Synthesis and Structure of a Novel Ruthenium Hydrido Bis(dihydrogen) Complex with 1,4,7-Trimethyl-1,4,7-triazacyclononane Ligand: A Useful Precursor for Synthesis of Heterometallic Complexes

Abstract

The ruthenium hydrido bis(dihydrogen) complex [Cn*RuH(H2)2][PF6] (2-PF 6 ; Cn* = 1,4,7-trimethyl-1,4,7-triazacyclononane) was synthesized by treatment of Cn*RuCl3 with NaBH4. Complex 2-PF 6 undergoes a H/D exchange between its hydrido ligands and CD3OD, D2, or THF-d 8. Treatment of 2-PF 6 with Cp*IrH4 or Cp*OsH5 (Cp* = C5Me5) affords the heterometallic dinuclear polyhydrido complexes [Cn*Ru(μ-H)3IrCp*][PF6] (3-PF 6 ) and [Cn*Ru(μ-H)3OsHCp*][PF6] (4-PF 6 ), respectively. Treatment of 3-PF 6 with triphenylphosphine affords the complex [Ru(PPh3)(μ-η3:η1-Cn*CH2)(μ-H)2IrCp*][PF6] (5-PF 6 ), in which the triphenylphosphine is coordinated to the Ru atom as a terminal ligand and the C−H bond of the methyl group in the Cn* ligand is cleaved by the Ir atom. Reaction of 3-PF 6 with acetylene gives a bis(μ-vinyl) complex, [Cn*Ru(μ-σ,π-CHCH2)IrH(μ-σ,π-CHCH2)Cp*][PF6] (6-PF 6 ), in which one vinyl ligand is σ-bonded to the Ru atom and the other is σ-bonded to the Ir atom. The molecular structures of 2-PF 6 , [Cn*Ru(μ-H)3Ir(C5Me4Et)][BPh4] (3′-BPh 4 ), 4-BPh 4 , 5-BPh 4 , and 6-PF 6 were confirmed by X-ray analyses, and the coordination modes of the hydrido ligands in 2-PF 6 were confirmed by density functional theory calculations.

Polyhydrides of Platinum Group Metals: Nonclassical Interactions and σ-Bond Activation Reactions

“…Complex 164 is converted into the tetranuclear octahydride cluster compound [{(TACN)­Ru} 4 (μ-H) 6 (μ 3 –H) 2 ] 4+ ( 166 ), whereas the dehydrogenation of 165 affords the diruthenium-trihydride derivative [{(TACN*)­Ru} 2 (μ-H) 3 ] 2+ ( 167 ). Reactions of 165 with 5d-polyhydrides give rise to heterobimetallic dinuclear species. , …”

“…They have been mainly prepared through two procedures. Reduction of the ruthenium-(III) precursors RuCl 2 Tp(PR 3 ) (PR 3 = PPh 3 (143), P i PrPh 2 (144), P i Pr 3 (145), PCy 3 (146)) with NaBH 4 in a mixture of tetrahydrofuran-ethanol affords RuHTp(η 2 -H 2 )(PR 3 ) (PR 3 = PPh 3 (147), P i PrPh 2 (148), P i Pr 3 (149), PCy 3 (150)), 147 whereas the hydrogenation of RuHTp R (η 4 -COD) (Tp R = hydridetris(3,5-dimethylpyrazolyl)borate (Tp Me2 ; 151), hydridetris(3-isopropyl-4-bromopyrazolyl)borate (Tp′; 152)) in the presence of a monodentate ligand leads to RuHTp R (η 2 -H 2 )L (Tp R = Tp Me2 , L = PCy 3 (153), py (154), THT (155); Tp R = Tp′, L = PCy 3 (156), py (157), THT (158), NHEt 2 (159)). 148,149 The octahedral geometry of these compounds (Scheme 17) has been confirmed by the X-ray structure of 149.…”

Synthesis, Structure, and Reactivity of Mixed-Ligand Dinuclear Ruthenium Polyhydrido Complexes Supported by 1,4,7-Trimethyl-1,4,7-triazacyclononane and Bulky Phosphine Ligands

“…Dehydrogenative coupling between two metal hydride fragments is one of the useful methods to synthesize polyhydrido clusters. ,,, Recently, we reported the synthesis of the heterometallic mixed-ligand complexes [Cn*Ru(μ-H) 3 IrCp*] + and [Cn*Ru(μ-H) 3 OsHCp*] + , by treating [Cn*RuH(H 2 ) 2 ] + ( 1 ) with Cp*IrH 4 and Cp*OsH 5 , respectively, and we applied this dehydrogenative coupling method to the current study. Cn*-phosphine mixed-ligand diruthenium complexes [Cn*Ru(μ-H) 3 Ru(H) 2 (PR 3 ) 2 ] + (R = Cy ( 3a ), i Pr ( 3b ), Cyp ( 3c )) were synthesized by reacting 1 with Ru(H) 2 (H 2 ) 2 (PR 3 ) 2 (R = Cy ( 2a ), i Pr ( 2b ), Cyp ( 2c )), prepared according to the method reported by Chaudret and co-workers. − …”

“…We were not able to obtain elemental analyses of 5a – c due to the lability of the N 2 ligand. Ru(η 4 -C 8 H 12 )(η 6 -C 8 H 10 ), [Cn*RuH(H 2 ) 2 ](PF 6 ) ( 1-PF 6 ), [Cn*RuH(H 2 ) 2 ](BPh 4 ) ( 1-BPh 4 ), Ru(H) 2 (H 2 ) 2 (PCy 3 ) 2 ( 2a ), Ru(H) 2 (H 2 ) 2 (P i Pr 3 ) 2 ( 2b ), and Ru(H) 2 (H 2 ) 2 (PCyp 3 ) 2 ( 2c ) were prepared according to previously published methods.…”

Syntheses and Properties of Triruthenium Polyhydrido Complexes Composed of 1,2,4-tri-tert-butylcyclopentadienyl and p-Cymene Ruthenium Units

“…Condensation reactions using polyhydrido complexes are some of the most reliable methods for preparing polyhydride clusters. However, this method is restricted to the cases where the individual starting polyhydrido complexes are readily available and are stable enough to be handled under normal conditions. − As an alternative method, we recently reported the direct synthesis of polyhydride clusters from metal halides via gentle heating in 2-propanol in the presence of a base. Using this method, a diruthenium tetrahydrido complex, [(Cp ‡ Ru) 2 (μ-H) 4 ] ( 1b , Cp ‡ = 1,2,4-C 5 H 2 t Bu 3 ), was obtained in 98% yield from [Cp ‡ RuCl 2 ] 2 .…”