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A series of tailored fulleropyrrolidine derivatives with thiophene substituents was synthesized and studied as electron acceptor materials in inverted organic bulk heterojunction (BHJ) solar cells. The study concentrated on seeking correlation between the molecular structure of the acceptor and its capability to form a photovoltaic BHJ film with the used electron donor material poly(3-hexylthiophene), P3HT. Atomic force and scanning electron microscopy imaging showed that the sensitivity of the BHJ morphology is tied to the molecular structure of the acceptor, which was further studied by photovoltaic characterization of the model solar cells. The photovoltaic performance clearly depended on the molecular structure of the fulleropyrrolidine substituents although there was only slight difference in the BHJ surface morphology. Fulleropyrrolidine derivatives with one or two thiophene units performed better as acceptor materials than those with three or four thiophene units. Additionally, hexyl side chains attached to the four thiophene unit increased the compatibility of a fulleropyrrolidine derivative with P3HT compared to a similar derivative without of the hexyl groups. The results provide new knowledge of the effect of the molecular structure of fulleropyrrolidine derivatives on the BHJ morphology in organic photovoltaics.

Supramolecular donor-acceptor hybrids composed of few-layer graphene as an electron acceptor and phthalocyanine or porphyrin bearing four pyrene entities as photosensitizer donors have been synthesized, and occurrence of ultrafast charge separation in the order of 10(11)-10(12) s(-1) due to close proximity of the donor and acceptor entities is demonstrated.

Effect of positioning of the cyanoacrylic acid anchoring group on ring periphery of phenothiazine dye on the performance of dye-sensitized solar cells (DSSCs) is reported. Two types of dyes, one having substitution on the C-3 aromatic ring (Type 1) and another through the N-terminal (Type 2), have been synthesized for this purpose. Absorption and fluorescence studies have been performed to visualize the effect of substitution pattern on the spectral coverage and electrochemical studies to monitor the tuning of redox levels. B3LYP/6-31G* studies are performed to visualize the frontier orbital location and their significance in charge injection when surface modified on semiconducting TiO₂. New DSSCs have been built on nanocrystalline TiO₂ according to traditional two-electrode Grätzel solar cell setup with a reference cell based on N719 dye for comparison. The lifetime of the adsorbed phenothiazine dye is found to be quenched significantly upon immobilizing on TiO₂ suggesting charge injection from excited dye to semiconducting TiO₂. The performances of the cells are found to be prominent for solar cells made out of Type 1 dyes compared to Type 2 dyes. This trend has been rationalized on the basis of spectral, electrochemical, computational, and electrochemical impedance spectroscopy results.

New chemical sensors for adrenaline Adr were fabricated. For that, a thin film of a molecularly imprinted polymer (MIP) was templated with protonated adrenaline HAdr. Differential pulse voltammetry (DPV), capacitive impedometry (CI), or piezoelectric microgravimetry (PM) was integrated within each chemosensor for analytical signal transduction. First, molecular structure of prepolymerization complex of HAdr with bis(2,2'-bithienyl)methane substituted with the benzo-(18-crown-6) 2 and 4-carboxyphenyl 3 was thermodynamically optimized at the B3LYP/6-31g(d) level. Then, a HAdr-templated MIP film was deposited on the Pt disk electrode and on the Au film electrode of a 10-MHz quartz crystal resonator (QCR) by potentiodynamic electropolymerization from solution of HAdr, 2, 3, and the cross-linking tris([2,2'-bithiophen]-5-yl)methane 4 monomer at the HAdr:2:3:4 = 1:1:1:2 mole ratio. For determination of Adr, the DPV peak current for the K4[Fe(CN)6] redox probe under batch conditions and the resonant frequency and capacity of the electrical double layer under FIA conditions were measured. The lower limits of detection (LOD) were 2 nM, 0.5 μM, and 1.5 μM for the DPV, PM, and CI chemosensor, respectively, indicating suitability of the DPV chemosensor for Adr determination in biological systems (-50 nM). The chemosensors were appreciably selective to Adr in the presence of common interferents.

Two selective chemosensors for adenosine-5′-triphosphate (ATP) determination featuring molecularly imprinted polymer (MIP) film recognition units were fabricated. For imprinting, three different thiophene derivatives were used as functional monomers. That is, the uracil substituent of bis(2,2′-bithienyl)methane 2 complementarily H-bond paired the adenine moiety of ATP, the boronic acid substituent of thiophene 3 covalently bound vicinal diols of the ribofuranose moiety, and amide substituents of bis(2,2′-bithienyl)methanes 4 bound to the pyrophosphate moieties. Different binding motifs adopted for the ATP recognition and the structure of the supramolecular pre-polymerization complex were optimized with the DFT computing at the B3LYP/3-21G( ⁎ ) level. MIP films were prepared by potentiodynamic electropolymerization of this complex with the imprinting factor of 9.47±0.2. An analytical signal was transduced with a 10-MHz resonator of EQCM and a Pt electrode for the piezoelectric microgravimetry (PM) and capacitive impedometry (CI) determination of ATP, respectively, under FIA conditions. Analytical properties of the MIP film were unraveled by spectroscopic ellipsometry, XPS, IRRAS, and DPV. The limit of detection was 0.1 and 0.2 μM for the PM and CI chemosensor, respectively, being an order of magnitude lower than the ATP concentration in biological systems. Moreover, cross-selectivity was demonstrated with the adenosine-5′-diphosphate (ADP) imprinting and ATP discrimination.