Correction to Additivity of Interligand Substituent Effects for the

Addition/Correction pubs.acs.org/Organometallics

Correction to Additivity of Interligand Substituent Effects for the Isoelectronic [(η5‑C6H7)Fe(η6‑MenC6H6−n)]+ and [(η5‑C5H5)Fe(η6‑MenC6H6−n)]+ Sandwich Cations ́ Jan Turek, Roman Olejnik, and Bohumil Štıbr* Organometallics 2013. DOI: 10.1021/om500165w

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e apologize to the readers for incomplete citation in the original article.1 The authors unintentionally overlooked an article by Gassman and Deck published in 1994.2 These authors were first to observe a good linear correlation between δ(1H) NMR shifts of the Cp ligand and the number of arene− methyl substituents (n) for the complete series of [(η5C5H5)Fe(η6-MenC6H6−n)]+ (2+) cations; correlation between the Fe(2p3/2) binding energies and n is also well-defined in this article. These linear phenomena should be taken as a consequence of the transannular (interligand) substituent effect (TASE), which is of additive character. The additive nature was earlier demonstrated by the pioneering work by Nesmeyanov et al.3 on the series of [CpFe(C6H6)]+ cations substituted by various substituents on either the Cp or C6H6 ring to show an interesting linear relation between 1H NMR data and Hammett−Taft σ parameters of the substituents. In view of these facts, the 1H NMR data for cations of type 2+ used in the present article1 now serve only for comparative purposes (see, for example, black circles in Figure 1 and 1H NMR data in Table 2 in the original article), as these are practically identical with those given in ref 2. Nevertheless, the main objective of the present work1 was to extend the TASE hypothesis onto the complete (n = 0−6) series of the isoelectronic cationic methylarene−cyclohexadienyl sandwiches of general structure [(η 5 -C 6 H 7 )Fe(η 6 MenC6H6−n)]+ (1+), which are isoelectronic analogues of the aforementioned [(η5-C5H5)Fe(η6-MenC6H6‑n)]+ (2+) cations2 but exhibit a broader range of 1H and 13C resonances for the Chd ring and different sensitivities (k values) to changes in the methyl substitution on the arene ligand. Also demonstrated was the extension of the TASE concept to 13C NMR shifts that interestingly exhibit a reversed linear behavior. Moreover, it has become obvious that the k values derived from linear relations of 1H and 13C chemical shifts with n might be used as an alternative tool for the quantitative determination of electrondonating (or withdrawing) efficiency of an arbitrary substituent.

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ACKNOWLEDGMENTS We thank Professor P. A. Deck (Virginia Polytechnic Institute and State University, Blacksburg, VA, USA) for helpful discussions.

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REFERENCES

(1) Turek, J.; Olejník, R.; Š tíbr, B. Organometallics 2014, DOI: dx.doi.org/10.1021/om500165w. (2) Gassman, P. G.; Deck, P. A. Organometallics 1994, 13, 2890. (3) Nesmeyanov, A. N.; Leshchova, I. F.; Ustynyuk, Yu. A.; Sirotkina, Ye. I.; Bolesova, I. N.; Isayeva, L. S.; Vol’kenau, N. A. J. Organomet. Chem. 1970, 22, 689. © 2014 American Chemical Society

Published: May 28, 2014 2919

dx.doi.org/10.1021/om500516w | Organometallics 2014, 33, 2919−2919