Novel Ligand-Unsupported Diruthenium Compounds, [Ru₂(Cl₄Cat)₄]^n- (Cl₄Cat = Tetrachlorocatecholate; n = 2 and 3)

Effects of Countercations on the Structures and Redox and Spectroscopic Properties of Diruthenium Catecholate Complexes with Ligand-Unsupported Ru−Ru Bonds

“…The Na + cations are further chelated by DME (1b) or coordinated by THF (2b s ), exhibiting a distorted octahedral or tetrahedral coordination geometry. On the other hand, the second mode, called the "out-of-plane connection", was found in [Na (THF) 11,12 (Figure 1b). The Na The connecting structures of the Na + cations to the [Ru 2 (R 4 Cat)] 2-/3units are among the fascinating features of the present complexes, especially for the development of molecular assemblages based on cation‚‚‚anion interactions.…”

“…Interestingly, the isomeric forms of the [Ru(3,5-DTBCat) 2 ] unit in 1a-1d do not vary with the cations; that is, all the complexes ]. 11,12 The axial ligands, substituents of the catecholates, and solvent molecules that bind to the Na + cations are omitted for clarity. have cis-configulated [Ru(3,5-DTBCat) 2 ] halves, and these are combined in an eclipsed form so that each half is related by 180°rotation around the Ru-Ru bond.…”

“…6 On the other hand, the effects of cations on structures and physical properties in the solid state and solution have been less well-described for dimetallic com- plexes accompanying by countercations represented by [M 2 X 8 ] n-(X ) halogen atom), 7 [M 2 (CO 3 ) 4 ] n-, 8 [M 2 (SO 4 ) 4 ] n-, 9 and [M 2 (HPO 4 ) 4 ] n-. 10 In the preceding paper of this series, 11 we reported the synthesis and the structural and physicochemical diversity of a variety of diruthenium complexes, generally formulated as [Na n {Ru 2 (R 4 Cat) 4 }] (n ) 2 or 3; R 4 ) F 4 , Cl 4 , 12 Br 4 , H 4 , 3,5-di-t-Bu, and 3,6-di-t-Bu), and clearly demonstrated that the complexes with ligand-unsupported Ru-Ru bonds can sensitively respond to redox reactions and ligand substituents on the basis of the greater degree of freedom in their molecular structures. Although special attention had not been paid to the interaction between the [Ru 2 (R 4 Cat) 4 ] 2-/3units and countercations in the literature, the countercations, Na + , bind to the O Cat atoms of R 4 Cat 2in all of the complexes.…”

Substituent-Directed Structural and Physicochemical Controls of Diruthenium Catecholate Complexes with Ligand-Unsupported Ru−Ru Bonds

“…6 The reaction between Ru 2 (OAc) 4 Cl (OAc -) acetate) with tetrachlorocatecholate (Cl 4 CatH 2 ) afforded complexes [Na (THF) The structural characterization shows that these complexes possess ligand-unsupported Ru-Ru bonds with short Ru-Ru bonds, 2.273(1) (2 s ) and 2.2233(6) Å (2′ s ). The transformation of ligand-supported Ru-Ru bonds to ligandunsupported Ru-Ru bonds has great potential for developing new synthetic entries into dimetallic complexes with ligandunsupported M-M bonds.…”

Alkyne Oxidations by cis-Dioxoruthenium(VI) Complexes. A Formal [3 + 2] Cycloaddition Reaction of Alkynes with cis-[(Cn*)(CF3CO2)RuVIO2]ClO4 (Cn* = 1,4,7-Trimethyl-1,4,7-triazacyclononane)

“…The Ru(1)-O( 1) and Ru(1)-O(2) distances are 1.977( 5) and 1.979(6) Å, respectively, comparable to the related 2), and 1.973(2) Å] (Cl 4 Cat ) tetrachlorocatecholate) (see Table 2). 34 The respective C( 11)-O(2) and C(10)-O( 1) bond distances are 1.305(10) and 1.301( 9) Å, which are slightly shorter than the related C(sp 2 )-O single bond distances (1.32-1.35 Å) found in [Ru 2 (Cl 4 Cat) 4 ] 3-34 and [ n Bu 4 N][Ru VI (N)(L)]. 33 On the other hand, the measured C( 11)-C(10) bond distance [1.439(12) Å] is significantly elongated from a typical CdC double (1.33 Å); this value is comparable to that of a CH-C(O) linkage [1.382-(11) Å] found in [Cn*Ru III (acac)(OH)]PF 6 ‚H 2 O (acac ) acety-lacetonate).…”