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The synthesis of nanoscaled β-Bi(2)O(3) starting from the bismuth oxido clusters [Bi(6)O(4)(OH)(4)](NO(3))(6)·H(2)O, [Bi(22)O(26)(OSiMe(2)(t)Bu)(14)], [Bi(38)O(45)(NO(3))(20)(DMSO)(28)](NO(3))(4)·4DMSO and [Bi(38)O(45)(OMc)(24)(DMSO)(9)]·2DMSO·7H(2)O (OMc = O(2)CC(3)H(5)) under ambient conditions is reported. The metal oxido clusters are regarded as ideal precursors for β-Bi(2)O(3) due to their structural relationship with the latter. Nevertheless, different bismuth oxide polymorphs are accessible dependent on the hydrolysis protocol. Hydrolysis over a period of 18 h gave stable α-Bi(2)O(3) whereas after 3 min an amorphous material is observed. Annealing of the amorphous material at 370 °C gave nanoscaled β-Bi(2)O(3). An unusual high reactivity of the β-Bi(2)O(3) particles with SiO(2) and Al(2)O(3) is observed at temperatures above 400 °C. Powder X-ray diffraction studies, transmission electron microscopy, diffuse reflectance UV/Vis spectroscopy and nitrogen adsorption measurements are used for characterization of the as-prepared β-Bi(2)O(3) nanoparticles. The properties of the β-Bi(2)O(3) nanoparticles depend on the starting bismuth oxido clusters with regard to particle size and optical band gap. The β-Bi(2)O(3) nanoparticles show excellent photocatalytic activity as demonstrated by dye decomposition (rhodamine B, methyl orange, methylene blue and orange G) under visible light.

The synthesis of the nanoscaled bismuth oxido clusters [Bi(38)O(45)(NO(3))(20)(DMSO)(28)](NO(3))(4)·4DMSO (1a) and [Bi(38)O(45)(OH)(2)(pTsO)(8)(NO(3))(12)(DMSO)(24)](NO(3))(2)·4DMSO·2H(2)O (2) starting from the basic bismuth nitrate [Bi(6)O(4)(OH)(4)](NO(3))(6)·H(2)O is reported herein. Single-crystal X-ray diffraction analysis, ESI mass spectrometry, thermogravimetric analysis, and molecular dynamics simulation were used to study the formation, structure, and stability of these large metal oxido clusters. Compounds 1a and 2 are based on a [Bi(38)O(45)](24+) core, which is structurally related to δ-Bi(2)O(3). Examination of the fragmentation pathways of 1a and 2 by infrared multi-photon dissociation (IRMPD) tandem MS experiments allows the identification of novel bismuth oxido cluster species in the gas phase.

Gold nanoparticles (NPs) have been loaded into mesoporous photonic cellulose (MPC) films. The NPs show a low polydispersity and a nanoparticle-based plasmonic chiroptical activity with potential for novel sensing materials.

Hydrolysis of Bi(NO(3))(3) in aqueous solution gave crystals of the novel compounds [Bi(6)O(4)(OH)(4)(NO(3))(5)(H(2)O)](NO(3)) (1) and [Bi(6)O(4)(OH)(4)(NO(3))(6)(H(2)O)(2)]·H(2)O (2) among the series of hexanuclear bismuth oxido nitrates. Compounds 1 and 2 both crystallize in the monoclinic space group P2(1)/n but show significant differences in their lattice parameters: 1, a = 9.2516(6) Å, b = 13.4298(9) Å, c = 17.8471(14) Å, β = 94.531(6)°, V = 2210.5(3) Å(3); 2, a = 9.0149(3) Å, b = 16.9298(4) Å, c = 15.6864(4) Å, β = 90.129(3)°, V = 2394.06(12) Å(3). Variation of the conditions for partial hydrolysis of Bi(NO(3))(3) gave bismuth oxido nitrates of even higher nuclearity, [{Bi(38)O(45)(NO(3))(24)(DMSO)(26)}·4DMSO][{Bi(38)O(45)(NO(3))(24)(DMSO)(24)}·4DMSO] (3) and [{Bi(38)O(45)(NO(3))(24)(DMSO)(26)}·2DMSO][{Bi(38)O(45)(NO(3))(24)(DMSO)(24)}·0.5DMSO] (5), upon crystallization from DMSO. Bismuth oxido clusters 3 and 5 crystallize in the triclinic space group P1 both with two crystallographically independent molecules in the asymmetric unit. The following lattice parameters are observed: 3, a = 20.3804(10) Å, b = 20.3871(9) Å, c = 34.9715(15) Å, α = 76.657(4)°, β = 73.479(4)°, γ = 60.228(5)°, V = 12021.7(9) Å(3); 5, a = 20.0329(4) Å, b = 20.0601(4) Å, c = 34.3532(6) Å, α = 90.196(1)°, β = 91.344(2)°, γ = 119.370(2)°, V = 12025.8(4) Å(3). Differences in the number of DMSO molecules (coordinated and noncoordinated) and ligand (nitrate, DMSO) coordination modes are observed.

Photocatalytic studies under visible light irradiation using nanosized β-Bi2O3 are reported. β-Bi2O3 nanoparticles are prepared starting from the well-defined bismuth oxido cluster [Bi38O45(OMc)24(DMSO)9]⋅2 DMSO⋅7 H2O (OMc=O2CC3H5) using a straightforward hydrolysis and annealing protocol. Powder X-ray diffraction studies, transmission electron microscopy, diffuse reflectance UV/Vis spectroscopy and nitrogen adsorption measurements (using the Brunauer–Emmett–Teller (BET) theory) are used for the characterization of the as-prepared β-Bi2O3. By time-dependent annealing, the crystallite size can be controlled between (17±2) nm and (45±5) nm with BET surface areas of 7 to 29 m2 g−1. The indirect band gap of the as-prepared β-Bi2O3 amounts to (2.15±0.05) eV. The decomposition rates for rhodamine B (RhB) solutions are in the range of 2.46×10−5 to 4.01×10−4 s−1 and depend on the crystallite size, amount of catalyst and concentration of RhB. Photocorrosion experiments have shown the formation of Bi2O2CO3 after several catalytic cycles. However, the catalyst can be recycled to phase-pure β-Bi2O3 nanoparticles by annealing for one hour under argon atmosphere at 380 °C. Furthermore, the photocatalytic activity of as-prepared β-Bi2O3 nanoparticles for the decomposition of phenol, 4-chlorophenol, 2,4-dichlorphenol, 4-nitrophenol, triclosan and ethinyl estradiol is demonstrated.

The mass spectrometric characterisation of bismuth–oxido clusters is described together with tandem mass spectrometric experiments aimed at investigating their gas‐phase chemistry. Clusters with different ligand shells (nitrate, salicylates, and methacrylate) and different sizes ({Bi6O8}, {Bi22O26}, and {Bi38O45}) were selected for this study. The following aspects were addressed by (tandem) electrospray ionisation Fourier‐transform ion‐cyclotron‐resonance (ESI‐FTICR) mass spectrometry: 1) Electrospray ionisation was used successfully for the generation of intact cluster ions, but led to rather complicated distributions of charge states and solvent adducts. The cluster core remained intact. 2) Mass spectrometry was used to follow the cluster growth from {Bi6O8} to {Bi22O27} and finally {Bi38O45} clusters. These experiments revealed that careful tuning of the conditions is required to avoid precipitates forming that hamper ESI ionisation. The stages of growth strongly depend on the experimental conditions. 3) Fragmentation experiments in the gas phase performed with the {Bi22O27} clusters obtained in the growth experiments resulted in the preferential formation of {Bi6O8} fragments and point to the particular stability of this cluster and its role in cluster growth. 4) Solution‐phase ligand‐exchange reactions on {Bi22O26} salicylate clusters were qualitatively monitored by mass spectrometry, but were limited by the complicated ion series formed that led to overlapping isotope patterns. 5) A number of fragmentation reactions occurred within the ligand shell when the clusters surrounded by an organic ligand shell were subjected to infrared multiphoton dissociation experiments. 6) For the nitrate clusters, fragmentation within the core was observed yielding {Bi6O8} fragments together with the corresponding clusters of reduced size.

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