Volume 232, Issue 6

Hierarchical structured microplates consisting of nanoparticles were grown based on a self-assembly approach via a hydrothermal synthesis route without using any additive. Experimental parameters, such as reaction temperature, time and solvent play crucial roles in determining the morphology of final product. The nanoscale shape and macroscopically assembled architecture of [Cu(salen)] 2 {salen = N,N′-bis(salicylidene)1,2-ethyelenediimine} crystals were totally controlled by preparation conditions for crystal growth. The synthesized [Cu(salen)] 2 hierarchical architectures were characterized with UV-Vis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric (TGA) analyses. The thickness of the fabricated plates changes from 25 nm to 3.5 μm. The as-prepared nanoplates are actually composed of nanoparticles with diameters under 100 nm. Furthermore, the formation mechanism of the microplates decorated with nanorods has also been discussed, based on the influence of the kinetics of nucleation and crystal growth.

The transitions between the room temperature phase III (space group P 6 3 ) and the two high-temperature phases II ( Pcmn ) and I ( P 6 3 / mmc ) of KLiSO 4 and the domain structures generated by them were investigated by high-temperature polarisation optics (birefringence) and room-temperature X-ray topography, optical activity and nematic–liquid–crystal (NLC) surface decoration. The transition from the polar hexagonal phase III into the centrosymmetric orthorhombic phase II at 708 K leads, due to the loss of the trigonal axis and the radial temperature gradient of the optical heating chamber used, to a roughly hexagonal arrangement of three sets of thin orthorhombic {110} lamelleae with angles of 60° (120°) between them. The associated twin law “reflection m {110} orth ” corresponds to the frequent growth twin m {101̅0} hex of phase III. The domains are easily ferroelastically switched. Upon further heating above 949 K into phase I ( P 6 3 / mmc ) all domains vanish. Upon cooling back into phase II the three domain states related by 60°(120°) reflections m {110} orth re-appear, however (due to the higher thermal agitation at 949 K) with a completely different domain structure consisting of many small, irregularly arranged {110} orth domains. Particular attention is paid to the domain structure of the hexagonal room temperature phase III generated during the re-transition from the orthorhombic phase II. Curiously, from the expected three twin laws inversion 1̅, rotation 2⊥[001] hex and reflection m {101̅0} hex only the latter, which corresponds to the frequent growth twinning, has been found. Finally a short treatise of the structural relations of the KLiSO 4 high-temperature polymorphs is given.

Tm 5 Pd 4 Ge 8 was synthesized by melting of the elements in an arc-melting furnace. The new germanide was characterized by powder and single-crystal X-ray diffraction: own structure type, P 2 1 / m , a =574.3(1), b =1380.4(3), c =836.4(1) pm, β =107.57(2)°, V=0.6321 nm 3 , wR 2=0.0578, 2533 F 2 values, 86 variables. The palladium and germanium atoms built up a three-dimensional [Pd 4 Ge 8 ] 15− polyanionic network which contains a unique germanium substructure composed of the Zintl anions Ge 2 6− dumb-bells and Ge 4 10− chains in cis -conformation. The palladium atoms within the network have distorted square pyramidal germanium coordination. The three crystallographically independent thulium atoms have coordination numbers 15, 16 and 17 with partial motifs of the Frank-Kasper type polyhedra. The isotypic germanide Er 5 Pd 4 Ge 8 forms only after annealing the arc-melted sample at 1070 K for 1 week: a =575.14(9), b =1386.3(3), c =838.4(1) pm, β =107.51(2)°, V=0.6375 nm 3 .

The title structure, (3 R *, 1′ S *, 3′ R *)-3-(1′- tert- butylamino-1′ H ,3′ H -benzo[ c ]furan-3′-yl)-2- tert -butyl-2,3-dihydro-1 H- benzo[ c ]pyrrol-1-one has been determined at 290 and 150 K by single-crystal X-ray diffraction. The structure comprises two symmetry independent molecules with very similar conformations which differ mostly by orientations of the tert -butyl groups, situated at the periphery of these molecules. The molecules are composed of two parts, the cores of which are isoindolinone and isobenzofuran rings being bound by C–C bonds. The planarities of the pyrrolone and furan rings are compared with the known structures retrieved from the Cambridge Crystal Structure Database. It transpires in the title molecules, the planarity of the carbonyl-substituted pyrrole rings is exceptionally distorted in contrast to the furan rings. This fact is just the opposite of the tendency inferred from the Cambridge Crystal Structure Database. The reason may be the influence of the voluminous tert -butyl group which is attached to the nitrogen of the pyrrole group, as well as short centroid–centroid distances between the carbonyl-substituted pyrrole and furan rings. Cohesion forces between the molecules and their parts are provided by weak interactions only: The packing suggests C–H···O, π – π -electron ring interactions, N–H··· π -electron ring as well as C–H··· π -electron ring interactions. The structure determination of the title compound, the product of the reaction of o -phthalaldehyde with tert -butylamine, has provided indication about the mechanism of a chemical reaction which resulted in the formation of the title molecule.

Tetraethyl 1,3-phenylenebis(phosphoramidate) was synthesized and characterized by 1 H, 13 C, 31 P NMR, IR and mass spectroscopies. The asymmetric unit is composed of two half-molecules, each residing on a two-fold axis, and two complete molecules, thus leading to a Z′ =(2+0.5+0.5)=3 structure. The most plausible explanation for the occurrence of multiple independent molecules is a frustration between relatively strong hydrogen bond interactions and weaker CH···π interactions. In each of the molecules, the P atoms are in a similar distorted tetrahedral environment. The N atoms bonded to P atoms have mainly sp 2 character tending towards a planar environment. In the crystal structure, the phosphoryl O atoms are involved in classical N–H···O=P and weaker C–H···O=P hydrogen bonds as (N–H)(C–H) ···O=P, acting as a double hydrogen-bond acceptor. These hydrogen bonds along with other C–H···O hydrogen bonds and C–H···π interactions create a 3D crystalline network. Hirshfeld surfaces and two-dimensional (2D) fingerprint plots are calculated for analyzing intermolecular interactions in each of the independent molecules of the title compound. For all four independent molecules, the contribution of H···H contacts to the total interactions is decisive, being larger than 60% for each molecule. The O···H/H···O contacts are the characteristic intermolecular contacts in the corresponding molecules. Furthermore, the C···H/H···C, including the C–H···π interactions, and N···H/H···N contacts cover other intermolecular contacts in the crystal lattice.

The crystal structure of sodium naphthalene 2-sulfonate (Na2-NS) is reported. This compound raised the attention as a pollutant, being widely used in industry, and its intercalation in inorganic matrices, such as layered double hydroxides (LDH), could be a suitable removal strategy. The crystal structure of the title compound, despite its simplicity, is not known in the literature, so we looked for a strategy to grow crystals suitable for a single crystal study. Although many attempts were made to recrystallize it, Na2-NS grows in bunches of very thin laminae, with a high degree of mosaicity and intergrowth, explaining the absence of a reported crystal structure. The crystal structure shows layers of Na + cations with the organic part arranged in between. The crystals grow easily in the layer plane, whilst the growth perpendicular to the layers is driven by weak non-bonding interaction and thus unfavored. The crystal packing features were related to the density of charges in the cationic layer with respect to the size of the anion. By comparing the crystal structures of 2-NS salts with different cations, and with or without an amino substituent in different positions, it was possible to find the relationship between the density of the positive charges and the deepness of interdigitation of the 2-NS moieties. We exploited this information to shed light on the structural features of 2-NS and related compounds intercalated into LDH. The X-ray powder diffraction pattern of 2-NS intercalated LDH (V. Toson, E. Conterosito, L. Palin, et al. Facile intercalation of organic molecules into hydrotalcites by liquid-assisted grinding: yield optimization by a chemometric approach. Cryst. Growth Des. 2015 , 15 , 5368) resulted consistent with a crystal packing characterized by the partial interdigitation of the 2-NS anions.

The preparation, X-ray single-crystal structure determination and vibrational spectroscopic characterisation of five novel salts, i.e. bis(4,6-diaminopyrimidinium(1+)) oxalate tetrahydrate; 4,6-diaminopyrimidinium(1+) hydrogen malonate monohydrate; bis(4,6-diaminopyrimidinium(1+)) succinate octahydrate; bis(4,6-diaminopyrimidinium(1+)) glutarate dihydrate and bis(4,6-diaminopyrimidinium (1+)) adipate octahydrate, are presented. It is the first crystallographic study with the title cation. All the structures are centrosymmetric. The oxalate, succinate and adipate anions are situated about inversion centres in their respective structures. The dependence on the parity of the number of carbon atoms in the anions is apparent in the interplanar angles of the carboxylate or carboxylic groups. In all of the structures, there are intermolecular N–H···N, N–H···O acid , N–H···O water , O water –H···O acid and O water –H···O water hydrogen-bonds of moderate strength. The most common graph set motif, R 2 2 (8), describes the arrangement of the involved carboxylic as well as of the primary- and secondary-amine groups. There is a growing complexity of arrangement of water molecules in the structures with longer anionic molecules. In 4,6-diaminopyrimidinium(1+) hydrogen malonate monohydrate, there is an intramolecular O acid –H···O acid bond, and the conformation of the hydrogen malonate ions with non-parallel carboxylic and carboxylate groups is not often observed. The structural parameters of the carboxylic or carboxylate groups in the dicarboxylic acids or their derivatives found in the Cambridge Structural Database (CSD) are compared with the title structures.