# Organorhodium and Iridium-Containing Derivatives of the 48-Tungsto-8-phosphate Wheel: Synthesis, Characterization, and Catalytic Activity

## TL;DR

This paper describes the synthesis and catalytic activity of new organorhodium and iridium compounds based on a tungsto-phosphate wheel structure.

## Contribution

The novel synthesis of organorhodium- and iridium-containing derivatives of the P8W48 wheel and their application in selective hydrogenation.

## Key findings

- The polyanions were successfully synthesized using mild one-pot conditions.
- The supported catalysts showed high activity in the selective hydrogenation of o-xylene.
- Little cracking occurred even under high temperature and pressure conditions.

## Abstract

We report on the
synthesis, characterization, and catalysis of
organorhodium- and iridium-containing derivatives of the 48-tungsto-8-phosphate
wheel, [{Rh­(Cp*)­(H2O)}4P8W48O184]32– (1) and [{Ir­(Cp*)­(H2O)}4P8W48O184]32– (2). The novel polyanions 1 and 2 were synthesized by the reaction of (MCp*Cl2)2 (M = RhIII, IrIII) with
the mixed potassium–lithium salt of the cyclic P8W48 precursor in an aqueous medium using mild one-pot
conditions, and four organometallic moieties are covalently bound
to the central cavity of the P8W48 wheel via
two M-O­(W) oxygen bridges. Both polyanions were structurally characterized
in the solid state by single-crystal X-ray diffraction, FT-IR spectroscopy,
and thermogravimetric analysis, as well as in solution by 31P and 13C NMR spectroscopy. The hydrogenation of olefins
was investigated after supporting polyanions 1 and 2 on mesoporous SBA15. The supported catalysts exhibited high
activity in the selective hydrogenation of o-xylene with very little
cracking products, even under high temperature and pressure conditions.