Luis-Raya Gilgamesh, Ramírez-Cardona Màrius, Luna-Bárcenas Gabriel, Hernández-Landaverde Martín A, Jiménez-Nieto Adair, García-Rivas Jose Luis, España-Sánchez Beatriz Liliana, Sanchez Isaac C
Área Académica de Ciencias de la Tierra y Materiales, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, Col. Carboneras, Mineral de la Reforma, 42184 Hidalgo, Mexico.
Universidad Politécnica de Pachuca, Carretera Pachuca-Cd. Sahagún km 20 Ex-Hacienda de Santa Bárbara, Zempoala, 43830 Hidalgo, Mexico.
Molecules. 2017 Jun 8;22(6):956. doi: 10.3390/molecules22060956.
Differences on molecular arrangement in two forms of long-chain 1,ω-alkanediols (CHO₂ with = 10, 11, 12, 13) are explained from the analysis of O-H···O hydrogen-bond sequences in infinite chains and the role of a C-H···O intramolecular hydrogen-bond in stabilization of a defect, as well as the inter-grooving effectiveness on molecular packing. GIXD (Glancing Incidence X-ray Diffraction) experiments were conducted on polycrystalline monophasic samples. Diffracted intensities were treated with the multi-axial March-Dollase method to correlate energetic and geometrical features of molecular interactions with the crystalline morphology and textural pattern of samples. The monoclinic (P₁/, = 2) crystals of the even-numbered members ( = 10, 12; DEDOL and DODOL, respectively) are diametrical prisms with combined form {104}/{-104}/{001} and present a two-fold platelet-like preferred orientation, whereas orthorhombic (P₁₁₁, = 4) odd-numbered members ( = 11, 13; UNDOL and TRDOL, respectively) present a dominant needle-like orientation on direction [101] (fiber texture). We show that crystalline structures of medium complexity and their microstructures can be determined from rapid GIXD experiments from standard radiation, combined with molecular replacement procedure using crystal structures of compounds with higher chain lengths as reference data.
通过对无限链中O-H···O氢键序列的分析、C-H···O分子内氢键在缺陷稳定中的作用以及分子堆积的相互沟纹效应,解释了两种形式的长链1,ω-链烷二醇(n = 10、11、12、13时的CHO₂)在分子排列上的差异。对多晶单相样品进行了掠入射X射线衍射(GIXD)实验。用多轴March-Dollase方法处理衍射强度,以将分子相互作用的能量和几何特征与样品的晶体形态和织构模式联系起来。偶数成员(分别为n = 10、12;DEDOL和DODOL)的单斜晶系(P2₁/c,Z = 2)晶体是具有{104}/{-104}/{001}组合形式的双径棱柱,并呈现出双重片状择优取向,而正交晶系(P2₁₁₁,Z = 4)奇数成员(分别为n = 11、13;UNDOL和TRDOL)在[101]方向上呈现出主导的针状取向(纤维织构)。我们表明,中等复杂度的晶体结构及其微观结构可以通过标准辐射的快速GIXD实验,并结合使用链长更长的化合物的晶体结构作为参考数据的分子置换程序来确定。