meso‐Nitro‐ and meso‐Aminosubporphyrinatoboron(III)s and meso‐to‐meso Azosubporphyrinatoboron(III)s

meso‐Nitrosubporphyrinatoboron(III) was synthesized by nitration of meso‐free subporphyrin with AgNO₂/I₂. The subsequent reduction with a combination of NaBH₄ and Pd/C gave meso‐aminosubporphyrinatoboron(III). meso‐Nitro‐ and meso‐amino‐groups significantly influenced the electronic properties of subporphyrin, which has been confirmed by NMR and UV/Vis spectra, electrochemical analysis, and DFT calculations. Oxidation of meso‐aminosubporphyrinatoboron(III)s with PbO₂ cleanly gave meso‐to‐meso azosubporphyrinatoboron(III)s that exhibited almost coplanar conformations and large electronic interaction through the azo‐bridge.     

meso‐Free BIII Subporphyrins with Electron‐donating Groups

meso‐Free B^III 5,10‐bis(p‐dimethylaminophenyl)subporphyrins were synthesized. They display red‐shifted absorption and fluorescence spectra, bathochromic behaviors in polar solvents, a high fluorescence quantum yield (Φ_F=0.57), and a small HOMO–LUMO gap mainly due to destabilized HOMO as compared with meso‐free B^III 5,10‐diphenylsubporphyrin. This subporphyrin serves as a nice precursor of various meso‐substituted B^III subporphyrins such as B^III meso‐nitrosubporphyrin, B^III meso‐aminosubporphyrin, and meso‐meso’ linked B^III azosubporphyrin dimer. Reactions of meso‐free B^III subporphyrins with NBS or bis(2,4,6‐trimethylpyridine)bromonium hexafluorophosphate gave meso‐meso′ linked subporphyrin dimers, often as a major product along with meso‐bromosubporphyrins.     

Synthesis,Computational Modeling,and Properties of Benzo‐Appended BODIPYs

A series of new functionalized mono‐ and dibenzo‐appended BODIPY dyes were synthesized from a common tetrahydroisoindole precursor following two different synthetic routes. Route A involved the assembly of the BODIPY core prior to aromatization, while in Route B the aromatization step was performed first. In general, Route A gave higher yields of the target dibenzo‐BODIPYs, due to the ease of aromatization of the BODIPYs compared with the corresponding dipyrromethenes, probably due to their higher stability under the oxidative conditions (2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone in refluxing toluene). However, due to the slow oxidation of highly electron‐deficient BODIPY 3 c bearing a meso‐C₆F₅ group, dibenzo‐BODIPY 4 c was obtained, in 35 % overall from dipyrromethane, only by Route B. Computational calculations performed at the 6‐31G(d,p) level are in agreement with the experimental results, showing similar relative energies for all reaction intermediates in both routes. In addition, BODIPY 3 c had the highest molecular electrostatic potential (MEPN), confirming its high electron deficiency and consequent resistance toward oxidation. X‐ray analyses of eight BODIPYs and several intermediates show that benzannulation further enhances the planarity of these systems. The π‐extended BODIPYs show strong red‐shifted absorptions and emissions, about 50–60 nm per benzoannulated ring, at 589–658 and 596–680 nm, respectively. In particular, db‐BODIPY 4 c bearing a meso‐C₆F₅ group showed the longest λ_max of absorption and emission, along with the lowest fluorescence quantum yield (0.31 in CH₂Cl₂); on the other hand monobenzo‐BODIPY 8 showed the highest quantum yield (0.99) of this series. Cellular investigations using human carcinoma HEp2 cells revealed high plasma membrane permeability for all dibenzo‐BODIPYs, low dark‐ and photo‐cytotoxicities and intracellular localization in the cell endoplasmic reticulum, in addition to other organelles. Our studies indicate that benzo‐appended BODIPYs, in particular the highly stable meso‐substituted BODIPYs, are promising fluorophores for bioimaging applications.     

Large Porphyrin Squares from the Self‐Assembly of meso‐Triazole‐Appended L‐Shaped meso–meso‐Linked ZnII–Triporphyrins: Synthesis and Efficient Energy Transfer

meso‐Triazolyl‐appended Zn^II–porphyrins were readily prepared by Cu^I‐catalyzed 1,3‐dipolar cycloaddition of benzyl azide to meso‐ethynylated Zn^II–porphyrin (click chemistry). In noncoordinating CHCl₃ solvent, spontaneous assembly occurred to form tetrameric array ( 3 )₂ from meso–meso‐linked diporphyrins 3 , and dodecameric porphyrin squares ( 4 )₄ and ( 5 )₄ from the L ‐shaped meso–meso‐linked triporphyrins 4 and 5 . The structures of these assemblies were examined by ¹H NMR spectra, absorption spectra, and their gel permeation chromatography (GPC) retention time. Furthermore, the structures of the dodecameric porphyrin squares ( 4 )₄ and ( 5 )₄ were probed by small‐ and wide‐angle X‐ray scattering (SAXS/WAXS) measurements in solution using a synchrotron source. Excitation‐energy migration processes in these assemblies were also investigated in detail by using both steady‐state and time‐resolved spectroscopic methods, which revealed efficient excited‐energy transfer (EET) between the meso–meso‐linked Zn^II–porphyrin units that occurred with time constants of 1.5 ps^?1 for ( 3 )₂ and 8.8 ps^?1 for ( 5 )₄.     

Effect of long alkyl chains of aniline donor on the photovoltaic performance of D‐π‐A zinc porphyrin for dye‐sensitized solar cells

Three novel dyes of JJ1 , JJ2 , and JJ6 featured zinc porphyrin as a basic core structure; N, N‐alkyl‐4‐(prop‐1‐yn‐1‐yl)aniline as an electron donor linked to meso‐10‐position; 4‐(prop‐1‐yn‐1‐yl)benzoic acid as an electron acceptor linked to meso‐20‐position; and 2,6‐bis(dodecyloxy)phenyl or 2,6‐bis(octyloxy)phenyl respectively linked to meso‐5 and meso‐15‐positions of zinc porphyrin have been synthesized and used for dye‐sensitized solar cells. Porphyrin JJ6 featured the shortest alkyl group (─C₄H₉) on the donor, whereas JJ2 contained the longest alkyl groups (─C₁₂H₂₅), and JJ1 has a medium length of octyl groups. With these new porphyrin sensitizers, we observed that JJ6 has 7.55% power conversion efficiency under simulated one‐sun illumination (AM 1.5 G, 100 mW/cm²) with J_SC = 18.64 mA/cm², V_OC = 0.66 V, and fill factor (FF) = 0.61, which was higher than the other two; JJ1 (7.35%) with J_SC = 18.83 mA/cm², V_OC = 0.68 V, and FF = 0.60; and JJ2 (6.33%) with J_SC = 15.69 mA/cm², V_OC = 0.62 V, and FF = 0.65. The power conversion efficiency of JJ6 and JJ1 were higher than JJ2 , demonstrating that the lengthy alkyl groups on the aniline cause a decrease in efficiency of the devices.     

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.     

Dibutylsilylene Derivatives of Tartaric Acid

Crystals of the bis(tert‐butyl)silylene (DTBS) derivatives of the tartaric acids were synthesized from D ‐, L ‐, rac‐, and meso‐tartaric acid and DTBS bis(trifluoromethanesulfonate): two polymorphs of Si₂tBu₄(L ‐Tart1,2;3,4H_–4) (L ‐ 1a and L ‐ 1b ), the mirror image of the denser modification (D ‐ 1b ) as well as the racemate ( 2 ), and the meso analogue Si₂tBu₄(meso‐Tart1,3;2,4H_–4) ( 3 ). The structures were determined by single‐crystal X‐ray diffraction. The threo‐configured D ‐ and L ‐ (and rac‐) tartrates were coordinated by two tBu₂Si units forming five‐membered chelate rings, whereas the erythro‐configured meso‐tartrate formed six‐membered chelate rings. The new compounds were analyzed by NMR techniques, including ²⁹Si NMR spectroscopy, and single‐crystal X‐ray crystallography.     

Nitrous‐Acid‐Mediated Synthesis of Iron–Nitrosyl–Porphyrin: pH‐Dependent Release of Nitric Oxide

Two iron–nitrosyl–porphyrins, nitrosyl[meso‐tetrakis(3,4,5‐trimethoxyphenylporphyrin]iron(II) acetic acid solvate ( 3 ) and nitrosyl[meso‐tetrakis(4‐methoxyphenylporphyrin]iron(II) CH₂Cl₂ solvate ( 4 ), were synthesized in quantitative yield by using a modified procedure with nitrous acid, followed by oxygen‐atom abstraction by triphenylphosphine under an argon atmosphere. These nitrosyl porphyrins are in the {FeNO}⁷ class. Under an argon atmosphere, these compounds are relatively stable over a broad range of pH values (4–8) but, under aerobic conditions, they release nitric oxide faster at high pH values than that at low pH values. The generated nitric‐oxide‐free iron(III)–porphyrin can be re‐nitrosylated by using nitrous acid and triphenylphosphine. The rapid release of NO from these Fe^II complexes at high pH values seems to be similar to that in nitrophorin, a nitric‐oxide‐transport protein, which formally possesses Fe^III. However, because the release of NO occurs from ferrous–nitrosyl–porphyrin under aerobic conditions, these compounds are more closely related to nitrobindin, a recently discovered heme protein.     

Selective Cycloaddition of Tetracyanoethene (TCNE) and 7,7,8,8‐Tetracyano‐p‐quinodimethane (TCNQ) to Afford meso‐Substituted Phenylethynyl Porphyrins

π‐Extended TCBD‐porphyrins that contained a 1,1,4,4‐tetracyanobuta‐1,3‐diene unit were prepared by a highly efficient [2+2] cycloaddition of tetracyanoethene (TCNE) or 7,7,8,8‐tetracyano‐p‐quinodimethane (TCNQ) with meso‐substituted trans‐A₂B₂‐porphyrins that contained two phenylethynyl groups, followed by a retro‐electrocyclization reaction. Depending on the electronic properties of the arylethynyl groups, the cycloaddition reaction took place exclusively on either one or two ethynyl moieties with high yield. The addition of TCNQ proceeded with complete regioselectivity. The resulting π‐expanded TCBD‐porphyrins had a hypsochromically shifted Soret band and showed unique, broad absorption in the visible region.     

meso‐Free Corroles: Syntheses,Structures, Properties,and Chemical Reactivities

5,10‐Bis(pentafluorophenyl)corrole ( 5 ) and 5,15‐bis(pentafluorophenyl)corrole ( 9 ) have been synthesized as meso‐free corroles by rational synthetic routes. Both the structures of these corroles have been unambiguously revealed by X‐ray diffraction analysis and their optical and electrochemical properties have been studied. Chlorination and oxidative dimerization of 5 and 9 have been explored, which revealed a marked different reactivity of the free meso‐positions in 5 and 9 . 10‐Chlorinated corrole 11 was effectively prepared by the reaction of 9 with Palau‘chlor in the presence of 1 % pyridine whereas 5‐chlorinated corrole 12 was obtained in a trace amount from similar chlorination of 5 . 5,5′‐Linked corrole dimer 13 was produced by reaction of 5 with AgNO₂ in a good yield, whereas 10,10′‐linked corrole dimer 14 was formed in a moderate yield by the reaction of 9 with [bis(trifluoroacetoxy)iodo]benzene. Observed large electronic interaction between the two corroles in 13 as compared with that in 14 has been ascribed mainly to conformational flexibility of the former, which allows more coplanar conformation.     

Probing the Rotational Dynamics of meso‐(2‐Substituted)aryl Substituents in A2B‐Type Subporphyrins

A₂B‐type B‐methoxy subporphyrins 3 a – g and B‐phenyl subporphyrins 7 a – c , e , g bearing meso‐(2‐substituted)aryl substituents are synthesized, and their rotational dynamics are examined through variable‐temperature (VT) ¹H NMR spectroscopy. In these subporphyrins, the rotation of meso‐aryl substituents is hindered by a rationally installed 2‐substituent. The rotational barriers determined are considerably smaller than those reported previously for porphyrins. Comparison of the rotation activation parameters reveals a variable contribution of ΔH^≠ and ΔS^≠ in ΔG^≠. 2‐Methyl and 2‐ethyl groups of the meso‐aryl substituents in subporphyrins 3 e , 3 f , and 7 e induce larger rotational barriers than 2‐alkoxyl substituents. The rotational barriers of 3 g and 7 g are reduced by the presence of the 4‐dibenzylamino group owing to its ability to stabilize the coplanar rotation transition state electronically. The smaller rotational barriers found for B‐phenyl subporphyrins than for B‐methoxy subporphyrins indicate a negligible contribution of S_N1‐type heterolysis in the rotation of meso‐aryl substituents.     

An Optically and Thermally Switchable Electronic Structure Based on an Anthracene–BODIPY Conjugate

An optically and thermally responsive boron dipyrromethene (BODIPY) dye, namely, meso‐2‐(9,10‐dihydro‐9,10‐ethanoanthracene‐11,12‐dione) (DK)‐linked, bicyclo[2.2.2]octadiene (BCOD)‐fused BODIPY ( BCOD‐DK ), was synthesized. The weakly luminous structure of BCOD‐DK can be changed quantitatively to that of the strongly fluorescent BODIPY BCOD‐Ant by optical excitation at the DK unit, which induces double decarbonylation of the DK unit to give an anthracene unit. The solvent effect on the fluorescence properties of BCOD‐DK suggests that the dramatic change in fluorescence intensity is controlled by intramolecular electron transfer from the BODIPY moiety to the meso‐DK substituent. BCOD‐DK is converted to meso‐ DK benzene‐fused BODIPY ( Benzo‐DK ) by heating at 220 °C with 64–70 nm redshift of absorption and fluorescence peaks without changing the fluorescence quantum yield of Φ_F=0.08 in dichloromethane. Benzo‐DK can be converted to strongly fluorescent meso ‐ anthracene benzene‐fused BODIPY Benzo‐Ant by optical excitation. Thus, BCOD‐DK can show four different optical performances simply by irradiation and heating, and hence may be applicable for optical data storage and security data encryption.     

Ring‐opening polymerization of rac‐ and meso‐lactide initiated by indium bis(phenolate) isopropoxy complexes

Ring‐opening polymerization of rac‐ and meso‐lactide initiated by indium bis(phenolate) isopropoxides {1,4‐dithiabutanediylbis(4,6‐di‐tert‐butylphenolate)}(isopropoxy)indium ( 1 ) and {1,4‐dithiabutanediylbis(4,6‐di(2‐phenyl‐2‐propyl)phenolate)}(isopropoxy)indium ( 2 ) is found to follow first‐order kinetics for monomer conversion. Activation parameters ΔH^? and ΔS^? suggest an ordered transition state. Initiators 1 and 2 polymerize meso‐lactide faster than rac‐lactide. In general, compound 2 with the more bulky cumyl ortho‐substituents in the phenolate moiety shows higher polymerization activity than 1 with tert‐butyl substituents. meso‐Lactide is polymerized to syndiotactic poly(meso‐lactides) in THF, while polymerization of rac‐lactide in THF gives atactic poly(rac‐lactides) with solvent‐dependent preferences for heterotactic (THF) or isotactic (CH₂Cl₂) sequences. Indium bis(phenolate) compound rac‐(1,2‐cyclohexanedithio‐2,2′‐bis{4,6‐di(2‐phenyl‐2‐propyl)phenolato}(isopropoxy)indium ( 3 ) polymerizes meso‐lactide to give syndiotactic poly(meso‐lactide) with narrow molecular weight distributions and rac‐lactide in THF to give heterotactically enriched poly(rac‐lactides). © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4983–4991     

Synthesis of meso‐Pyrrole‐Substituted 22‐Oxacorroles by a “3+2” Approach

Unsymmetrical 22‐oxacorrole containing two aryl groups and one pyrrole group at the meso position was synthesized by condensing one equivalent of 16‐oxatripyrrane with one equivalent of meso aryl dipyromethane under mild acid‐catalyzed conditions followed by oxidation with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ). This [3+2] condensation approach was expected to yield meso‐free 25‐oxasmaragdyrin but unexpectedly afforded unsymmetrical meso‐pyrrole‐substituted 22‐oxacorrole. We demonstrated the versatility of the reaction by synthesizing four new meso‐pyrrole‐substituted 22‐oxacorroles. The reactivity of α‐position of meso‐pyrrole was tested by carrying out various functionalization reactions such as bromination, formylation, and nitration and obtained the functionalized meso‐pyrrole‐substituted 22‐oxacorroles in decent yields. The X‐ray structure obtained for one of the functionalized meso‐pyrrole substituted 22‐oxacorrole revealed that the macrocycle was nearly planar and the meso‐pyrrole was in the perpendicular orientation with respect to the macrocyclic plane. The meso‐pyrrole‐substituted 22‐oxacorroles absorb strongly in 400–700 nm region with one strong Soret band and four weak Q bands. The 22‐oxacorroles are strongly fluorescent and showed emission maxima at ≈650 nm with decent quantum yields and singlet‐state lifetimes. The 22‐oxacorroles are redox‐active and exhibited three irreversible oxidations and one or two reversible reduction(s). A preliminary biological study indicated that meso‐pyrrole corroles are biocompatible.     

Oligoporphyrin Arrays Conjugated to [60]Fullerene: Preparation,NMR Analysis,and Photophysical and Electrochemical Properties

We report the synthesis and physical properties of novel fullerene–oligoporphyrin dyads. In these systems, the C‐spheres are singly linked to the terminal tetrapyrrolic macrocycles of rod‐like meso,meso‐linked or triply‐linked oligoporphyrin arrays. Monofullerene–mono(Zn^II porphyrin) conjugate 3 was synthesized to establish a general protocol for the preparation of the target molecules (Scheme 1). The synthesis of the meso,meso‐linked oligopophyrin–bisfullerene conjugates 4 – 6 , extending in size up to 4.1 nm ( 6 ), was accomplished by functionalization (iodination followed by Suzuki cross‐coupling) of the two free meso‐positions in oligomers 21 – 23 (Schemes 2 and 3). The attractive interactions between a fullerene and a Zn^II porphyrin chromophore in these dyads was quantified as ΔG=−3.3 kcal mol⁻¹ by variable‐temperature (VT) ¹H‐NMR spectroscopy (Table 1). As a result of this interaction, the C‐spheres adopt a close tangential orientation relative to the plane of the adjacent porphyrin nucleus, as was unambiguously established by ¹H‐ and ¹³C‐NMR (Figs. 9 and 10), and UV/VIS spectroscopy (Figs. 13–15). The synthesis of triply‐linked diporphyrin–bis[60]fullerene conjugate 8 was accomplished by Bingel cyclopropanation of bis‐malonate 45 with two C₆₀ molecules (Scheme 5). Contrary to the meso,meso‐linked systems 4 – 6 , only a weak chromophoric interaction was observed for 8 by UV/VIS spectroscopy (Fig. 16 and Table 2), and the ¹H‐NMR spectra did not provide any evidence for distinct orientational preferences of the C‐spheres. Comprehensive steady‐state and time‐resolved UV/VIS absorption and emission studies demonstrated that the photophysical properties of 8 differ completely from those of 4 – 6 and the many other known porphyrin–fullerene dyads: photoexcitation of the methano[60]fullerene moieties results in quantitative sensitization of the lowest singlet level of the porphyrin tape, which is low‐lying and very short lived. The meso,meso‐linked oligoporphyrins exhibit ¹O₂ sensitization capability, whereas the triply‐fused systems are unable to sensitize the formation of ¹O₂ because of the low energy content of their lowest excited states (Fig. 18). Electrochemical investigations (Table 3, and Figs. 19 and 20) revealed that all oligoporphyrin arrays, with or without appended methano[60]fullerene moieties, have an exceptional multicharge storage capacity due to the large number of electrons that can be reversibly exchanged. Some of the Zn^II porphyrins prepared in this study form infinite, one‐dimensional supramolecular networks in the solid state, in which the macrocycles interact with each other either through H‐bonding or metal ion coordination (Figs. 6 and 7).     

The Marriage of Peripherally Metallated and Directly Linked Porphyrins: Bromidobis(phosphine)platinum(II) as a Cation‐Stabilizing Substituent on Directly Linked and Fused Triply Linked Diporphyrins

A meso‐bromidoplatiniobis(triphenylphosphine) η¹‐organometallic porphyrin monomer was prepared by the oxidative addition of meso‐bromoZnDPP (DPP=dianion of 5,15‐diphenylporphyrin) to a platinum(0) species. The meso–meso directly linked dimeric porphyrin ( 5 ) was prepared from this monomer by silver(I)‐promoted oxidative coupling and planarized to give a triply linked dizinc(II) porphyrin dimer ( 8 ). Acidic demetallation of 8 afforded the bis(free base) 9 . Dimer 5 was demetallated then remetallated with nickel(II) to give the dinickel(II) analogue 10 , the X‐ray crystal structure of which showed a twisted molecule with ruffled, orthogonal NiDPP rings, terminated by square‐planar trans‐[Pt(PPh₃)₂Br] units. New compounds were fully characterized spectroscopically, and the fused diporphyrin exhibited a broad, low‐energy, near‐IR electronic absorption band near 1100 nm. Electrochemical measurements of this series indicate that the organometallic fragment is a strong electron donor towards the porphyrin ring. The triply linked organometallic diporphyrin has a substantially lowered first one‐electron oxidation potential (?0.35 V versus the ferrocene/ferrocenium couple (Fc/Fc⁺)) and a narrow HOMO–LUMO gap of 0.96 V. Solutions prepared for NMR spectroscopy slowly decompose with degradation of the signals, which is attributed to partial oxidation to the cation radical. This paramagnetic species can be reduced in situ by hydrazine to restore the NMR spectrum to its former appearance. The combined influence of the two [Pt(PPh₃)₂Br] electron‐donating substituents is sufficient to make dimer 5 too aerobically unstable to allow further elaboration.     

Mesoporous Co3O4 Nanobundle Electrocatalysts

Tailoring metal oxide nanostructures with mesoporous architectures is vital to improve their electrocatalytic performance. Herein, we demonstrate the synthesis of 2D mesoporous Co₃O₄ (meso‐Co₃O₄) nanobundles with uniform shape and size by employing a hard‐template method. In this study, the incipient wetness impregnation technique has been chosen for loading metal precursor into the silica hard template (SBA‐15). The results reveal that the concentration of a saturated precursor solution plays a vital role in mesostructured ordering, as well as the size and shape of the final meso‐Co₃O₄ product. The optimized precursor concentration allows us to synthesize ordered meso‐Co₃O₄ with four to seven nanowires in each particle. The meso‐Co₃O₄ structure exhibits excellent electrocatalytic activity for both glucose and water oxidation reactions.     

Syntheses of Amino Group‐Substituted N‐Confused Porphyrins

Tetraphenyl N‐confused porphyrins (NCTPP) bearing amino substituents were synthesized for the purpose of functionalization toward water‐soluble and biocompatible molecules. The Pd‐catalyzed coupling reaction of 4‐ethynylaniline with the 2‐bromo NCTPP Ag(III) complex yields Pd(II) and Ag(III) coupling products ( 4a and 4b ), at 39% and 55%, respectively. The identities of these products were confirmed by the differences in the isotope patterns of their molecular ion peaks as well as other spectroscopic data. The Ag(III) coupling product, 4b , was demetallated to form the final product, 5 , with a yield of 85%. The meso‐tetrakis(4‐nitrophenyl) N‐confused porphyrin, 6 , was synthesized through a methanesulfonic acid catalyzed condensation of pyrrole with the 4‐nitrobenzaldehyde with a yield of 6.8%. Reduction of the compound to meso tetrakis(4‐aminophenyl) N‐confused porphyrin, 7 , was achieved with a yield of 90%.     

A Facile Electrochemical Immunosensor with Mesoporous Alumina for Detection of Carcinoembryonic Antigen

A label‐free electrochemical immunosensor for the sensitive determination of carcinoembryonic antigen (CEA) was fabricated by immobilizing anti‐CEA onto mesoporous alumina (meso‐Al₂O₃) dispersed in chitosan (0.5 %wt) by the cross‐linking method using glutaraldehyde. Due to its plenty of active sites, meso‐Al₂O₃ showed high catalysis towards hydroquinone. With the electrocatalytic ability of meso‐Al₂O₃ for the reduction of hydroquinone, the current signal of the antigen‐antibody reaction was amplified and the enhanced sensitivity was achieved. The current decreased linearly with CEA concentration in the range of 0.04 to 10 ng/mL (26 pg/mL, S/N=3). The immunosensor had good selectivity and wonderful stability. Furthermore it was applied to the analysis of CEA in serum sample with satisfactory results.     

meso‐Pyrrole‐Substituted 22‐Oxacorroles: Building Blocks for the Synthesis of BODIPY‐Bridged 22‐Oxacorrole Dyads

Novel boron‐dipyrromethene (BODIPY)‐bridged 22‐oxacorrole dyads, using meso‐pyrrolyl 22‐oxacorrole as a key synthon, have been synthesized. The reactivity of the meso‐pyrrolyl group of 22‐oxacorrole was exploited to synthesize the first examples of BODIPY‐bridged 22‐oxacorrole dyads in ≈40 % yield. The dyads are stable and exhibited interesting spectral and electrochemical properties.