Iron complex of a quadruply fused porphyrin: Synthesis, structure and redox properties

2020 ◽  
Vol 24 (01n03) ◽  
pp. 252-258
Author(s):  
Tomoya Ishizuka ◽  
Keiyu Komamura ◽  
Yuta Saegusa ◽  
Shogo Tanaka ◽  
Yoshihito Shiota ◽  
...  
Keyword(s):  
Differential Pulse ◽  
Iron Complex ◽  
X Ray Diffraction ◽  
Ring Fusion ◽  
H Nmr ◽  
Axial Ligands ◽  
Peripheral Ring ◽  
Controlled Potential ◽  
Bulk Electrolysis ◽  
Porphyrin Synthesis

An iron(II) complex of a quadruply ring-fused porphyrin (QFP), Fe-1, in which four mesityl groups were introduced at the periphery to improve the solubility in organic solvents, has been newly synthesized and characterized. In the pyridine solution, two pyridine molecules bind to the low-spin Fe[Formula: see text] center of Fe-1 as axial ligands to make the complex stable even under air. Characterization of Fe-1 was performed using 1H NMR spectroscopy, MALDI-TOF-MS spectrometry and single-crystal X-ray diffraction analysis. The 1H NMR signals of Fe-1 were observed in the diamagnetic region, reflecting the low-spin state of the FeII center. In the differential pulse voltammogram of Fe-1, three oxidation waves and four reduction waves were observed in pyridine; the first oxidation wave at -0.08 V vs. Fc/Fc[Formula: see text] can be ascribed to the oxidation process of the FeII center, FeII/FeIII, and other six waves can be assigned to the redox processes of the QFP ligand. Furthermore, the ESR measurement of 1e[Formula: see text]-reduced Fe-1 upon controlled-potential bulk electrolysis in pyridine exhibited a signal at [Formula: see text] = 2.003 with a well-resolved 45-line hyperfine splitting at room temperature, due to the coupling with four nitrogen nuclei and twelve hydrogen ones of the QFP ligand. This indicates that the ligand radical anion of Fe-1 is stabilized by delocalization of the spin density owing to the peripheral ring fusion and resultant expansion of the [Formula: see text]-conjugation.

Synthesis and characterization of a new (phthalocyani-nato)bis(carboxylate) silicon(IV) compound with increased solubility

2002 ◽  
Vol 06 (03) ◽  
pp. 198-202 ◽  
Author(s):  
José L. Sosa-Sánchez ◽  
Alberto Galindo ◽  
Dino Gnecco ◽  
Sylvain Bernès ◽  
George R. Fern ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Structure Determination ◽  
Spectroscopic Characterization ◽  
X Ray Diffraction ◽  
H Nmr ◽  
Axial Ligands ◽  
Nmr Characterization ◽  
Soluble Silicon ◽  
Soluble Material

The synthesis and spectroscopic characterization of a new soluble silicon(IV) phthalocyanine complex is presented. The compound shows an increased solubility compared to its SiPcCl 2 precursor and this allowed solution 1 H NMR characterization. The assignment of the 1 H NMR signals for the axial ligands is greatly facilitated due to the anisotropic high ring current effects from the macrocycle. In addition, good quality crystals were grown from this more soluble material for molecular structure determination by single-crystal X-ray diffraction analysis. The molecular structure determination shows that the complex crystallizes in a non-centrosymmetric space group due to the inherent chirality of the naproxene ligands. Bond lengths and angles fit well to other analogous compounds previously reported.

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.

Synthesis and Electrochemistry of Aluminum Porphycenes: Crystal and Molecular Structure of Methyl-σ-Bonded Aluminum Etioporphycene

1997 ◽  
Vol 01 (02) ◽  
pp. 109-119 ◽  
Author(s):  
ROGER GUILARD ◽  
VIRGINIE PICHON-PESME ◽  
HASSANE LACHEKAR ◽  
CLAUDE LECOMTE ◽  
ALLY M. AUKAULOO ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Structural Data ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Axial Ligands ◽  
Uv Visible

The synthesis and characterization of three monomeric aluminum porphycenes with anionic or σ-bonded axial ligands is reported. The investigated compounds are represented as ( EtioPc ) Al ( CH 3) and ( EtioPc ) AlX where EtioPc represents the dianion of etioporphycene and X = Cl − or OH −. Each synthesized complex was characterized by mass spectrometry. 1 H NMR, IR and UV-visible spectroscopies as well as by electrochemistry. Comparisons are made between the properties of complexes in the aluminum etioporphycene series and related chloro- or methyl σ-bonded Al ( III ) porphyrins containing octaethylporphyrin ( OEP ) or tetraphenylporphyrin ( TPP ) macrocycles. Comparisons are also made between the currently investigated compounds and a previously reported Al ( III ) μ-oxo dimer, [( EtioPc ) Al ]2 O . In addition, the crystal and molecular structure of ( EtioPc ) Al ( CH 3) was determined by X-ray diffraction. The molecular structure of this methyl-σ-bonded aluminum etioporphycene provides the first structural data for an aluminum porphycene compound. The aluminum(III) atom in ( EtioPc ) Al ( CH 3) is pentacoordinated and is located 0.54 Å from the plane of the four N -nitrogens.

Synthesis, spectroscopy and electrochemistry of a new phthalonitrile derivative with substituted PDT-TTF unit

2003 ◽  
Vol 07 (03) ◽  
pp. 191-198
Author(s):  
Yingyu Hu ◽  
Yongjia Shen ◽  
Xu Xu ◽  
Xiaohong Li ◽  
Yongfang Li
Keyword(s):  
Title Compound ◽  
Differential Pulse ◽  
Ring Expansion ◽  
Reduction Peak ◽  
Cyclic Voltammogram ◽  
X Ray Diffraction ◽  
H Nmr ◽  
Irreversible Oxidation ◽  
Irreversible Reduction ◽  
Ring Expansion Reaction

A phthalonitrile derivative with a substituted propylenedithio-tetrathiafulvalene (PDT-TTF) unit was synthesized and characterized. 1 H NMR spectra disclosed an unexpected ring expansion reaction, by which the title compound was formed. Its crystal structure was determined by single crystal X-ray diffraction. The cyclic voltammogram and differential pulse voltammogram of the title compound showed two couples of redox peaks arising from TTF, one additional irreversible oxidation peak and one irreversible reduction peak.

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

scholarly journals Tautomerisation in 1-(4-Methylphenylazo)naphthalen-2-ol and 2-(4-Methylphenylazo)-4-methylphenol: A Crystallographic and 13C{1H}NMR Study

1999 ◽  
Vol 23 (3) ◽  
pp. 178-179
Author(s):  
Wendy I. Cross ◽  
Kevin R. Flower ◽  
Robin G. Pritchard
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Resonant Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Nmr Study ◽  
Acetic Acid Esters ◽  
Acid Esters ◽  
Equivalent Carbon

The acetic acid esters of 1-(4-methylphenylazo)naphthalen-2-ol 1 and 2-(4-methylphenylazo)-4-methylphenol 3 are prepared and characterised by single crystal X-ray diffraction studies and 13C{1H}NMR spectroscopy; the position of the C(2)13C resonance for the ester is used to predict the position of resonant frequency of the equivalent carbon in the parent alcohols and hence, calculate the position of the azo-hydrazone equilibrium in these compounds.

Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi
Keyword(s):  
Liquid Crystalline ◽  
Spectroscopic Method ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Subsequent Reaction ◽  
Scanning Calorimetry ◽  
Polar Solvents ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

The Influence of the Axial Ligands of a Series of Platinum(IV) Anti-Cancer Complexes on Their Reduction to Platinum(II) and Reaction With DNA

1995 ◽  
Vol 48 (4) ◽  
pp. 793 ◽  
Author(s):  
LT Ellis ◽  
HM Er ◽  
TW Hambley
Keyword(s):  
Crystal Structure ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduction Potentials ◽  
Axial Ligands ◽  
Carboxylate Anions ◽  
Anti Cancer ◽  
Molecular Modelling Studies ◽  
Modelling Studies

The electrochemical reduction and DNA binding have been studied for a series of platinum(IV) complexes with Cl-, OH-, and carboxylate anions as the axial ligands ; [Pt(en)Cl4], [Pt(en)Cl2(OH)2], and [Pt(en)Cl2(OC(O)R)2], R = CH3, CH2CH3, CH2CH2CH3. Cathodic reduction potentials vary by more than 650 mV with the tetrachloro complex reduced most readily and the dihydroxo least readily. The binding of the complexes correlates with the reduction potentials with the more readily reduced complexes binding more readily to DNA. The influence of the reducing agent glutathione on platinum binding to DNA was found to depend on whether it was added before or after Pt/DNA incubation. The results are consistent with octahedral platinum(IV) binding monofunctionally to DNA, and molecular modelling studies have been used to confirm that this is sterically feasible. The crystal structure of [Pt(en)Cl2(OC(O)CH3)2] has been determined by X-ray diffraction methods and refined to R = 0.028 (977 F). The crystals are monoclinic, space group C2/c, a 15.569(6), b 8.104(1), c 13.188(1) Ǻ, β 136.38(2)°.

scholarly journals Insertion of Phosphenium Ions into a Bicyclo[1.1.0]Tetraphosphabutane Iron Complex

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3920
Author(s):  
Martin Weber ◽  
Gábor Balázs ◽  
Alexander V. Virovets ◽  
Eugenia Peresypkina ◽  
Manfred Scheer
Keyword(s):  
Diffraction Analysis ◽  
Room Temperature ◽  
31P Nmr ◽  
Spectroscopic Studies ◽  
Iron Complex ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phosphenium Ions

By reacting [{Cp‴Fe(CO)2}2(µ,η1:1-P4)] (1) with in situ generated phosphenium ions [Ph2P][A] ([A]− = [OTf]− = [O3SCF3]−, [PF6]−), a mixture of two main products of the composition [{Cp‴Fe(CO)2}2(µ,η1:1-P5(C6H5)2)][PF6] (2a and 3a) could be identified by extensive 31P NMR spectroscopic studies at 193 K. Compound 3a was also characterized by X-ray diffraction analysis, showing the rarely observed bicyclo[2.1.0]pentaphosphapentane unit. At room temperature, the novel compound [{Cp‴Fe}(µ,η4:1-P5Ph2){Cp‴(CO)2Fe}][PF6] (4) is formed by decarbonylation. Reacting 1 with in situ generated diphenyl arsenium ions gives short-lived intermediates at 193 K which disproportionate at room temperature into tetraphenyldiarsine and [{Cp‴Fe(CO)2}4(µ4,η1:1:1:1-P8)][OTf]2 (5) containing a tetracyclo[3.3.0.02,7.03,6]octaphosphaoctane ligand.

Synthesis and characterization of meso-to-meso directly linked porphyrin-diazaporphyrin triads

2018 ◽  
Vol 22 (09n10) ◽  
pp. 814-820
Author(s):  
Yingying Jia ◽  
Ling Xu ◽  
Bangshao Yin ◽  
Mingbo Zhou ◽  
Jianxin Song
Keyword(s):  
Nickel Complex ◽  
High Resolution Mass Spectrometry ◽  
Dihedral Angles ◽  
X Ray Diffraction ◽  
Extinction Coefficients ◽  
X Ray ◽  
H Nmr ◽  
First Time ◽  
Molar Extinction Coefficients

Beginning with 5,10,15-triarylporphyrin-nickel complex, five meso-to-meso directly linked porphyrin-diazaporphyrin triads were successfully prepared for the first time through a series of reactions including formylation via Vilsmeier–Haack reaction, condensation with pyrrole, bromination with [Formula: see text]-Bromosuccinimide (NBS), oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), metal-templated cyclization of dibromodipyrrin-metal complexes with NaN[Formula: see text] and demetalization. All these triads were comprehensively characterized by [Formula: see text]H NMR, high-resolution mass spectrometry and UV-vis absorption. In addition, the structure of compound 6Ni was unambiguously determined by X-ray diffraction analysis, which showed that the two dihedral angles are both 86.65 (4)[Formula: see text] between each mean plane of porphyrin and that of central diazaporphyrin The UV-vis absorption spectra disclosed that the longest wavelengths of Soret bands and Q bands for these triads were observed at 429 and 642 nm, respectively. In contrast to diazaporphyrin-porphyrin dyads, diazaporphyrin dimers and diazaporphyrin monomers reported previously the molar extinction coefficients, particularly for triad 8Ni are much higher.

Sign in / Sign up

Export Citation Format

Share Document