Redox chemistry of ruthenium ions in mono-substituted Keggin tungstophosphate: a new synthetic extension for ruthenium derivatives based on [PW₁₁O₃₉Ru^VIN]⁴⁻

Abstract

We herein report the synthesis and characterization of a series of ruthenium-substituted Keggin-type heteropolytungstates containing {Ru(II)(NO)}, {Ru(III)(H2O)} or {Ru(IV)Cl} species. Although anionic [PW11O39Ru(II)(NO)](4-) (1) and [PW11O39Ru(III)(H2O)](4-) (2) are known, a new synthetic method for the preparation of (n-Bu4N)4[1] and (n-Bu4N)4[2] is developed in this paper. Treatment of (n-Bu4N)4[XW11O39(Ru[triple bond, length as m-dash]N)] with Me3NO afforded the ruthenium(ii) nitrosyl complex (n-Bu4N)4[1] in almost quantitative yield. Photolysis of (n-Bu4N)4[1] solution in CH3CN/H2O gives (n-Bu4N)4[2], which is readily oxidized by PhICl2 to yield the Ru(IV) complex (n-Bu4N)4[PW11O39Ru(IV)Cl] ((n-Bu4N)4[3]). These complexes are fully characterized by (1)H NMR and (31)P NMR spectroscopy, infrared spectroscopy, cyclic voltammetry, elemental analysis, thermogravimetric-differential thermal analysis, electrospray ionization mass spectrometry (ESI-MS) and X-ray photoelectron spectroscopy (XPS).

A Novel Ruthenium-Decorating Polyoxomolybdate Cs3Na6H[MoVI14RuIV2O50(OH)2]·24H2O: An Active Heterogeneous Oxidation Catalyst for Alcohols

“…Simultaneously, two μ 3 -OH bridges (O5 and O5A; BVS: 1.19) in the cluster were also determined by the BVS calculations (Table S3). From these results, the chemical composition of polyanion 1 was defined as [Mo VI 14 Ru IV 2 O 50 (OH) 2 ] 10− ( 1a ), which was confirmed by the combined analyses of XPS and EDX (Figure S2) [41,43]. …”

“…Although the oxidation of Ru III to Ru IV in aqueous solution is known in POMs chemistry [24,27,38], a high-resolution Ru 3d XPS spectrum was nevertheless obtained to further characterize their oxidation states, as Ru is a highly specific element, and is known to have a wide range of oxidation states varying from –II to VIII. As shown in Figure 4b, the Ru 3d peaks in the high-resolution XPS spectra of the title compound centered on 286.8 eV and 282.6 eV, corresponding to energy regions of Ru 3d 3/2 and Ru 3d 5/2 , which are attributed to Ru IV centers [43,56,57]. This oxidation state of Ru assignment was also supported by the BVS results, which indicated a IV valence [38,58].…”

“…Among them, the wholly inorganic Ru-containing POMs represent an important subclass, which had been studied previously but with only a few structures reported as compared to those with inorganic-organic hybrid Ru-containing POMs. Up until now, the majority of investigations in this area of research have been dominated by the preparations and characterizations of Ru-substituted or -sandwiched lacunary Keggin/Dawson-type heteropolytungstates [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43], such as mono-Ru substituted polyanions [XW 11 O 39 Ru III (H 2 O)] n− (X = Si, Ge, P) [2,3,4,5,20,21,22,23,24,25] and [P 2 W 17 O 61 Ru III (H 2 O)] 5− [26,27,28], di-Ru-sandwiched/substituted polyanions {O[Ru IV (X)P 2 W 17 O 61 ] 2 } 16− (X = OH, Cl) [27], {[(XZnRu 2 III (OH)(H 2 O)](ZnW 9 O 34 ) 2 } n− (X = W, Zn) [29,30,…”

Synthesis, cytotoxicity, apoptosis and cell cycle arrest of a ruthenium multi-substituted Keggin-type polyoxotungstate

“…Therefore, the synergistic effect of ruthenium and vacancy POMs is expected to endow rutheniumsubstituted polyoxometalates (Ru-POMs) with high antitumor activity. At present, a multitude of Ru-POMs have been reported [19][20][21][22][23][24][25][26][27] . It is noteworthy that the antitumor activities of these compounds have been seldom reported.…”

“…During our research on the exploration of Ru-POMs, the antitumor activities of a monoruthenium(II)-substituted Dawson polyoxotungstate have been investigated [28] . However, we also noticed that the majority of the syntheses of Ru-POMs have used the monolacunary Keggin [XW 11 O 39 ] n− (X = P, Ge and Si) or Dawson-type [P 2 W 17 O 61 ] 10− polyoxoanions as reagents/ligands for the coordination to ruthenium [19][20][21][22][23][24][25] . The compounds synthesized by other types of lacancy POMs and ruthenium were rarely reported.…”