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对位溴代苯甲酸ｐ－ＢｒＣ６ Ｈ５ＣＯＯＨ晶体属单斜晶系，空间群是 Ｃ５２ｈ－Ｐ２１ ／ｃ；晶胞参数为：ａ＝３．９５Ａ，ｂ＝６．１４ａ，ｃ＝２９．４Ａ， β＝９４．４５’；晶胞中含四个分子。这四个分子两两地通过羧基间所形成的氢键（Ｏ－Ｈ…Ｏ＝２．６５Ａ）结合成为具有对称心的双聚分子。羧基和苯环基本上共面。双聚分子的长轴差不多就在（１０２ ）面上，与ｂ轴的交角为５４°１２’；它的平面绕着分子长轴偏离（１０２ ）面的角度为２８°１２’。
The crystal of p-BrC6H5COOH is a monoclinic with space group C52h-P21 / c. The unit cell parameters are: a = 3.95A, b = 6.14a, c = 29.4A, = 94.45 ’; unit cell contains four molecules. These four molecules couple each other through a hydrogen bond formed between the carboxyl groups (O-H ... O = 2.65A) to form a centrosymmetric dimeric molecule. The carboxyl and benzene rings are substantially coplanar. The long axis of the dimeric molecule is almost on the (102) plane and the angle of intersection with the b axis is 54 ° 12 ’; its plane is offset by an angle of 28 ° 12’ about the long axis of the molecule.