Hydridotris(3,5-dimethylpyrazolyl)borate Tungsten Alkyne Complexes for Nonlinear Optics

摘要

Deprotonation of the propargyl site of racemic or enantiomerically pure Tp′(CO)IW-(C_6H_5C≡CCH_3) (Tp′= hydridotris(3,5-dimethylpyrazolyl)borate) yields an η~2-allenyl anion which has been reacted with a series of aldehydes and ketones possessing electron-donating substituents. Elimination under either acidic or basic conditions generates chiral trans conjugated enynes. Characterization has been accomplished by NMR, IR, UV-vis, and elemental analysis. Additionally, X-ray diffraction has been used to structurally characterize racemic Tp′(CO)IW(C_6H_5C≡CCH=C(CH_3)C_5H_4FeC_5H_5). The structural analysis reveals a centrosymmetric space group (P1); cell dimensions of a = 10.690(5) A, b = 13.360(7) A, c = 15.392(7) A, α = 92.57(6)°, β = 101.70(5)°, and γ = 100.97(4)°; Z = 2 molecules/unit cell; and R_w = 4.7% and R = 3.9%. Second harmonic generation of the enynes has been measured by the Kurtz powder technique.