296768-62-2Relevant academic research and scientific papers
Bis-ortho-chelated diaminoaryl platinum compounds with σ-acetylene substituents. Investigations into their stability and subsequent construction of multimetallic systems. The crystal structure of [(μ2-[(η2-NCN)Pt(η 1-CO)C≡CSiMe3])Co2(CO)6] (NCN = 2,6-bis[(dimethylamino)methyl]phenyl)
Back, Stephan,Gossage, Robert A.,Lutz, Martin,Del Río, Ignacio,Spek, Anthony L.,Lang, Heinrich,van Koten, Gerard
, p. 3296 - 3304 (2000)
A series of related platinum σ-acetylide complexes {Pt}C≡CR ({Pt} = [Pt(C6H3{Me2NCH2} 2-2,6)]+) were prepared by reacting lithium acetylides with {Pt}Cl (1) in order to investigate the stability of the Pt-acetylide σ-bond and their possible application in the assembly of multimetallic compounds containing the {Pt} "pincer" unit. This may be achieved by η2-coordination of the acetylide or by incorporating a second ligating site in the acetylide anion. Both of these approaches are demonstrated herein. {Pt}C≡CSiMe3 (2) was reacted with [M][BF4] ([M] = [Cu(NCMe)4], Ag) and different forms of Cu(I) halides. Only with the former was the formation of stable π-coordinated M(I) compounds observed. [(η2-[{Pt}C≡CSiMe3]2)-Cu][BF 4] exhibits η2-coordination of both acetylenic units to a formal Cu(I) metal center, thus forming a heterotrimetallic compound. In the presence of halide ions, 2 undergoes cleavage of the Pt-C≡C σ-bond with concomitant formation of {Pt}X (X = Cl or I). The reaction of 2 with Co2(CO)8 leads via π-coordination to the formation of a trimetallic dicobaltatetrahedrane. The structure of [(μ2-[(η2-NCN)Pt(η 1-CO)C≡CSiMe3])Co2(CO)6] in the solid state shows that one ortho-CH2NMe2 substituent of the NCN ligand is no longer coordinated to the Pt metal center. Instead, a CO ligand coordinates trans to the Pt-N bond, yielding a metal center with four different ligand donor atoms. Attempts to obtain related Pt(IV) acetylides by reaction of 2 with CuCl2 resulted in the formation of {Pt}Cl3, [CuX]n, and [CuC≡CSiMe3]n. The reaction with I2 gave neither a Pt(IV) diiodide nor a Pt(II) η1-I2 complex, but instead led to Pt-C(acetylide) bond cleavage and formation of {Pt}I and IC≡CSiMe3. The reaction of {Pt}C≡CC6H4CN-4 with [{Pt}H2O][BF4] and {Ru}N≡N{Ru} ({Ru} = [RuCl2(C5H3N{CH2NMe 2}2-2,6)]) gives air-stable well-defined bimetallic compounds. In contrast, the reaction of {Pt}C≡CC6H4CN-4 with [AuCl3]2 or Au(CO)Cl leads to the formation of a gold mirror, NCC6H4(C≡C)2C6H4CN, and {Pt}Cl3 or {Pt}Cl, respectively. Cyclic voltammetry studies with representative Pt-acetylides show irreversible oxidative processes which are shifted to a more negative potential upon substitution of Cl by acetylide.
