Investigation of polar crystalline materials containing hydrochlorothiazide: electron density distribution and optical properties
The polar hydrochlorothiazide polymorph (I) (systematic name: 6-chloro-1,1-dioxo-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide, C7H8ClN3O4S2) and, recently designed by us, the polar 2-aminopyridine hydrochlorothiazide water (C7H8ClN3O4S2 · C5H6N2 · H2O), (II), have been investigated. The crystal structures of both materials were determined using the single-crystal X-ray diffraction technique. The intermolecular interactions in (I) and (II) were studied in detail via topological electron-density analysis. The obtained results showed hydrogen bonds with a character intermediate between closed-shell and shared-shell i...
Source: Acta Crystallographica Section B - November 15, 2021 Category: Chemistry Authors: Wojnarska, J. Gryl, M. Seidler, T. Stadnicka, K.M. Tags: crystal engineering electron density hydrochlorothiazide linear birefringence second-harmonic generation research papers Source Type: research
Strategic synthon approach in obtaining cocrystals and cocrystal polymorphs of a high-Z ′ system deferiprone – an anti-thalassemia drug
Compounds with more than one molecule in the crystallographic asymmetric unit (Z ′> 1) display a noticeably stronger propensity to form cocrystals. Deferiprone is an anti-thalassemia drug known to exhibit polymorphic behaviour. Previously, three polymorphs were reported out of which one of them exhibited Z ′> 1. In the present manuscript, a fourth polymorph of deferiprone was identified and it also possessed Z ′> 1. All the four polymorphs showed similar hydrogen bonding features and differed in crystal packing. The ability of deferiprone to crystallize as Z ′> 1 prompted us to investigate the hydrogen bonding and ...
Source: Acta Crystallographica Section B - November 12, 2021 Category: Chemistry Authors: Rajendrakumar, S. Surampudi Venkata Sai Durga, A. Balasubramanian, S. Tags: deferiprone cocrystals polymorphs synthon analysis PXRD phase quantification research papers Source Type: research
On the transfer of theoretical multipole parameters for restoring static electron density and revealing and treating atomic anharmonic motion. Features of chemical bonding in crystals of an isocyanuric acid derivative
The crystal and electronic structure of an isocyanuric acid derivative was studied by high-resolution single-crystal X-ray diffraction within the Hansen – Coppens multipole formalism. The observed deformation electron density shows signs of thermal smearing. The experimental picture meaningfully assigned to the consequences of unmodelled anharmonic atomic motion. Straightforward simultaneous refinement of all parameters, including Gram – Charlier coefficients, resulted in more significant distortion of apparent static electron density, even though the residual density became significantly flatter and more featureless. ...
Source: Acta Crystallographica Section B - November 9, 2021 Category: Chemistry Authors: Shteingolts, S.A. Voronina, J.K. Saifina, L.F. Shulaeva, M.M. Semenov, V.E. Fayzullin, R.R. Tags: Gram – Charlier parameters local electronic temperature probability density function quantum crystallography π ... interaction research papers Source Type: research
Interpreting the different emissive properties of cyclic triimidazole-based CuI and AgI coordination polymers: a QTAIM and IQA study
A QTAIM and IQA investigation on model compounds of two isostructural AgI and CuI coordination polymers (CPs) based on cyclic triimidazole (L), i.e. the [MIL]n 1D double-stranded stair chain and the [MClL]n 3D network (M = Cu, Ag), has allowed light to be shed on the different emissive behaviour associated with the two metal ions. According to a previously reported investigation [Malpicci et al. (2021). Inorg. Chem. Front. 8, 1312 – 1323], AgI CPs showed both fluorescence and multiple ligand-centred room-temperature phosphorescences, whereas CuI CPs displayed non-thermally equilibrated halogen and metal-to-ligand charge ...
Source: Acta Crystallographica Section B - November 9, 2021 Category: Chemistry Authors: Forni, A. Cariati, E. Carlucci, L. Lucenti, E. Marinotto, D. Pieraccini, S. Sironi, M. Tags: AgI and CuI coordination polymers room-temperature phosphorescence metal – ligand interaction QTAIM IQA source function halogen bond quantum crystallography research papers Source Type: research
Crystal structure of the high-P polymorph of Ca2B6O6(OH)10 · 2(H2O) (meyerhofferite)
The crystal structure of the high-pressure polymorph of meyerhofferite, ideally Ca2B6O6(OH)10 · 2(H2O), has been determined by means of single-crystal synchrotron X-ray diffraction data. Meyerhofferite undergoes a first-order isosymmetric phase transition to meyerhofferite-II, bracketed between 3.15 and 3.75   GPa, with a large volume discontinuity. The phase transition is marked by an increase in the coordination number of the boron B1 site, from III to IV, leading to a more interconnected and less compressible structure. The main structural differences between the two polymorphs and the P-induced deformation mechanism...
Source: Acta Crystallographica Section B - November 5, 2021 Category: Chemistry Authors: Comboni, D. Poreba, T. Pagliaro, F. Battiston, T. Lotti, P. Gatta, G.D. Garbarino, G. Hanfland, M. Tags: meyerhofferite borates B-rich aggregates high pressure phase transition research papers Source Type: research
Analytical description of nanowires. I. Regular cross sections for zincblende and diamond structures. Corrigendum
In the paper by K ö nig& Smith [Acta Cryst. (2019), B75, 788 – 802], several equations had minor errors in their coefficients defining characteristic lengths and area of zinc-blende nanowire cross sections, thereby deviating from the exact analytical solution by 1.4   ± 0.8   %. A fully corrected version of the paper is provided. (Source: Acta Crystallographica Section B)
Source: Acta Crystallographica Section B - September 28, 2021 Category: Chemistry Authors: K ö nig, D. Smith, S.C. Tags: nanowires zincblende structure diamond structure analytical descriptions addenda and errata Source Type: research
The influence of refinement strategies on the wavefunctions derived from an experiment
The synergy between theory and experiment found in X-ray wavefunction refinement (XWR) makes it one of the most compelling techniques available for chemical physics. The foremost benefit of XWR – obtaining wavefunctions constrained to experimental data – is at the same time its Achilles heel, because of the dependence of the results on the quality of both empirical and theoretical data. The purpose of this work is to answer the following: What is the effect of the refinement strategy and manipulation of input data on the physical properties obtained from XWR? With that in mind, cutoffs based on data resolution and F/ Ï...
Source: Acta Crystallographica Section B - September 28, 2021 Category: Chemistry Authors: Landeros-Rivera, B. Contreras-Garc à a, J. Dominiak, P.M. Tags: Hirshfeld atom refinement quantum crystallography X-ray constrained wavefunction X-ray wavefunction refinement sulfur dioxide research papers Source Type: research
Spin-resolved charge density and wavefunction refinements using MOLLYNX: a review
MOLLYNX is a new crystallographic tool developed to access a more precise description of the spin-dependent electron density of magnetic crystals, taking advantage of the richness of experimental information from high-resolution X-ray diffraction (XRD), unpolarized neutron (UND) and polarized neutron diffraction (PND). This new program is based either on the well known Hansen – Coppens multipolar model (MOLLYNX-mult) or on a new expansion over a set of atomic orbitals (MOLLYNX-orb). The main difference between the two models is the basis of the expansion: in MOLLYNX-mult the expansion is over atom centered real spherical...
Source: Acta Crystallographica Section B - September 24, 2021 Category: Chemistry Authors: Souhassou, M. Kiblin, I. Deutsch, M. Voufack, A.B. Lecomte, C. Claiser, N. Tags: charge density wavefunction joint refinement magnetism research papers Source Type: research
Self-assembling of three rare structurally various homomultinuclear CuII complexes derived from a bis(salamo)-based multioxime ligand
A family of rare structurally different homometal multinuclear CuII bis(salamo)-based complexes, [Cu4(L)2(MeOH)2](ClO4)2 · 2MeOH (1), [Cu4(L)2(EtOH)2](NO3)2 · 2EtOH (2) and [Cu2(HL)(EtOH)Br2] · CHCl3 (3), has been successfully synthesized by the reactions of cupric salts with a bis(salamo)-based multidentate chelate ligand (H3L). The salamo-based ligand [R-CH=N — O — (CH2)n — O — N=CH — R] is a new type of salen-based analog. Complexes (1) and (2) are isostructural structures, and crystallize in monoclinic space group P21/n with centrosymmetric spiral structures, where the main structures contain two fully dep...
Source: Acta Crystallographica Section B - September 22, 2021 Category: Chemistry Authors: Li, P. Zhang, T. Li, L.-L. Dong, W.-K. Tags: bis(salamo)-based ligand X-ray crystallography analysis Hirshfeld surface analysis DFT calculation fluorescence property research papers Source Type: research
Anion substitution and influence of sulfur on the crystal structures, phase transitions, and electronic properties of mixed TiO2/TiS2 compounds
Recent studies of TiO2/TiS2 nanostructures with various morphologies have been reported, usually showing improved properties with applications from electronics and catalysis to solar cells and medicine. However, there is a limited number of studies on the crystal structures of TiO2/TiS2 compounds with corresponding properties. In this research, relevant crystal structures of TiO1 – xSx (x = 0, 0.25, 0.5, 0.75 and 1) solid solutions were investigated using an ab initio method. For each composition, crystal structures adopting anatase, rutile and CdI2 structure type were calculated on LDA-PZ and GGA-PBE levels of theory. N...
Source: Acta Crystallographica Section B - September 22, 2021 Category: Chemistry Authors: Jovanovic, D. Zagorac, D. Matovic, B. Zarubica, A. Zagorac, J. Tags: TiO2/TiS2 ab initio anion substitution electronic properties phase transition research papers Source Type: research
X-ray restrained extremely localized molecular orbitals for the embedding of quantum mechanical calculations
The X-ray restrained wavefunction (XRW) method is a quantum crystallographic technique that allows the calculation of molecular wavefunctions adapted to minimize the difference between computed and reference structure factor amplitudes. The latter result from experimental measurements on crystals or from advanced theoretical calculations with periodic boundary conditions, and are used as external restraints in a traditional least-squares structural refinement. Detailed investigations have shown that the technique is able to reliably capture the effects of the crystal field on the molecular electron density. In a recent app...
Source: Acta Crystallographica Section B - September 22, 2021 Category: Chemistry Authors: Macetti, G. Macchi, P. Genoni, A. Tags: X-ray restrained wavefunction (XRW) extremely localized molecular orbitals (ELMOs) quantum embedding quantum crystallography QM/ELMO method research papers Source Type: research
Crystal and magnetic structures of R2Ni1.78In compounds (R = Tb, Ho, Er and Tm)
The crystal and magnetic structures in R2Ni1.78In (R = Ho, Er and Tm) have been studied by neutron diffraction. The compounds crystallize in a tetragonal crystal structure of the Mo2FeB2 type (space group P4/mbm). At low temperatures, the magnetic moments, localized solely on the rare earth atoms, form antiferromagnetic structures described by the propagation vector k = [kx, kx, ½ ], with kx equal to ¼ for R = Er and Tm or 0.3074   (4) for R = Ho. The magnetic moments are parallel to the c axis for R = Ho or lie within the (001) plane for R = Er and Tm. The obtained magnetic structures are discussed on the basis of sym...
Source: Acta Crystallographica Section B - September 18, 2021 Category: Chemistry Authors: Baran, S. Deptuch, A. Hoser, A. Penc, B. Tyvanchuk, Y. Szytu Å‚ a, A. Tags: magnetic structure antiferromagnetism neutron diffraction magnetometric measurements symmetry analysis research papers Source Type: research
Preparation of polyethylene oxide single crystals via liquid gating technology and morphology design strategy
A novel type of liquid gating technology has been developed to prepare a polyethylene oxide (PEO) single-crystal film, and the crystal growth was observed via atomic force microscopy. The self-seeding method has been widely used in the preparation of polymer single crystals, but the mechanism through which single polymer crystals are formed via the combination of liquid gating technology and the self-seeding method remains unclear. To elucidate the mechanism of this process, a series of experiments were conducted in which a dilute polymer solution was sprayed onto a mica substrate to form a single-crystal film through liqu...
Source: Acta Crystallographica Section B - September 18, 2021 Category: Chemistry Authors: Li, S. Zhao, J. Wang, X. Li, Z. Gui, X. Hu, J. Lin, S. Tu, Y. Tags: polymers AFM liquid gating technology single crystals research papers Source Type: research
A new guaninate hydrate K+ · C5H4N5O − · H2O: crystal structure from 100 to 300   K in a comparison with 2Na+ · C5H3N5O2 − · 7H2O
A new guanine salt hydrate, K+ · C5H4N5O − · H2O, was obtained and characterized by single-crystal X-ray diffraction in the temperature range 100   K – 300   K and compared with that of the previously documented sodium salt hydrate (2Na+ · C5H3N5O2 − · 7H2O) [Gur& Shimon (2015). Acta Cryst. E71, 281 – 283; Gaydamaka et al. (2019). CrystEngComm, 21, 4484 – 4492]. Both sodium and potassium salt hydrates have channels. However, the structure of the channels, the cation coordination, the protonation (and, respectively, the charge) of the guanine anions, as well as the role of water molecules in the crystal st...
Source: Acta Crystallographica Section B - September 18, 2021 Category: Chemistry Authors: Gaydamaka, A.A. Arkhipov, S.G. Boldyreva, E.V. Tags: guanine single-crystal X-ray diffraction nucleobase tautomers anisotropy of thermal expansion structure – properties relations crystal salt hydrates role of water in forming a crystal structure channel structures intermolecular int Source Type: research
Crystal structure and magnetic properties of the layered hybrid organic – inorganic compounds M2(OH)2(C14H8O4) (M = Mn, Fe)
The structure of M2(OH)2(bpdc) (bpdc = biphenyl dicarboxylate, C14H8O4) is distinct from that of the isoreticular compounds M2(OH)2(bdc) (bdc = benzene dicarboxylate, C8H4O4) (M = Mn, Fe), in the sense that no disorder of the bpdc molecules from one layer to the other needs to be considered. The global symmetry is lower in the bpdc compounds (P1) than in the bdc compounds (C2/m). Both Mn2(OH)2(bpdc) and Fe2(OH)2(bpdc) order magnetically at 36.8 and 46.5   K, respectively, and can be considered as uncompensated antiferromagnets, whereas Mn2(OH)2(bdc) (N é el temperature TN = 38.5   K) and Fe2(OH)2(bdc) (TN = 66   K) ...
Source: Acta Crystallographica Section B - September 17, 2021 Category: Chemistry Authors: Sibille, R. Mazet, T. Diop, L.V.B. Fran ç ois, M. Tags: crystal structure MOF magnetism hybrid compound layered compound research papers Source Type: research
