196620-58-3Relevant academic research and scientific papers
Trigonal-planar-coordinated organogold(I) complexes stabilized by organometallic 1,4-diynes: Reaction behavior, structure, and bonding
K?hler, Katrin,Silverio, Sandro J.,Hyla-Kryspin, Isabella,Gleiter, Rolf,Zsolnai, Laszlo,Driess, Alexander,Huttner, Gottfried,Lang, Heinrich
, p. 4970 - 4979 (2008/10/08)
The reaction of the bis(alkynyl) titanocenes [Ti](C≡CR1)(C≡CR2) ([Ti] = (η5-C5H4SiMe3)2-Ti; 1a R1 = R2 = SiMe3; 1b R1 = R2 = tBu; 1c R1 = SiMe3, R2 = tBu) with (C5H5N)AuCl3 (2), LAuCl (5a, L = PPh3; 5b, L = SMe2) as well as (Me2S)AuR3 (6b, R3 = C≡CSiMe3; 6c, R3 = C≡C4Bu; 6d, R3 = C6H2(CF3)3-2,4,6; 6e, R3 = Me) is described. Treatment of [Ti](C≡CSiMe3)2 (1a) with (C5H5N)AuCl3 (2) produces [Ti]Cl2 (3) and Me3SiC≡C-C≡CSiMe3 (4a) together with Au(0). However, the linear two-coordinated gold(I) chlorides LAuCl (5a,b) react with 1a to afford different products, depending on the Lewis bases applied. While in the reaction of the Ph3P donor-stabilized gold(I) chloride 5a, the titanocene dichloride (3) along with (Ph3P)AuC≡CSiMe3 (6a) is obtained, with the appropriate Me2S donor-stabilized molecule 5b, the titanocene dichloride (3) along with the heterobimetallic tweezer molecule {[Ti]-(C≡CSiMe3)2}AuC≡CSiMe3 (7a) is formed. A possible mechanism for the different chemical behavior is discussed. Likewise, molecules of the latter type (compounds 7a-e) can be synthesized in much better yields by the reaction of [Ti](C≡CR1)(C≡CR2) (1a-c) with (Me2S)-AuR3 (6b-e). In the heterobimetallic titanium-gold complexes {[Ti](C≡CR1)(C≡CR2)}AuR3 (7a, R1 = R2 = SiMe3, R3 = C≡CSiMe3; 7b, R1 = R2 = tBu, R3 = C≡CtBu; 7c, R1 = SiMe3, R2 = tBu, R3 = C≡CSiMe3; 7d, R1 = R2 = SiMe3, R3 = C6H2(CF3)3-2,4,6; 7e, R1 = R2 = SiMe3, R3 = Me), a low-valent monomeric organogold(I) moiety in a trigonal-planar environment is present, which is stabilized by the chelating effect of the organometallic π-tweezer bis(alkynyl) titanocene. The thermolysis of selected organogold(I) complexes affords, on elimination of the bis(alkynyl) titanocene fragment, the coupling products R3-R3 (4) and gold films. The X-ray structure analyses of compounds 7a, 7b, and 7d are reported. It is found that in all compounds short titanium-gold bond lengths are present (7a, 3.007(2) A?; 7b, 2.975(1) A?; 7d, 2.995(1) A?). Calculations show that the complexation of the Au-R3 monomers with the organometallic π-tweezer bis(alkynyl) titanocene is described by a four-center two-electron bond. The monomeric organogold(I) moieties are stabilized by a synergetic in-plane donation and back-donation of electron density between the bis(alkynyl) titanocene and the Au-R3 species. A direct donor-acceptor Au-Ti interaction contributes to this stabilization.
New neutral and anionic alkynylgold(I) complexes via new synthetic methods. Crystal and molecular structures of [Au(C≡CSiMe3)(CNtBu)], and [Au(C≡CR)PR′3] (R′ = cyclohexyl, R = CH2Cl, CH2Br; R′ = Ph, R = SiMe3, tBu)
Vicente, José,Chicote, María-Teresa,Abrisqueta, María-Dolores,Jones, Peter G.
, p. 5628 - 5636 (2008/10/08)
[(PPh3)2N][Au(acac)2] (acac = acetylacetonate) reacts with terminal alkynes RC≡CH to give [(PPH3)2N][Au(C≡CR)2] (R = H, tBu, SiMe3, CH2X (X = Cl, Br, OH)) complexes. The reactions between [(PPh3)2N][Au(C≡CH)2] and [(PPh3)2N][AuX2] (X = Cl, Br, I) give [(PPh3)2N][Au(C≡CH)X] complexes. Neutral mononuclear [Au(C≡CR)(NHEt2)] (R = SiMe3, tBu), [Au(C≡CR)(PR′3)] (R = H, R′ = Ph, C6H4OMe-4; R = CH2Cl, CH2Br, CH2OH, R′ = Cy = cyclohexyl; R = SiMe3, R′ = Ph, C6H4OMe-4, Cy; R = tBu, R′ = Ph, Cy, C6H4OMe-4), [Au(C≡CR)(CNtBu)] (R = SiMe3, tBu), and [Au(C≡CR){C(NHtBu)(NEt2)}] (R = H, SiMe3, tBu) or dinuclear [(AuL)2{μ-C≡C(CH2)5C≡C)] (L = PPh3, CNtBu, C(NHtBu)(NEt2)) are obtained via a variety of synthetic methods: (i) reaction between [(PPh3)2N][Au(C≡CH)2] and [Au(PR3)2]ClO4, (ii) reaction of terminal alkynes with [Au(acac)(L)], (iii) reaction of [AuClL] complexes with terminal alkynes in diethylamine, (iv) substitution reactions (e.g., [Au(C≡CR)(NHEt2)] + PR′3), (v) reaction of diethylamine with alkynyl isocyanide derivatives to give alkynylcarbene complexes. The crystal structures of [(PPh3)2N][Au(C≡CCH2OH)2], [Au(C≡CSiMe3)(CNtBu)], and [Au(C≡CR)(PR′3)] (R′ = Cy, R = CH2Cl, CH2Br; R′ = Ph, R = SiMe3, tBu) were determined.
