Influence of the Ligand Alkyl Chain Length on the Solubility, Aqueous Speciation, and Kinetics of Substitution Reactions of Water-Soluble M3S4 (M = Mo, W) Clusters Bearing Hydroxyalkyl Diphosphines
| Autor: | F. Beltrán, Tomás, Llusar, Rosa, Sokolov, Maxim, G. Basallote, Manuel, Fernández-Trujillo Rey, María Jesús, García Basallote, Manuel, Pino Chamorro, Jose Ángel |
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| Přispěvatelé: | Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica |
| Rok vydání: | 2013 |
| Předmět: |
chemistry.chemical_classification
Substitution reaction Kinetics of Substitution Reactions of Water-Soluble M3S4 (M = Mo W) Stereochemistry Ligand Medicinal chemistry Inorganic Chemistry Solvent chemistry.chemical_compound chemistry Diphosphines Halogen Hydroxymethyl Physical and Theoretical Chemistry Solubility Clusters Bearing Hydroxyalkyl Diphosphines Alkyl |
| Zdroj: | Inorganic Chemistry 2013, 52, 8713−8722 |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/ic400897y |
| Popis: | Water-soluble [M3S4X3(dhbupe)3](+) diphosphino complexes (dhbupe = 1,2-bis(bis(hydroxybutyl)phosphino)ethane), 1(+) (M = Mo, X = Cl) and 2(+) (M = W; X = Br), have been synthesized by extending the procedure used for the preparation of their hydroxypropyl analogues by reaction of the M3S4(PPh3)3X4(solvent)x molecular clusters with the corresponding 1,2-bis(bishydroxyalkyl)diphosphine. The solid state structure of the [M3S4X3(dhbupe)3](+) cation possesses a C3 symmetry with a cuboidal M3S4 unit, and the outer positions are occupied by one halogen and two phosphorus atoms of the diphosphine ligand. At a basic pH, the halide ligands are substituted by hydroxo groups to afford the corresponding [Mo3S4(OH)3(dhbupe)3](+) (1OH(+)) and [W3S4(OH)3(dhbupe)3](+) (2OH(+)) complexes. This behavior is similar to that found in 1,2-bis(bis(hydroxymethyl)phosphino)ethane (dhmpe) complexes and differs from that observed for 1,2-bis(bis(hydroxypropyl)phosphino)ethane (dhprpe) derivatives. In the latter case, an alkylhydroxo group of the functionalized diphosphine replaces the chlorine ligands to afford Mo3S4 complexes in which the deprotonated dhprpe acts in a tridentate fashion. Detailed studies based on stopped-flow, (31)P{(1)H} NMR, and electrospray ionization mass spectrometry techniques have been carried out in order to understand the solution behavior and kinetics of interconversion between the different species formed in solution: 1 and 1OH(+) or 2 and 2OH(+). On the basis of the kinetic results, a mechanism with two parallel reaction pathways involving water and OH(-) attacks is proposed for the formal substitution of halides by hydroxo ligands. On the other hand, reaction of the hydroxo clusters with HX acids occurs with protonation of the OH(-) ligands followed by substitution of coordinated water by X(-). |
| Databáze: | OpenAIRE |
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