Different Contributions of Aliphatic and Conjugated Organic Cations to Both the Crystal and Electronic Structures: Three Hybrid Iodoargentates Showing Two Isomers of the (AgI 2 ) - Chain: Three Hybrid Iodoargentates Showing Two Isomers of the (AgI 2 ) - Chain

AgX-based hybrid coordination polymers: mechanochemical synthesis, structure and luminescence property characterization

Hybrid coordination polymers are interesting for their ability to converge the properties of both inorganic and organic systems in one single compound and recently attention has been focused on silver based hybrid coordination polymers due to their luminescence properties. We searched the CSD to establish the propensity of AgXL (X = Cl^-, Br^- and I^-) with L as an organic ligand to form hybrid coordination polymers. About 800 AgXL structures are deposited in the CSD, with huge structural variability: indeed, it is possible to recognize some structural preferences based on the halide nature. The formation of an inorganic polymeric unit is favoured by iodide but it is also possible with the other halides. This research continues with the synthesis of AgX (X = I^-, Br^-) based coordination polymers with 2-, 3- and 4-picolylamine (n-pica) as ligands. By mechanochemical synthesis five new hybrid coordination polymers and one coordination polymer have been obtained and their structures determined. While [(AgI)(n-pica)]_n are not luminescent, [(AgBr)(n-pica)]_n emit and their profile depends on the crystallinity of the sample.

Transition-Metal-Complex-Directed Synthesis of Hybrid Iodoargentates with Single-Crystal to Single-Crystal Structural Transformation and Photocatalytic Properties

We synthesized and characterized three types of isostructural iodoargentates, [TM(phen)₃]Ag₂I₄·3DMF (TM = Co (1), Ni (2), Zn (3)), [TM(phen)₃]Ag₃I₅·DMF (TM = Co (4), Ni (5), Zn (6)), and [TM(phen)₃]₂Ag₈I₁₂·7DMF (TM = Co (7), Ni (8), Zn (9)) (phen = 1,10-phenanthroline, DMF = dimethylformamide) using transition-metal (TM) complexes as the structure-directing agents. Compounds 1-3 and compounds 4-6 feature zero-dimensional anionic [Ag₄I₈]^4- and [Ag₆I₁₀]^4- clusters, respectively. All of the [TM(phen)₃]²⁺ cations in compounds 1-6 are arranged into a two-dimensional (2D) (6,3) net layer. Interestingly, compounds 1-3 are kinetically unstable in the mother solution, and they can be converted to compounds 4-6 via irreversible single-crystal to single-crystal transformation processes, respectively, with distinct changes in the crystal morphology and structure. Compounds 7-9 feature one-dimensional (1D) zigzag chains constructed from [Ag₈I₁₂]^4- units. The UV-vis diffuse reflectance measurements demonstrate that compounds 1-9 possess the characteristics of semiconductors with band gaps of 2.58-2.71 eV and visible-light-irradiation-induced photocatalytic activities. Especially, compound 3 possesses higher photocatalytic degradation activity toward crystal violet (CV) and rhodamine B (RhB) in comparison to P25 under identical conditions. Moreover, the mechanism study reveals that the TM complex cations make a great contribution to the photocatalytic activity.

Semiconducting crystalline inorganic-organic hybrid metal halide nanochains

One-dimensional (1D) inorganic-organic metal halide hybrids at the molecular level, which can be considered as arrays of nanochains isolated by organic components, have shown remarkable optical and electric properties. This review summarizes their reported structural types and shows how to modify their band gaps and optical and electric properties.

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.

New photoluminescent iodoargentates with bisimidazole derivatives as countercations

In this article, three bisimidazole derivatives (1,4-bis(2-ethylimidazol-1-yl)butane, L1; 4,4′-di(1H-imidazol-1-yl)-1,1′-biphenyl, L2′; and 1,3-bis(2-ethylimidazol-1-yl)propane, L3) were employed to solvothermally react with AgI in an acidic environment, creating three new 1-D chained iodoargentates [H(L1)][Ag₅I₆]·DMF (DMF = N,N′-dimethylformamide) 1, [L2][Ag₃I₅] (L2²⁺ = 4,4′-di(1H-imidazol-1-ium)-1,1′-biphenyl) 2, and [H₂(L3)][Ag₂I₄] 3. L2²⁺ in 2 originated from the in situ N-alkylation of L2′ with the CH₃OH solvent. X-ray single-crystal diffraction analysis reveals that (i) in 1, Ag⁺ and I⁻ aggregate to form a 1-D tube-like iodoargentate, which exhibits the same topology as the carbon tube; (ii) the chain structure of the iodoargentate in 2 is based on a kind of trinuclear Ag–I cluster, which can be viewed as a segment of the classical cubic M₄I₄ cluster; (iii) the chain structure of the iodoargentate in 3 is simple, which can be described as a linear arrangement of the AgI₄ tetrahedra by sharing edges. The photoluminescence analysis reveals that at 77 K, (i) 1 and 2 emit strong yellow light with ms-grade photoluminescence lifetimes (5.460 ms for 1, 6.931 ms for 2); (ii) 3 possesses photochromic luminescence properties. Upon excitation at 254 nm, it emits blue-green light, whereas upon excitation at 365 nm, it emits yellow light.

Three bisimidazole-based chained iodoargentates were solvothermally synthesized, and their photoluminescent behaviors at different temperatures were investigated. Of those, 3 has been found to possess photochromic luminescence properties.

The structures, water stabilities and photoluminescence properties of two types of iodocuprate(i)-based hybrids

The effects of aromatic and aliphatic cations on the structure, water stability and photoluminescence of iodocuprate(i)-based materials were disclosed.

Iodoargentates from clusters to 1D chains and 2D layers induced by solvated lanthanide complex cations: syntheses, crystal structures, and photoluminescence properties

Lanthanide(iii) iodoargentates [Ln(DMSO)₈]₄Ag₂₂I₃₄·2H₂O (Ln = La (1), Ce (2)), [Ln(DMSO)₈]Ag₇I₁₀(Ln = Eu (3), Tb (4), Dy (5)), and [Yb(DMSO)₇]Ag₅I₈(6) were synthesized by a diffusion method.

Comparison studies of hybrid lead halide [MPb2X7]2− (M = Cu, Ag; X = Br, I) chains: band structures and visible light driven photocatalytic properties

A series of inorganic–organic hybrid heterometallic halides of [TM(2,2-bipy)₃]MPb₂X₇ (M = Ag/Cu, X = Br, I) have been solvothermally prepared with visible light driven photocatalytic properties.

New discrete iodometallates with in situ generated triimidazole derivatives as countercations (Mn+ = Ag+, Pb2+, Bi3+)

By employing solvothermal in situ N-alkylation of organic bases with alcohols, four new iodometallates were obtained, and their structures are reported.

Relaxor-like and switchable dielectric behavior in a rare noncentrosymmetric 3D iodoargentate hybrid

A rare noncentrosymmetric three-dimensional (3D) iodoargentate hybrid, namely, [Cd(en)₃]Ag₂I₄ (1), was prepared using a simple solution process.

Syntheses, crystal structures and photocatalytic properties of four hybrid iodoargentates with zero- and two-dimensional structures

Four new hybrid iodoargentates have been solvothermally prepared and structurally characterized. The title compounds possess semiconductor characterizations and efficient photocatalytic activities under visible light irradiation.

Stoichiometry-controlled structural and functional variation in two photochromic iodoargentates with a fast and wide range response

Two MCMP⁺/iodoargentate hybrids have been synthesized and they exhibit rare electron transfer photochromsim with a fast response rate, a wide response range and a long-lived charge-separated state, which is largely ascribed to the flexible aggregation of electron-deficient MCMP⁺ counterions.

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.