Crystalline Molecular Gyroscopes: The Effects of Subtle Molecular Differences on the Crystal Packing of Triphenylmethyl and Triphenylsilyl Stators
摘要:
Single crystals of molecular gyroscopes, 1,4-bis(3,3,3-triphenylpropynyl)benzene and 1, 4-bis(triphenyl-silanylethynyl)- benzene were studied by single crystal X-ray diffraction (XRD) analysis and their packing tendencies were compared to those of analogous structures without the central phenylene rotator.
The first synthesis of conjugated triynes by molybdenum-catalysed alkyne metathesis is reported. Strategic to the success of this approach is the utilization of sterically-hindered diynes that allowed for the site-selective alkyne metathesis to produce the desired conjugated triyne products. The steric hindrance of the alkyne moiety was found to be crucial in preventing the formation of diyne byproducts
Ethynylsilanes, RnSi(CCH)4-n (n = 0 to 3), can be prepared in satisfactory yields from RnSiCl4-n and HCCMgCl in tetrahydrofuran. Losses occur through (a) polymerization under the influence of the cyclic ether and (b) metallation of the ethynylsilanes to SiCCMgCl which provokes the formation of sila-acetylene chains and rings. Some of these compounds of higher molecular weight have been isolated
乙炔基硅烷R n Si(CCH)4-n(n = 0至3),可以由R n SiCl 4-n和HCCMgCl在四氢呋喃中以令人满意的产率制备。损失是通过(a)在环醚的影响下聚合和(b)乙炔基硅烷金属化成SiCCMgCl引起的,从而促使形成硅乙炔链和环。这些高分子量化合物中的一些已经被分离出来。