Monomeric alkyne-stabilized complexes of organo-copper(I) and -silver(I)

The synthesis of heterobimetallic {[Ti](C equivalent to CR1)(2)}MX {[Ti] = (eta(5)-C5H4SiMe3)(2)Ti; M = Cu, R-1 = SiMe3: 4a, X = SCF3; 4b, X = SEt; M = Ag, R-1= Bu-t: 5a, X = OC(O)Me; 5e, X = NO3; M = Ag, R-1 = SiMe3: 5b, X = OC(O)Me; 5c, X = OC(O)Ph; 5d, X = NO3} is described. These compounds toget her with {[Ti](C equivalent to CR1)(2)}CuX (4c, R-1 = SiMe3, X = SC6H4CH2NM e2-2; 4d, R-1 = Bu-t, X = SC6H4CH2NMe2-2) can be used for the preparation o f a large variety of different organo-copper(I) and -silver(I) species. The titanium-copper complexes {[Ti](C equivalent to CR1)(2)}CuR2 [R-1= SiMe3: 6a, R-2 = C6F5; 6b, R-2 = C6H2(CF3)(3)-2,4,6; 6c, R-2 = C6H2Ph3-2,4,6; R-1 = Bu-t: 6d, R-2 = C6H2Ph3-2,4,6; 7, R-2 = Me] are accessible by the reactio n of 4c or 4d with suitable organic nucleophiles. Monomeric organo-silver(I ) compounds can be prepared by using different starting materials: While th e silver(I) aryls {[Ti](C equivalent to CSiMe3)(2)}AgR2 [8a, R-2 = C6H2(CF3 )(3)-2,4,6; 8b, R-2 = C6H2Ph3-2,4,6] are only available by the reaction of 5b with LiC6H2(CF3)(3)-2,4,6 or BrMgC6H2Ph3-2,4,6, the silver(I) methyl spe cies {[Ti](C equivalent to CR1)(2)}AgMe (9a, R-1 = SiMe3; 9b, R-1 = Bu-t) c an be synthesized by using 5a, 5b, 5d, or 5e as starting materials. While c ompounds 6-8 are stable under the reaction conditions applied, 9a already s tarts to decompose at low temperature: The heterobimetallic titanium-silver acetylide {[Ti](C equivalent to CsiMe(3))(C equivalent to CAg)}(2) (10) is formed by nucleophilic substitution of one of the alkynyl Me3Si groups, wh ereby SiMe4 is eliminated. Moreover, compounds 6-9 react with Br-2 to produ ce R-2-Br along with {[Ti](C equivalent to CR1)(2)}MBr (M = Cu; 11a, R-1 = Bu-t; 11b, R-1 = SiMe3 M =Ag, 11c, R-1 = SiMe3), which yield with equimolar amounts of LiR2 or BrMgR2 the starting materials 6-9 back. The solid-state structures of 4a, 5c, 6c, and 8b are reported. All complexes contain a mon omeric (eta(2)-alkyne)(2)M(eta(1)-X) (4, 5) or (eta(2)-alkyne)(2)M(eta(1)-R -2) (6-9) entity in which the group 11 metal atom M is trigonally coordinat ed by the two alkynyl ligands C equivalent to CR1 and the eta(1)-bonded gro ups X or R-2, respectively.