Synthesis and Characterization of New Conjugated Fluorenyl‐Porphyrin Dendrimers for Optics

A new family of conjugated meso‐tetraphenylporphyrin‐based dendrimers with four ( TPP1 , TPP2 ), eight ( TPP3 , TPP4 , TPP5 ) and up to sixteen ( TPP6 ) fluorenyl groups has been synthesized and fully characterized. These tetraphenylporphyrin‐cored dendrimers present peripheral alkynyl π‐conjugated dendrons with fluorenyl termini. The meso‐aryl rings of these porphyrins are functionalized either in para‐ ( TPP1 , TPP2 , and TPP3 ) or meta‐positions ( TPP4 , TPP5 , and TPP6 ). Their detailed luminescence properties are discussed in reference to two porphyrins lacking fluorenyl dendrons ( TPP ‐ H_1,2,3 and TPP ‐ H_4,5,6 ). A strong dependence of their luminescence quantum yield and lifetime on their structures is stated, their nonlinear optical properties were also discussed.     

Ligand exchange in the complexone-porphyrin macrocycle system in reactions of copper(II) ethylenediaminetetraacetate with porphyrins and phthalocyanines

Complexation between 5,10,15,20-tetraphenylporphine H₂TPP and tetra(tert-butyl)phthalocyanine H₂(t-Bu)₄Pc with copper(II) ethylenediaminetetraacetate in DMSO was studied by spectrophotometry. The kinetic parameters of the reaction were calculated and the mechanism of ligand exchange in the complexone-porphyrin macrocycle system was proposed. The reactivities of H₂TPP and H₂(t-Bu)₄Pc in reactions with copper ethylenediaminetetraacetate and some other copper chelate complexes were compared.     

金属卟啉/异烟酸/二氧化钛复合光催化剂制备及其光催化性能研究

合成了四苯基卟啉(H2TPP)及铜卟啉(CuTPP)和锌卟啉(ZnTPP),获得了配合物[Zn(TPP)(DMF)]的晶体。制备了金属卟啉、异烟酸共修饰的二氧化钛复合光催化剂:金属卟啉/异烟酸/二氧化钛,红外光谱和X-射线衍射(XRD)分析结果表明金属卟啉和异烟酸负载于TiO2表面,未改变TiO2的晶型。在光催化降解水中污染物4-硝基苯酚(4-NP)时显示了好的催化效果。     

Broad Hexagonal Columnar Mesophases Formation in Bioinspired Transition‐Metal Complexes of Simple Fatty Acid meta‐Octaester Derivatives of meso‐Tetraphenyl Porphyrins

A series of meta‐substituted fatty acid octaester derivatives and their transition‐metal complexes of meso‐ tetraphenyl porphyrins (TPP‐8OOCR, with R=C_n?1H_2n?1, n=8, 12, or 16) have been prepared through very simple synthesis protocols. The thermotropic phase behavior and the liquid crystalline (LC) organization structures of the synthesized porphyrin derivatives were systematically investigated by a combination of differential scanning calorimetry (DSC), polarized optical microscopy (POM), and variable‐temperature small‐angle X‐ray scattering/wide‐angle X‐ray scattering (SAXS/WAXS) techniques. The shorter octanoic acid ester substituted porphyrin (C8‐TPP) did not show liquid crystallinity and its metal porphyrins exhibited an uncommon columnar mesophase. The lauric acid octaester (C12‐TPP) and the palmitic acid octaester (C16‐TPP) series porphyrins generated hexagonal columnar mesophase Col_h. Moreover, the metal porphyrins C12‐TPPM and C16‐TPPM with M=Zn, Cu, or Ni, exhibited well‐organized Col_h mesophases of broad LC temperature ranges increasing in the order of TPPNi<TPPCu≤TPPZn with their increased effective ionic radii in the square‐planar coordination. The simplicity in synthesis, the well intercolumnar organization of Col_h mesophase, the broadness of the discotic LC range, and the specific UV/Vis absorption and fluorescence emission behaviors make the symmetrically substituted fatty acid octaester porphyrins and their metal complexes very attractive for variant applications.     

Charge and substituent effects on the stability of porphyrin/G‐quadruplex adducts

The adduct ions of two tetramolecular G‐quadruplexes formed from the d(TGGGGT) and d(TTGGGGGT) single strands with a group of cationic porphyrins, with different charges and substituents, and one neutral porphyrin, were investigated by ESI‐MS and ESI‐MS/MS in the negative ion mode. Formation of [Q + nNH₄⁺+P^p+‐(z + n + p)H⁺]^z‐ adduct ions (where Q = quadruplex, n = number of quartets minus 1, P = porphyrin and p⁺ =0,1,2,3,4) indicates that the porphyrins are bound outside the quadruplexes providing an additional stabilization to those structures. The fragmentation pathways of the [Q + nNH₄⁺+P^p+‐(z + n + p)H⁺]^z‐ adduct ions depend on the number of positive charges (p⁺) of the porphyrins and on the overall complex charge (z^‐), but do not show a significant dependence on the type of the substituent groups in the porphyrins. Formation of the ‘unfilled’ ions [Q + P^p+‐(z + p)H⁺]^z‐ predominates for porphyrins with a higher number of positive charges. Strand separation with the formation of [T + P^p+‐(z‐2 + p)H⁺]^(z‐2)‐ and (SS‐2H⁺)^2‐ ions, where T = [d(TG₄T)]₃ and [d(T₂G₅T)]₃ and SS = d(TG₄T) and d(T₂G₅T) is only observed for the complexes with a higher overall negative charge. Porphyrin loss with the formation of [Q + nNH₄⁺‐(z + n)H⁺]^z‐ ions occurs predominantly for the neutral and monocharged porphyrins. The predominant formation of the ‘unfilled’ ions, [Q + P^p+‐(z + n)H⁺]^z‐, for porphyrins with a higher number of charges shows that these porphyrins can prevent strand separation and preserve, at least partially, the quadruplex structure. Copyright © 2012 John Wiley & Sons, Ltd.     

Solid phase extraction of trace amount of Cu(II) using functionalized-graphene

A novel and selective method for the fast determination of trace amounts of Cu(II) ions in water samples has been developed. The first organic-solution-processable functionalized-graphene (SPF-Graphene) hybrid material with porphyrins, porphyrin-graphene nanohybrid, 5-(4-aminophenyl)-10, 15, 20-triphenyl porphyrin and its photophysical properties including optical (TPP) and grapheme oxide molecules covalently bonded together via an amide bond (TPP-NHCO-SPFGraphene) were used as absorbent for extraction of Cu(II) ions by solid phase extraction method. The complexes were eluted with HNO₃ (2 M) 10% (vol/vol) methanol in acetone and determined the analyte by flame atomic absorption spectrometry. The procedure is based on the selective formation of Cu(II) at optimum pH by elution with organic eluents and determination by flame atomic absorption spectrometry. The method is based on complex formation on the surface of the ENVI-18 DISK? disks modified porphyrin-graphene nanohybrid, 5-(4-aminophenyl)-10,15,20-triphenyl porphyrin (TPP) and grapheme oxide molecules covalently bonded together via an amide bond (TPP-NHCO-SPFGraphene) followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution is efficient and quantitative. The effect of potential interfering ions, pH, TPP-NHCO-SPFGraphene, amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about 1000 mL providing a preconcentration factor of 600. The maximum capacity of the disks was found to be 398 ± 3 μg for Cu²⁺. The limit of detection of the proposed method is 5 ng per 1000 mL. The method was applied to the extraction and recovery of copper in different water samples.     

Thermodynamic investigation of the molecular interactions of 4-nitrophenol with free-bases meso-tetraarylporphyrins

The molecular interactions of 4-Nitrophenol (4NP) with free-base meso-tetraarylporphyrins (H₂T(4-X)PP; X = OCH₃, CH₃, H, Cl) have been studied. The formation constants and other thermodynamic parameters were calculated by using UV-Vis spectrophotometry titration results. The formation constants show the following trend relative to X substituent of porphyrins: H₂T(4-CH₃O)PP > H₂T(4-CH₃)PP > H₂TPP > H₂T(4-Cl)PP.     

Luminescence and triplet—triplet absorption spectra of rhodium (III) porphyrins

Photophysical studies of four rhodium(III) porphyrins [RhTPPS (H₂O)₃^3?, RhTPP (Cl) (L), RhOEP (Cl) (L) and RhMesoPMEI(CI) (L)] show that these porphyrins are characterised by a moderate phosphorescence (φ ? 10^?2) and a very weak fluorescence (φ ? 5 × 10^?4) in solution at room temperature. TPP derivatives also have moderately intense triplet—triplet absorption extending to 900 nm.     

Volumetric properties of tetraphenylporphine,their metallo-complexes and some substituted tetraphenylporphines in benzene solution

Densities, apparent molar volumes and partial molar volumes of benzene solutions of tetraphenylporphine, H₂TPP, tetraphenylporphine metallo-complexes, MTPP (where M=Ni,Cu,Zn,Pd,Ag, and Cd), and some substituted tetraphenylporphines H₂T(i-R)PP (where i=2–4 and R=–Cl,–CH₃,–OCH₃) H₂T(i-F)PP (where i-2,3), H₂T(3-Br)PP, and H₂T(3-I)PP were determined at 25°C. It was found that the partial molar volumes of the studied compounds correlate linearly with the first ionization potential of the corresponding metal atom. The calculated values of the surface and volume accessible to the solvent, and the solvent-excluded volume for different conformations of H₂TPP, were compared with experimental data. The volume per molecule for different crystalline forms of H₂TPP and MTPP were compared with the partial molar volumes of the corresponding compounds in benzene solutions. The correlation between the partial molar volumes of H₂T(3-R)PP and their Van der Waals volumes are presented for R=–H, –F,–CH₃,–Cl,–Br,–OCH₃, and –I. The experimental data are rationalized in terms of differences in the conformational states of the molecules.     

Effect of Successive Meso-Phenyl Substitution on the Dissociation Kinetics of Copper(II) Octaethylporphyrin

We have synthesized complexes of copper(II) with octaethyl-, 5-phenyl octaethyl-, 5,15-diphenyl octaethyl-, and 5,10,15,20-tetraphenyl octaethylporphyrins. We have studied their dissociation kinetics in mixed solvents AcOH – H₂SO₄ at temperatures of 298 K to 343 K. We have determined the complete kinetic equations for dissociation of copper porphyrins for different compositions of the binary solvent AcOH – H₂SO₄. We provide a rational basis for electronic and steric effects on the stability of copper(II) octaethylporphyrin upon meso-phenyl substitution as a function of the degree of substitution.     

Tetraphenylporphyrin molecules containing heteroatoms other than nitrogen: 8—A carbon-13 NMR study

The ¹³C NMR spectra of new hetero-substituted tetraphenylporphyrin (TPP) molecules have been studied. It was found that most of the carbon chemical shifts are similar to those found in TPP. The similar chemical shifts of the different β-carbons in S₂TPP and in Se₂TPP free bases and, moreover, the considerable downfield shift of the α-carbons of the S(Se)-rings on protonation are in agreement with the previously suggested theory of inner and outer aromaticity in these porphyrins.     

The role of cobalt,copper, nickel,and zinc in the DNA replication inhibitory activity of p‐aminophenyl triphenylporphyrin

Cationic porphyrins have been widely used as tumor localizers in cancer therapies. When cationic porphyrins are flat they intercalate with double‐stranded DNA, duplexes of RNA or RNA–DNA. The antitumor activity of some cationic porphyrins depends on their interaction with human telomeric quadruplexes. Here, we report that noncationic meso‐(4‐aminophenyl)triphenylporphyrin (H₂TPPNH₂) ( 3 ) and its cobalt, copper, nickel, and zinc metallo derivatives ( 4 – 7 ) have DNA replication inhibitory activity in B16 mouse melanoma line cells. By means of quantification of ³HdTT radio‐labeled DNA, we observed that the nonplanar porphyrin [CoTPPNH₂] has the highest activity against carcinogenic DNA replication. Copyright © 2004 John Wiley & Sons, Ltd.     

Ion-molecular interactions in the metalloporphyrin-acid system in liquid solutions

A new form of MP...H _solv ⁺ metalloporphyrins is found and studied in the strong acid medium, the conditions of its formation and the qualitative reaction of its determination are established. It is shown that the same form has the H₄TPP²⁺ dication (TPP is the 5,10,15,20-tetraphenyl-21H,23H-porphyrine dianion). The stability in different acid media and in the isolated state, spectral properties and the structure of H⁺-associates of porphyrins are analyzed in detail by UV-visible and ¹H NMR spectroscopy and quantum chemical calculations. It is shown that they have a unique two-band visible electronic spectrum with the bands near 540 nm and 700 nm, which weakly depend on the type of the central atom in the complex and noticeably change when the chromophore is functionally substituted. The proton location the ion-molecular associate and the cases of the formation of H⁺-associates with higher stoichiometry are revealed.     

Characterization and reactivity of nanoscale La(Co,Cu)O3 perovskite catalyst precursors for CO hydrogenation

The characterization of La(Co,Cu)O₃ perovskites has been performed by several techniques including XRD, BET, H₂-TPR, O₂-TPO, TPRS, and the solids tested as catalysts for the hydrogenation of CO. The reducibility of the perovskites is strongly affected by the preparation route, calcination temperature, catalyst morphology, and the amount of remnant alkali. Compared with the citrate-derived perovskite, LaCoO₃ sample prepared by mechano-synthesis has various distinct Co³⁺ ions in perovskite lattice, which are reduced at different temperatures. Under typical conditions, the reduction of cobalt ions occurs in two consecutive steps: Co³⁺/Co²⁺ and Co²⁺/Co⁰, while the intra-lattice copper ions are directly reduced from Cu²⁺ to Cu⁰. The reducibility of cobalt ions is promoted by the presence of metallic copper, which is formed at a lower reduction temperature. The re-oxidation of the reduced lanthanum cobaltite perovskite could regenerate the original structure, whereas that of the reduced Co-Cu-based samples is less reversible under the same experimental conditions.The cobalt atom in the reduced perovskites plays an important role in the dissociation of CO, but the presence of a neighboring copper along with remnant sodium ions on the catalyst surface has remarkably affected the reactivity of cobalt for CO hydrogenation. The addition of copper into the perovskite framework leads to a change in the product distribution of CO hydrogenation and a decrease in reaction temperature. An increased copper content leads to a substantial decline in the rate of methanation and an increase in the formation of higher alcohols. A close proximity between cobalt and copper sites on the Na⁺-modified catalyst surface of the reduced nanocrystalline Co-Cu-based perovskites plays a crucial role in the synthesis of higher alcohols from syngas.     

Crystallographic identification of a series of manganese porphyrin complexes with nitrogenous bases

Studying the axial ligation behavior of metalloporphyrins with nitrogenous bases helps to better understand not only the biological function of heme‐based protein systems, but also the catalytic properties of porphyrin‐based reaction sites in other biomimetic synthetic support environments. Unlike iron porphyrin complexes, little is known about the axial ligation behavior of Mn porphyrins, particularly in the solid state with Mn in the +3 oxidation state. Here, we present the syntheses and crystal and molecular structures of three new high‐spin manganese(III) porphyrin complexes with the different amine‐based axial ligands imidazole (im), piperidine (pip), and 1,4‐diazabicyclo[2.2.2]octane (DABCO), namely bis(imidazole)(5,10,15,20‐tetraphenylporphyrinato)manganese(III) chloride chloroform disolvate, [Mn(C₄₄H₂₈N₄)(C₃H₄N₂)₂]Cl·2CHCl₃ or [Mn(TPP)(im)₂]Cl·2CHCl₃ (TPP = 5,10,15,20‐tetraphenylporphyrin), (I), bis(piperidine)(5,10,15,20‐tetraphenylporphyrinato)manganese(III) chloride, [Mn(C₄₄H₂₈N₄)(C₅H₁₁N)₂]Cl or [Mn(TPP)(pip)₂]Cl, (II), and chlorido(1,4‐diazabicyclo[2.2.2]octane)(5,10,15,20‐tetraphenylporphyrin)manganese(III)–1,4‐diazabicyclo[2.2.2]octane–toluene–water (4/4/4/1), [Mn(C₄₄H₂₈N₄)Cl(C₆H₁₂N₂)]·C₆H₁₂N₂·C₇H₈·0.25H₂O or [Mn(TPP)Cl(DABCO)]·(DABCO)·(toluene)·0.25H₂O, (IV). A fourth complex, chlorido(pyridine)(5,10,15,20‐tetraphenylporphryinato)manganese(III) pyridine disolvate, [Mn(C₄₄H₂₈N₄)Cl(C₅H₅N)]·2C₅H₅N or [Mn(TPP)Cl(py)]·2(py), (III), acquired using different crystallization methods from published data, is also reported and compared to the previous structures.     

Spectral study of the dioxygen and carbonyl adducts of ferrous porphyrins ligated by neutral S-donors

A series of the six-coordinated ferrous porphyrin complexes (L)Fe(II)TPP(O₂) and (L)Fe(II)TPP(CO) (L, (CH₃)₂S, or C₂H₅SH, TPP, meso-tetraphenylporphyrin dianion) was prepared. UV–vis and FTIR spectroscopy were applied to follow the reaction of O₂ and CO adducts of Fe(II) porphyrins with neutral thiol and thioether. Using sublimed layers methodology and low temperature technique, as well as isotope substitution, the formation of six-coordinate complexes was monitored in situ. The comparison of CO and O₂ stretching frequencies of thiol and thioether adducts indicates that the degree of electron donation is similar for these ligands. The complexes of Me₂S and EtSH with Fe(TPP)(O₂) are stable at 150 K and slowly decompose at elevated temperatures. In contrast, the carbonyl complexes of Fe(Por) with Me₂S and EtSH are relatively stable and retain six-coordination at room temperature. The electronic effects of axial S-donor ligands on the coordinated O₂ and CO are discussed and compared with the effects of N- and O-donors.     

Microwave-assisted synthesis and reverse saturable absorption of phthalocyanines and porphyrins

Soluble phthalocyanines, including tetrakis(2,9,16,23-cumylphenoxy) copper phthalocyanines (CuPc(β-CP)₄), tetrakis(1,8,15,22-cumylphenoxy) copper phthalocyanines (CuPc(α-CP)₄) as well as tetrakis(2,9,16,23-tert-butyl) copper phthalocyanines (CuPc(β-t-butyl)₄), and porphyrins (5,10,15,20-tetrakis(4-tert-butylphenyl)porphyrins; M(TBP), M=H₂, Zn, Cu, Mg, InCl, AlCl) have been quickly synthesized by microwave irradiation. Furthermore, their reverse saturable absorption have also been investigated by dissolving them in solvent or incorporating them in polymer-silica hybrid material with a sol-gel process with polyvinyl butyral and tetraethyl orthosilicate as precursors. A new method for the preparation process of phthalocyanines and porphyrins in the solids has been successfully used.     

Acid-base and coordination properties of some palladium(II)porphyrins

The speciation and reactions of palladium(II) complexes with meso-tetraphenylporphine (H₂TPP) and meso-tetraphenyl-β-octaethylporphine (H₂TetPOEP) were studied in H₂SO₄-H₂O and H₂SO₄-HOAc protic solvents. H-associated species of PdTPP and PdTetPOEP were found to exist in sulfuric acid with concentrations of 16.33–17.38 and 17.48–18.22 mol/L, respectively. The kinetics of one-electron oxidation of complexes in the coordinated aromatic macrocycle were studied. A third-order rate equation was determined, and the mechanism of the oxidation reaction was substantiated with kinetically significant stages of dioxygen coordination, electron transfer from the macrocyclic aromatic system to dioxygen, and H-association equilibrium between the complex and sulfuric acid. The effects of peripheral ethyl substituents in the macrocyclic ligand on the reactivity of palladium(II)porphyrins were revealed.     

Synthesis and chemical stability of (5,15-bis(2-thienyl)- and 5,15-diphenyl-3,7,13,17-tetramethyl-2,8,12,18-tetra-n-butyl-21H,23H-porphinato)copper(II)

(5,15-Bis(2-thienyl)-and 5,15-diphenyl-3,7,13,17-tetramethyl-2,8,12,18-tetra-n-butyl-21H,23H-porphinato)copper(II) complexes were synthesized and the basicity, absorption spectra (UV-Vis, IR, ¹H NMR) of the macrocyclic ligands and the stability of the complexes in AcOH-H₂SO₄ mixed solvents were studied with the aim to reveal the effect of 2-thienyl substituent on the properties of substituted porphyrins. Data on kinetics were obtained, reaction mechanism of complex dissociation was reasoned, and the effect of functional substitution on the properties of macrocyclic bases and their complexes with copper(II) were determined.     

Synthesis,crystal structure and magnetic behavior of a two-dimensional copper(II) complex with mellitic anion as bridging ligand

A two-dimensional complex Cu₃[C₆(COO)₆](H₂O)₁₀ · 2H₂O has been prepared and its crystal structure determined by X-ray crystallography. In the complex each mellitic anion provides four carboxylate groups as coordinate groups and, according to the coordination, the four carboxylate groups are classified as two types according to its coordinate modes. The first is that a carboxylate group coordinates a copper(II) ion via its one oxygen atom, and the second one is that a carboxylate group, as a two-dentate ligand, coordinates to two copper(II) ions. The copper(II) ions also are classified as being of two types according to their coordinate modes. The configuration around each copper(II) ion is a distorted pyramid. The variable-temperature magnetic susceptibility of the complex was measured in the 4–300 K range and the magnetic data indicate that the magnetic interaction between bridging copper(II) ions displays an antiferromagnetic coupling below 42 K, while above 42 K a ferromagnetic interaction appears.