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A series of a fully conjugated ferrocene-containing coumarins and B,O-chelated coumarins was prepared and characterized by a variety of spectroscopic (UV–vis, NMR, and mass spectrometry), electrochemical (CV and DPV) and spectroelectrochemical methods. The photophysical properties of the target compounds were investigated by steady-state fluorescence and ultrafast transient absorption spectroscopy methods. Selective photoexcitation of the coumarin core was followed by ultrafast electron transfer from the ferrocene fragment, resulting in formation of a charge-separated Fc+-coumarin-. state. This charge-separated state undergoes ultrafast ground state recovery in 20–25 ps, shortening the excited state lifetime of the organic coumarin precursors (1.2–1.5 ns) by almost two orders of magnitude. Formation of the charge-separated states was supported by the experimental (steady-state fluorescence oxidative titrations) and theoretical DFT and TDDFT calculations.

A new aza-BODIPY-hydrazone-based fluorescence probe with red-emission for selective detection of HClO was synthesized and characterized using 1H and 13C NMR, IR, and HRMS. The probe demonstrated a fast, red fluorescence response in the detection of HClO. The sensing mechanism originated from the imine C N bond cleavage by HClO which resulted in the formation of a fluorescent aza-BODIPY aldehyde. The probe showed low toxicity to living cells and the fluorescence imaging experiments in living RAW264.7 cells showed intracellular red fluorescence developed when NaClO and PMA were incubated with the probe, suggesting its potential application for the detection of exogenous and endogenous HClO in living cells. Reactive oxygen and nitrogen species do not interfere with activation of a new fluorescence probe.

A two-step synthetic pathway for direct introduction of the nitromethyl functional group at the meso-position of BODIPY core was explored using a number of meso-unsubstituted BODIPY platforms. Spectral properties of the resulting meso-nitromethyl containing BODIPYs was found to be sensitive to the pH change as well as to the presence of water in organic solvents. Meso-nitromethyl group can be used for further modification of the BODIPY core via reduction or condensation reactions. DFT-PCM and TDDFT-PCM calculations correlate well with the experimental data and explain the observed spectral properties.

Acetyl ferrocene and diacetyl ferrocene both readily react with an excess of hydrazine to afford the corresponding hydrazone compounds. These compounds can then be linked to Re(CO)3 via a metal-mediated Schiff base reaction, resulting in a series of ferrocene-Re(CO)3 conjugates with different stoichiometries. Conjugates with 1:1, 1:2, and 2:1 ferrocene: Re(CO)3 ratios can be produced via this "modular" type synthesis approach. Several examples of these conjugates were structurally characterized, and their spectroscopic, electrochemical, and spectroelectrochemical behaviors were investigated. The electronic structures of these compounds were also probed using DFT and TDDFT calculations.

New developments as well as a historic overview on synthetic strategies for preparation of the rare-earth complexes with porphyrins, phthalocyanines, naphthalocyanines, tetraazaporphyrins, and related systems are discussed in detail with emphasis on selective synthetic pathways for preparation of single-, double-, and triple-decker architectures.

The bis(pyridylimino)isoindoline (BPI) ligand is a tridentate chelate that binds to metals via a meridional coordination mode. However, when this ligand forms a complex with Re(CO)(3), an almost exclusively facial moiety, the BPI ligand deforms to coordinate in a facial mode. We have in-vestigated this deformation via structural and theoretical means, and the non-planar binding mode of the ligand bathochromically shifts the metal to ligand charge transfer (MLCT) transition.

The benzoylcyanoxime, NC-C(=N-OH)-C(O)-C(6)H(5) (later H(BCO)), represents a new ampolydentate ligand that received attention in the light of useful biological properties of its coordination compounds. Colorless H(BCO), upon deprotonation, gains color that depends on the counter-cation and the system in general. Five derivatives of H(BCO), with colorless organic and inorganic mono-cations – Cs, Tl, Ag, N(CH(3))(4) and As(C(6)H(5))(4) – were synthesized and characterized by the X-ray analysis, vibrational and electronic spectroscopy. Compounds exhibited unexpected and significant differences in color, both in solid state and in solutions, that were challenging to explain, thereby warranting detailed investigation including high-level DFT/TDFT computations. It was found that the BCO(−) anion demonstrates negative solvatochromic in polar protic ROH (R = H, CH(3), C(2)H(5), C(3)H(7), C(4)H(9)) solvents, and appears yellow in color, as tetraalkylammonium or alkali metal salts. In polar aprotic solvents, such as CH(3)CN, DMF, and DMSO, solutions of the BCO(−) anion are red. The color originates from n→π* transition in the anion. Solid state structures evidenced a considerable dependence on planarity of the BCO(−) anion on its color, as well as on the character of bonding in the C-N-O fragment: yellow color is associated with an oxime (bond length C-N is shorter than N-O), while red color is due to the nitroso character (bond length C-N is longer than the N-O). An addition of ethanol to red solutions of the BCO(−)containing salts leads to the color change to yellow, which is the result of the formation of an H-bond between the C-N-O fragment of cyanoxime and the solvent, also leading to the flattening of the structure. An explanation for this new color-changing effect was offered, based on experimental evidence and TD/DFT calculations. Glossary: H(BCO) is 1-cyano-1-oximino-acetophenone, or benzoylcyanoxime; BCO(−) is anion of the benzoylcyanoxime; AsPh(4)(+) is tetraphenylarsonium cation; MMe(4)(+) is tetramethyammonium cation; ROH – alcohols; DMF – dimethylformamide; DMSO – dimethylsulfoxide; AN – acetonitrile; DFT -Density Functional Theory; TDDFT – Time-Dependent Density Functional Theory

In this report, we present the synthesis and characterization of 1H-pyrrol-2-ylmethylenes, prepared from Knoevenagel condensations between pyrrole aldehydes and several organic CH acids. New compounds were characterized by a variety of spectroscopic methods, electrochemistry as well as X-ray crystallography. DFT calculations on these compounds indicates an appreciable amount of electronic delocalization between the pyrrole and acid-derived alkene units. The compounds display a single intense π→π∗ transitions in the UV–visible region. Ab initio and semi-empirical calculations suggest that the HOMO to LUMO single-electron excitations are responsible for the most intense absorption in new chromophores.

Binuclear iron(III) octakis(perfluorophenyl)tetraazaporphyrin μ-oxodimer complex was prepared by the reaction of bis(perfluorophenyl)maleonitrile and Fe(CO)5 and tested in catalytic oxygenation reactions of several hydrocarbons in comparison with the analogous non-fluorinated phthalocyanine complexes. Results of the study demonstrate that this complex is a highly efficient catalyst for the oxygenation of anthracene, 2-tert-butylanthracene, naphthalene, 2-methylnaphthalene, phenanthrene, adamantane, and toluene using iodosylbenzene, oligomeric iodosylbenzene sulfate, or Oxone as stoichiometric oxidants.

Four novel phthalocyanine complexes containing carbazole moieties were synthesized and characterized by 1H & 13C NMR, IR, and UV–visible spectroscopies, magnetic circular dichroism (MCD), elemental analysis, matrix-assisted laser desorption ionization mass spectrometry (MALDI), and X-ray crystallography. In all new compounds, characteristic interligand charge transfer transitions were observed in the 400–600 nm range and are indicative of interligand charge transfer transitions. The electrochemical and spectroelectrochemical methods used to probe the redox properties of 2–5 suggested phthalocyanine-centered first oxidation and reduction processes. Photophysical measurements of the prepared complexes in different solvents exhibited interesting properties due to the charge transfer effect and consequently prolonged excited state lifetime (5.00 ns) with high singlet oxygen quantum yield (ФΔ = 0.825) were acquired. Due to their remarkable solvatochromism phenomena and enhanced photo-related properties, the presented compounds have high potential in chemo-sensors and optical limiting material applications.

Two cationic zinc phthalocyanines have been tested for their interactions with several DNA secondary structures. Despite different aggregation properties, both phthalocyanines bind to DNA in monomeric forms. The strong photodynamic activity of phthalocyanines was demonstrated by in vitro experiments and correlate well with high singlet oxygen yields determined experimentally with 1,3-diphenylisobenzofurane. Both phthalocyanines accumulate in the cell cytoplasm prior to radiation; however, only the octacationic photosensitizer was observed in the cell nuclei after irradiation.

Electronic structures, energies and splitting of the Qx and Qy bands for positional isomers of zinc mono-, di-, tri-, and tetra pyridinoporphyrazines as well as parent zinc phthalocyanine were investigated using density functional theory (DFT) and time-dependent (TD) DFT approaches. The influence of the Hartree–Fock exchange on excited state energies and Qx and Qy bands splitting were studied using GGA BP86 and hybrid B3LYP and PBE1PBE exchange-correlation functionals. Solvent effects were estimated using the polarized continuum model (PCM) approach and cyclohexane, toluene, or DMSO as solvents. It was found that general trends in the Qx and Qy band energies and splitting correlate very well with the available experimental data on pyridinoporphyrazines and follow the trends in HOMO–LUMO and HOMO–LUMO + 1 energy gaps as well as LUMO–LUMO + 1 splitting. TDDFT trends allow estimation of the Qx and Qy band energies and splitting in unknown tripyridinoporphyrazines and in individual positional isomers of tetrapyridinoporphyrazines.

Electronic structures, geometries, and vertical excitation energies of chloroboron subphthalocyanine, tribenzodiazasubporphyrin, tribenzomonoazasubporphyrin, and tribenzosubporphyrin were calculated using density functional theory (DFT) and time-dependent (TD) DFT coupled with polarized continuum model (PCM) approach. Molecular geometries calculated at the BP86/6-311G(d) level reveal bowl-shape, trigonal prismatic conformations for all compounds with a variable bowl-depth that depends on the number of meso-nitrogen atoms in corresponding molecule. TDDFT-PCM calculations predict that the Q-band should undergo gradual high-energy shift, while the B-band should undergo low-energy shift upon stepwise substitution of the meso-nitrogen atoms in subphthalocyanine toward tribenzosubporphyrin. The TDDFT-PCM predicted trend was rationalized on the basis of electronic structures of target macrocycles. When comparison between theory and experiment is available, TDDFT-PCM calculations are in qualitative and quantitative agreement with experimental data.

The reaction between substituted cyan-acetamides NC–CH2–C(O)X (X = N-piperidyne or N-morpholyl residues) and gaseous methylnitrite CH3ONO in isopropanol at room temperature in the presence of a base within minutes leads to colorless cyanoximes 2-cyano-2-isonitroso-N-piperidynylacetamide (further as HPiPCO), and 2-cyano-2-isonitroso-N-morpholylacetamide (HMCO) in 70–90% yield. The deprotonation of HPiPCO and HMCO with a base such as NaOEt affords anionic Na-salts, bright-yellow in color originated from n ? p ⁄ transitions in the nitroso-chromophore. Anionic cyanoximates react with aqueous solutions of K2MCl4 (M = Pd, Pt) to form yellow-orange PdL2 and dark blue-green polymeric [PtL2]n (L = PiPCO � , MCO � ), which upon treatment with DMSO or DMF breaks down to pale-yellow monomeric PtL2. Synthesized metal complexes were characterized by spectroscopic methods (IR, UV–Vis), measurement of the electric conductivity and the X-ray analysis. Both PdL2 and PtL2 exhibit non-electrolyte behavior in DMSO and DMF. Crystal structures of Pd(PiPCO)2 and Pt(PiPCO)2 were determined and revealed the formation of the cis-complexes with nearly planar geometry around the metal core and an adoption of the cis-anti configuration by anions, in contrast to the trans–anti geometry in structures of uncomplexed HPiPCO and HMCO. Ab initio calculations were performed for all six compounds: two cyanoxime ligands and four Pd and Pt metal complexes. A very satisfactory agreement between the calculated and experimental values of geometrical parameters of all evaluated compounds was attained. The electron densities, energies of HOMO and LUMO orbitals and molecular electrostatic potentials were calculated as well.

Novel, efficient, and recyclable bifunctional catalysts bearing ionic liquid supported (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) and iodoarene moieties were developed and used for environmentally benign catalytic oxidation of alcohols. The reactions using peracetic acid as a green and practical co-oxidant afforded the corresponding carbonyl compounds in high yields under mild conditions and convenient work-up. Furthermore, these ionic liquid supported bifunctional catalysts could be simply recovered and reused.

Binuclear iron(III) phthalocyanine-(μ-oxodimer) complex was tested in catalytic oxygenation reactions of several hydrocarbons using tetrabutylammonium oxone as the oxidant in dichloromethane solution at room temperature. Results of the study demonstrate that this is an extremely powerful catalytic system for oxidative conversion of aromatic hydrocarbons (anthracene, 2-tert-butylanthracene, 2-methylnaphthalene, 9,10-dihydroanthracene, 1,2,3,4-tetrahydronaphthalene, indane, ethylbenzene, toluene, and benzene) to the respective p-quinones in high yields in 5–30 min. Under these conditions, adamantane is oxidized with 71% conversion after 10 min affording a mixture of 1-adamantanol, 2-adamantanone, 1-hydroxy-2-adamantanone, and 4-protoadamantanone.

A new dithiolene ligand with 3,5-dibromo substituted phenyl groups was designed and synthesized. The protected form of the ligand was reacted with a nickel salt providing neutral Ni(S(2)C(2)(3,5-C(6)H(3)Br(2))(2))(2) and anionic [Ni(S(2)C(2)(3,5-C(6)H(3)Br(2))(2))(2)](-) isolated as a Bu(4)N(+) salt. Both were characterized by UV-visible and IR spectroscopy and compared with the similar known molecular systems. They exhibit intense low-energy transitions that are characteristic of such systems. The electrochemical behavior of these molecules was investigated by cyclic voltammetry.

Several transition metal-mediated oxidations using hypervalent iodine species are reported. A convenient procedure for preparation of iodylarenes via RuCl3-catalyzed oxidation of iodoarenes has been developed. This procedure allows the generation of highly reactive monomeric iodine(V) species, which are excellent oxidants toward alcohols and hydrocarbons in situ. A broad range of substrates can be oxidized to carbonyl compounds by a tandem catalytic system based on the Ru(III)-catalyzed reoxidation of ArIO to ArIO2 using Oxone® as oxidant. It was shown that electrophilic iodine(III) species, originating from oligomeric iodosylbenzene sulfate (PhIO)3SO3, are efficient oxygenating agents in catalytic oxidation of aromatic hydrocarbons in the presence of metalloporphyrin complexes.

Six structurally related cyano ferrocenes have been examined by temperature-dependent Mossbauer effect spectroscopy (MES) to yield information concerning the isomeric shift (IS), quadrupole splitting (QS), and related parameters characterizing the iron atom in these compounds. The IS is related to the s-electron density at the Fe nucleus, while the QS is related to the symmetry and magnitude of the electrostatic field. In addition, these data can yield information related to the dynamics of the metal atom and are in excellent agreement with X-ray crystal data. Density functional theory (DFT) calculations have been used to obtain values for the three principal components of the electric field gradient tensor as well as the electron density at the metal atom site. The results of the DFT calculations and the MES data are found to be in exceptionally good agreement in these compounds.

The oxygen atom transfer reactivity of Tp( *)MoO(2)(SPh) (1) (where Tp( *)=hydrotris-(3,5-dimethylpyrazol-1-yl)borate) with trimethyl phosphine (PMe(3)) has been investigated. The reaction proceed through a diamagnetic phosphoryl intermediate complex, Tp( *)MoO(SPh)(OPMe(3)) (2), which has been isolated and characterized by IR, NMR, UV-visible spectroscopy, and mass spectrometry. The molecular structure of 2 has been determined by X-ray crystallography. The complex crystallizes in monoclinic (P2(1)/n) space group, a=19.81 (1)A, b=11.1 (4)A, c=18.416 (5)A, beta=121.2 (3) degrees , V=3463.8 (25)A(3) with Z=4. In acetonitrile, complex 2 exchanges its phosphoryl ligand with a solvent molecule resulting in Tp( *)MoO(SPh)(MeCN) (3), which has been isolated and also characterized spectroscopically and by X-ray crystallography. Compound 3 crystallizes in triclinic (P1 ) space group, a=10.159 (6)A, b=18.563 (5)A, c=7.986 (3)A, alpha=96.22 (3) degrees , beta=121.2 (3) degrees , gamma=84.64 (3) degrees , V=1452.4 (11)A(3) with Z=2. The electronic structures of the complexes have been investigated by density functional theory and the redox chemistry has been investigated by cyclic and differential pulse voltammetry. In acetonitrile, complex 2 spontaneously transforms to complex, 3 at a rate of 5.6x10(-4)s(-1).

In this Letter the synthesis of benzospiro-indolizidinepyrrolidinones is described by a domino atom transfer radical cyclization reaction using a copper catalyst. The structure of one of the products was established by single crystal X-ray diffraction. The investigated precursors, bearing a homo allyl substituent on the N -indole, result in a 5- exo - trig , followed by a 6- endo - trig cyclization. When the N -indole is substituted with an allyl group, only the spiro-cyclization occurs.

The first optically active rigid covalently linked by enantiomerically pure (R)- or (S)-BINOL metal-free phthalocyanine dimers have been prepared and characterized using electronic absorption, CD, MCD, MS, and NMR techniques as well as semi-empirical molecular orbital calculations.

The reaction of 1,2-dicyanobenzene-4-sulfonyl chloride with different polyfluoro alcohols leads to the formation of 1,2-dicyano-4-polyfluoroalkoxysulfonyl benzenes. The tetramerization of such nitriles in the presence of zinc or cobalt salts results in the corresponding phthalocyanines. The influence of solvent and substituents on the aggregation of the phthalocyanine complexes was studied by electronic spectroscopy. The polyfluoroalkoxysulfonyl groups were shown to stabilize both HOMO and LUMO of the complexes in comparison with alkoxy- or polyfluoroalkoxy-substituted analogs. The first oxidation potential for zinc-containing complexes was estimated as 1.47–1.65 V ©

The pseudocyclic iodine(V) oxidants, such as esters of iodoxybenzoic acid (IBX-esters) and 2-iodylphenol ethers, can serve as stable and efficient sources of oxygen in catalytic oxidations, and their reactivity is similar to the commonly used thermally unstable and potentially explosive iodosylbenzene. In a specific example, primary or secondary benzylic alcohols are selectively oxidized by isopropyl IBX-ester in the presence of μ-oxo-(tetra-tert-butylphthalocyaninato)iron(III) (0.1 mol equiv) in dichloromethane at room temperature in 0.5–2 h to afford the respective carbonyl compounds in 100% conversion and preparative yields 91–95% after column chromatography.

Solvated tris-complexes of (R)- and (S)-1,1'-binaphthyl-2,2'-dyil phosphate with lanthanum(III) and europium(III) centers were prepared and characterized by spectroscopic methods and elemental analysis. Circularly polarized luminescence (CPL) spectra for the optically active isomers of the europium complexes are also reported.

A phthalocyanine (Pc)-analogue containing two pyridine units is dimerized via two pyridine-Pd-pyridine bridges to form a novel type of planar or nearly planar Pc dimer. Because of the structural constraint in the constituent monomer, this dimer has a rhombic-shaped square in its center, which has not been attained previously in porphyrin-based supramolecules.