1034927-46-2Relevant articles and documents
Diphenylphosphinoferrocene gold(I) acetylides: Synthesis of heterotri- And heterotetrametallic transition metal complexes
Packheiser, Rico,Jakob, Alexander,Ecorchard, Petra,Walfort, Bernhard,Lang, Heinrich
, p. 1214 - 1226 (2009/01/30)
The synthesis and reaction chemistry of heterobimetallic FcPPh 2AuCl (1) and FcPPh2Au-C≡CR compounds (3a, R = bipy; 3b, R = C6H4-4-C≡N; 3c, R = C5H 4N-4; 3d, R = NCN-H; 3e, R = NCN-I; Fc = (η5-C 5H5)(η5-C5H4)Fe; bipy = 2,2′-bipyridyl-5-yl; NCN = [C6H2(CH 2NMe2)2-2,6]-) toward diverse organometallic molecules is described. In context with this background, 1 was prepared by reacting FcPPh2 with (tht)AuCl (tht = tetrahydrothiophene). The reaction of 1 either with HC≡CR (2a, R = bipy; 2b, R = C6H4-4-C≡N; 2c, R = C5H 4N-4) or with the lithium acetylides LiC≡CR (2d, R = NCN-H; 2e, R = NCN-I) gave complexes 3a-3e in good yield. In 1 the gold(I) chloride entity was further reacted with the organometallic alkyne HC≡CMLn (4a, MLn = (η-C6H5)Cr(CO)3; 4b, MLn = Fc; 4c, MLn = Rc; Rc = (η5-C 5H5)(η5-C5H4)Ru) to afford the heterotrimetallic complexes FcPPh2Au-C≡CML n (5a, MLn = (η6-C6H 5)Cr(CO)3; 5b, MLn = Fc; 5c, MLn = Rc) in which three different transition metal atoms are connected via rigid-rod structured carbon-rich units. Complexes 3a-3e feature with their terminal nitrogen donor groups a further binding site, which allows the introduction of a third metal-containing fragment. In this context, the reaction of 3b with [Ru]N≡N[Ru] (6) ([Ru] = [η3-mer-(2,6-(Me 2NCH2)2C5H3N}-RuCl 2]) resulted in the formation of neutral heterotrimetallic FcPPh 2Au-C≡C-C6H4-4-C≡N-[Ru] (7). The synthesis of an even heterotetrametallic complex [FcPPh2Au-C≡C- C5H4N-Cu {(Me3SiC≡C)2[Ti]}]OTf (9) could be achieved by treatment of 3c with the organometallic π-tweezer {[Ti](μ-σ,π-C≡CSiMe3)2} CuOTf (8a). Heterobimetallic 3a afforded in a straightforward reaction with equimolar amounts of (nbd)Mo(CO)4 (14) (nbd = 1,5-norbornadiene) and {[Ti](μ-σ,π-C≡CSiMe3)2}MX (8b, M = Cu(N≡CMe), X = PF6; 8c, M = Ag, X = OClO3), respectively, compounds FcPPh2Au-C≡C-bipy[Mo(CO)4] (15) and (FcPPh2Au-C≡C-bipy[{[Ti](μ-σ,π- C≡CSiMe3)2}M])X (16a, M = Cu, X = PF6; 16b, M = Ag, X = ClO4). The synthesis of the Fe-Au-Pt NCN pincer molecule FcPPh2Au-C≡C-NCN-Pt-C=CR (13a, R = bipy; 13b, R = C6H4-4-C≡N) was possible by the consecutive reaction of Me3SiC=C-NCN-PtCl (10) with Li-2a or Li-2b to give Me 3SiC≡C-NCN-Pt-C=CR (11a, R = bipy; lib, R = C6H 4-4-C≡N), which with [n-Bu4N]F produced HC≡C-NCN-Pt-C=CR (12a, R = bipy; 12b, R = C6H 4-4-C≡N). On reacting 12a and 12b with 1, complexes 13a and 13b were formed, which are highly insoluble, and hence, no further reactions were carried out. The solid state structures of 3a, 3b, 3e, 5b, 5c, and 16a are reported. Most characteristic for these complexes is that the appropriate transition metals are linked by carbon-rich organic bridging units. The electrochemical properties of selected samples (3a-3c, 5a-5c, 7, 9, 16a, and 16b) are reported. The cyclovoltammetric data show that there is no significant influence of the organic and organometallic acetylide units on the redox potential of the diphenylphosphino ferrocene in 3a- 3c and 5a-5c. Remarkable is that the chelate coordination of the bipyridyl unit to Cu(I) in 16a results in a reduction of Cu(I) followed by reoxidation of Cu(0) without any structural change of the molecule involved, which is unique in titanium(IV)-copper(I) chemistry.
