A comparative study of optical properties and X-ray induced luminescence of octahedral molybdenum and tungsten cluster complexes

Abstract

Octahedral metal cluster complexes have high potential for biomedical applications. In order to evaluate the benefits of these moieties for combined CT/X-ray luminescence computed tomography, this paper compares photoluminescence, radiodensity and X-ray induced luminescence properties of eight related octahedral molybdenum and tungsten cluster complexes [{MI}L] (where M is Mo or W and L is I, NO, OTs or OH/HO). This article demonstrates that despite the fact that molybdenum cluster complexes are better photoluminescence emitters, tungsten cluster complexes, in particular (BuN)[{WI}I], demonstrate significantly higher X-ray induced luminescence due to a combination of relatively good photoluminescence properties and high X-ray attenuation. Additionally, photo-degradation of [{MI}(NO)] was evaluated.

Synthesis, Structure, and Luminescence Properties of a {Mo6I8} Complex with (C6F5)2PO2 Ligands

“…The complex also produces X‐ray induced luminescence in solid state (Figure ) with the emission spectrum reproducing the spectrum of photoluminescence, similar to those few examples of {Mo 6 I 8 } 4+ ‐based cluster complexes, for which X‐ray induced luminescence has been reported , . The spectroscopic and photophysical data (emission maximum wavelength ( λ em ), the full‐width at half‐maximum (fwhm) of the emission spectrum, quantum yield ( Φ em ) and lifetime ( τ em ) with the corresponding amplitudes (A) for the solid phase) of 1 and some other assorted {Mo 6 I 8 } 4+ ‐based complexes with apical O‐donor organic ligands are listed in the Table .…”

“…The spectrum of X‐ray induced luminescence was recorded from a neat solid at ambient conditions on a home‐built spectrometer following the protocol described in reference, to which the reader is referred for additional details. A sample in the form of an island of finely ground powder with dimensions 3x8 mm and thickness of about 0.1 mm was fixed on a vertical aluminum plate with a polypropylene‐based double‐sided Scotch tape.…”

“…154.5–155.0 °C (hexane ‐ tert ‐butyl methyl ether; m.p. 154 °C in ). 1 H NMR (CD 3 CN, c = 0.1 mol · L –1 ): δ = 4.99 br.s.…”

Molybdenum Iodides – from Obscurity to Bright Luminescence

“…The nitrate complex undergoes degradation upon irradiation at 0.56 %/min rate. It was found that emission profiles of X‐ray luminescence more or less correspond to the profiles of the light‐induced phosphorescence …”

The Ouzo effect to selectively assemble molybdenum clusters into nanomarbles or nanocapsules with increased HER activity

“…They offer a vast compositional and structural diversity, and among all possible structures, the octahedral molybdenum cluster units [{Mo 6 X 8 }L 6 ] 2-(where X are inner halide ligands and L are apical anionic organic or inorganic ligands) have been the most investigated moieties, owing to their photophysical properties as well as their catalytic performances in water splitting. [1][2][3][4][5][6][7][8][9] Furthermore, in the broad context of nanoarchitectonics [10][11][12][13] 20 Nanoprecipitation by solvent shifting is the most straightforward strategy to obtain nanoparticles, widely used in pharmacy to produce nanoparticulate drugs. 21 The elaboration of nanocapsules is more challenging although it provides interesting opportunities resulting from their internal cavity, with potential applications in catalysis, photonics, enzyme protection or drug carriers.…”