Reaction of a (benzene)Ru 2+ complex, [Ru(C 6 H 6 )Cl 2 ] 2 , with a di-lacunary γ-Keggin-type silicodecatungstate, K 8 [γ-SiW 10 O 36 ], at a (C 6 H 6 )Ru 2+ /[γ-SiW 10 O 36 ] 8ratio of 1 produces [γ-SiW 10 O 36 Ru(C 6 H 6 )] 6-. The cesium salt was characterized using experimental and theoretical methods; one (C 6 H 6 )Ru 2+ moiety is attached through three bridging oxygen atoms of the nonlacunary site, and the anion is stable in aqueous solution. 1 H NMR spectroscopy and high-resolution electrospray ionization [a] 1778 Figure 3. 1 H NMR spectra of [γ-SiW 10 O 36 Ru(C 6 H 6 )] 6dissolved in (a) D 2 O and (b) acetate buffer in D 2 O (pH 4.7). (c) 13 C MAS NMR spectrum of Cs 6 [γ-SiW 10 O 36 Ru(C 6 H 6 )], and 13 C NMR spectra of [γ-SiW 10 O 36 Ru(C 6 H 6 )] 6dissolved in (d) D 2 O and (e) D 2 O with acetone as an internal standard.

Invited for the cover of this issue is Masahiro Sadakane from Hiroshima University, Japan, collaborating with groups from Okayama University, Japan, and Universitat Rovira i Virgili, Spain. The cover image shows a new Ru‐containing‐heteropolytungstate.

The Front Cover shows the structure of a mono‐(benzene)Ru‐attached di‐lacunary (defect) γ‐Keggin‐type silicotungstate, [γ‐SiW10O36]8–. We found that the (C6H6)Ru2+ first reacts with three bridging oxygen atoms of the non‐lacunary site of the di‐lacunary γ‐Keggin‐type silicotungstate to form [γ‐SiW10O36Ru(C6H6)]6–; it then reacts with the terminal oxygen atoms of the lacunary site to form a 2:1 [γ‐SiW10O36{Ru(C6H6)}2]4– complex. More information can be found in the https://doi.org/10.1002/ejic.201701311 For more on the story behind the cover research, see the https://doi.org/10.1002/ejic.201800315.