Search results for " surface"
showing 10 items of 2838 documents
Crystal structure and Hirshfeld surface analysis of 4-allyl-2-methoxy-6-nitrophenol
2020
The crystal structure of 4-allyl-2-methoxy-6-nitrophenol, which crystallizes in the centrosymmetric space group P with three independent molecules in the asymmetric unit, is reported along with the Hirshfeld surface analysis.
Crystal structure and Hirshfeld surface analysis of (E)-3-[(4-fluorobenzylidene)amino]-5-phenylthiazolidin-2-iminium bromide
2019
TARAMAPUBMED TARAMASCOPUS TARAMAWOS In the cation of the title salt, C16H15FN3S+·Br−, the phenyl ring is disordered over two sets of sites with a refined occupancy ratio of 0.503 (4):0.497 (4). The mean plane of the thiazolidine ring makes dihedral angles of 13.51 (14), 48.6 (3) and 76.5 (3)° with the fluorophenyl ring and the major- and minor-disorder components of the phenyl ring, respectively. The central thiazolidine ring adopts an envelope conformation. In the crystal, centrosymmetrically related cations and anions are linked into dimeric units via N—H...Br hydrogen bonds, which are further connected by weak C—H...Br hydrogen bonds into chains parallel to [110]. Hirshfeld surface an…
Stabilisation of Exotic Tribromide (Br3−) Anions via Supramolecular Interaction with A Tosylated Macrocyclic Pyridinophane. A Serendipitous Case.
2020
Tetraaza-macrocyclic pyridinophane L-Ts, decorated with a p-toluenesulfonyl (tosyl
Geometrical and conformational preferences of the 9‐fluorenylmethoxycarbonyl‐amino moiety
2004
Structural parameters, originating from x-ray crystallographic data, have been compiled for 13 derivatives of amino acids, peptides and related compounds, which contain a total of 14 Fmoc-NH- moieties. For these moieties, molecular geometries and conformations--described by the omegao, theta1, theta2 and theta3' torsion angles--were analysed and compared with the corresponding parameters for the Z-NH- and Boc-NH-moieties (290 and 553, respectively). To gain a deeper insight into the conformational features of the Fmoc-NH- moiety, ab initio free molecule calculations were performed for fully relaxed minima. Also the potential energy surface as a function of the torsion angles (theta3', theta…
Intramolecular 1,5-S...N σ-hole interaction in (E)-N′-(pyridin-4-ylmethylidene)thiophene-2-carbohydrazide
2020
The hydrazide-hydrazone forms inverse dimers via hydrogen bonding, but its conformation is defined by the presence of an intramolecular chalcogen bond. Electrostatic forces dominate in the crystal packing and give rise to a layered supramolecular structure.
Crystal structures of (E)-3-(4-hydroxybenzylidene)chroman-4-one and (E)-3-(3-hydroxybenzylidene)-2-phenylchroman-4-one
2019
The synthesis and crystal structures of (E)-3-(4-hydroxybenzylidene)chroman-4-one, C16H12O3, I, and (E)-3-(3-hydroxybenzylidene)-2-phenylchroman-4-one, C22H16O3, II, are reported. These compounds are of interest with respect to biological activity. Both structures display intermolecular C—H...O and O—H...O hydrogen bonding, forming layers in the crystal lattice. The crystal structure of compound I is consolidated by π–π interactions. The lipophilicity (logP) was determined as it is one of the parameters qualifying compounds as potential drugs. The logP value for compound I is associated with a larger contribution of C...H interaction in the Hirshfeld surface.
A second solvatomorph of poly[[μ4-N,N′-(1,3,5-oxadiazinane-3,5-diyl)bis(carbamoylmethanoato)]nickel(II)dipotassium] : crystal structure, Hirshfeld su…
2021
The title compound, poly[triaquabis[μ4-N,N′-(1,3,5-oxadiazinane-3,5-diyl)bis(carbamoylmethanoato)]dinickel(II)tetrapotassium], [K4Ni2(C7H6N4O7)2(H2O)3] n , is a second solvatomorph of poly[(μ4-N,N′-(1,3,5-oxadiazinane-3,5-diyl)bis(carbamoylmethanoato)nickel(II)dipotassium] reported previously [Plutenko et al. (2021). Acta Cryst. E77, 298–304]. The asymmetric unit of the title compound includes two structurally independent complex anions [Ni(C7H6N4O7)]2−, which exhibit an L-shaped geometry and consist of two almost flat fragments perpendicular to one another: the 1,3,5-oxadiazinane fragment and the fragment including other atoms of the anion. The central Ni atom is in a square-planar N2O2 co…
GeoHeritage-GIS: il sito web del patrimonio monumentale del Centro Storico di Palermo
2009
Abstract GeoHeritage-GIS (GH-GIS), a web site concerning Palermo Historic Centre monumental Heritage, developed within Project 7T7 Cluster C29, funded by MIUR, has been designed as a permanent interface between who studies the hazard factors interesting this area and a vast category of final users which operate to safeguard Palermo Monumental Heritage, a very precious common weal. These end-users will benefit from homogeneously collected, frequently improved and periodically updated data concerning soil properties, seismic effects and all of that can help to define the hazard exposition of each monument, having an important tool in establishing a scale of priorities for interventions and re…
On Grinbergs' differential geometry and finite fields
2019
Emanuels Grinbergs, in his youth, during ten years, from 1933 until 1943, wrote three dissertations on one subject, namely, differential geometry [1, 2, 3]. We think that his work in this direction has been neglected for many years, and it is the last time to try to understand the significance of these works. Here, in this short article we touch only one aspect of this work, and compare and put together two approaches, one from thesis of Grinbergs [3], and another, of the author's, [5, 6], where we show close relation between both.
Ozone-Based Atomic Layer Deposition of Al2O3 from Dimethylaluminum Chloride and Its Impact on Silicon Surface Passivation
2017
Dimethylaluminum chloride (DMACl) as an aluminum source has shown promising potential to replace more expensive and commonly used trimethylaluminum in the semiconductor industry for atomic layer deposited (ALD) thin films. Here, the Al2O3 DMACl-process is modified by replacing the common ALD oxidant, water, by ozone that offers several benefits including shorter purge time, layer-by-layer growth, and improved film adhesion. It is shown that the introduction of the ozone instead of water increases carbon and chlorine content in the Al2O3, while long ozone pulses increase the amount of interfacial hydrogen at silicon surface. These are found to be beneficial effects regarding the surface pass…