Molybdenum(VI) complexes of Schiff bases derived from salicylaldehyde and 2-aminoethanethiol (cysteamine)

1984 ◽  
Vol 37 (11) ◽  
pp. 2235 ◽  
Author(s):  
W Goh ◽  
M Lim
Keyword(s):  
Solid State ◽  
Dimethyl Sulfoxide ◽  
Schiff Bases ◽  
Empirical Formula ◽  
Oxidation Product ◽  
Tetramethylammonium Hydroxide ◽  
Crystalline Solid ◽  
Pale Yellow

The reaction of salicylaldehyde and 2-aminoethanethiol (cysteamine) in methanol results in two distinct products: a yellow oil, 2-(2-mercaptoethyliminomethyl)phenol, and a yellow crystalline solid, 2,2'-[dithiobis(ethane-1,2-diyl)bis(nitrilomethylidyne)]bisphenol, which is an oxidation product of the former. The latter compound may also be prepared from salicylaldehyde and 2,2'-dithio-bis(ethylamine) (cystamine) in methanol. 2-(2''-Mercaptoethyliminomethyl)phenol reacts with MoO2(acac)2 (acac = pentane-2,4-dionate) in methanol to yield a red crystalline solid with empirical formula MoO2(mep) [mep = 2-(2"- mercaptoethyliminomethyl)phenolate]. This red solid exists as a dimer in the solid state. It forms adducts with dimethyl sulfoxide, hexamethylphosphoric acid triamide and pyridine. 2,2'-[Dithiobis(ethane-1,2-diyl)bis(nitrilomethylidyne)]bisphenol reacts with MoO2(acac)2 to yield a pale yellow solid. It is a monomeric compound whose formula is MoO2(dbp) {dbp = 2,2'- [dithiobis(ethane-1,2-diyl)bis(nitrilomethylidyne)]bisphenolate}. It does not form an adduct and is decomposed by an excess of tetramethylammonium hydroxide in methanol.

scholarly journals Four Thermochromic o-Hydroxy Schiff Bases of α-Aminodiphenylmethane: Solution and Solid State Study

Crystals ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 25 ◽  
Author(s):  
Marija Zbačnik ◽  
Katarina Pičuljan ◽  
Jelena Parlov-Vuković ◽  
Predrag Novak ◽  
Andreas Roodt
Keyword(s):  
Solid State ◽  
Schiff Bases ◽  
State Study

scholarly journals Mesomorphic Behavior in Silver(I) N-(4-Pyridyl) Benzamide with Aromatic π–π Stacking Counterions

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1666 ◽  
Author(s):  
Issac Torres ◽  
Mauro Ruiz ◽  
Hung Phan ◽  
Noemi Dominguez ◽  
Jacobo Garcia ◽  
...  
Keyword(s):  
Solid State ◽  
Organic Semiconductors ◽  
Flexible Electronics ◽  
Crystalline Solid ◽  
Naval Research ◽  
Scanning Calorimetry ◽  
New Family ◽  
Π Stacking ◽  
Capable Groups ◽  
New Generation

Organic semiconductor materials composed of π–π stacking aromatic compounds have been under intense investigation for their potential uses in flexible electronics and other advanced technologies. Herein we report a new family of seven π–π stacking compounds of silver(I) bis-N-(4-pyridyl) benzamide with varying counterions, namely [Ag(NPBA)2]X, where NPBA is N-(4-pyridyl) benzamine, X = NO3− (1), ClO4− (2), CF3SO3− (3), PF6− (4), BF4− (5), CH3PhSO3− (6), and PhSO3− (7), which form extended π−π stacking networks in one-dimensional (1D), 2D and 3D directions in the crystalline solid-state via the phenyl moiety, with average inter-ring distances of 3.823 Å. Interestingly, the counterions that contain π–π stacking-capable groups, such as in 6 and 7, can induce the formation of mesomorphic phases at 130 °C in dimethylformamide (DMF), and can generate highly branched networks at the mesoscale. Atomic force microscopy studies showed that 2D interconnected fibers form right after nucleation, and they extend from ~30 nm in diameter grow to reach the micron scale, which suggests that it may be possible to stop the process in order to obtain nanofibers. Differential scanning calorimetry studies showed no remarkable thermal behavior in the complexes in the solid state, which suggests that the mesomorphic phases originate from the mechanisms that occur in the DMF solution at high temperatures. An all-electron level simulation of the band gaps using NRLMOL (Naval Research Laboratory Molecular Research Library) on the crystals gave 3.25 eV for (1), 3.68 eV for (2), 1.48 eV for (3), 5.08 eV for (4), 1.53 eV for (5), and 3.55 eV for (6). Mesomorphic behavior in materials containing π–π stacking aromatic interactions that also exhibit low-band gap properties may pave the way to a new generation of highly branched organic semiconductors.

Wide electrochemical window ionic salt for use in electropositive metal electrodeposition and solid state Li-ion batteries

2014 ◽  
Vol 2 (7) ◽  
pp. 2194-2201 ◽  
Author(s):  
Sankaran Murugesan ◽  
Oliver A. Quintero ◽  
Brendan P. Chou ◽  
Penghao Xiao ◽  
Kyusung Park ◽  
...  
Keyword(s):  
Solid State ◽  
Crystalline Solid ◽  
Li Ion Batteries ◽  
Ionic Salt ◽  
Metal Electrodeposition ◽  
Electrochemical Window ◽  
Li Ion

A stable hydrophobic ionic crystalline solid comprised of the N-propyl-N-methylpiperidinium cation and hexafluorophosphate anion PP13PF6 exhibits a remarkably wide electrochemical window of 7.2 V.

Protein structure by solid-state NMR spectroscopy

1987 ◽  
Vol 19 (1-2) ◽  
pp. 7-49 ◽  
Author(s):  
S. J. Opella ◽  
P. L. Stewart ◽  
K. G. Valentine
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Structural Information ◽  
Biological Systems ◽  
Genetic Regulation ◽  
Protein Structures ◽  
Crystalline Solid ◽  
Solid State Nmr Spectroscopy ◽  
Nmr Methods

The three-dimensional structures of proteins are among the most valuable contributions of biophysics to the understanding of biological systems (Dickerson & Geis, 1969; Creighton, 1983). Protein structures are utilized in the description and interpretation of a wide variety of biological phenomena, including genetic regulation, enzyme mechanisms, antibody recognition, cellular energetics, and macroscopic mechanical and structural properties of molecular assemblies. Virtually all of the information currently available about the structures of proteins at atomic resolution has been obtained from diffraction studies of single crystals of proteins (Wyckoff et al, 1985). However, recently developed NMR methods are capable of determining the structures of proteins and are now being applied to a variety of systems, including proteins in solution and other non-crystalline environments that are not amenable for X-ray diffraction studies. Solid-state NMR methods are useful for proteins that undergo limited overall reorientation by virtue of their being in the crystalline solid state or integral parts of supramolecular structures that do not reorient rapidly in solution. For reviews of applications of solid-state NMR spectroscopy to biological systems see Torchia and VanderHart (1979), Griffin (1981), Oldfield et al. (1982), Opella (1982), Torchia (1982), Gauesh (1984), Torchia (1984) and Opella (1986). This review describes how solid-state NMR can be used to obtain structural information about proteins. Methods applicable to samples with macroscopic orientation are emphasized.

scholarly journals Different BCS Class II Drug-Gelucire Solid Dispersions Prepared by Spray Congealing: Evaluation of Solid State Properties and In Vitro Performances

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 548 ◽  
Author(s):  
Serena Bertoni ◽  
Beatrice Albertini ◽  
Nadia Passerini
Keyword(s):  
Solid State ◽  
Drug Carrier ◽  
Solid Dispersions ◽  
Class Ii ◽  
Water Soluble ◽  
Drug Dissolution ◽  
Crystalline Solid ◽  
Dissolution Behavior ◽  
Bcs Class Ii

Delivery of poorly water soluble active pharmaceutical ingredients (APIs) by semi-crystalline solid dispersions prepared by spray congealing in form of microparticles (MPs) is an emerging method to increase their oral bioavailability. In this study, solid dispersions based on hydrophilic Gelucires® (Gelucire® 50/13 and Gelucire® 48/16 in different ratio) of three BCS class II model compounds (carbamazepine, CBZ, tolbutamide, TBM, and cinnarizine, CIN) having different physicochemical properties (logP, pKa, Tm) were produced by spray congealing process. The obtained MPs were investigated in terms of morphology, particles size, drug content, solid state properties, drug-carrier interactions, solubility, and dissolution performances. The solid-state characterization showed that the properties of the incorporated drug had a profound influence on the structure of the obtained solid dispersion: CBZ recrystallized in a different polymorphic form, TBM crystallinity was significantly reduced as a result of specific interactions with the carrier, while smaller crystals were observed in case of CIN. The in vitro tests suggested that the drug solubility was mainly influenced by carrier composition, while the drug dissolution behavior was affected by the API solid state in the MPs after the spray congealing process. Among the tested APIs, TBM-Gelucire dispersions showed the highest enhancement in drug dissolution as a result of the reduced drug crystallinity.

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