Hexaruthenium Carbonyl Cluster Complexes with Basal Edge-Bridged Square Pyramidal Metallic Skeleton: Efficient Synthesis of 2-Imidopyridine Derivatives and Determination of Their Reactive Sites in Car
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- 作者：Javier A. Cabeza ; Ignacio del Rí ; o ; Pablo Garcí ; a-Á ; lvarez ; Daniel Miguel ; and Ví ; ctor Riera
- 刊名：Inorganic Chemistry
- 出版年：2004
- 出版时间：August 23, 2004
- 年：2004
- 卷：43
- 期：17
- 页码：5450 - 5458
- 全文大小：239K
- 年卷期：v.43,no.17(August 23, 2004)
- ISSN：1520-510X
文摘
The reactions of [Ru3(CO)12] with half equivalent of 2-amino-6-methylpyridine (H2ampy) or 2-aminopyridine (H2apy)in refluxing xylene give the hexanuclear products [Ru6(
3-H)2(5-
2-L)(-CO)2(CO)14] (L = ampy, 1; apy, 2). Thesereactions represent the first high-yield syntheses of hexanuclear complexes with a basal edge-bridged squarepyramidal metallic skeleton. Five metal atoms of these complexes are bridged by the N-donor ligand in such a waythat the edge-bridging metal atom is attached to the pyridine nitrogen, while the basal atoms of the square pyramidare capped by an imido fragment that arises from the activation of both N-H bonds of the NH2 group. The reactivesites of these complexes in CO substitution reactions have been determined by studying the reactivity of 1 withtriphenylphosphine. Two kinetically controlled monosubstitutions take place on the edge-bridging metal atom inpositions cis to the pyridine nitrogen, leading to a mixture of two isomers of formula [Ru6(3-H)2(5-2-ampy)(-CO)2(CO)13(PPh3)] (3 and 4). On heating at 80 
C, these monosubstituted isomers are transformed, via a dissociativepathway, into the product of thermodynamic control (5), which has the PPh3 ligand on the apical Ru atom. The di-and trisubstituted derivatives [Ru6(3-H)2(5-2-ampy)(-CO)2(CO)12(PPh3)2] (6) and [Ru6(3-H)2(5-2-ampy)(-CO)2(CO)11(PPh3)3] (7) are stepwise formed from 3-5 and PPh3. Compound 6 has the PPh3 ligands on the edge-bridging and apical Ru atoms, and compound 7 has an additional PPh3 ligand on an unbridged basal Ru atom.The compound [Ru6(3-H)2(5-2-ampy)(-CO)2(CO)12(-dppm)] (8), in which a basal and the apical Ru atoms arespanned by the dppm ligand, has been isolated from the reaction of 1 with bis(diphenylphosphino)methane.
3-H)2(5-2-L)(-CO)2(CO)14] (L = ampy, 1; apy, 2). Thesereactions represent the first high-yield syntheses of hexanuclear complexes with a basal edge-bridged squarepyramidal metallic skeleton. Five metal atoms of these complexes are bridged by the N-donor ligand in such a waythat the edge-bridging metal atom is attached to the pyridine nitrogen, while the basal atoms of the square pyramidare capped by an imido fragment that arises from the activation of both N-H bonds of the NH2 group. The reactivesites of these complexes in CO substitution reactions have been determined by studying the reactivity of 1 withtriphenylphosphine. Two kinetically controlled monosubstitutions take place on the edge-bridging metal atom inpositions cis to the pyridine nitrogen, leading to a mixture of two isomers of formula [Ru6(3-H)2(5-2-ampy)(-CO)2(CO)13(PPh3)] (3 and 4). On heating at 80 C, these monosubstituted isomers are transformed, via a dissociativepathway, into the product of thermodynamic control (5), which has the PPh3 ligand on the apical Ru atom. The di-and trisubstituted derivatives [Ru6(3-H)2(5-2-ampy)(-CO)2(CO)12(PPh3)2] (6) and [Ru6(3-H)2(5-2-ampy)(-CO)2(CO)11(PPh3)3] (7) are stepwise formed from 3-5 and PPh3. Compound 6 has the PPh3 ligands on the edge-bridging and apical Ru atoms, and compound 7 has an additional PPh3 ligand on an unbridged basal Ru atom.The compound [Ru6(3-H)2(5-2-ampy)(-CO)2(CO)12(-dppm)] (8), in which a basal and the apical Ru atoms arespanned by the dppm ligand, has been isolated from the reaction of 1 with bis(diphenylphosphino)methane.