Xiao-Wu Lei

Two Types of 2D Layered Iodoargentates Based on Trimeric [Ag3I7] Secondary Building Units and Hexameric [Ag6I12] Ternary Building Units: Syntheses, Crystal Structures, and Efficient Visible Light Responding Photocatalytic Properties

With mixed transition-metal-complex, alkali-metal, or organic cations as structure-directing agents, a series of novel two-dimensional (2D) layered inorganic-organic hybrid iodoargentates, namely, Kx[TM(2,2-bipy)3]2Ag6I11 (TM = Mn (1), Fe (2), Co (3), Ni (4), Zn (5); x = 0.89-1) and [(Ni(2,2-bipy)3][H-2,2-bipy]Ag3I6 (6), have been solvothermally synthesized and structurally characterized. All the title compounds feature 2D microporous layers composed by [Ag3I7] secondary building units based on AgI4 tetrahedra. Differently, the [Ag3I7] trimers are directly interconnected via corner-sharing to form the 2D [Ag6I11](5-) layer in compounds 1-5, whereas two neighboring [Ag3I7] trimers are initially condensed into a hexameric [Ag6I12] ternary building unit as a new node, which further self-assembles, leading to the 2D [Ag6I10](4-) layer in compound 6. The UV-vis diffuse-reflectance measurements reveal that all the compounds possess proper semiconductor behaviors with tunable band gaps of 1.66-2.75 eV, which lead to highly efficient photocatalytic degradation activities over organic pollutants under visible light irradiation compared to that of N-dotted P25. Interestingly, all the samples feature distinct photodegradative speeds at the same reaction conditions, and compound 1 features the highest photocatalytic activity among the title phases. The luminescence properties, band structures, and thermal stabilities were also studied.

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

With a [TM(phen)3]2+ (TM = transition metal, phen = 1,10-phenanthroline) complex and N-alkylated [(Me)2-2,2′-bipy]2+ (Me = methyl, 2,2′-bipy = 2,2′-bipyridine) as cations, a series of hybrid iodoargentates, namely [TM(phen)3]2Ag3I7 (TM = Mn (1), Fe (2)), [Mn(phen)3]Ag5I7 (3) and [(Me)2-2,2′-bipy]2Ag7I11 (4), have been solvothermally prepared and structurally characterized. Compounds 1 and 2 feature isolated windmill-shaped [Ag3I7]4− trimers based on [AgI3] triangles, whereas compound 3 contains two-dimensional (2D) microporous [Ag5I7]2− layers composed of [Ag3I7] and [Ag7I13] secondary building units (SBUs) based on [AgI4] tetrahedra. In compound 4, a 2D [Ag7I11]4− slab is formed by alternating interconnection of two different types of [Ag7I12] double chains via corner-sharing with one-dimensional (1D) large channels occupied by [(Me)2-2,2′-bipy]2+ cations. UV-vis diffuse-reflectance measurements reveal that the title compounds possess semiconducting behaviors with smaller band gaps of 1.85, 1.78, 1.89 and 2.03 eV, respectively. Sample 4 shows highly efficient photocatalytic degradation activity over organic pollutants than N-doped TiO2 (P25) under visible light irradiation. Moreover, a possible mechanism for the stable photocatalytic activity is proposed based on band structure calculation. Finally, the luminescence properties and thermal stabilities of the title compounds are also studied.

[Mn(dien)2]MnSnS4, [Mn(1,2-dap)]2Sn2S6 and [Mn(en)2]MnGeS4: from 1D anionic and neutral chains to 3D neutral frameworks

Three new organic–inorganic hybrid manganese thiogermanates and thiostannates, namely, [Mn(en)2]MnGeS4 (1, en = ethylenediamine), [Mn(dien)2]MnSnS4 (2, dien = diethylenetriamine) and [Mn(1,2-dap)]2Sn2S6 (3, 1,2-dap = 1,2-diaminopropane), have been solvothermally synthesized and structurally characterized. Compound 1 has a three-dimensional (3D) neutral framework composed of one-dimensional (1D) [MnGeS4]2− chains and unsaturated [Mn(en)2]2+ cations interconnected via Mn–S bonds, whereas compounds 2–3 feature 1D [MnSnS4]2− anionic chains and 1D neutral [Mn(1,2-dap)]2Sn2S6 chains, respectively. Investigation into the magnetic properties of the title compounds reveals antiferromagnetic and ferromagnetic coupling interactions between the Mn(II) ions for compounds 1 and 3, respectively. The optical and luminescence properties, as well as the thermal stabilities, were also studied.

Two manganese–amine complexes incorporating thioantimonates and exhibiting diversiform roles of amine ligands

Two manganese–amine complexes incorporating thioantimonates, namely (dienH3)[(dienH)MnSb8S15]·H2O (dien = diethylenetriamine) (1) and [Mn(teta)(H2O)2]2[Mn(tren)]2Sb3S12·H3O (2, teta = triethylenetetramine, tren = tris(2-aminoethyl)amine), have been solvothermally synthesized and structurally characterized. Interestingly, the organic amines show diversiform structure-directing actions in the title compounds. In compound 1, two dien molecules exhibit partial coordination to Mn2+ ions and protonated cations, and compound 2 contains mixed tetradentate tren and teta chelating amines. The optical properties, thermal stabilities and magnetic properties have also been studied.