UV-Vis), electrochemistry (CV, DPV), and X-ray crystallography. Hirshfeld surface analysis was also performed to visualize intermolecular interactions. Furthermore, the potential antibiofilm activity of the complexes against Pseudomonas aeruginosa PAO1 was investigated and the effect of the compounds on the production of pyoverdine, one of the virulence factors of the Pseudomonas strain, was assessed. The results show that particularly complex 1 reduces biofilm formation and pyoverdine production. Additionally, the bioavailability of these complexes in biological systems (by fluorescence quenching of human serum albumin (HSA) and molecular docking studies) is discussed, assessing how their chemical properties influence their interactions with biological molecules and their potential therapeutic applications.

Supramolecular Assembly of Halide Perovskite Building Blocks

The structural diversity and tunable optoelectronic properties of halide perovskites originate from the rich chemistry of the metal halide ionic octahedron [MX₆]^n- (M = Pb²⁺, Sb³⁺, Te⁴⁺, Sn⁴⁺, Pt⁴⁺, etc.; X = Cl^-, Br^-, and I^-). The properties of the extended perovskite solids are dictated by the assembly, connectivity, and interaction of these octahedra within the lattice environment. Hence, the ability to manipulate and control the assembly of the octahedral building blocks is paramount for constructing new perovskite materials. Here, we propose a systematic supramolecular strategy for the assembly of [MX₆]^n- octahedra into a solid extended network. Interaction of alkali metal-bound crown ethers with the [M(IV)X₆]^2- octahedron resulted in a structurally and optoelectronically tunable "dumbbell" structural unit in solution. Single crystals with diverse packing geometries and symmetries will form as the solid assembly of this new supramolecular building block. This supramolecular assembly route introduces a new general strategy for designing halide perovskite structures with potentially new optoelectronic properties.

Down and up conversion luminescence of the lead-free organic metal halide material: (C9H8NO)2SnCl6·2H2O

The present work deals with the optical properties of hybrid organic metal halide material namely (C9H8NO)2SnCl6·2H2O. Its structure is built up from isolated [SnCl6]2- octahedral dianions surrounded by Hydroxyl quinolinium organic cations (C9H8NO)+, abbreviated as [HQ]+. Unlike the usual hybrid materials, where metal halide ions are luminescent semiconductors while the organic ones are optically inactive, [HQ]2SnCl6·2H2O contains two optically active entities: [HQ]+ organic cations and [SnCl6]2- dianions. The optical properties of the synthesized crystals were studied by optical absorption spectroscopy, photoluminescence measurements and DFT calculations of electronic density of states. These studies have shown that both organic and inorganic entities have very close HOMO-LUMO gaps and very similar band alignments favoring the resonant energy transfer process. In addition, measurements of luminescence under variable excitations reveal an intense green luminescence around 497 nm under UV excitation (down conversion) and infrared excitation (up conversion luminescence). The down conversion luminescence is assigned to the π-π* transition within the [HQ] + organic cations involving charge transfer between the organic and inorganic entities, whereas the up-conversion luminescence is based on the triplet-triplet annihilation mechanism (TTA).

Synthesis, Crystal Structure, Hirshfeld Surface, and Physicochemical Characterization of New Salt Bis(2-ethyl-6-methylanilinium)tetrachloromercurate (II) [C9H14N]2HgCl4

In this paper, a new organic salt bis(2-ethyl-6-methylanilinium)tetrachloromercurate (II)) has been synthesized, characterized, and studied theoretically using DFT. The synthesized compound was found to crystallize in the monoclinic system with space group P21/c with the following unit cell parameters a = 23.1696(2), b = 25.7951 (6), c = 7.5980 (4) Å, β = 96.5790 (11)°, and Z = 8. Its atomic arrangement can be described asmutually alternating organic and inorganic entities in the (ab) plane. The cohesion is achieved through N-H…Cl hydrogen bonds and π…π stacking interacting neighboring aromatic cations. The PXRD was carried out. The intermolecular interactions in the crystal packing were investigated using Hirshfeld surface analysis. Its associated 2D fingerprint plots revealed their contribution quantitatively. High-resolution images of the surface were obtained by the SEM technique, and the EDX spectrum assured the existence of all nonhydrogen atoms. The infrared spectrum was used to gain more information about vibrational modes. Analysis of thermal differential and gravimetric (TGA/DTA) shows two-phase transitions observed at 362 and 394 K. AC conductivity measurements were performed to confirm these two-phase transitions.

Recent progress of zero-dimensional luminescent metal halides

This review provides in-depth insight into the structure–luminescence–application relationship of 0D all-inorganic/organic–inorganic hybrid metal halide luminescent materials.