Dimers of [Ru2(Xap)4] bridged by 1,3,5-hexatriyn-diyl (Xap are 2-anilinopyridinate and its aniline substituted derivatives), [Ru 2(Xap)4]2(μ-C6) (1), were prepared. Compounds 1 reacted with 1 equiv of tetracyanoethene (TCNE) to yield the cyclo-addition/insertion products [Ru2(Xap)4] 2{μ-C≡CC(C(CN)2)-C(C(CN)2)C≡C} (2) and 1 equiv of Co2(dppm)(CO)6 to yield the η2-Co2 adducts to the middle C≡C bond, [Ru 2(Xap)4]2(μ-C6)(Co 2(dppm)(CO)4) (3). Voltammetric and spectroelectrochemical studies revealed that (i) two Ru2 termini in 1 are sufficiently coupled with the monoanion (1-) as a Robin-Day class II/III mixed valence species; (ii) the coupling between two Ru2 is still significant but somewhat weakened in 3; and (iii) the coupling between two Ru2 is completely removed by the insertion of TCNE in 2. The attenuation of electronic couplings in 2 and 3 was further explored with both the X-ray diffraction study of representative compounds and spin-unrestricted DFT calculations.

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Persistent URL dx.doi.org/10.1021/ja204813h
Journal American Chemical Society Journal
Citation
Xi, B. (Bin), Liu, I.P.-C. (Isiah P.-C.), Xu, G.-L. (Guo-Lin), Choudhuri, M.M.R. (Mohommad M. R.), DeRosa, M.C, Crutchley, R, & Ren, T. (Tong). (2011). Modulation of electronic couplings within Ru2-polyyne frameworks. American Chemical Society Journal, 133(38), 15094–15104. doi:10.1021/ja204813h