# Structure and Spectroscopy of Triruthenium Dodecacarbonyl, Ru3(CO)12

## TL;DR

This study investigates the structure and vibrational properties of triruthenium dodecacarbonyl using multiple spectroscopic techniques and neutron diffraction.

## Contribution

The paper provides the most precise structural determination of Ru3(CO)12 and reassigns vibrational modes using INS and low-temperature spectroscopy.

## Key findings

- The P21/n structure of Ru3(CO)12 is stable down to 10 K with a 5.9% volume contraction.
- INS spectroscopy revealed all fundamentals below 700 cm–1 for the first time.
- Vibrational mode assignments were revised based on new spectroscopic data.

## Abstract

We have reinvestigated the structure and vibrational
spectroscopy
of triruthenium dodecacarbonyl, Ru3(CO)12, in
the solid state by neutron powder diffraction, inelastic neutron scattering
(INS), infrared and Raman spectroscopies. We find that the known room
temperature P21/n structure
is maintained down to 10 K. The unit-cell parameters follow a Debye
relationship, with an overall 5.9% volume contraction from 300 to
10 K. The high resolution data at 10 K has enabled the most precise
determination of the structure to date. INS spectroscopy, which has
no selection rules, has allowed the observation of all the fundamentals
below 700 cm–1 for the first time. In combination
with new low temperature infrared and Raman spectra, this has resulted
in the reassignment of several of the modes. Our previous work has
shown that density functional theory calculations of the vibrational
spectra of metal carbonyls produces mixed results. For M­(CO)6, M = Cr, Mo, W the calculated spectra are in good agreement with
the experimental spectra, whereas for Fe­(CO)5, and Fe2(CO)9 the agreement was poor. We find that for
Ru3(CO)12 the agreement is also poor.