Meso-substituted porphyrin photosensitizers with enhanced near-infrared absorption: Synthesis,characterization and biological evaluation for photodynamic therapy

Porphyrin derivatives are widely explored and used in photodynamic therapy, for their marvelous therapeutic properties. In order to fill in the gaps of insufficient photosensitizers with near-infrared absorption, three porphyrin molecules, 5,10,15,20-tetrakis(3,4-bis(2-(-2-(2-hydroxyethoxy)ethoxy)ethoxy)benzyl)zinc porphyrin(P1), 5,15-bis(3,4-bis(2-(-2-(2-hydroxyethoxy)ethoxy)ethoxy)benzyl)-10,20-bis(2-(2-(2-(4-ethynylphenoxy)ethoxy)ethoxy)ethanol)zincporphyrin(P2),5,15-bis(3,4-bis(2-(-2-(2-hydroxyethoxy)ethoxy)ethoxy)benzyl)-10,20-N,N-dibutyl-4-ethynylaniline zinc porphyrin(P3), were designed and synthesized targeting for more efficient cancer treatment. Excellent photophysical properties were illustrated by UV–vis absorption and emission spectra with enhanced absorbance between 650 and 750?nm and fluorescence emission within 600–800?nm. Besides, with high ¹O₂ quantum yield, especially P2 (0.89), all porphyrins were further evaluated in vitro by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay against Hela cells and exhibited negligible dark toxicity and robust phototoxicity. Fluorescence confocal laser microscopy confirmed cellular uptake and diffusion of these porphyrins, therefore demonstrated their potential and promising applications in photodynamic therapy.     

Porphyrin-acetylene-thiophene polymer wires

5,15-Bis[acetylene-4-(ethylenedioxy)thiophene]-10,20-bis(4-carboxyphenyl)porphyrin was synthesized by a Sonogashira coupling and polymerized to fibres; TEM and AFM images show uniform porphyrin wires with a length of several micrometers and a thickness of less than 4 nm.     

Decoupling optical and potentiometric band gaps in pi-conjugated materials

Syntheses, optical spectroscopy, potentiometric studies, and electronic structural calculations are reported for two classes of conjugated (porphinato)metal oligomers that feature a meso-to-meso ethyne-bridged linkage topology. One set of these systems, bis[(5,5'-10,20-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]ethyne (DD), 5,15-bis[[5'-10',20'-bis[3,5-di(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]ethynyl]-10,20-bis[3,5-di(9-methoxy-1,4,7-trioxanonyl)phenyl]porphinato)zinc(II) (DDD), and 5,15-bis[[15' '-(5'-10',20'-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]-[(5' '-10' ',20' '-bis[3,5-di(9-methoxy-1,4,7-trioxanonyl)phenyl]porphinato)zinc(II)]ethyne]ethynyl]-10,20-bis[3,5-di(9-methoxy-1,4,7-trioxanonyl)phenyl]porphinato)zinc(II) (DDDDD), constitute highly soluble analogues of previously studied examples of this structural motif having simple 10,20-diaryl substituents, while a corresponding set of conjugated oligomers, [(5-10,20-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]-[(5'-15'-ethynyl-10',20'-bis[10,20-bis(heptafluoropropyl)porphinato)zinc(II)]ethyne (DA), 5,15-bis[[5'-10',20'-bis[3,5-di(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]ethynyl]-10,20-bis(heptafluoropropyl)porphinato]zinc(II) (DAD), and 5,15-bis[[15' '-(5'-10',20'-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]-[(5' '-(10' ',20' '-bis(heptafluoropropyl)porphinato)zinc(II)]ethyne]ethynyl]-10,20-bis[3,5-di(9-methoxy-1,4,7-trioxanonyl)phenyl]porphinato)zinc(II) (DADAD), features alternating electron-rich and electron-poor (porphinato)zinc(II) units. Electrooptic and computational data for these species demonstrate that it is possible to engineer conjugated oligomeric structures that possess highly delocalized singlet (S1) excited states yet manifest apparent one-electron oxidation and reduction potentials (E1/20/+ and E1/2-/0 values) that are essentially invariant with respect to those elucidated for their constituent monomeric precursors.     

POLYROTAXANE WITH π-CONJUGATED PORPHYRIN AND POLYAZOMETHINE SYSTEMS PREPARED FROM A TYPE OF PORPHYRIN-DIALDEHYDE AND COMPLEX OF β-CYCLODEXTRIN WITH 1,4-PHENYLENEDIAMINE

The synthesis of 5,15-bis[4-(methoxycarbonyl)phenyl]-10,20-diphenylporphyrin (2) and its reduction to 5,15-bis[4-(hydroxymethyl)phenyl]-10,20-diphenylporphyrin (3), and so its oxidation to provide 5,15-bis(4-formylphenyl)-10,20-diphenylporphyrin (4) are reported. The copolymer possessing β-cyclodextrin (β-CD), π-conjugated porphyrin and polyazomethine systems was synthesized by the polycondensation of porphyrin-dialdehyde monomer (4) and β-cyclodextrin/1,4-phenylenediamine complex (5). The monomers and the copolymer were characterized by UV-Vis, 1H-NMR and IR spectra. Furthermore, 1H-NMR and FT-IR spectra confirmed locating the aromatic ring of 1,4-phenylenediamine molecule in the center of β-cyclodextrin cavity.     

Synthesis and investigation of photovoltaic properties for polymer semiconductors based on porphyrin compounds as light-harvesting units

We reported on two polymer semiconducting copolymers based on porphyrin compounds, poly[9,9-dioctylfluorene-co-5,15-bis(hexoxybenzyl)-10,20-bis(benzo-4-yl)porphyrin] (PFPor) and poly[9-(heptadecan-9-yl)carbazole-co-5,15-bis(hexoxybenzyl)-10,20-bis(benzo-4-yl)porphyrin] (PCPor), for use as organic photovoltaic materials. The thermal, optical, electrochemical, and photovoltaic properties of the two polymers were investigated. In addition, PC₆₁BM and PC₇₁BM were introduced as acceptor materials to confirm the acceptor effect in bulk heterojunction photovoltaic devices. Moreover, in order to establish acceptor effects, morphologies of polymer/PCBM blend films were analyzed through atomic force microscopy (AFM). PFPor and PCPor exhibited the best device performance with power conversion efficiencies (PCE) of 0.62% and 0.76%, respectively, upon the introduction of PC₇₁BM as the acceptor in the device where 86 wt.% of the PC₇₁BM was contained in the active layer (pol:PC₇₁BM = 1:6, w/w).     

3-Cyclobutenyl-1,2-dione-substituted porphyrins. A general and efficient entry to porphyrin-quinone and quinone-porphyrin-quinone architectures

A new and efficient synthesis of meso-linked porphyrin-quinone dyads and quinone-porphyrin-quinone triads has been developed via the intermediacy of porphyrins bearing 3-cyclobutenyl-1,2-dione and 3-(1-ethenyl)cyclobutenyl-1,2-dione substituents at one or two nonadjacent meso-positions. The free-base porphyrins 5-bromo-10,20-diphenylporphyrin and 5,15-dibromo-10,20-diphenylporphyrin undergo facile palladium-catalyzed Stille coupling with 3-isopropoxy-2-tri-n-butylstannyl-cyclobutene-1,2-dione to produce the corresponding mono- and bis(3-cyclobutenyl-1,2-dione)-substituted porphyrins in good yields. In contrast, the zinc bromoporphyrins reacted with the same tin reagent only slowly and with the formation of side products. The free-base bromoporphyrins also were coupled with tri-n-butylvinyltin to afford vinylporphyrins in very good yields. 5,15-Diphenyl-10-vinylporphyrin was converted into trans-bromovinylporphyrin, which underwent facile Stille coupling with 3-isopropoxy-2-tri-n-butylstannylcyclobutene-1,2-dione to afford the vinylogous 3-cyclobutenyl-1,2-dione-substituted porphyrin. The molecular structure of 5,15-bis(3-cyclobutenyl-1,2-dione)-10,20-diphenylporphyrin(Z n) was determined by X-ray crystallography. Although the data revealed a fairly large dihedral angle between the cyclobutenedione and the porphyrin rings (57 degrees), the UV-vis spectra of both the mono- and bis(3-cyclobutenyl-1,2-dione)-substituted porphyrins showed B- and Q-band red shifts indicative of strong electronic coupling between the porphyrin and cyclobutenedione chromophores in solution. Introduction of a double bond between the cyclobutenedione and porphyrin rings resulted in a significant red shift of both the B- and Q-bands compared to those of the nonvinylogous system. All porphyrinic cyclobutenediones were metalated with zinc and then, using established cyclobutenedione chemistry, converted into a variety of porphyrin-quinones in excellent yields with aryllithium and vinylic Grignard reagents. From the mono(3-cyclobutenyl-1,2-dione)-substituted porphyrin, 7, a variety of directly linked monoquinone-porphyrin dyads were easily synthesized. Substituents could also be introduced at the free meso-position of 7 by bromination followed by palladium-catalyzed cross-coupling reactions, and additional porphyrinic monoquinones were then prepared from these starting materials. The vinylogous squarylporphyrin was converted into a double bond linked porphyrin-quinone via reaction with phenyllithium followed by thermal rearrangement and oxidation. As a result of the hindered rotation around the C-C bond between the porphyrin and the quinone, pairs of stable, separable, and thermally interconvertable atropisomers of porphyrin-quinones were obtained from 5,15-bis(3-cyclobutenyl-1,2-dione)-10,20-diphenylporphyrin(Z n). The structure of one of the atropisomers was determined by X-ray crystallography.     

Deposition of thermally unstable molecules with the spray-jet technique on Au(111) surface

A porphyrin derivative (5,15-bis(4-ethynylphenyl)-10,20-bis(3,5-di-tert-butylphenyl)porphyrin: trans-BETBPP) possessing chemically reactive substituents was successfully deposited on an Au(111) surface with a new molecular beam deposition system with use of a spray-jet technique (Spray-jet-MBD) without denaturing the molecules. The deposited molecular overlayers were observed at 77 K under ultrahigh vacuum condition by scanning tunneling microscopy (STM). They form two different overlayer structures: a linear arrangement and a square lattice structure. In these overlayers, some molecules were accidentally moved by STM tip agitation, which indicates that the molecules were not polymerized during the deposition process.     

Linked porphyrin systems

Porphyrin monomers, 5-(monopyridyl)-10,15,20-(triphenyl)porphyrin ( 1 ), 5,10-(dipyridyl)-15,20-(diphenyl)-porphyrin ( 2 ), and 5,15-(dipyridyl)-10,20-{diphenyl)porphyrin ( 3 ), were linked by hydrocarbon chains to form a series of dimers, trimers and polymers. The 5-(monopyridyl)-10,15,20-(triphenyl)porphyrin monomers were linked by 2, 4, 6, 8 and 10 carbon chains through the alkylation of the pyridine nitrogens using the appropriate diiodoalkane to form positively charged linked dimers 4–8 . A trimer 12 was synthesized from two 5-(monopyridyl)-10,15,20-(triphenyl)porphyrin and one 5,10-(dipyridyl)-15,20-(diphenyl)porphyrin linked by a six carbon chain. Hydrocarbon linked (5,10-(dipyridyl)-15,20-(diphenyl)porphyrin)_n ( 13 ) and (5,15-(dipyridyl)-10,20-(diphenyl)porphyrin)_n ( 14 ) were also prepared.     

Metalloporphyrins as chemical shift reagents: the unambiguous NMR characterization of the cis- and trans-isomers of meso-(bis)-4′-pyridyl-(bis)-4′-carboxymethylphenylporphyrins

The condensation of pyrrole with 4-pyridylcarboxyaldehyde and methyl 4-formyl benzoate under Adler-Longo conditions yielded the series of meso-(4′-pyridyl)/(4′-carboxymethylphenyl)porphyrins as a mixture. Careful column chromatography afforded each isomer in pure form. In this paper we focus on the two bis-substituted isomeric meso-porphyrins, 5,10-bis(4′-pyridyl)-15,20-bis(4′-carboxymethylphenyl)porphyrin and 5,15-bis(4′-pyridyl)-10,20-bis(4′-carboxymethylphenyl)porphyrin, respectively, 4′-cis and 4′-transDPyDMeP. The assignment of the geometry of the two isomers was performed by ¹H NMR spectroscopy on the trinuclear adducts [(4′-cisDPyDMeP){Ru(TPP)(CO)}₂] and [(4′-transDPyDMeP){Ru(TPP)(CO)}₂], obtained by selective coordination of [Ru(TPP)(CO)(EtOH)] (TPP=tetraphenylporphyrin) to the peripheral nitrogen atoms. The axially bound ruthenium porphyrins act as chemical shift reagents on the central porphyrin, allowing a clear distinction of the pyrrole proton resonances and consequent unambiguous assignment of the geometry of each isomer based upon symmetry considerations.     

Convergent synthesis of meso-ferrocenyl porphyrins for TiO2 sensitization

Electron-donating ferrocenyl moieties have been incorporated into supramolecular carboxyporphyrin architectures Zn(II)-5-ferrocenyl-10,20-bistolyl-15-(4-methylbenzoate)porphyrin (trans-Fc-ZnP-CO₂Me), Zn(II)-5-ferrocenyl-10,15,20-tris(4-methylbenzoate)porphyrin [trans-Fc-ZnP-(CO₂Me)₃], and Zn(II)-5,15-bisferrocenyl-10,20-bis(4-benzoate)porphyrin [trans-Fc₂-ZnP-(CO₂Me)₂] for self-assembly on metal oxide nanoparticles. Efficient and economic synthesis has required a convergent strategy toward reduced symmetry trans-A₂B₂ and trans-AB₂C substitution patterns about the porphyrin macrocycle minimizing the production of porphyrin side products and increasing yields of the target ferrocenylporphyrins. Preliminary spectroscopic data in solution and in the solid state bound to mesoporous TiO₂ films are discussed.     

Titrations in non-aqueous media: potentiometric investigation of symmetrical and unsymmetrical tetra-aryl porphyrins with 4-nitrophenyl and 4-aminophenyl substituents in nitrobenzene solvent

The basicity of the symmetrical and unsymmetrical tetraphenylporphyrins, namely 5,10,15,20-tetraphenylporphyrin (I) (references), 5-(4-nitrophenyl)-10,15,20-triphenylporphyrin (II), a mixture of 5,10-bis(4-nitrophenyl)-15,20-diphenylporphyrin and 5,15-bis(4-nitrophenyl)-10,20-diphenylporphyrin (III), 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin (IV), 5,10,15,20-tetrakis(4-nitrophenyl)porphyrin (V), 5-(4-aminophenyl)-10,15,20-triphenylporphyrin (VI), a mixture of 5,10-bis(4-aminophenyl)-15,20-diphenylporphyrin and 5,15-bis(4-aminophenyl)-10,20-diphenylporphyrin (VII), 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin (VIII) and 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (IX), was investigated potentiometrically in nitrobenzene solvent. This investigation showed that these compounds are basic rather than acidic. Although they can not be titrated even with tetrabuthylammonium hydroxide, they can easily be titrated with perchloric acid to give well shaped and stoichiometric end-points. In addition they all undergo two proton reactions per porphyrin molecule. However, compounds VI, VII, VIII and IX each shows a second end-point to give three, four, five and six proton reactions, respectively, per porphyrin molecule. Half neutralization potentials (measures of their basicity) of these compounds are: I=368, II=409, III=432, IV=461, V=520, VI=340, VII=302, VIII=238 and IX=225 mV versus Ag/AgCl in methanol. These potentials clearly indicate that, if para-hydrogen with respect to the porphyrin core of tetraphenylporphyrin (I) is replaced with an acidifying nitro group (II, III, IV and V) the basicity of I decreases. This decrease is approximately proportional to the number of nitro groups. Each nitro group decreases the half neutralization potential by about 35 mV. On the other hand, if para-hydrogen indicated above is replaced with a basifying amino group (VI, VII, VIII and IX) the basicity increases. This increase is also approximately proportional to the number of amino groups. Each amino group increases the half neutralization potential by about 36.7 mV. The values 35 and 36.7 mV indicate that in nitrobenzene solvent the electron releasing power of an amino group to the porphyrin system is a little stronger than the electron withdrawing power of a nitro group from the porphyrin system. All these observations reveal that the nitrogen atoms at the core of the porphyrin molecules are strongly influenced by changes at the periphery of the molecules, which is a very good indication that the substituted phenyl groups and the cores of the porphyrins are nearly in the same plane.     

Unusual frequency dispersion effects of the nonlinear optical response in highly conjugated (polypyridyl)metal-(porphinato)zinc(II) chromophores

The syntheses and electrooptic properties of a new family of nonlinear optical chromophores are reported. These species feature an ethyne-elaborated, highly polarizable porphyrinic component and metal polypyridyl complexes that serve as integral donor and acceptor elements. Examples of this structural motif include ruthenium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2';6',2' '-terpyridine)(2+) bis-hexafluorophosphate (Ru-PZn); osmium(II) [5-(4'-ethynyl-(2,2';6',2'-terpyridinyl))-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2';6',2'-terpyridine)(2+) bis-hexafluorophosphate (Os-PZn); ruthenium(II) [5-(4'-ethynyl-(2,2';6',2'-terpyridinyl))-15-(4'-nitrophenyl)ethynyl-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phen-yl)porphinato]zinc(II)-(2,2';6',2' '-terpyridine)(2+) bis-hexafluorophosphate (Ru-PZn-A); osmium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-15-(4'-nitrophenyl)ethynyl-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2';6',2' '-terpyridine)(2+) bis-hexafluorophosphate (Os-PZn-A); and ruthenium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))osmium(II)-15-(4'-ethynyl-(2,2';6',2'-terpyridinyl))-10,20-bis (2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-bis(2,2';6',2'-terpyridine)(4+) tetrakis-hexafluorophosphate (Ru-PZn-Os). The frequency dependence of the dynamic hyperpolarizability of these compounds was determined from hyperRayleigh light scattering (HRS) measurements carried out at fundamental incident irradiation wavelengths (lambda(inc)) of 800, 1064, and 1300 nm. These data show that (i) coupled oscillator photophysics and metal-mediated cross-coupling can be exploited to elaborate high beta(0) supermolecules that exhibit significant excited-state electronic communication between their respective pigment building blocks; (ii) high-stability metal polypyridyl compounds constitute an attractive alternative to electron releasing dialkyl- and diarylamino groups, the most commonly used donor moieties in a wide range of established nonlinear optical dyes; (iii) this design strategy enables ready elaboration of chromophores having extraordinarily large dynamic hyperpolarizabilities (beta(lambda) values) at telecommunication relevant wavelengths; and (iv) porphyrin B- and Q-state-derived static hyperpolarizabilities (beta(0) values) can be designed to have the same or opposite sign in these species, thus providing a new means to regulate the magnitude of lambda(inc)-specific dynamic hyperpolarizabilities.     

UV-visible and fluorescence spectral study on a pH controlled transfer process of an amphiphilic porphyrin in nonionic micelle

5,15-di(4-hydroxyphenyl)-10,20-di(hexadecyloxyphenyl) porphyrin P was solubilized in nonionic polyoxyethylene(9.5) octylphenol (Triton X-100 or TX-100) micelle solutions. By means of analyzing the UV-visible and fluorescence spectra of the synthesized amphiphilic porphyrin P in different solvent environments, and the relationship between the solubilizing location of the porphyrins in TX-100 micelle and the microenvironment polarity, P is shown to involve in a transfer process for the porphyrin moiety from inner to the outer surface of TX-100 micelle as the pH is increased. The kinetic study of porphyrin incorporate with Cu(II) shows that metalation rate of porphyrin increases with the pH increasing, indicating that metalation rate could be controlled by changing pH.     

Use of orthoesters in the synthesis of meso-substituted porphyrins

The use of two orthoesters, trimethyl orthoacetate and trimethyl orthobenzoate, in the synthesis of porphyrins from 5-phenyldipyrromethanes is described. Previously unreported 5,15-diphenyl-10,20-dimethyl porphyrins can be accessed conveniently by this route. A relationship between the steric bulk of the orthoester and the amount of scrambling of the porphyrin products has been found. Strong electron-withdrawing substituents on the phenyl ring of the dipyrromethane also enhance scrambling.     

Photocurrent generation in multilayer organic-inorganic thin films with cascade energy architectures

Zirconium organobisphosphonate multilayer thin films of viologen derivatives were grown on copper dithiolate multilayers of 5,15-di(p-thiolphenyl)-10,20-di(p-tolyl)porphyrin (POR) and 5,15-di(p-thiolphenyl)-10,20-di(p-tolyl)porphyrinzinc (ZOR) on a variety of substrates (e.g. Au, SiO(2)), using solution depositions methods. The multilayer structures were studied by atomic force microscopy, UV-vis spectroscopy, and ellipsometry. In the case of copper dithiolate thin films, layer-by-layer lamellar growth with low surface roughness resulted, while higher surface roughness was observed in the growth of Zr viologen bisphosphonate films. Gold electrodes modified with zirconium bisphosphonate multilayers of viologen on top of copper dithiolate multilayers of porphyrin derivatives (ZOR or POR) were photoelectroactive and produced efficient and stable photocurrents using visible light. By arranging the zinc-porphyrin (ZOR) and the free base porphyrin (POR) donors in an energetically favorable fashion, according to their redox potentials and optical energy gaps, the photoinduced charge separation was improved, and higher photocurrent quantum yields ( approximately 4%) and fill factor ( approximately 50%) of the photoelectrode were achieved.     

Rational synthesis of meso- or beta- fluoroalkylporphyrin derivatives via halo-fluoroalkylporphyrin precursors: electronic and steric effects on regioselective electrophilic substitution in 5-fluoroalkyl-10,20-diarylporphyrins

[reaction: see text] Electrophilic nitration, formylation or bromination of metalated 5-fluoroalkyl-10,20-diphenylporphyrin (fluoroalkyl = CF3, ClCF2CF2, n-C6F13) proceeded with high regioselectivity, exclusively affording corresponding meso-substituted porphyrins, while the iodination reaction mainly took place at the adjacent beta site giving 2-iodo-10-fluoroalkyl-5,15-diphenylporphyrin. Suzuki, Sonogashira, and trifluoromethylation reactions of the obtained 5-bromo-15-fluoroalkyl-10,20-diphenylporphyrins or 2-iodo-10-fluoroalkyl-5,15-diphenylporphyrins could perform smoothly to give the corresponding various meso- or beta-functionalized fluoroalkylated porphyrin derivatives. Accordingly, two meso-to-meso butadiyne-bridged bisporphyrin dimers and two beta-to-beta butadiyne-linked dimeric porphyrins were prepared by the coupling reactions of 5-ethynyl-15-fluoroalkyl-10,20-diphenylporphyrins and 2-ethynyl-10-fluoroalkyl-5,15-diphenylporphyrins, respectively.     

Solvothermal synthesis and crystal structure of a 3-D hexagonal metal-porphyrin coordination network

A hexagonal-shaped hybrid metal-porphyrin framework containing 5,15-di(4-pyridyl)-10,20-diphenylporphyrin (trans-H₂DPyP) and Zn(NO₃)₂6H₂O in DMF has been self-assembled solvothermally. The solvothermal reaction of Zn(II) with conformationally versatile 5,15-di(4-pyridyl)-10,20-diphenylporphyrin, which can coordinate axially to two ligands, resulted in metalation of the porphyrin core and then self-coordination of the metalated porphyrin-produced single crystals of 3-D polymeric arrays. The trans-ZnDPyP framework is thermally stable at 450?°C and allows solvent exchange without losing the crystal structure.     

Synthesis, characterization, and DNA-binding and -photocleavage properties of water-soluble lanthanide porphyrinate complexes

A series of cationic lanthanide porphyrinate complexes of the general formula [(Por)Ln(H(2)O)(3)](+) (Ln(3+)=Yb(3+) and Er(3+)) were synthesized in moderate yields through the interaction of meso-pyridyl-substituted porphyrin free bases (H(2)Por) with [Ln{N(SiMe(3))(2)}(3)]·x[LiCl(thf)(3)], and the corresponding neutral derivatives [(Por)Ln(L(OMe))] (L(OMe)(-)=[(η(5)-C(5)H(5))Co{P(=O)(OMe)(2)}(3)](-)) were also prepared from [(Por)Ln(H(2)O)(3)](+) by the addition of the tripodal anion, L(OMe)(-), an effective encapsulating agent for lanthanide ions. Furthermore, the water-soluble lanthanide(III) porphyrinate complexes--including [(cis-DMPyDPP)Yb(H(2)O)(3)]Cl(3) (cis-DMPyDPP=5,10-bis(N-methylpyridinium-4'-y1)-15,20-di(phenyl)porphyrin), [(trans-DMPyDPP)Yb(H(2)O)(3)]Cl(3) (trans-DMPyDPP=5,15-bis(N-methylpyridinium-4'-y1)-10,20-di(phenyl)porphyrin), [(TMPyP)Yb(L(OMe))]I(4), and [(TMPyP)Er(L(OMe))]I(4) (TMPyP=tetrakis(N-methylpyridinium-4-y1)porphyrin)--were obtained by methylation of the corresponding complexes with methyl iodide and unambiguously characterized. The binding interactions and photocleavage activities of the water-soluble lanthanide(III) porphyrinate complexes towards DNA were investigated by UV-visible, fluorescence, and near-infrared luminescence spectroscopy, as well as circular dichroism and gel electrophoresis.     

Highly conjugated (polypyridyl)metal-(porphinato)zinc(II) compounds: long-lived, high oscillator strength, excited-state absorbers having exceptional spectral coverage of the near-infrared

Transient dynamical studies of ruthenium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2';6',2' '-terpyridine)2+ bis-hexafluorophosphate (Ru-PZn), osmium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2';6',2' '-terpyridine)2+ bis-hexafluorophosphate (Os-PZn), ruthenium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-15-(4'-nitrophenyl)ethynyl-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2';6',2' '-terpyridine)2+ bis-hexafluorophosphate (Ru-PZn-A), osmium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-15-(4'-nitrophenyl)ethynyl-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2';6',2' '-terpyridine)2+ bis-hexafluorophosphate (Os-PZn-A), and ruthenium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-ruthenium(II)-15-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-bis(2,2';6',2' '-terpyridine)4+ tetrakis-hexafluorophosphate (Ru-PZn-Ru), and ruthenium(II) [5-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-osmium(II)-15-(4'-ethynyl-(2,2';6',2' '-terpyridinyl))-10,20-bis(2',6'-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-bis(2,2';6',2' '-terpyridine) tetrakis-hexafluorophosphate (Ru-PZn-Os) show that these highly conjugated supermolecular chromophores feature electronically excited states that absorb over broad NIR spectral windows with considerable oscillator strength and manifest lifetimes (1-50 mus) that are extraordinarily long relative to those of classic low band-gap organic materials. The excited-state absorptive domains of these strongly coupled multipigment ensembles can be extensively modulated. For sequential one-photon absorptive processes, these compounds evince large sigmae, sigmae/sigmag, and sigmae - sigmag values. As the combination of all these properties within single chromophoric entities have heretofore lacked precedent within the NIR, these and closely related structures may find particular utility in a variety of technologically important optical-limiting applications.     

Tris(porphyrinyl-oxinato)Ga Complexes as a Photosynthetic Antenna Miniature

Two oxinylporphyrins, 5-(8-hydroxy-5-quinolinyl)-10,15,20-( p -tolyl)- porphyrin ( 1 ) and 5,15-bis(8-hydroxy-5-quinolinyl)-10,20-bis( n -heptyl)-porphyrin ( 2 ), were prepared and coordinated with Ga(III) to afford tris(oxinato) complex 3 and poly(oxinato) complex 4 , respectively. The structure of 3 was analyzed by variable temperature NMR study with referring to tris(8-hydroxy-5-quinolinyl)Ga(III) complex 5 to be in a meridional form. Oxinato ligands of 3 and 5 were exchanged with one another, with keeping the meridional structure. UV-Vis and fluorescence spectra of tris(oxinato)complex 3 and poly(oxinato)complex 4 were compared with each monomeric compound 1 and 2 . The absorption spectra showed only a slight broadening of the Soret band, suggesting trivial electronic and excitonic interactions. The fluorescence intensity was increased significantly compared with each monomeric compound 1 and 2 . At the same time, efficient excitation energy transfer among three porphyrins has been observed.