Three high-level correlated ab initio studies have recently been performed on the electronic absorption spectrum of free base porphin (FBP), but significant differences between various assignments low-lying bands remain. In view importance FBP as basic building block porphyrins, further reliable results are evidently required and provided here, using time-dependent density functional theory (TDDFT). Our strongly support recent CASPT2 interpretation which is consistent with traditional...

The first time-dependent DFT study of the excited states ZnPc is presented. theoretical results provide an accurate description UV−vis and vacuum−UV spectra prove to be in excellent agreement with gas-phase generally line deconvolution analyses solution Ar/matrix absorption MCD spectra. nature intensity main spectral features are highlighted interpreted on basis ground state electronic structure complex. A fragment approach where four benzopyrrole rings aza bridges taken as building blocks...

The ground- and excited-state properties of a series meso-tetraphenylporphyrin (H2TPP) diacids, [H4TPP](X)2 (X = F, Cl, Br, I), ad hoc synthesized characterized by 1H NMR, RLS, UV−vis spectroscopies, have been studied theoretically using density functional theory (DFT) time-dependent (TDDFT). Several conformations corresponding to different deformations the porphyrin core explored. nearly degenerate purely saddled (sad) hybrid (saddled with small superimposed ruffling: sadruf) are preferred...

Time-dependent density functional calculations have been performed on the symmetry and spin-allowed Eu excited states of nickel tetrapyrrole series, NiP, NiPz, NiTBP, NiPc. Optical spectra collected in noncoordinating solvents are presented for newly synthesized octaethyl porphyrazine, NiOEPz, MgOEPz. The theoretical results prove to agree very well with experimental data, providing an accurate description UV−vis spectra. effects optical introducing basic porphyrinic ring, aza bridges, benzo...

The structural chemistry of meso-aryl-substituted porhyrins has uncovered a bewildering variety macrocycle distortions. Saddling angles range up to 40°, while the plane phenyl groups at meso positions may be anywhere between perpendicular porphyrin (θ = 90°) and tilted quite acute 30° or even less). These two distortions appear correlated. This naturally been explained by steric hindrance: when phenyls rotate toward plane, for instance, coerced packing forces, pyrrole rings can alleviate...

Abstract New discotic metallomesogens of 2,3,7,8,12,13,17,18-octakis (alkyl-thio) 5,10,15,20 tetraaza porphyrin (H2Pn) and some related complexes, obtained by reaction first row transition metal ions Ni(II), Co(II), Cu(II), Zn(II) with the free porphyrin, have been prepared. All materials were characterized DSC measurements optical observations. The microscopic structure all mesophases was checked X-ray diffraction. Except for H2P(7–12), compounds are mesogenic; a few them exhibit...

A new pyrazinoporphyrazine macrocycle carrying externally appended pyridine rings, tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazine (hydrated), [Py(8)TPyzPzH(2)].2H(2)O, was prepared in high yield by direct cyclotetramerization of the precursor, 2,3-dicyano-5,6-di(2-pyridyl)-1,4-pyrazine, [(CN)(2)Py(2)Pyz], presence 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). The single-crystal X-ray structure [(CN)(2)Py(2)Pyz] shows a noncoplanar positioning pyrazine and rings two slightly different...

Boron neutron capture therapy (BNCT) is an anticancer based on the incorporation of 10B in tumors, followed by irradiation. Recently, synthesis and delivery new boronated compounds have been recognized as some main challenges BNCT application. Here, we report use liposomes carriers for active compounds. Two carborane derivatives, i.e., o-closocarboranyl β-lactoside (LCOB) 1-methyl-o-closocarboranyl-2-hexylthioporphyrazine (H2PzCOB), were loaded into bearing different surface charges. The...

Arguments are put forward that the active α-oxygen site in Fe-ZSM-5 catalyst consists of FeO2+ moiety. It is demonstrated this zeolite for indeed obeys design principles high reactivity moiety proposed earlier: a ligand environment consisting weak equatorial donors (rather oxygen based than nitrogen based) and very or absent trans axial donor. The would then owe its to same electronic structure features lends activity biological systems, as well classical Fenton chemistry.

Functionalization of the β-pyrrolic positions corrole macrocycle with -NO(2) groups is limited at present to metallocorrolates due instability exhibited by free bases under oxidizing conditions. A careful choice oxidant can limit transformation corroles into decomposition products or isocorrole species, preserving aromaticity, and thus allowing insertion nitro onto framework. Here we report results obtained reacting 5,10,15-tritolylcorrole (TTCorrH(3)) AgNO(2)/NaNO(2) system, give mono-...

Time-dependent density functional theory calculations are presented for the excitation energies and oscillator strengths of title mixed sandwich. They prove to agree very well with experimental data, providing that an accurate description salient features UV−vis spectrum is given. The nature excitations, intraligand (excitonic) or interligand (charge-resonance), discussed compared previous theoretical deductions bisporphyrins. An measurement first hyperpolarizability β (−2ω; ω, ω), related a...

Thin films consisting of two fulleropyrrolidine derivatives 1 or 2 and a water-soluble porphyrin, TPPS4, were prepared by the Langmuir−Schäfer (LS, horizontal lifting) method. In particular, solution in chloroform dimethyl sulfoxide was spread on water surface, while porphyrin (bearing peripheral anionic sulfonic groups) dissolved into aqueous subphase. To best our knowledge, such versatile method for film fabrication fullerene/porphyrin mixed composite has never been used other researchers....

Upon dilution from a concentrated solution in dichloromethane, the diacid form of tetraphenylporphyrin {H(4)TPP(X)(2)} (X = Cl, PF(6) and tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, TFPB) affords eventually unprotonated free base species H(2)TPP. At difference chloride, case PF(6)(-) TFPB(-) anions conversion occurs with intermediacy species, which has been assigned to monoacid derivative on basis UV/vis absorption, fluorescence emission (static dynamic), resonance light scattering....

The structural, optical, and photophysical properties of 1,4,8,11,15,18,22,25-octabutoxyphthalocyaninato-palladium(II), PdPc(OBu)(8), the newly synthesized platinum analogue PtPc(OBu)(8) are investigated combining X-ray crystallography, static transient absorption spectroscopy, relativistic zeroth-order regular approximation (ZORA) Density Functional Theory (DFT)/Time Dependent DFT (TDDFT) calculations where spin-orbit coupling (SOC) effects explicitly considered. results compared to those...

We analyze with DFT calculations the charge effects on reactivity of polycationic Compound I (Cpd I) and II II) mimics experimentally investigated by Bell Groves (Bell, S. R.; Groves, J. T. Am. Chem. Soc. 2009, 131, 9640). Specifically, we consider Cpd model [(4-THPyP)•+(H2O)FeIV═O]5+ (THPyP = 5,10,15,20-tetrakis(N-hydro-4-pyridinium) porphyrinate), 1H2O, its counterparts [(4-THPyP)FeIV═O]4+, 2, [(4-THPyP)(H2O)FeIV═O]4+, 2H2O. In gas phase simulations it is found that all positive charges...

Potential energy curves (PECs) have been calculated for a number of excited states Mn2(CO)10, along the Mn−Mn bond dissociation coordinate and Mn−COax Mn−COeq coordinates, in order to understand why irradiation into σ → σ* band does not only lead breaking but also Mn−CO dissociation. homolysis can straightforwardly occur dissociative 3B2 PEC. The state is itself dissociative. CO occurs since PECs that correspond at equilibrium geometry dπ* 1,3E1 (nearly degenerate with state) are (both 1E1...

Abstract The voltammetric behavior in alkaline solution of a nickel‐based chemically modified electrode (Ni‐CME) prepared by oxidative electropolymerization nickel–tetraazaannulene complex (Ni II L) was investigated. After electrochemical deposition the n film dichloromethane on conducting substrate, continuously cycled until steady profile obtained. Although upon treatment basic solutions nickel–nitrogen tetracoordination is probably lost, nickel species remain entrapped inside polymeric...

Reported herein is a combination of experimental and DFT/TDDFT theoretical investigations the ground excited states 1,4,8,11,15,18,22,25-Octabutoxyphthalocyaninato-nickel(II), NiPc(BuO)8, dynamics its deactivation after excitation into S1(π,π*) state in toluene solution. According to X-ray crystallographic analysis NiPc(BuO)8 has highly saddled structure solid state. However, DFT studies suggest that solution complex likely flap from one D2d-saddled conformation opposite through D4h-planar...

Abstract The electrochemical treatment of an electropolymerized (Ni II L) n thin film (where L represents 5,7,12,14‐tetramethyl‐dibenzo[ b , i ]‐1,4,8,11‐tetraaza [14] annulene) gives rise to a nickel‐based catalytic deposit on conducting substrates [glassy carbon (GC), platinum, or gold electrodes], which shows strong similarities the nickel hydroxide electrode. effect potential cycling surface composition, chemical status, and morphology this chemically modified electrode (Ni‐CME) has been...

The ground- and excited-state properties of a Ni(II) porphyrin bearing peripheral alkylthio group, NiOMTP (OMTP = 2,3,7,8,12,13,17,18-octakis methylthio porphyrinate) have been investigated by steady-state time-resolved absorption spectrometry DFT/TDDFT theoretical methods. Several conformations corresponding to different deformations the core orientations groups theoretically explored. nearly degenerate, purely ruffled D2d hybrid (ruffled with modest degree saddling) D2conformations, both...

The redox properties of the phthalocyanine-like tetrakis(thiadiazole)porphyrazines, [TTDPzM] (M = MgII(H2O), ZnII, CuII, 2HI), were investigated by cyclic voltammetry, and their ground- excited-state electronic studied in detail density functional theory (DFT) time-dependent DFT (TDDFT) methods. Bulk specific (axial ligation) solvent effects on molecular structure also taken into account. title compounds show stepwise reversible ligand-centered one-electron reductions range 0 to −2.0 V vs...