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High variability of the heterogeneous ice nucleation potential of oxalic acid dihydrate and sodium oxalate  [PDF]
R. Wagner,O. M?hler,H. Saathoff,M. Schnaiter
Atmospheric Chemistry and Physics Discussions , 2010, DOI: 10.5194/acpd-10-11513-2010
Abstract: The heterogeneous ice nucleation potential of airborne oxalic acid dihydrate and sodium oxalate particles in the deposition and condensation mode has been investigated by controlled expansion cooling cycles in the AIDA aerosol and cloud chamber of the Karlsruhe Institute of Technology at temperatures between 244 and 228 K. Previous laboratory studies have highlighted the particular role of oxalic acid dihydrate as the only species amongst a variety of other investigated dicarboxylic acids to be capable of acting as a heterogeneous ice nucleus in both the deposition and immersion mode. We could confirm a high deposition mode ice activity for 0.03 to 0.8 μm sized oxalic acid dihydrate particles that were either formed by nucleation from a gaseous oxalic acid/air mixture or by rapid crystallisation of highly supersaturated aqueous oxalic acid solution droplets. The critical saturation ratio with respect to ice required for deposition nucleation was found to be less than 1.1 and the size-dependent ice-active fraction of the aerosol population was in the range from 0.1 to 22%. In contrast, oxalic acid dihydrate particles that had crystallised from less supersaturated solution droplets and had been allowed to slowly grow in a supersaturated environment from still unfrozen oxalic acid solution droplets over a time period of several hours were found to be much poorer heterogeneous ice nuclei. We speculate that under these conditions a crystal surface structure with less-active sites for the initiation of ice nucleation was generated. Such particles partially proved to be almost ice-inactive in both the deposition and condensation mode. At times, the heterogeneous ice nucleation ability of oxalic acid dihydrate significantly changed when the particles had been processed in preceding cloud droplet activation steps. Such behaviour was also observed for the second investigated species, namely sodium oxalate. Our experiments address the atmospheric scenario that coating layers of oxalic acid or its salts may be formed by physical and chemical processing on pre-existing particulates such as mineral dust and soot. Given the broad diversity of the observed heterogeneous ice nucleability of the oxalate species, it is not straightforward to predict whether an oxalate coating layer will improve or reduce the ice nucleation ability of the seed aerosol particles.
High variability of the heterogeneous ice nucleation potential of oxalic acid dihydrate and sodium oxalate  [PDF]
R. Wagner,O. M?hler,H. Saathoff,M. Schnaiter
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2010, DOI: 10.5194/acp-10-7617-2010
Abstract: The heterogeneous ice nucleation potential of airborne oxalic acid dihydrate and sodium oxalate particles in the deposition and condensation mode has been investigated by controlled expansion cooling cycles in the AIDA aerosol and cloud chamber of the Karlsruhe Institute of Technology at temperatures between 244 and 228 K. Previous laboratory studies have highlighted the particular role of oxalic acid dihydrate as the only species amongst a variety of other investigated dicarboxylic acids to be capable of acting as a heterogeneous ice nucleus in both the deposition and immersion mode. We could confirm a high deposition mode ice activity for 0.03 to 0.8 μm sized oxalic acid dihydrate particles that were either formed by nucleation from a gaseous oxalic acid/air mixture or by rapid crystallisation of highly supersaturated aqueous oxalic acid solution droplets. The critical saturation ratio with respect to ice required for deposition nucleation was found to be less than 1.1 and the size-dependent ice-active fraction of the aerosol population was in the range from 0.1 to 22%. In contrast, oxalic acid dihydrate particles that had crystallised from less supersaturated solution droplets and had been allowed to slowly grow in a supersaturated environment from still unfrozen oxalic acid solution droplets over a time period of several hours were found to be much poorer heterogeneous ice nuclei. We speculate that under these conditions a crystal surface structure with less-active sites for the initiation of ice nucleation was generated. Such particles partially proved to be almost ice-inactive in both the deposition and condensation mode. At times, the heterogeneous ice nucleation ability of oxalic acid dihydrate significantly changed when the particles had been processed in preceding cloud droplet activation steps. Such behaviour was also observed for the second investigated species, namely sodium oxalate. Our experiments address the atmospheric scenario that coating layers of oxalic acid or its salts may be formed by physical and chemical processing on pre-existing particulates such as mineral dust and soot. Given the broad diversity of the observed heterogeneous ice nucleability of the oxalate species, it is not straightforward to predict whether an oxalate coating layer will improve or reduce the ice nucleation ability of the seed aerosol particles.
Sodium 2-nitrocinnamate dihydrate: a one-dimensional hydrogen-bonded coordination polymer
Graham Smith,Urs D. Wermuth
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809030402
Abstract: The title compound catena-poly[aquasodium-μ2-aqua-μ3-2-nitrocinnamato], [Na(C9H6NO4)(H2O)2]n, the sodium salt of trans-2-nitrocinnamic acid, is a one-dimensional coordination polymer based on six-coordinate octahedral NaO6 centres, comprising three facially related monodentate carboxylate O-atom donors from separate ligands (all bridging) [Na—O = 2.4370 (13)–2.5046 (13) ], and three water molecules (two bridging and one monodentate) [Na—O = 2.3782 (13)–2.4404 (17) ]. The structure is also stabilized by intra-chain water–carboxylate and water–nitro O—H...O hydrogen bonds.
Growth and Solvent Effects of a Promising Nonlinear Optical Sodium Paranitrophenolate Dihydrate (NO2-C6H4-ONa 2H2O) Single Crystal

BMilton Boaz,ALeyo Rajesh,SXavier Jesu Raja,SJerome Das,

材料科学技术学报 , 2004,
Abstract: Sodium paranitrophenolate dihydrate (NPNa 2H2O) is an excellent semiorganic nonlinear optical (NLO) material, crystallizes both in water and methanol with high degree of transparency. Good optical quality single crystals of dimension upto 18 mm×6 mm×3 mm are obtained by sothermal solvent evaporation technique. The solubility of the crystal in different solvents was measured gravimetrically. The single crystals of NPNa 2H2O show variation in physical properties and growth rate in different solvents. Methanol or ethanol solution yields crystals of bipyramidal shape with clear morphology. However, methanol grown crystal is exhibiting improved hardness parameters and possesses excellent thermal stability as compared to water grown crystals. The effects of solvent on hardness parameter along with thermal and optical properties of NPNa 2H2O was revealed in this paper.
Decaaquadioxidobis[μ3-N-(phosphonatomethyl)iminodiacetato]dizinc(II)divanadium(IV) dihydrate
Luís Cunha-Silva,Fa-Nian Shi,Jacek Klinowski,Tito Trindade
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536807062253
Abstract: The title compound, [Zn2V2(C5H6NO7P)2O2(H2O)10]·2H2O, contains a [V2O2(pmida)2]4 dimeric anionic unit [where H4pmida is N-(phosphonomethyl)iminodiacetic acid] lying on a centre of symmetry which is exo-coordinated via the two deprotonated phosphonate groups to two Zn2+ cations, with the coordination environment of Zn completed by five water molecules. The crystal packing is mediated by an extensive network of strong and highly directional O—H...O hydrogen bonds involving the water molecules (coordinated and uncoordinated) and the functional groups of pmida4 , leading to a three-dimensional supramolecular network.
Synthesis, Structural and Dielectric Properties of Ferroelectric Dichloridoglycine Zinc Dihydrate Single Crystals  [PDF]
S. Suresh, A. Ramanand, D. Jayaraman, S.M. Priya, R. Vasanthakumari
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2011, DOI: 10.4236/jmmce.2011.104024
Abstract: The strong electro mechanical coupling exhibited by the ferroelectric materials is the remarkable feature of these materials. Therefore, they find applications in sensors, actuators for producing ultrasonics and micro positioning. The material dichloridoglycine zinc dihydrate is a centrosymmetric ferroelectric crystal. In the present study, this crystal has been grown from a mixture of glycine and zinc chloride. The dielectric constant and the dielectric loss of the grown crystal were studied as a function of frequency and temperature, and the corresponding relaxation time (τ), relaxation frequency (Fr) and the activation energy have been calculated. The ferroelectric property of the crystal has been confirmed by dielectric studies. The ferroelectric characteristics of the crystal have been studied and reported.
Hexa-μ2-acetato-triaqua-μ3-oxido-triiron(III) nitrate acetic acid solvate  [cached]
Sumei Yao,Jianhua Liu,Qiuxia Han
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808019806
Abstract: The asymmetric unit of the title compound, [Fe3(CH3COO)6O(H2O)3]NO3·CH3COOH, consists of a hexa-μ2-acetato-triaqua-μ3-oxo-triiron(III) macrocation, a nitrate ion and an acetic acid solvent molecule. In the cation, each Fe3+ ion is coordinated by four carboxylate O atoms, one central bridged O atom and one water molecule, resulting in distorted FeO6 octahedra. A network of O—H...O hydrogen bonds helps to establish the packing.
Triaqua(1,10-phenanthroline-2,9-dicarboxylato)cobalt(II) dihydrate
Zi-Fa Shi,Zhu-Qing Gao,Jin-Zhong Gu
Acta Crystallographica Section E , 2010, DOI: 10.1107/s1600536810007567
Abstract: The title compound, [Co(C14H6N2O4)(H2O)3]·2H2O, has twofold crystallographic symmetry. The CoII atom is in a distorted pentagonal-bipyramidal coordination environment with two N atoms and two O atoms from a tetradentate 1,10-phenanthroline-2,9-dicarboxylate ligand and one O atom from a water molecule forming the pentagonal plane, and two O atoms from two water molecules occupying axial positions. In the crystal, adjacent molecules are linked by O—H...O hydrogen bonds, forming a three-dimensional network.
Triaqua(2-{[(E)-5-formyl-2-oxidobenzylidene]amino}ethanesulfonato)cobalt(II) dihydrate
Ju-Lan Zeng,Yi-Min Jiang,Li-Xian Sun,Zhong Cao
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809031274
Abstract: The title compound, [Co(C10H9NO5S)(H2O)3]·2H2O, is a cobalt–Schiff base complex derived from taurine. There are two complex molecules and four solvent water molecules in the asymmetric unit. The central Co atom is six coordinated by two O atoms and one N atom of the ligand and three O atoms of water molecules, forming a slightly distorted octahedral geometry. The crystal structure is stabilized by several O—H...O hydrogen bonds.
Sodium piperidine-1-carbodithioate dihydrate
Ana C. Mafud,Maria Teresa P. Gambardella
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811022604
Abstract: The asymmetric unit of the title compound, Na+·C6H10NS2 ·2H2O, is composed of a sodium cation, a piperidinedithiocarbamate anion which exhibits positional disorder, and two lattice water molecules. The atoms of the piperidine ring are divided over two sites with occupancy factors of 0.554 (6) and 0.446 (6). In the crystal, the sodium cation (coordination number of 6) and the piperidinedithiocarbamate anion are linked, forming an infinite two-dimensional network extending parallel to (001). O—H...S hydrogen bonds, involving the lattice water molecules, also aid in stabilizing the crystal sructure.
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