Dichloro-μ₂,μ₂-naphthalene-1,8-diyl-bis(N,N,N′,N′-tetramethylethylenediamino)tetracopper(I)

Round 1

Reviewer 1 Report

The paper by Kilian et al. describe the synthesis and the structure elucitation of a novel and interesting copper(I) cluster. The presentation is clear and the discussion is embedded in the related field of research.

Unfortunately, there are some problems with the purity of the studied sample. This does not concern the single-crystal X-ray study, but the bulk of the compound, which was used for the spectroscopic characterization. I see here some room for improvements, and some additional data and/or explanation should be included prior acceptance:

(1) The synthetic procedure is more or less straightforward and does not contain any advanced purification steps, not even recrystallization (the red precipitate formed is simply washed and 'defined' as a pure product). Later with the NMR spectra, the authors mention a 'decomposition' of the product. Has it ever been pure? All attempts to purify the bulk of the product, which was formed with 80 per cent yield and in a gram scale, should be described. Furthermore, the described instability of the compound might be visualized by subsequent NMR spectra of such solutions.

(2) Elemental analysis must be included to ensure the purity of the bulk. This is standard and good practice in scientific publications describing new compounds.

(3) NMR spectra: Please add intergrations to the 1H spectrum and assign solvent peaks and signals of decomposition products (where possible). Please reprocess the 13C spectrum to a satisfactory quality. What means 31P{1H} in both spectra?

(4) line 83: Removal of 'solvated TMEDA' during the drying procedure is reported here. The described crystal structure does not show any solvate molecules... Repeat the NMR study with (e.g. pentane-washed and not vacuum dried) single crystals of the compound to clarify this point.

(5) line 223. A 'high reactivity' of the cluster is concluded. Did you do any reactions with the product to justify this statement? If 'yes', please report. Or do you simply mean 'instability', then please do the the experiment suggested in paragraph (1).

Overall, the submission describes the crystal structure of a a nice new compound. The structure determination is well done, but the "chemistry part" of the paper needs some essential improvements, which can probably be done during a revision process.

Author Response

Please see the attached file.

Author Response File: Author Response.pdf