Molecular water-oxidation catalysts can deactivate by side reactions or decompose to secondary materials over time due the harsh, oxidizing conditions required drive oxygen evolution. Distinguishing electrode surface-bound heterogeneous (such as iridium oxide) from homogeneous molecular is often difficult. Using an electrochemical quartz crystal nanobalance (EQCN), we report a method for probing electrodeposition of metal oxide precursors. previously reported [Cp*Ir(H(2)O)(3)](2+) complex,...

The first example of covalently linked free-base corrole-fullerene dyads is reported. In the newly synthesized dyads, free-energy calculations performed by employing redox and singlet excited-state energy in both polar nonpolar solvents suggested possibility electron transfer from excited state corrole to fullerene entity. Accordingly, steady-state time-resolved emission studies revealed efficient fluorescence quenching entity dyads. Further involving femtosecond laser flash photolysis...

By employing well-defined self-assembly methods, a biomimetic bacterial photosynthetic reaction center complex has been constructed, and photoinduced electron transfer originating in this supramolecular donor−acceptor conjugate investigated. The model of the "special pair" donor, cofacial zinc phthalocyanine dimer, was formed via potassium ion induced dimerization 4,5,4′,5′,4′′, 5′′,4′′′,5′′′-zinc tetrakis(1,4,7,10,13-pentaoxatridecamethylene)phthalocyanine. dimer subsequently self-assembled...

Aqueous two-phase extraction has recently been demonstrated as a new method to separate single-wall carbon nanotubes (SWCNTs). In this work, we determined that the mechanism of separation is driven by hydrophobicity surfactant, or combination surfactants, at SWCNT surface. This knowledge allowed us develop simple approach for obtaining highly enriched single-chirality suspensions in only 1 2 steps. These results were obtained strategically combining multiple surfactants with different...

A 'molecular clip' featuring a near-IR emitting fluorophore, BF(2)-chelated tetraarylazadipyrromethane (aza-BODIPY) covalently linked to two porphyrins (MP, M = 2H or Zn) has been newly synthesized host three-dimensional electron acceptor fullerene via 'two-point' metal-ligand axial coordination. Efficient singlet-singlet excitation transfer from (1)ZnP* aza-BODIPY was witnessed in the dyad and triad nonpolar less polar solvents, such as toluene o-dichlorobenzene, however, additional...

Water into oxygen: Mono-iridium complexes (see picture; L=PO3H2 or COOH) were immobilized on an indium tin oxide (ITO) surface to form a molecular electrocatalytic water oxidation assembly that mimics photosystem II in producing oxygen with high turnover numbers (TONs). The catalyst shows TONs for O2 higher than 210 000 and frequencies 6.7 s−1 during electrochemical catalytic splitting.

Effect of positioning the cyanoacrylic acid anchoring group on ring periphery phenothiazine dye performance dye-sensitized solar cells (DSSCs) is reported. Two types dyes, one having substitution C-3 aromatic (Type 1) and another through N-terminal 2), have been synthesized for this purpose. Absorption fluorescence studies performed to visualize effect pattern spectral coverage electrochemical monitor tuning redox levels. B3LYP/6-31G* are frontier orbital location their significance in...

Photoinduced electron transfer in a self-assembled single-wall carbon nanotube (SWNT)-fullerene(C60) hybrid with SWNT acting as an donor and fullerene acceptor has been successfully demonstrated. Toward this, first, SWNTs were noncovalently functionalized using alkyl ammonium pyrene (Pyr-NH3+) to form SWNT/Pyr-NH3+ hybrids. The entity of hybrids was further utilized complex benzo-18-crown-6 fullerene, crown-C60, via ammonium−crown ether interactions yield SWNT/Pyr-NH3+/crown-C60 nanohybrids....

An elegant method of self-assembly for modification a TiO(2) surface using coordinating ligands followed by immobilization variety sensitizers and dyad is reported. This highly versatile method, in addition to testing the photoelectrochemical behavior different zinc tetrapyrroles, allowed use fairly complex structures involving more than one donor entity. Utilization porphyrin-ferrocene markedly improved current-voltage performance cell through an electron transfer-hole migration mechanism....

A supramolecular oligochromophoric system possessing exclusive binding sites for both a guest electron acceptor and an anionic cofactor species is developed, anion-binding-induced stabilization of the charge-separated (CS) state demonstrated. Toward this, intramolecular intermolecular photochemical processes complex bis-porphyrinyl-substituted oxoporphyrinogen with bis(4-pyridyl)-substituted fullerene were investigated by using femtosecond nanosecond laser flash photolysis measurements....

The synthesis, structure, electrochemistry and photodynamics of a BF(2)-chelated azadipyrromethene-fullerene dyad are reported in comparison with azadipyrromethene without fullerene. attachment fullerene resulted efficient generation the triplet excited state via photoinduced electron transfer.

A self-assembled supramolecular triad, a model to mimic the photochemical events of photosynthetic antenna−reaction center, viz., sequential energy and electron transfer, has been newly constructed studied. Boron dipyrrin, zinc porphyrin, fullerene respectively constitute donor, acceptor segments center mimicry. For construction, first, boron dipyrrin was covalently attached porphyrin entity bearing benzo-18-crown-6 host segment at opposite end ring. Next, an alkyl ammonium functionalized...

Efficient electronic energy transfer (EET) in the newly synthesized dyads comprised of zinc porphyrin covalently linked to one, two or four numbers boron dipyrrin (BDP) entities is investigated. Both steady-state and time-resolved emission as well transient absorption studies revealed occurrence efficient singlet–singlet from BDP with time scale ranging between 28 48 ps. A decrease constants for increasing number units observed revealing better antenna effect bearing higher entities....

A near-IR-emitting sensitizer, boron-chelated tetraarylazadipyrromethane, has been utilized as an electron acceptor to synthesize a series of dyads and triads linked with well-known donor, ferrocene. The structural integrity the newly synthesized was established by spectroscopic, electrochemical, computational methods. DFT calculations revealed 'molecular clip'-type structure for wherein donor entities were separated about 14 Å. Differential pulse voltammetry combined spectroelectrochemical...

A series of edge-sharing condensed oligopyrazine analogues acenes, the pyrazinacenes, were synthesized and characterized. X-ray crystallographic determinations revealed intermolecular interactions that affect propensity molecules to undergo π−π stacking. Increasing heteroatom substitution acene framework induces shorter stacking distances (shorter than for graphite) probably due lower van der Waals radius nitrogen atoms. Hydrogen bonding is also a determining factor in case compounds...

We report a universal platform for the synthesis of monolithic porous gold materials with hierarchical bicontinuous morphology and combined macro- mesoporosity using synergistic combination nanocasting chemical dealloying. This robust accessible approach offers new design paradigm parallel optimization active surface area mass transport in metal electrodes.

Abstract A series of molecular triads, composed closely positioned boron dipyrrin–fullerene units, covalently linked to either an electron donor (donor 1 –acceptor 2 ‐type triads) or energy (antenna–donor was synthesized and photoinduced energy/electron transfer leading stabilization the charge‐separated state demonstrated by using femtosecond nanosecond transient spectroscopic techniques. The structures newly triads were visualized DFT calculations, whereas energies excited states...

Improved performance of a photosynthetic antenna–reaction center mimicking supramolecular solar cell is demonstrated. Toward this, porphyrin–phthalocyanine conjugates connected by amide linkers, as wide-band capturing energy harvesting materials, have been newly synthesized and characterized. Efficient singlet–singlet transfer from the zinc or free-base porphyrin to phthalocyanine evidenced steady-state emission transient absorption studies in nonpolar polar solvents. Further, dyad was...

An ammonium ion-crown ether interaction has been successfully used to construct porphyrin-single-walled carbon nanotube (SWNT) donor-acceptor hybrids. The [18]crown-6 alkyl ion binding strategy resulted in porphyrin-SWNT nanohybrids that are stable and soluble DMF. hybrids were characterized by spectroscopic, TEM, electrochemical techniques. Both steady-state time-resolved emission studies revealed efficient quenching of the singlet excited state porphyrins free-energy calculations suggested...

Singlet−singlet energy transfer in self-assembled via axial coordination of imidazole-appended (at different positions one the meso-phenyl entities) free-base tetraphenylporphyrin, H2PIm, to either zinc phthalocyanine, ZnPc, or naphthalocyanine, ZnNc, dyads is investigated noncoordinating solvents, o-dichlorobenzene and toluene, using both steady-state time-resolved transient absorption techniques. The newly formed supramolecular were fully characterized by spectroscopic, computational,...

Transparent conductors (TCs) are an important component of optoelectronic devices and nanoscale engineering TCs is for optimization the device performance through improved light trapping. In this work, patterned periodic arrays nanopillars nanolines pitch size ~700 nm were created on fluorine-doped tin oxide (FTO) using nanoimprint lithography reactive ion etching environmentally friendly gases. The FTO exhibits enhanced trapping as compared to unpatterned FTO, which agrees well with...

Photoinduced electron transfer in self-assembled (via ion-pairing) porphyrin−single-wall carbon nanotube (SWNT) donor−acceptor hybrids has been demonstrated. Toward this, first, SWNTs were solubilized by π−π stacking of pyrene (Pyr) functionalized with either a cationic (alkyl ammonium; Pyr-NH3+) or anionic (butyric acid; Pyr-COO−) terminal groups. The SWNT/Pyr-NH3+ and SWNT/Pyr-COO− thus obtained subsequently used to generate ion-pairing free-base zinc(II) porphyrins bearing peripheral...

Photoelectrochemical behavior of self-assembled C60 via axial coordination to an electrochemically polymerized zinc porphyrin film was systematically investigated unravel the importance coordinated fullerene in improving photocurrent and photovoltage generation resulting donor−acceptor dyad. For this, tetrakis(4-(N,N-diphenylamino)-phenyl)porphyrinato-zinc(II), (Ph2N)4ZnP, bearing electropolymerizable triphenylamine peripheral substituents first electropolymerized form a on electrode...

Self-assembled phthalocyanine-multifullerene donor-acceptor conjugates have been formed by crown ether-ammonium cation dipole-ion binding strategy to probe the photochemical charge separation. To achieve this, phthalocyanine is functionalized possess four 18-crown-6 moieties on macrocycle periphery, whereas fullerene an alkyl ammonium of short and long chain lengths. Stable accommodating multifullerene entities obtained inclusion complexation. From efficient fluorescence quenching zinc bound...