Syntheses, structures, and electronic and photophysical properties of unsymmetrically substituted butadiynediyl and hexatriynediyl complexes derived from (C6F5)(R3P)(2)Pt, (p-tol)(R3P)(2)Pt, and (Ph3P)Au end-groups
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abstract
The CuCl-catalyzed reaction of butadiynyl complex trans-(C 6F5)(Et3P)2Pt(Cs;C) 2 (6) and trans-(p-tol)(Et3P)2PtCl (7) in HNEt2 affords trans,trans-(C6F5)(Et 3P)2Pt(CC)2Pt(PEt3) 2(p-tol) (8; 62%), but similar reactions of p-tol3P- substituted coupling partners, or of 6 and ?ranj-(p-tol)(p-tol 3P)2PtCl (4), are not successful. However, 6 and 4 react under modified conditions (t-BuOK, KPF6, cat. CuCl, THF/methanol) to give trans,trans-(C6F5)(Et3P) 2Pt(CC)2Pt(Pp-tol3) 2(p-tol) (9; 91%). The hexatriynyl complexes trans-(C 6F5)(R3P)2Pt(CC) 3H (R = p-tol, Et) are treated with 4 and 7, respectively, under the original or modified conditions. Workups give trans,trans-(C6F 5)(R3P)2Pt(CC)3Pt(PR 3)2(p-tol) (R = p-tol, 12, 40-63%; Et, 17, 59%). The reaction of 6 and ClAu(PPh3) and KN(SiMe3)2 affords trans(C6F5)(Et3P) 2Pt(CC)2Au(PPh3) (18, 97%). The CuCl-catalyzed reaction of (5-C5H5)W(CO) 3(CC)2H and trans-(C6F 5)(Et3P)2PtCl in HNEt2 generates trans-(C6F5)(Et3P)2Pt(CC) 2W(CO)3(5-C5H5). The crystal structures of 8, 9, 17, and 18, or solvates thereof, are determined and analyzed in detail. The square-planar end-groups in the C4 adducts 8 and 9 define angles of 62.3-34.7, as opposed to ca. 0 in the C 6 adduct 17. Both 9 and 18 exhibit phosphorescence from triplet states concentrated on the C4 segments. Data with 9 in low-temperature glasses suggest two conformers with different end-group-end-group orientations. 2008 American Chemical Society.
