Oxidatively Induced P鈥揙 Bond Formation through Reductive Coupling between Phosphido and Acetylacetonate, 8-Hydroxyquinolinate, and Picolinate Groups

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• 作者：Andersson Arias ; Juan Forni茅s ; Consuelo Fortu帽o ; Antonio Mart铆n ; Piero Mastrorilli ; Stefano Todisco ; Mario Latronico ; Vito Gallo
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：May 6, 2013
• 年：2013
• 卷：52
• 期：9
• 页码：5493-5506
• 全文大小：658K
• 年卷期：v.52,no.9(May 6, 2013)
• ISSN：1520-510X

文摘

The dinuclear anionic complexes [NBu₄][(R_F)₂M^II(渭-PPh₂)₂M鈥?sup>II(NO)] (R_F = C₆F₅. NO = 8-hydroxyquinolinate, hq; M = M鈥?= Pt 1; Pd 2; M = Pt, M鈥?= Pd, 3. NO = o-picolinate, pic; M = Pt, M鈥?= Pt, 4; Pd, 5) are synthesized from the tetranuclear [NBu₄]₂[{(R_F)₂Pt(渭-PPh₂)₂M(渭-Cl)}₂] by the elimination of the bridging Cl as AgCl in acetone, and coordination of the corresponding N,O-donor ligand (1, 4, and 5) or connecting the fragments 鈥?i>cis-[(R_F)₂M(渭-PPh₂)₂]^{2鈥?/sup>鈥?and 鈥淢鈥?NO)鈥?(2 and 3). The electrochemical oxidation of the anionic complexes 1鈥?b>5 occurring under HRMS(+) conditions gave the cations [(R_F)₂M(渭-PPh₂)₂M鈥?NO)]+, presumably endowed with a M(III),M鈥?III) core. The oxidative addition of I₂ to the 8-hydroxyquinolinate complexes 1鈥?b>3 triggers a reductive coupling between a PPh₂ bridging ligand and the N,O-donor chelate ligand with formation of a P鈥揙 bond and ends up in complexes of platinum(II) or palladium(II) of formula [(R_F)₂MII(渭-I)(渭-PPh₂)M鈥?sup>II}(P,N-PPh₂hq)], M = M鈥?= Pt 7, Pd 8; M = Pt, M鈥?= Pd, 9. Complexes 7鈥?b>9 show a new Ph₂P-OC₉H₆N (Ph₂P-hq) ligand bonded to the metal center in a P,N-chelate mode. Analogously, the addition of I₂ to solutions of the o-picolinate complexes 4 and 5 causes the reductive coupling between a PPh₂ bridging ligand and the starting N,O-donor chelate ligand with formation of a P鈥揙 bond, forming Ph₂P-OC₆H₄NO (Ph₂P-pic). In these cases, the isolated derivatives [NBu₄][(Ph₂P-pic)(R_F)Pt^II(渭-I)(渭-PPh₂)M^II(R_F)I] (M = Pt 10, Pd 11) are anionic, as a consequence of the coordination of the resulting new phosphane ligand (Ph₂P-pic) as monodentate P-donor, and a terminal iodo group to the M atom. The oxidative addition of I₂ to [NBu₄][(R_F)₂Pt^II(渭-PPh₂)₂Pt^II(acac)] (6) (acac = acetylacetonate) also results in a reductive coupling between the diphenylphosphanido and the acetylacetonate ligand with formation of a P鈥揙 bond and synthesis of the complex [NBu₄][(R_F)₂Pt^II(渭-I)(渭-PPh₂)Pt^II(Ph₂P-acac)I] (12). The transformations of the starting complexes into the products containing the P鈥揙 ligands passes through mixed valence M(II),M鈥?IV) intermediates which were detected, for M = M鈥?= Pt, by spectroscopic and spectrometric measurements.