Heptabismuthate [Bi7I24]3–: A Main Group Element Anderson-Type Structure and Its Relationships with the Polyoxometalates

Syntheses, structures, photoelectric properties and photocatalysis of iodobismuthate hybrids with lanthanide complex cations

New iodobismuthate hybrids with lanthanide complex counter cations, [Ln(DMF)₈][Bi₂I₉] (Ln = La (1), Eu (2)) and [Tb(DMF)₈]₂[Bi₂I₉]₂ (3) (DMF = N,N-dimethylformamide), were prepared using solvated Ln(III) complexes formed in situ as structure-directing agents. The dimeric [Bi₂I₉]^3- anion moieties of compounds 1-3 are aggregated by two slightly twisted BiI₆ octahedra through face-sharing mode. The different crystal structures of 1-3 are due to the different I⋯I and C-H⋯I hydrogen bond interactions. Compounds 1-3 have narrow semiconducting band gaps at 2.23, 1.91 and 1.94 eV, respectively. Under Xe light irradiation, they exhibit steady photocurrent densities that are 1.81, 2.10 and 2.18 times higher than that of pure BiI₃, respectively. Compounds 2 and 3 exhibited higher catalytic activities than 1 in the photodegradation of organic dyes CV and RhB, which are attributed to the stronger photocurrent response derived from the redox cycles of Eu³⁺/Eu²⁺ and Tb⁴⁺/Tb³⁺.

Bismuth(III) Iodide Complexes with 1-Ethyl-4-Dimethylaminopyridinium: Structure, Thermal Stability, and Optical Properties

Abstract

Polynuclear bismuth(III) iodide complexes with 1-ethyl-4-dimethylaminopyridinium (1-EtDMAP)4[Bi8I28] (1) and (1-EtDMAP)BiI4 (2) have been obtained by the reactions of bismuth(III) iodide with an organic iodide salt cations in organic solvents and characterized by X-ray diffraction. The optical properties and thermal stability of the obtained compounds have been studied.

On iodido bismuthates, bismuth complexes and polyiodides with bismuth in the system BiI3/18-crown-6/I2

The iodido bismuthates [Bi(18-crown-6)I2][BiI4] (1) and [Bi(18-crown-6)I2][Bi3I10] (2), the neutral complex [Bi(C6H14O4)I3](18-crown-6) (3) as well as the polyiodides [Bi(18-crown-6)I2][I5](18-crown-6) (4), [Bi(18-crown-6)I2]2[I14] (5) and [Bi(18-crown-6)I2]2[I19] (6) were prepared by reaction of BiI3, 18-crown-6, and I2 at T = 60–120 °C. The compounds 1–5 were prepared in [n-Bu3MeN][N(Tf)2] as an ionic liquid ([n-Bu3MeN]: tributylmethylammonium, [N(Tf)2]: bis(trifluoromethylsulfonyl)imide), whereas 6 was obtained only by direct reaction of the starting materials. The title compounds exhibit two different constitutions of the [Bi(18-crown-6)I2]+ cation as well as a non-charged, molecular [Bi(C6H14O4)I3] unit with a triethylene glycol ligand generated in situ by cleavage of the crown ether. Infinite chain-like [ BiI 2 / 1 I 4 / 2 ] − ∞ 1 ${}_{\infty }{}^{1}\left[{{\text{BiI}}_{2/1}{\text{I}}_{4/2}\right]}^{-}$ and [ Bi 6 I 18 / 1 I 4 / 2 ∞ 1 ] − ${{}_{\infty }{}^{1}\left[{\text{Bi}}_{6}{\text{I}}_{18/1}{\text{I}}_{4/2}\right]}^{-}$ anions occur in 1 and 2, whereas various polyiodide anions (e.g. [I3]−, [I5]−, [I7]−, [I9]−) with partly complex interaction are observed in 4, 5, and 6. The title compounds were characterized by single-crystal X-ray diffraction analysis and infrared spectroscopy. In the case of 1 and 2, the optical band gap was determined to be E g  = 1.91 and 1.62 eV, respectively. Especially, the ionic-liquid-based synthesis affords the different metastable compounds with variable composition and structure in a narrow temperature range.

Iodoargentate/iodobismuthate-based materials hybridized with lanthanide-containing metalloviologens: thermochromic behaviors and photocurrent responses

New hybrids combined metalloviologens with Ag/Cu iodides exhibit reversible thermochromisms, photocurrent responses, whose mechanisms are disclosed.

Synthesis, structure and optoelectronic properties of hybrid iodobismuthate & iodoantimonate semiconducting materials

The syntheses, structures and optical absorption spectra of five iodobismuthate and nine iodoantimonate hybrid materials are presented.

Transition Metal Single-Molecule Magnets: A {Mn31} Nanosized Cluster with a Large Energy Barrier of ∼60 K and Magnetic Hysteresis at ∼5 K

The first {Mn₃₁} cluster (1) has been prepared from carboxylate ions and the chelating/bridging ligand α-methyl-2-pyridine-methanol. Compound 1 possesses a unique nanosized structural topology with one of the largest energy barriers reported to-date for high-nuclearity 3d-metal clusters. Single-crystal magnetic hysteresis studies reveal the presence of hysteresis loops below 5 K, one of the highest temperatures below which molecular hysteresis has been observed for 3d-based SMMs.

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.

Synthesis and structure of pseudo-three dimensional hybrid iodobismuthate semiconductors

The synthesis, structures and semiconducting properties of three isostructural, piperazinium-cation based iodobismuthates, [NH₂(CH₂)₄NH₂][BiI₄]₂·4H₂O, [CH₃NH(CH₂)₄NH₂][BiI₄]₂·3H₂O and [CH₃NH(CH₂)₄HNCH₃][BiI₄]₂·2H₂O, are reported. The materials have pseudo-three dimensional structures consisting of infinite chains formed from edge/face sharing [BiI₆] octahedra with short interchain II interactions of <3.8 Å. The materials have band gaps of ∼1.9-2.0 eV and show variable optoelectronic properties based on the degree of methylation of the templating piperazinium ring-based organic species and the accordingly associated level of solvation in the structure.

Transition metal complex directed lead bromides with tunable structures and visible light driven photocatalytic properties

Six new compounds were synthesized and characterized as [Co(2,2-bipy)₃]₂{[Co(2,2-bipy)]₃Pb₇Br₂₄} (1), [Co(2,2-bipy)₂Br]PbBr₃(2), [TM(phen)₃]Pb₂Br₆(TM = Co (3) and Ni (4)), [Co(2,2-bipy)₃]Pb₃Br₉(5) and [Co(2,2-bipy)₃]Pb₅Br₁₃·CH₃CN (6).

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.

Semimetal-functionalised polyoxovanadates

Polyoxovanadates (POVs), known for their wide applicability and relevance in chemical, physical and biological sciences, are a subclass of polyoxometalates and usually self-assemble in aqueous-phase, pH-controlled condensation reactions. Archetypical POVs such as the robust [VO42](12-) polyoxoanion can be structurally, electronically and magnetically altered by heavier group 14 and 15 elements to afford Si-, Ge-, As- or Sb-decorated POV structures (heteroPOVs). These main-group semimetals introduce specific chemically engineered functionalities which cause the generally hydrophilic heteroPOV compounds to exhibit interesting reactivity towards organic molecules, late transition metal and lanthanoid ions. The fully-oxidised (V(V)), mixed-valent (V(V)/V(IV) and V(IV)/V(III)), "fully-reduced" (V(IV)) and "highly-reduced" (V(III)) heteroPOVs possess a number of intriguing properties, ranging from catalytic to molecular magnet characteristics. Herein, we review key developments in the synthetic and structural chemistry as well as the reactivity of POVs functionalised with Si-, Ge-, As- or Sb-based heterogroups.

Iron-bismuth halido compounds: molecules, clusters, and polymers

The pentamethylcyclopentadienyl substituted iron-bismuth halides [Bi{FeCp*(CO)2}X2] [X = Cl (1), Br (2), I (3); Cp* = η(5)-C5Me5] were synthesized starting from [FeCp*(CO)2]2 and BiX3 (X = Cl, Br), followed by halogen exchange reaction with KI in case of 3. From a reaction mixture of [FeCp*(CO)2]2 with BiCl3 in CH2Cl2 to which CH3CN had been added, a novel coordination polymer of the formula [FeCp*(CO)2(CH3CN)]2n[Bi4Cl14]n (4) was isolated. The change of the molar ratio from 1:1 to 1:2 in the reaction of [FeCp*(CO)2]2 with BiBr3 afforded the novel ionic complex [{FeCp*(CO)2Br]2[Bi6Br22{FeCp*(CO)2}]·CH2Cl2 (5·CH2Cl2). It is demonstrated that treatment of [FeCp*(CO)2X] (X = Cl, Br) with BiCl3 and BiBr3, respectively, is a more convenient route to synthesize the new halido bismuthates 4 and 5.

Assembling anionic Sb(v)/(iii) containing polyoxostibonates stabilized by triphenyltellurium cations

Mixed valent polyoxostibonates ligated by tetraorganoditelluroxane and stabilized by weak interactions from triaryltellurium cations are presented. Successive reactions like reduction, dearylation and disproportionation have been observed en route to the formation of these novel POMs.

A step closer to the binary: the 1∞[Bi6I20]2−anion

A series of crown ether based iodidobismuthates explores the influence of increasing I/Bi ratio and I⋯I interactions on the compounds’ optical properties. This includes [(Dibenzo-18-crown-6)Na(MeCN)₂]₂1∞[Bi₆I₂₀], which contains a strand-like anion with an unprecedentedly low I/Bi ratio.