From Intermolecular Interactions to Texture in Polycrystalline Surfaces of 1,ω-alkanediols (ω = 10-13).

Gilgamesh Luis-Raya,Jose García-Rivas,Adair Jiménez-Nieto,Gabriel Luna-Bárcenas,Màrius Ramírez-Cardona,Isaac Sanchez,Martín Hernández-Landaverde,Beatriz España-Sánchez

doi:10.3390/molecules22060956

Abstract

Differences on herringbone molecular arrangement in two forms of long-chain 1,ω-alkanediols (CnH2n+2O2 with n = 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 gauche 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 (P21/c, Z = 2) crystals of the even-numbered members (n = 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 (P212121, Z = 4) odd-numbered members (n = 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.

Highlights

IntroductionOdd-numbered compounds (orthorhombic with space group of P21 21 21 , Z = 4) present a molecular packing in layers but, so far, they have been described with molecules oriented parallel to each other [2,3,4,5,6,7,8,9,10,11,12,13]
The compounds of the 1,ω-alkanediols (Cn H2n+2 O2 ) series with n ≥ 9 crystallize at low temperatures into two ordered forms according to the parity of carbon atom numbers in the chain [1].Molecules 2017, 22, 956; doi:10.3390/molecules22060956 www.mdpi.com/journal/molecules1,ω-alkanediols with an even number of carbons crystallize into a structure with layers of the type herringbone, where interlayer hydrogen bonds form zigzag chains
Crystal structures of 1,ω-alkanediols with 10, 11, 12 and 13 carbon atoms in the skeleton chain were determined from GIXD data in combination with lattice energy minimization by means of a force field that includes the hydrogen bond component

Summary

Introduction

Odd-numbered compounds (orthorhombic with space group of P21 21 21 , Z = 4) present a molecular packing in layers but, so far, they have been described with molecules oriented parallel to each other [2,3,4,5,6,7,8,9,10,11,12,13] In this case, the pattern of hydrogen bond is formed by alternation of inter and intralayer O-H···O. The presence of the terminal (-OH) polar groups results in molecular aggregation and surfactant properties, which lead to the formation of layers or films in the air-water interface [14]. These aggregates are presented in the form of amphiphilic monolayers (2-D), or nano-crystalline multilayer aggregates (3-D) [15]. Its important interactivity with water does not preclude its solubility in mixed micelles [16]

Objectives

Results

Conclusion