The [N]phenylenes display marked deformation from planarity in the crystalline state. In order to probe the generality of this phenomenon, several derivatives were synthesized and their single-crystal X-ray structures were obtained. All new compounds displayed some degree of nonplanarity. Thus, for example, the parent triangular [4]phenylene (4b) has a median bend angle at the ring junction of 1.5 degrees and a range of 0.3 degrees to 3.5 degrees, whereas hexakis[triisopropylsilyl(ethynyl)] triangular [4]phenylene (4c) possesses the bulkiest appendages and the largest median bend angle and range (3.8 degrees and 1.7 degrees-5.6 degrees, respectively). A detailed analysis of the bending and twisting angles at the ring junctions, however, revealed that the magnitude of deformations were independent of topology, molecular size, and substituent type. In contrast to the phenylenes, a Cambridge Structural Database (CSD) search of unsubstituted and non-peri-substituted naphthalenes and anthracenes shows these molecules to be virtually planar in the solid state. A comparison of the single-point energies (HF/6-31G*) of the phenylenes with the acenes calculated for molecules possessing a fixed bend angle at the ring fusion of 3 degrees, 6 degrees, 9 degrees, and 12 degrees reveals the former to be 26% to 45% easier to deform than the latter. Based on these results, the nonplanarity seen for the phenylenes is most likely a consequence of crystal-packing forces deforming particularly flexible molecules.
BERRIS, B. C.;HOVAKEEMIAN, G. H.;LAI, YEE-HING;MESTDAGH, H.;VOLLHARDT, K.+, J. AMER. CHEM. SOC., 1985, 107, N 20, 5670-5687
作者:BERRIS, B. C.、HOVAKEEMIAN, G. H.、LAI, YEE-HING、MESTDAGH, H.、VOLLHARDT, K.+
DOI:——
日期:——
HIRTHAMMER, M.;VOLLHARDT, K. P. C., J. AMER. CHEM. SOC., 1986, 108, N 9, 2481-2482
作者:HIRTHAMMER, M.、VOLLHARDT, K. P. C.
DOI:——
日期:——
A new approach to the construction of biphenylenes by the cobalt-catalyzed cocyclization of o-diethynylbenzenes with alkynes. Application to an iterative approach to [3]phenylene, the first member of a novel class of benzocyclobutadienoid hydrocarbons
作者:Bruce C. Berris、George H. Hovakeemian、Yee Hing Lai、Helene Mestdagh、K. Peter C. Vollhardt
DOI:10.1021/ja00306a013
日期:1985.10
Synthese de [3] phenylene, et de ses derives trimethylsilyles par reaction de diethynyl-1,2 benzene avec le bis-trimethylsilylacetylene en presence de η 5 -cyclopentadienyl dicarbonyl-cobalt. Oxydation et reduction des composes synthetises. Structure cristalline des derives silyles
合成这些 [3] 亚苯基,等 de ses 衍生出三甲基甲硅烷基反应 de diethynyl-1,2 苯 avec le 双三甲基甲硅烷基乙炔 en 存在 de η 5 - 环戊二烯基二羰基钴。氧化和还原合成合成。结构 cristalline des 派生 silyles