Suchetan P A, Suneetha V, Naveen S, Lokanath N K, Krishna Murthy P
Department of Chemistry, University College of Science, Tumkur University, Tumkur 572 103, India.
Department of Chemistry, Bapatla Engineering College (Autonomous), Bapatla A. P., India.
Acta Crystallogr E Crystallogr Commun. 2016 Mar 11;72(Pt 4):477-81. doi: 10.1107/S2056989016003777. eCollection 2016 Apr 1.
The title compounds, C10H11BrO4, (I), and C9H9BrO4, (II), are derivatives of bromo-hy-droxy-benzoic acids. Compound (II) crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. In both (I) and (II), the O-CH2-O-CH3 side chain is not in its fully extended conformation; the O-C-O-C torsion angle is 67.3 (3) ° in (I), and -65.8 (3) and -74.1 (3)° in mol-ecules A and B, respectively, in compound (II). In the crystal of (I), mol-ecules are linked by C-H⋯O hydrogen bonds, forming C(5) chains along [010]. The chains are linked by short Br⋯O contacts [3.047 (2) Å], forming sheets parallel to the bc plane. The sheets are linked via C-H⋯π inter-actions, forming a three-dimensional architecture. In the crystal of (II), mol-ecules A and B are linked to form R 2 (2)(8) dimers via two strong O-H⋯O hydrogen bonds. These dimers are linked into ⋯A-B⋯A-B⋯A-B⋯ [C 2 (2)(15)] chains along [011] by C-H⋯O hydrogen bonds. The chains are linked by slipped parallel π-π inter-actions [inter-centroid distances = 3.6787 (18) and 3.8431 (17) Å], leading to the formation of slabs parallel to the bc plane.
标题化合物C₁₀H₁₁BrO₄（I）和C₉H₉BrO₄（II）是溴代羟基苯甲酸的衍生物。化合物（II）在不对称单元中以两个独立分子（A和B）结晶。在（I）和（II）中，O-CH₂-O-CH₃侧链均未处于完全伸展构象；在（I）中，O-C-O-C扭转角为67.3（3）°，在化合物（II）的分子A和B中，该扭转角分别为-65.8（3）°和-74.1（3）°。在（I）的晶体中，分子通过C-H⋯O氢键相连，沿[010]方向形成C（5）链。这些链通过短的Br⋯O接触[3.047（2）Å]相连，形成平行于bc平面的片层。片层通过C-H⋯π相互作用相连，形成三维结构。在（II）的晶体中，分子A和B通过两个强O-H⋯O氢键相连形成R₂²（8）二聚体。这些二聚体通过C-H⋯O氢键沿[011]方向连接成⋯A-B⋯A-B⋯A-B⋯[C₂²（15）]链。这些链通过平行的滑移π-π相互作用[质心间距 = 3.
