scholarly journals Catechol-Containing Schiff Bases on Thiacalixarene: Synthesis, Copper (II) Recognition, and Formation of Organic-Inorganic Copper-Based Materials

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2334
Author(s):  
Pavel Padnya ◽  
Ksenia Shibaeva ◽  
Maxim Arsenyev ◽  
Svetlana Baryshnikova ◽  
Olga Terenteva ◽  
...  
Keyword(s):  
Nitrogen Atom ◽  
Ir Spectroscopy ◽  
Schiff Bases ◽  
Selective Recognition ◽  
Physical Methods ◽  
Imine Group ◽  
Partial Cone ◽  
Vis Spectroscopy ◽  
First Time ◽  
Thermal Stable

For the first time, a series of catechol-containing Schiff bases, tetrasubstituted at the lower rim thiacalix[4]arene derivatives in three stereoisomeric forms, cone, partial cone, and 1,3-alternate, were synthesized. The structure of the obtained compounds was proved by modern physical methods, such as NMR, IR spectroscopy, and HRMS. Selective recognition (Kb difference by three orders of magnitude) of copper (II) cation in the series of d-metal cations (Cu2+, Ni2+, Co2+, Zn2+) was shown by UV-vis spectroscopy. Copper (II) ions are coordinated at the nitrogen atom of the imine group and the nearest oxygen atom of the catechol fragment in the thiacalixarene derivatives. High thermal stable organic-inorganic copper-based materials were obtained on the base of 1,3-alternate + Cu (II) complexes.

scholarly journals PAMAM-calix-dendrimers: Synthesis and Thiacalixarene Conformation Effect on DNA Binding

2021 ◽  
Vol 22 (21) ◽  
pp. 11901
Author(s):  
Olga Mostovaya ◽  
Pavel Padnya ◽  
Igor Shiabiev ◽  
Timur Mukhametzyanov ◽  
Ivan Stoikov
Keyword(s):  
Convenient Method ◽  
First Generation ◽  
Pamam Dendrimers ◽  
Cone Conformation ◽  
Partial Cone ◽  
Sperm Dna ◽  
Vis Spectroscopy ◽  
High Yields ◽  
First Time ◽  
Salmon Sperm Dna

A convenient method for the synthesis of the first generation PAMAM dendrimers based on the thiacalix[4]arene has been developed for the first time. Three new PAMAM-calix-dendrimers with the macrocyclic core in cone, partial cone, and 1,3-alternate conformations were obtained with high yields. The interaction of the obtained compounds with salmon sperm DNA resulted in the formation of the associates of the size up to 200 nm, as shown by the UV-Vis spectroscopy, DLS, and TEM. It was demonstrated by the CD method that the structure of the DNA did not undergo significant changes upon binding. The PAMAM-calix-dendrimer based on the macrocycle in cone conformation stabilized DNA and prevented its degradation.

scholarly journals Optimization of Green Synthesis of Silver Nanoparticles from Leaf Extracts ofPimenta dioica(Allspice)

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Akshay Rajeev Geetha ◽  
Elizabeth George ◽  
Akshay Srinivasan ◽  
Jameel Shaik
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Leaf Extract ◽  
Synthesis Method ◽  
Leaf Extracts ◽  
Synthesis Of Nanoparticles ◽  
Hot Air ◽  
Vis Spectroscopy ◽  
Pimenta Dioica ◽  
First Time

Production of silver nanoparticles from the leaf extracts ofPimenta dioicais reported for the first time in this paper. Three different sets of leaves were utilized for the synthesis of nanoparticles—fresh, hot-air oven dried, and sun-dried. These nanoparticles were characterized using UV-Vis spectroscopy and AFM. The results were diverse in that different sizes were seen for different leaf conditions. Nanoparticles synthesized using sun-dried leaves (produced using a particular ratio (1 : 0.5) of the leaf extract sample and silver nitrate (1 mM), resp.) possessed the smallest sizes. We believe that further optimization of the current green-synthesis method would help in the production of monodispersed silver nanoparticles having great potential in treating several diseases.

scholarly journals Synthesis of L-DOPA Based Melanins with Reproducible Physic-Chemical Properties

2018 ◽  
Author(s):  
Koen Vercruysse ◽  
Jayla Moore
Keyword(s):  
Ir Spectroscopy ◽  
Enzymatic Synthesis ◽  
Chemical Properties ◽  
Size Exclusion ◽  
Synthesis Methods ◽  
Ongoing Research ◽  
Vis Spectroscopy ◽  
Exclusion Chromatography ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

This report expands our ongoing research efforts into the non-enzymatic synthesis of melanins. We have explored four different methods for the synthesis of L-DOPA based melanins and evaluated the reproducibility of some of their physic-chemical properties. The melanins were synthesized through the addition of NaOH, tyrosinate or Fe<sup>2+</sup>/H<sub>2</sub>O<sub>2</sub>. Two different approaches for the reactions involving Fe<sup>2+</sup> and H<sub>2</sub>O<sub>2</sub> were tested: a) addition of H<sub>2</sub>O<sub>2</sub> spread out over multiple days or b) addition of H<sub>2</sub>O<sub>2</sub> in one fraction at the start of the reaction. The physic-chemical properties of the melanins explored involved: 1) retention on size exclusion chromatography column, 2) FT-IR spectroscopy, 3) UV-Vis spectroscopy and 4) the capacity to reduce a redox dye, dichlorophenolindophenol. Overall the results obtained indicated that 1) the various synthesis methods lead to melanins with reproducible physic-chemical properties, 2) that the melanins synthesized in the presence of Fe<sup>2+</sup>/H<sub>2</sub>O<sub>2</sub> are distinctly different from the melanins synthesized in the presence of NaOH or tyrosinate and 3) that no distinctly different melanins were generated when comparing the two different synthesis approaches involving Fe<sup>2+</sup>/H<sub>2</sub>O<sub>2</sub>. Only the melanins synthesized in the presence of Fe<sup>2+</sup>/H<sub>2</sub>O<sub>2</sub> appeared to possess the capacity to reduce dichlorophenolindophenol.

scholarly journals The Bio-fabrication of Gold Nanoparticles (AuNPs) by Green Method and Study of its Electrochemical Applications

2020 ◽  
Vol 1 (4) ◽  
pp. 22-25
Author(s):  
Azwan Morni
Keyword(s):  
Gold Nanoparticles ◽  
Ir Spectroscopy ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Green Method ◽  
Oh Groups ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

This study reports a green method for the synthesis of gold nanoparticles (AuNPs) using the aqueous extract of Salix aegyptiaca extract. The effects of gold salt concentration, extract concentration and extract quantity were investigated on nanoparticles synthesis. Novel methods of ideally synthesizing AuNPs are thus thought that are formed at ambient temperatures, neutral pH, low costs and environmentally friendly fashion. AuNPs were characterized with different techniques such as UV–vis spectroscopy, FT-IR spectroscopy, X-ray diffraction, and TEM. FT-IR spectroscopy revealed that gold nanoparticles were functionalized with biomolecules that have primary carbonyl group, -OH groups and other stabilizing functional groups. TEM experiments showed that these nanoparticles are formed with various shapes and X-ray diffraction pattern showed high purity and face centered cubic structure of AuNPs. For electrochemical properties of AuNPs, a modified glassy carbon electrode using AuNPs (AuNPs/GCE) was investigated. The results show that electronic transmission rate between the modified electrode and [Fe (CN)6]3-/4- increased.

Ruthenium and Iron Carbonyl Clusters Catalyzed Reduction of N,N-dimethylbenzamide and N,N-diethyl-(3-methyl)benzamide

2011 ◽  
Vol 396-398 ◽  
pp. 2485-2488
Author(s):  
Bao Hua Zhu ◽  
Guo Hua Xu ◽  
Zhi Wei Xia
Keyword(s):  
Ir Spectroscopy ◽  
Elemental Analysis ◽  
Iron Carbonyl ◽  
Carbonyl Cluster ◽  
Carbonyl Clusters ◽  
Excellent Yield ◽  
Ruthenium Carbonyl ◽  
Vis Spectroscopy

One new Ruthenium and one known Iron bimetallic carbonyl clusters containing triphos (1,1,1-tris(diphenylphosphinomethyl)ethane) ligand have been prepared as catalyst to study the reduction of amide to amine. All clusters were characterized by elemental analysis, 1HNMR, 31PNMR and IR spectroscopy. The reduction of N,N-dimethylbenzamide and N,N-diethyl-(3-methyl) benzamide catalyzed by Ru and Fe carbonyl clusters were investigated at 100 ~ 110 °C for 24 ~ 28h, polymethylhydrogensiloxane (PMHS) as reduction agent. The products were analysized using GC-MS, IR and UV-vis spectroscopy and an excellent yield (97%) of N,N-diethyl- (3-methyl)benzamine was obtained when using 3 mol% of bimetallic ruthenium carbonyl cluster as catalyst. The data of IR and UV-vis show that the frameworks of clusters are not changed remarkably during the reaction.

N-Methylated 1,8-Diaminonaphthalenes as Bifunctional Nucleo­philes in Reactions with α,ω-Dihalogenoalkanes: A Facile Route to Heterocyclic and Double Proton Sponges

Synthesis ◽  
2020 ◽  
Vol 52 (22) ◽  
pp. 3427-3438
Author(s):  
Valery A. Ozeryanskii ◽  
Ekaterina V. Kolupaeva ◽  
Alexander F. Pozharskii
Keyword(s):  
Nitrogen Atom ◽  
Starting Material ◽  
One Pot ◽  
Heterocyclization Reaction ◽  
New Type ◽  
Organic Receptor ◽  
Proton Sponges ◽  
Short Time ◽  
First Time ◽  
Facile Route

The reaction of 1-dimethylamino-8-(methylamino)naphthalene with 1,3-dibromopropane chemoselectively leads to the product of N,N′-heterocyclization, while in the case of 1,4-dibromobutane and 1,2-bis(bromomethyl)benzene the process results in heterocyclization onto the same nitrogen atom with the formation of previously unknown 1-dimethylamino-8-pyrrolidino- and 1-dimethylamino-8-isoindolino-naphthalenes. The same reactions conducted without adding any auxiliary base lead to the formation of N,N′-linked double proton sponges as a new type of polynitrogen organic receptor. Proceeding as a sequence of quaternization–demethylation–cyclization steps, this heterocyclization process can also be used to construct six-membered rings (piperidino, morpholino), albeit in lower yields. The ability of 1,2-dibromoethane to brominate N-alkylated 1,8-diaminonaphthalenes is also described. It is shown for the first time that a commercially available 1,8-bis(dimethylamino)naphthalene (DMAN) can be used as a starting material in a heterocyclization reaction, which via a one-pot approach and in a short time can be converted into 1,5-dimethylnaphtho[1,8-bc]-1,5-diazacyclooctane or 1-dimethylamino-8-(pyrrolidin-1-yl)naphthalene.

scholarly journals Novel Cleaning-in-Place Strategies for Pharmaceutical Hot Melt Extrusion

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 588
Author(s):  
Martin Spoerk ◽  
Ioannis Koutsamanis ◽  
Josip Matić ◽  
Simone Eder ◽  
Carolina Patricia Alva Zúñiga ◽  
...  
Keyword(s):  
Hot Melt Extrusion ◽  
Production Equipment ◽  
Process Equipment ◽  
Melt Extrusion ◽  
Release Formulation ◽  
Sustained Release Formulation ◽  
Cleaning Procedure ◽  
Vis Spectroscopy ◽  
First Time ◽  
Hot Melt

To avoid any type of cross-contamination, residue-free production equipment is of utmost importance in the pharmaceutical industry. The equipment cleaning for continuous processes such as hot melt extrusion (HME), which has recently gained popularity in pharmaceutical applications, necessitates extensive manual labour and costs. The present work tackles the HME cleaning issue by investigating two cleaning strategies following the extrusion of polymeric formulations of a hormonal drug and for a sustained release formulation of a poorly soluble drug. First, an in-line quantification by means of UV–Vis spectroscopy was successfully implemented to assess very low active pharmaceutical ingredient (API) concentrations in the extrudates during a cleaning procedure for the first time. Secondly, a novel in-situ solvent-based cleaning approach was developed and its usability was evaluated and compared to a polymer-based cleaning sequence. Comparing the in-line data to typical swab and rinse tests of the process equipment indicated that inaccessible parts of the equipment were still contaminated after the polymer-based cleaning procedure, although no API was detected in the extrudate. Nevertheless, the novel solvent-based cleaning approach proved to be suitable for removing API residue from the majority of problematic equipment parts and can potentially enable a full API cleaning-in-place of a pharmaceutical extruder for the first time.

Luminescence studies of uranyl-aliphatic dicarboxylic acid complexes in acetonitrile medium

2020 ◽  
Vol 108 (5) ◽  
pp. 361-373 ◽  
Author(s):  
Siuli Maji ◽  
Satendra Kumar ◽  
Sundararajan Kalyanasundaram
Keyword(s):  
Dicarboxylic Acid ◽  
Adipic Acid ◽  
Glutaric Acid ◽  
Luminescence Spectra ◽  
Pimelic Acid ◽  
Effect Of Solvent ◽  
Solvent Water ◽  
Vis Spectroscopy ◽  
First Time ◽  
Acetonitrile Medium

AbstractThe uranyl (UO22+)-aliphatic dicarboxylic acid complexes are studied by luminescence and UV-Vis spectroscopy in acetonitrile (MeCN) medium. The ligands used are malonic acid (MA), succinic acid (SA), glutaric acid (GA), adipic acid (AA) and pimelic acid (PA). The complexes of UO22+ with the above ligands showed well resolved luminescence spectra at pH 4.0 with M/L = 5. Both luminescence and UV-Vis spectra indicated the formation of 1:2 and 1:3 complexes of UO22+ with MA and GA, AA, PA, respectively. DFT computations indicated the formation of 1:2 chelate complex of UO22+ with MA and two types of 1:3 complexes of UO22+ with SA, GA, AA and PA. Furthermore, the effect of solvent (water and acetonitrile) on the UO22+-ligand complexes has been performed using COSMO model. The present study demonstrates, for the first time, the formation of tris complexes of uranyl with these ligands in acetonitrile medium.

PREPARATION OF HEAT INSULATING FILM WITH MPS (MERCAPTOPROPYL TRIMETHOXYSILANE) COATED-SiO2 NANOPARTICLES

2006 ◽  
Vol 05 (02n03) ◽  
pp. 323-329
Author(s):  
YOUNG SOO KANG ◽  
YOUNG HWAN KIM ◽  
YONG JOO KIM
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ir Spectroscopy ◽  
Light Transmission ◽  
Surface Modifications ◽  
Sio2 Nanoparticles ◽  
Sodium Metasilicate ◽  
Homogeneous Distribution ◽  
Emulsion Method ◽  
Vis Spectroscopy

To improve the heat insulating property of EVA (ethylene vinylacetate), monodispersed spherical SiO 2 nanoparticles as inorganic insulating filler were prepared from sodium metasilicate by emulsion method in reverse micelle. In order to make a comparative study about effect of dispersibility on mechanical properties, aggregated microsized- SiO 2 particles were also prepared. Surface modifications of synthesized SiO 2 nanoparticles were accomplished with MPS (mercaptopropyl trimethoxysilane) to maximize homogeneous distribution and compatibility between obtained SiO 2 nanoparticles and EVA. Finally heat insulating nanocomposite film was prepared with MPS coated- SiO 2 nanoparticles at the ratio of 2 wt% and EVA. The insulating capacity was tested by IR spectroscopy and light transmission was observed by UV-vis spectroscopy. The mechanical properties such as tensile strength, elongation, impact strength, tear strength, clarity and haze were also studied.

scholarly journals Carbon dots as absorbance promoter probes for detection of Cu(ii) ions in aqueous solution: central composite design approach

2018 ◽  
Vol 17 (2) ◽  
pp. 245-255 ◽  
Author(s):  
S. A. R. Shahamirifard ◽  
M. Ghaedi ◽  
M. Montazerozohori ◽  
A. Masoudiasl
Keyword(s):  
Aqueous Solution ◽  
Central Composite Design ◽  
Carbon Dots ◽  
Design Approach ◽  
Complexing Agent ◽  
Vis Spectroscopy ◽  
First Time ◽  
Central Composite ◽  
Determination Of Copper

In this work, the use of carbon dots (CDs) as a complexing agent and sensitizer in a polymeric matrix for determination of copper(ii) by UV-vis spectroscopy is reported for the first time.

Sign in / Sign up

Export Citation Format

Share Document