Correction: HCOOH disproportionation to MeOH promoted by molybdenum PNP complexes.

[This corrects the article DOI: 10.1039/D1SC04181A.]. This journal is © The Royal Society of Chemistry.

The authors regret that in Scheme 2 of the original article, complexes 7 and 8 were drawn incorrectly. The solid-state structure of both complexes, as established by X-ray analysis, had been previously reported (7 (ref. 1) and 8 (ref. 2)). In both complexes, the PNP ligand adopts a facial tridentate coordination to molybdenum and not a meridional one, as erroneously shown in Scheme 2 of the original article. The correct ligand arrangements in the metal coordination sphere for complexes 7 and 8 are reported below in Scheme 1.

Scheme 2

Proposed mechanisms for HCOOH dehydrogenation (red), disproportionation (blue) and decarbonylation (green) promoted by 5. Evidence for the formation of a Mo(iv) species is based on the detection by NMR of H2 and HD following addition of DCOOD to Mo(H) species (see Fig. SI-31).

Scheme 1

Mo–PNP complexes tested in the dehydrogenation of HCOOH.

Please note that complex 8 is also shown in Scheme 4 in the proposed mechanism for HCOOH decarbonylation (green part), and in Fig. 2. In both cases, the correct structure for complex 8 is reported below in Scheme 2 and Fig. 1.

Fig. 2

Molecular structure of {Mo(CO)2(CH3CN)[CH3N(CH2CH2P(CH(CH3)2)2)2]} 9. Displacement ellipsoids correspond to 30% probability. Hydrogen atoms are omitted for clarity.

Fig. 1

1H and 31P{1H} NMR spectra of a toluene-d8 solution of {Mo(CH3CN)(CO)2(HN[(CH2CH2P)(CH(CH3)2)2]2} 4 in the presence of 100 equivalents of HCOOH ([Mo] 10−2 M, [HCOOH] 1 M), before (a) and after heating at 90 °C for 1 hour (b). Spectra were recorded at room temperature. Signals related to complex 5 are marked by red dots.

Furthermore, a mistake was made in the caption of Fig. 6, showing the solid-state structure of complex 9: the latter has been incorrectly described as a Mo(i)-hydride species {Mo(H)(CO)2(CH3CN)[CH3N(CH2CH2P(CH(CH3)2)2)2]}. The correct formula, in agreement with the X-ray structure, is as follows and is shown above in Fig. 2: {Mo(CO)2(CH3CN)[CH3N(CH2CH2P(CH(CH3)2)2)2]}.

The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.