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五氟丙酰基甲氧羰基亚甲基三苯基胂是无色透明晶体,属单斜晶系,空间群C_2~2-P2_1.晶胞参数:α=11.917(3)A,b=9.495(1)A,c=11.729(3)A,β=117.82(2)°,Z=2.用四圆衍射仪收集衍射强度数据,得到独立可观察点2558个.用重原子法确定晶体结构,并用块对角矩阵最小二乘法修正结构参数,最后的偏离因子R=0.042.该分子的结构表明,片段As,C(19),C(20),C(23),O(1),O(3)是共平面的. 由于C(19)—C(20)键长较短(1.39A),C(19)—C(23)键长较长(1.45A),因此可以认为叶立德碳上的负电荷主要是向五氟丙酰基上的羰基离域,它的形式为1.此结构信息,符合红外光谱给出的结构,说明该化合物是一稳定的叶立德.
Pentafluoropropionylmethoxycarbonylmethylene triphenylarsine is a colorless and transparent crystal, which belongs to the monoclinic space group C_2 ~ 2-P2_1. Cell parameters: α = 11.917 (3) A, b = 9.495 1) A, c = 11.729 (3) A, β = 117.82 (2) °, Z = 2. The diffraction intensity data were collected with a four-circular diffractometer to obtain 2558 independent observable points. The crystal structure was determined by heavy atom method, The structure parameters were corrected by least square method of block diagonal matrix with the final deviation factor of R = 0.042. The structure of the molecule showed that the fragment A, C (19), C (20), C (23), O (3) is coplanar, and the C (19) -C (23) bond length is longer (1.45 A) due to the shorter bond length of C (19) -C The negative charge is mainly delocalized to the carbonyl group of the pentafluoropropionyl group in the form of 1. This structural information conforms to the structure given by the infrared spectrum, indicating that the compound is a stable ylide.