Evidence for Effective p(Z)−π(Ar) Conjugations (Z = S, Se, and Te, as Well as Z = O) in 9-(Arylchalcogenyl)triptycenes: Experimental and Theoretical Investigations
摘要:
The p(Z)-pi(Ar) conjugations must operate fully in the ground states of 9-(arylchalcogenyl)triptycenes (p-YC(6)H(4)ZTpc:1 (Z = O), 2 (Z = S), 3 (Z = Se), and 4 (Z = Te)), where the p-YC6H4 group is placed in the bisected area between two phenyl planes of the triptycyl group with the parallel orientation. The ground-state geometries, which we call (A: pl), are confirmed by X-ray analysis. However, the conjugations never operate in the transition states between (A: pl) and/or the topomeric structures (A': pl'), where the Z-C-Tpc bond is perpendicular to the plane. The site-exchange processes correlate to the conjugations. Temperature-dependent H-1 NMR spectra are analyzed for 2 and 3 to demonstrate the effective p(Z)-pi(Ar) conjugations. The activation energies for the interconversion between (A: pl) and (A: pl) (GR: gear process) were obtained for 2 (Delta G(GR)(double dagger)(2)) and 3 (Delta G(GR)(double dagger)(3)). Delta G(GR)(double dagger)(3) correlate well with Delta G(GR)(double dagger)(2), and AG(GR)(double dagger)(2),ire well analyzed by the Hammett-type dual parameters. Delta G(GR)(double dagger)(2) and Delta G(GR)(double dagger)(3) are demonstrated to be controlled by the resonance interaction of the p(Z)-pi(C6H4)-p(Y) conjugations. QC calculations are performed on the ground and exited states of 1-4, which clarify the effective p(Z)-pi(C6H4)-p(Y) conjugations for Z of heavier atoms.
TripSH (4, Trip = 9-triptycyl) in toluene afforded cis-hydrido(thiolato) Pt IIcomplex [PtH(STrip)(PPh 3 ) 2 ] (5), as thermally and moisture-stable colorless crystals in 91% yield. Complex 5 was fully characterized by 1 H, 13 C 1 H}, and 31 P 1 H} NMR and IR spectroscopies, and the molecular structure of 5 was determined by X-ray crystallography.
[Pt(η 2 -nb)(PPh 3 ) 2 ] 与空间位阻硫醇 TripSH (4, Trip = 9-triptycyl) 在甲苯中的氧化加成得到顺式氢化(硫醇基)Pt II 复合物 [PtH(STrip )(PPh 3 ) 2 ] (5),作为热和湿稳定的无色晶体,产率为 91%。配合物 5 被 1 H、 13 C 1 H} 和 31 P 1 H} NMR 和 IR 光谱完全表征,5 的分子结构由 X 射线晶体学确定。