Synthesis, crystal structure, vibrational properties and dielectric properties of 1-(2-ammonium-ethyl) pipérazindiium hexachlorobismuthate(III)

Iodine-Rich Supramolecular Complexes of Chlorobismuthates(III): Unusual Lone Pair Activity and Features of Halogen Bonding in Crystals

The first chrorobismuthate(III) supramolecular hybrids with halogen-bond-linked I2, (Py(CH2)2Py){[BiCl5](I2)} (1) and (Py(CH2)3Py){[BiCl5](I2)0.5} (2), were synthesized via the reaction between Bi2O3, I2, and salts of the corresponding cations in HCl. The compounds featured one- and two-dimensional (2D) supramolecular motifs built by I···Cl contacts; in the case of 1, Bi(III) is pentacoordinated due to the lone pair activity, which also interacted with I2 pi-orbitals, as confirmed by density functional theory (DFT) calculations. Both complexes exhibited moderate thermal stabilities and relatively narrow optical band gaps.

Do alkyl groups on aromatic or aliphatic structure directing agents affect water stabilities and properties of hybrid iodoargentates?

Two types of in situ formed structure directing agents (SDAs) including aromatic triphenylphosphine (PPh₃)- and aliphatic piperazine (H₂pp)-derivative cations were used to synthesize five new hybrid iodoargentates, namely (EtPPh₃)Ag₃I₄ (1, Et = ethyl), (n-PrPPh₃)Ag₃I₄ (2, n-Pr = n-propyl), (i-PrPPh₃)Ag₅I₆ (3, i-Pr = isopropyl), (Me₄pp)_0.5AgI₂ (4, Me = methyl), and (H₃app)₂(Ag₂I₆)·2I·2H₂O (5, app = N-aminoethylpiperazine). A comparative study of the two types of SDAs on the structures, stabilities and properties of hybrid iodoargentates was performed in detail. Structurally, except for (EtPPh₃)⁺ and (n-PrPPh₃)⁺, which both directly form (Ag₃I₄)^- anionic chains in 1 and 2, three SDAs generate hybrid iodoargentates different from each other with inorganic anions ranging from a 0-D (Ag₂I₆)^4- dimer to 1-D α-type (AgI₂)^- and (Ag₅I₆)^- chains. With regard to the electronic structures, aromatic PPh₃-derivative cations make noticeable contributions to the bottom of the conduction bands, while aliphatic pp-derivative cations make nearly no contribution to the frontier orbitals, clearly indicating their different ways to adjust the band gaps. With regard to stability, the decomposition temperatures of 1-3 in the range of 324-349 °C are noticeably higher than the values of 217 and 225 °C for 4 and 5. Furthermore, 1-4 exhibit good water stabilities, which is ascribed to the alkylation reactions precluding the formation of strong hydrogen bonds between alkylated SDAs and extraneous H₂O molecules. Contrarily, the presence of typical hydrophilic [double bond, length as m-dash]NH₂⁺, [triple bond, length as m-dash]NH⁺ and -NH₃⁺ groups on the protonated (H₃app)³⁺ cation makes 5 sensitive to water and a hydrolysis reaction occurs to generate a cubic AgI phase. Finally, 1-3 exhibit high photocatalytic efficiencies for the degradation of rhodamine B (RhB) dye in wastewater under visible light. All conclusions obtained here will help a lot in the synthesis of stable functional metal halide-based hybrids.

Tin, Bismuth, and Tin-Bismuth Alloy Electrodeposition from Chlorometalate Salts in Deep Eutectic Solvents

The electrodeposition of tin, bismuth, and tin-bismuth alloys from SnII and BiIII chlorometalate salts in the choline chloride/ethylene glycol (1:2 molar ratio) deep eutectic solvent was studied on glassy carbon and gold by cyclic voltammetry, rotating disc voltammetry, and chronoamperometry. The SnII-containing electrolyte showed one voltammetric redox process corresponding to SnII/Sn0. The diffusion coefficient of [SnCl3]-, detected as the dominating species by Raman spectroscopy, was determined from Levich and Cottrell analyses. The BiIII-containing electrolyte showed two voltammetric reduction processes, both attributed to BiIII/Bi0. Dimensionless current/time transients revealed that the electrodeposition of both Sn and Bi on glassy carbon proceeded by 3D-progressive nucleation at a low overpotential and changed to instantaneous at higher overpotentials. The nucleation rate of Bi on glassy carbon was considerably smaller than that of Sn. Elemental Sn and Bi were electrodeposited on Au-coated glass slides from their respective salt solutions, as were Sn-Bi alloys from a 2:1 SnII/BiIII solution. The biphasic Sn-Bi alloys changed from a Bi-rich composition to a Sn-rich composition by making the deposition potential more negative.

Binuclear Bi(iii) halide complexes with 4,4′-ethylenepyridinium cations: luminescence tuning by reversible solvation

New binuclear chloride and bromide complexes of Bi(iii) demonstrate strong reversible solvatochromism.