Synthesis of low-symmetry subphthalocyanines with diverse functionalization patterns

2009 ◽  
Vol 13 (02) ◽  
pp. 203-214 ◽  
Author(s):  
David González-Rodríguez ◽  
Christian G. Claessens ◽  
Tomás Torres
Keyword(s):  
Molecular Modeling ◽  
Nmr Spectra ◽  
Careful Analysis ◽  
Complete Separation ◽  
H Nmr ◽  
Chromatographic Techniques ◽  
Structural Assignment ◽  
Isolation And Characterization ◽  
Low Symmetry

We report here on the synthesis, isolation and characterization of unsymmetrically substituted subphthalocyanines obtained from the mixed condensation of 4,5-substituted phthalonitriles and/or 4-substituted phthalonitriles in the presence of BCl 3. Compared to phthalocyanines, it is clear that the cone-shaped structure of subphthalocyanines facilitates the isolation of the different regioisomers formed by regular laboratory chromatographic techniques. However, we demonstrate that some factors, such as the solubility of the regioisomers formed or the intermolecular interactions between side chains, can sometimes impede their complete separation. We also show that the structural assignment of each regioisomeric compound can be performed by careful analysis of its 1 H NMR spectra and, in some cases, with the help of NOE NMR experiments and molecular modeling.

Extraction, isolation and characterization of Bauhinia variegata flower

2020 ◽  
pp. 9-12
Author(s):  
Akanksha Gupta ◽  
Abhishek K Tripathi ◽  
Pushpraj S Gupta
Keyword(s):  
Biological Activities ◽  
Molecular Formula ◽  
Native Plant ◽  
Compound A ◽  
Active Constituents ◽  
Chromatographic Techniques ◽  
Isolation And Characterization ◽  
Soxhlet Apparatus ◽  
Bauhinia Variegata

Background: Bauhinia variegata Linn. is a native plant of Asia and China. B. variegata is found in tropical regions of the world. It belongs to family Leguminosae. It is used for diarrhea, hemorrhoids, constipation, piles, edema, leprosy, wounds, tumors, etc.  Objective: The objective of the present study was to perform extraction of B. variegata flower and isolation of active constituents from the extract. Materials and Methods: The ethanolic extraction of B. variegata flower was performed using the Soxhlet apparatus. The isolation of active constituents from the extract was performed using chromatographic techniques. In column chromatographic studies, n-hexane- [dichloromethane (DCM)] (2:8) was used as an eluting system and further purified through thin layer chromatography (TLC). Compound A and B were isolated through chromatographic techniques, then the molecular formula and characterization of these compounds were carried out with mass and infrared (IR) spectral analysis. Results and Discussion: The percentage yield of B. variegata ethanolic extract (BVE) was found to be 20.8% w/w. The different fractions were F1 having 12.5 grams with n-hexane, F2 (17.1 grams) with CH2Cl2, F3 (21.2 grams) with EtOAc, and F4 (13.4 grams) with EtOH. Compound A and B were isolated from the solvent fractions of n-hexane-DCM (2:8) and EtOAc-DCM (1:9), respectively. The compound A was characterized as 3-hydroxy-6-methoxy-2-phenyl-4H-chromen-4-one. The compound B was characterized as 3-hydroxy-6-methyl-2-phenyl-4H-chromen-4-one. Conclusion: Thus, B. variegata flowers possess active components that need to identify their biological activities.

Isolation and characterization of new heme analogues with weakly coordinating anions: Formation of monoimidazole complex, OEPFe(Im)(SbF6)

2007 ◽  
Vol 11 (09) ◽  
pp. 691-696 ◽  
Author(s):  
Mozhgan Khorasani-Motlagh ◽  
Meissam Noroozifar ◽  
Asieh Moodi
Keyword(s):  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Spectroscopic Methods ◽  
H Nmr ◽  
Weakly Coordinating Anions ◽  
Axial Ligands ◽  
Isolation And Characterization ◽  
Pulse Polarography ◽  
Weakly Coordinating

The effects of weakly coordinating anions, BF 4, AsF 6 and SbF 6, as axial ligands on the formation and coordination chemistry of heme analogues have been examined. Three new five-coordinate and stable iron(III) heme analogues, OEPFeX , where OEP is the dianion of octaethylporphyrin and X = BF 4, AsF 6 and SbF 6, have been isolated. The compounds have been characterized by different spectroscopic methods as well as elemental analysis. 1 H NMR spectroscopy and magnetic moment measurements show that the OEPFeX are paramagnetic and iron is five-coordinate. In addition, monoimidazole ferric-porphyrin complex, OEPFe ( Im )( SbF 6) has been prepared in solution, by starting with OEPFe ( SbF 6). The electrochemical properties of OEPFeX ( X = BF 4, AsF 6, SbF 6) have been studied by cyclic voltammetry and differential pulse polarography.

Nine- and Eight-Vertex Polyhedral Dicarbaborane Chemistry: New arachno and hypho Dicarbaboranes from arachno-4,5-C2B7H13: Isolation and Characterization of the [arachno-4,5-C2B7H12]- and [hypho-7,8-C2B6H13]- Anions, and of the Neutral Ligand Derivatives exo-6-(MeNC)-arachno-4,5-C2B7H11 and exo-5-L-hypho-4,9-C2B7H13 (L = NMe3 and NEt3)

1994 ◽  
Vol 59 (7) ◽  
pp. 1584-1595 ◽  
Author(s):  
Tomáš Jelínek ◽  
Josef Holub ◽  
Bohumil Štíbr ◽  
Xavier L. R. Fontaine ◽  
John D. Kennedy
Keyword(s):  
Nmr Spectroscopy ◽  
Selective Removal ◽  
High Yield ◽  
Two Dimensional ◽  
Neutral Ligand ◽  
Tertiary Amines ◽  
Proton Sponge ◽  
H Nmr ◽  
Isolation And Characterization

Deprotonation of neutral arachno-4,5-C2B7H13 (1) either with 1, 8-(NMe2)2C10H6 (proton sponge, PS) or with a mixture of aqueous K2CO3 and [NMe4]Cl leads to the isolation in high yield of the [arachno-4,5-C2B7H12]- anion (2). Isostructural with this anion is the ligand derivative exo-6-(MeNC)-arachno-4,5-C2B7H11 (3), which is prepared in 20% yield from the reaction between arachno-4,5-C2B7H13 and MeNC in dichloromethane. Under comparable conditions compound 1 with tertiary amines gives the first representatives of the nine-vertex hypho family of dicarbaboranes, the ligand derivatives exo-5-(NR3)-hypho-4,9-C2B7H13 (4a and 4b, where R = Me and Et, respectively) in moderate yields (20 - 55%), whereas the reaction between 1 and aqueous NaCN results in the selective removal of one boron vertex to yield the eight-vertex [hypho-7,8-C2B6H13]- anion (5) in 61% yield. All compounds isolated were characterized by 11B and 1H NMR spectroscopy, with two-dimensional and selective decoupling techniques giving unambiguous assignments.

scholarly journals Preparation and Characterization of Styrene Bearing Diethanolamine Side Group, Styrene Copolymer Systems, and Their Metal Complexes

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Aslışah Açıkses ◽  
Necmittin Çömez ◽  
Fatih Biryan
Keyword(s):  
Free Radical ◽  
Electrical Properties ◽  
Metal Complexes ◽  
Nmr Spectra ◽  
Side Group ◽  
Conductivity Measurements ◽  
H Nmr ◽  
Ft Ir ◽  
Polymerization Method

The two copolymer systems of styrene bearing diethanol amine side group and styrene were prepared by free radical polymerization method at 60°C in presence of 1,4-dioxane as solvent and AIBN as initiator. Their metal complexes were prepared by reaction of the copolymer used as ligand P(DEAMSt-co-St)L′′ and Ni(II) and Co(II) metal ions, which was carried out in presence of ethanol and NaOH at 65°C for 48 h in pH = 7.5. The structures of the copolymers used as ligand and metal complexes were identified by FT-IR, 1H-NMR spectra, and elemental analysis. The properties of the copolymers used as ligand and metal complexes were characterized by SEM-EDX, AAS, DSC, TGA, and DTA techniques. Then, the electrical properties of the copolymers and metal complexes were examined as a function of the temperature and frequency, and the activation energies (Ea) were estimated with conductivity measurements.

scholarly journals A Novel Acylated Anthocyanin with a Linear Trisaccharide from Flowers of Convolvulus althaeoides

2015 ◽  
Vol 10 (11) ◽  
pp. 1934578X1501001 ◽  
Author(s):  
Luis Cabrita
Keyword(s):  
Absolute Configuration ◽  
Complete Characterization ◽  
H Nmr ◽  
Chromatographic Techniques ◽  
Maldi Tof ◽  
The Absolute

An acylated anthocyanin trioside was isolated from pink flowers of Convolvulus althaeoides using a combination of chromatographic techniques. On the basis of MS (MALDI-TOF) and NMR (1H NMR, 1H-1H COSY, 1D TOCSY, HSQC, HMBC, 13C CAPT) its structure was determined as cyanidin 3- O-[6- O-(4- O-(6- O-( E-caffeoyl)-β-D-glucopyranosyl)-α-L-rhamnopyranosyl)-β-D-glucopyranoside]-5- O-β-D-glucopyranoside. The absolute configuration of the aldose enantiomer moieties was determined from the separation of the corresponding thiazolidine diastereoisomer derivatives by HPLC-DAD. This is a novel trisaccharide within the flavonoids, and the first complete characterization of a linear glucosyl-rhamnosyl-glucoside (4′-glucosylrutinoside) within the anthocyanins. Whilst acylation of rhamnose moieties in position 4 is quite common, the occurrence in anthocyanins of a glycosylated rhamnose is a unique trait. Although many complex anthocyanins have been found amongst the Convolvulaceae, the genus Convolvulus had not yet been surveyed for anthocyanins and thus this account could be of significance within the current chemotaxonomy of this family.

scholarly journals Zur Struktur von verbrückten Photoisomeren der Cyclodieninsektizide / Structure of Bridged Photoisomers of Cyclodiene Insecticides

1980 ◽  
Vol 35 (4) ◽  
pp. 502-506
Author(s):  
J. Schmitzer ◽  
K. Hustert ◽  
H. Parlar ◽  
F. Körte
Keyword(s):  
Nmr Spectra ◽  
Coupling Constants ◽  
H Nmr ◽  
Structural Assignment ◽  
Cyclodiene Insecticides ◽  
Geminal Coupling

Abstract Asymmetrically substituted chlorinated tetrahydro-4,7-methano-1H-indanes can be bridged photochemically into two types of isomerization products. These photoisomers can be distinguished on the basis of different geminal coupling constants in their 1H NMR spectra. The structural assignment is not always certain, given only one photoisomer; it is unambiguous when both isomers are available.

Phenylsilane dehydrocoupling and addition to styrene catalyzed by (R-indenyl)Ni(phosphine)(methyl) complexes

2009 ◽  
Vol 87 (1) ◽  
pp. 280-287 ◽  
Author(s):  
Yaofeng Chen ◽  
Davit Zargarian
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Variable Temperature ◽  
Structural Parameters ◽  
Catalytic Cycle ◽  
Synthesis And Characterization ◽  
H Nmr ◽  
Solid State Structures ◽  
Indenyl Complexes

This report describes the synthesis and characterization of the Ni–Me complexes (R-indenyl)Ni(PR′3)Me (R = 1-i-Pr, 1-SiMe3, and 1,3-(SiMe3)2; R′= Me, Ph) and outlines their catalytic reactivities in the dehydrogenative oligomerization of PhSiH3 and its addition to styrene in the absence of initiators/activators. Observation of higher hydrosilylation activities for PPh3-based compounds featuring bulky substituents on the indenyl ligand confirms earlier suggestions that phosphine dissociation is an important component of the catalytic cycle for this reaction. In contrast, oligomerization of PhSiH3 is more facile with PMe3-based precursors and independent of the steric bulk of the indenyl ligand, implying that this reaction does not involve phosphine dissociation. These conclusions are consistent with the variable-temperature 1H NMR spectra of {1,3,-(SiMe3)2-indenyl}Ni(PR′3)Me and various structural parameters observed in the solid-state structures of {1,3,-(SiMe3)2-indenyl}Ni(PPh3)Me, {1,3,-(SiMe3)2-indenyl}Ni(PMe3)Cl, and {1-SiMe3-indenyl}Ni(PMe3)Me.Key words: nickel-indenyl complexes, hydrosilylation, hydrosilane oligomerization.

scholarly journals Isolation and characterization of a covalent CeIV-Aryl complex with an anomalous 13C chemical shift

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Grace B. Panetti ◽  
Dumitru-Claudiu Sergentu ◽  
Michael R. Gau ◽  
Patrick J. Carroll ◽  
Jochen Autschbach ◽  
...  
Keyword(s):  
Chemical Shift ◽  
Spin Orbit Coupling ◽  
H Nmr ◽  
Isolation And Characterization ◽  
Formidable Challenge ◽  
Bona Fide ◽  
13C Chemical Shift ◽  
Computational Analyses ◽  
Metal Ligand

AbstractThe synthesis of bona fide organometallic CeIV complexes is a formidable challenge given the typically oxidizing properties of the CeIV cation and reducing tendencies of carbanions. Herein, we report a pair of compounds comprising a CeIV − Caryl bond [Li(THF)4][CeIV(κ2-ortho-oxa)(MBP)2] (3-THF) and [Li(DME)3][CeIV(κ2-ortho-oxa)(MBP)2] (3-DME), ortho-oxa = dihydro-dimethyl-2-[4-(trifluoromethyl)phenyl]-oxazolide, MBP2– = 2,2′-methylenebis(6-tert-butyl-4-methylphenolate), which exhibit CeIV − Caryl bond lengths of 2.571(7) – 2.5806(19) Å and strongly-deshielded, CeIV − Cipso13C{1H} NMR resonances at 255.6 ppm. Computational analyses reveal the Ce contribution to the CeIV − Caryl bond of 3-THF is ~12%, indicating appreciable metal-ligand covalency. Computations also reproduce the characteristic 13C{1H} resonance, and show a strong influence from spin-orbit coupling (SOC) effects on the chemical shift. The results demonstrate that SOC-driven deshielding is present for CeIV − Cipso13C{1H} resonances and not just for diamagnetic actinide compounds.

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