名称:
Synthesis of Bi- and Trinuclear Bis(alkynyl) Complexes [PtM (M = Rh, Ir), PtRh2] Starting from [cis-Pt(C6F5)2(C⋮CR)2]2-
摘要:
The course of the reactions of Q(2)[cis-Pt(C6F5)(2)(C drop CR)(2)] (Q = PPh3Me, R = Ph 1a; Q = NBu4, R = Bu-t 1b, SiMe3 1c) with [M(mu-Cl)(COD)](2) (M = Rh, Ir) is strongly influenced by the metal and the substituents, as well as the stoichiometry. Thus, whereas treatment of 1a with either 0.5 or 1 equiv of [Rh(mu-Cl)(COD)](2) gives the chelating-type binuclear highly polar compound (PPh3Me)[cis-Pt(C6F5)(2)(mu-1 kappa C-alpha:eta(2)-C drop CPh)(2)Rh(COD)], 2a, analogous reactions using 1b as the precursor afford only the trinuclear complex (NBu4)[{cis-Pt(C6F5)(2)(mu-1 kappa C-alpha: eta(2)-C drop (CBu)-Bu-t)(2)}{Rh-2(mu-Cl)(COD)(2)}], 4b. On the other hand, related bi- and trinuclear SiMe3 derivatives (NBu4)[cis-Pt(C6F5)(2)(mu-1 kappa C-alpha:eta(2)-C drop CSiMe3)(2)Rh(COD)], 2c, and (NBu4)[{cis-Pt-(C6F5)2(mu-1 kappa C-alpha:eta(2)-C drop CSiMe3)(2)}{Rh-2(mu-Cl)(COD)(2)}], 4C, are easily obtained by treating 1c with the binuclear rhodium substrate in the adequate molar ratio [1:0.5 for 2c; 1:1 for 4c]. Complex 2b and, alternatively, 2a,c derivatives can be produced by reacting 1 with the cationic solvento species [Rh(COD)(Et2O)(x)](+) (prepared in situ). The molecular structures of 2a and 4b have been confirmed by X-ray diffraction. By contrast, whereas the reactions of 1a,b with [Ir(mu-Cl)(COD)](2) lead to the formation of undefined products, the heterobinuclear sigma,pi double-alkynyl-bridged complex (NBu4)[cis-Pt(C6F5)(2)(mu-1 kappa C-alpha:eta(2)-C drop CSiMe3)(mu-eta(2):2 kappa C-alpha-C drop CSiMe3)Ir(COD)], 3c, (X-ray) is isolated from reaction of 1c with the dimer iridium complex regardless of the molar ratio used (1:0.5 or 1:1).