Jones D W, Sowden J M
Cancer Biochem Biophys. 1979;4(1):43-7.
The crystal structure of 1-methylbenz[a]lanthracene, which is weakly carcinogenic, has been determined by application of direct methods to single-crystal X-ray diffractometric data and refined by least squares to R = 0.09 over 845 independent reflections. Crystals are monoclinic, space group P2(1), with a = 8.491(2), b = 7.138(2), c = 10.500(2)ABEta = 95.06(01), Z = 2. As in other benz[a]anthracenes, the K-region bond C(5)-C(6) is short [1.34(1)A]. The distinctive bay geometry, with a methyl group opposite to a hydrogen, H(12), peri to another hydrogen, H(11), has a long bond C(13)--C(18) = 1.47(1)A in the bay, and the angular benz-ring is inclined at 16.5 degrees to the mean plane of the anthracene fragment. The methyl carbon atom is 0.79 A out of the mean molecular plane (or 0.19 A out of the plane of the benz-ring) and the 1.50 A long C(1)-methyl bond makes angles of 117 degrees and 125 degrees at C(1).
1-甲基苯并[a]蒽具有弱致癌性，其晶体结构已通过对单晶X射线衍射数据应用直接法确定，并通过最小二乘法精修，在845个独立反射上R值为0.09。晶体为单斜晶系，空间群P2(1)，a = 8.491(2)，b = 7.138(2)，c = 10.500(2)，β = 95.06(01)，Z = 2。与其他苯并[a]蒽一样，K区域的键C(5)-C(6)较短[1.34(1)Å]。其独特的湾区几何结构中，甲基与一个氢（H(12)）相对，且与另一个氢（H(11)）邻位，湾区的键C(13)--C(18) = 1.47(1)Å较长，且角形苯环与蒽片段的平均平面倾斜16.5度。甲基碳原子偏离平均分子平面0.79 Å（或偏离苯环平面0.19 Å），1.50 Å长的C(1)-甲基键在C(1)处形成117度和125度的角。
