Hirshfeld surface analysis of the intermolecular interaction networks in cellulose Iα and Iß.

Due to the high crystallinity and natural abundance, the crystal structures of native cellulose allomorphs have been theoretically studied until today, but some details remain to be deciphered. In this work, research was extended on the visualization and quantification of intermolecular interactions related to hydrogen bonds and van der Waals interactions in cellulose crystals Iα and Iß based on previous studies. For each allomorph, the crystal structure has been described by two models of hydrogen bonding networks designated here as (A) and (B). This network diversity is due to the location of the hydrogen atoms of two disordered positions in the hydroxyl groups O6 and O2. Hirshfeld surface analysis (3D) was used to visualize the fidelity of intermolecular interactions O-H⋯O (involving O2 and O6) in the different cellulosic structural models Iα and Iß. Two-dimensional fingerprint plots were used to identify the individual type of intermolecular contact and its impact on crystal packaging by graphical representation. A crystal contact study using the enrichment ratio was performed to investigate the tendency of intermolecular interactions to form the crystalline packing. The control of O-H⋯O inter-chain interactions in each type of network shows that hydrogen bonding is more favored in the model (A) than in the model (B).

The interpenetrated three-dimensional framework of a new mixed lithium/ammonium perchlorate grown in a gel medium.

Mixed lithium/ammonium perchlorate, Li(0.41)(NH4)(0.59)ClO4, has been prepared by gel diffusion using agar agar gel as the medium of growth at ambient temperature. The Cl and mixed Li/N atoms are located on the 4a (½, ½, ½) and 4b (½, 0, ») special positions, respectively, in the space group I42d. The structure features a twofold interpenetrated three-dimensional entanglement architecture, in which single three-dimensional networks are constructed from tetrahedral coordination based on [-(ClO4)-(Li/NH4)-(ClO4)-]∞ diamondoid arrays. A comparison of the crystal structures of Li(0.41)(NH4)(0.59)ClO4, LiClO4·3H2O, LiClO4 and NH4ClO4 is given.

The solid solution (Fe0.81Al0.19)(H2PO4)3 with a strong hydrogen bond.

Single crystals of the solid solution iron aluminium tris(dihydrogenphosphate), (Fe(0.81)Al(0.19))(H(2)PO(4))(3), have been prepared under hydrothermal conditions. The compound is a new monoclinic variety (gamma-form) of iron aluminium phosphate (Fe,Al)(H(2)PO(4))(3). The structure is based on a two-dimensional framework of distorted corner-sharing MO(6) (M = Fe, Al) polyhedra sharing corners with PO(4) tetrahedra. Strong hydrogen bonds between the OH groups of the H(2)PO(4) tetrahedra and the O atoms help to consolidate the crystal structure.

Potassium cerium(III) bis(sulfate) monohydrate, KCe(SO4)2.H2O.

The crystal structure of potassium cerium(III) bis(sulfate) monohydrate, KCe(SO4)2.H2O, is built up from irregular independent SO4 tetrahedra, CeO9 polyhedra in the form of distorted tricapped trigonal prisms and K+ ions. Hydrogen bonding between the free water molecule and sulfate groups supplement the ionic bonds characteristic of the rest of the structure.