Problematika Permohonan Grasi Menurut Undang-undang Nomor 22 Tahun 2002

According to executor attorney opinion, no time limit for application clemency, it wills be performing deep constraint on dead punishment execution. Execution of dead punishment also constraint by rule that allows criminal to propose the second clemency application. This constraint still is added by condition that second clemency application is two years of first clemency rejection. Meanwhile according to criminal lawyer reception, with no rule upon, constitute a advantage by criminal dead, since it can propose clemency without time limit for first clemency application and also second application, so execution could be delayed. At Yogyakarta court since year 2002 until now there is no criminal propose clemencies. It is caused, firstly, certain verdict type that could be requested for clemency, secondary by apply clemency cause dead sentence is no postpone except for dead verdict, thirdly most criminal on narcotic and drug abuse case was pleased with first grade verdict

Rigid, Branched Porphyrin Antennas: Control over Cascades of Unidirectional Energy Funneling and Charge Transfer

Porphyrin arrays consisting of three peripheral Zinc porphyrins (ZnPs) and a central free base porphyrin (H₂P)all rigidly linked to each otherserve as light-harvesting antennas as well as electron donors and are flexibly coupled to an electron-accepting C₆₀ to realize the unidirectional flow of (i) excited-state energy from the ZnPs at the periphery to the H₂P, (ii) electrons to C₆₀, and (iii) holes to H₂P and, subsequently, to ZnP. Dynamics following photoexcitation are elucidated by time-resolved transient absorption measurements on the femto-, pico-, nano-, and microsecond time scales and are examined by multiwavelength as well as target analyses. Hereby, full control over the charge shift between H₂P and ZnP to convert the (ZnP)₃–H₂P^•+–C₆₀^•– charge-separated state into (ZnP)₃^•+–H₂P–C₆₀^•– charge-separated state is enabled by the solvent polarity: It is deactivated/switched-off in apolar toluene, while in polar benzonitrile it is activated/switched-on. Activating/switching impacts the recovery of the ground state via charge recombination rates, which differ by up to 2 orders of magnitude. All charge-separated states lead to the repopulation of the ground state with dynamics that are placed in the inverted region of the Marcus parabola

Charge Transfer Events in Semiconducting Single-Wall Carbon Nanotubes

Electron-donating ferrocene units have been attached to SWNTs, with different degrees of functionalization. By means of a complementary series of novel spectroscopic techniques (i.e., steady-state and time-resolved), we have documented that mutual interactions between semiconducting SWNT and the covalently attached electron donor (i.e., ferrocene) lead, in the event of photoexcitation, to the formation of radical ion pairs. In the accordingly formed radical ion pairs, oxidation of ferrocene and reduction of SWNT were confirmed by spectroelectrochemistry. It is, however, shown that only a few semiconducting SWNTs [i.e., (9,4), (8,6), (8,7), and (9,7)] are susceptible to photoinduced electron transfer processes. These results are of relevant importance for the development of SWNT-based photovoltaics

Theoretical and Experimental Insights into the Surface Chemistry of Semiconductor Quantum Dots

We present a series of non-stoichiometric cadmium sulfide quantum-dot (QD) models. Using density functional theory (DFT) and semi-empirical molecular orbital (MO) calculations, we explore the ligand binding and exchange chemistry of these models. Their surface morphology allows for these processes to be rationalized on the atomic scale. This is corroborated by ultraviolet–visible (UV–vis), infrared (IR), and inductively coupled plasma–optical emission spectroscopy (ICP–OES)

Iodine-Pseudohalogen Ionic Liquid-Based Electrolytes for <i>Quasi</i>-Solid-State Dye-Sensitized Solar Cells

In the current work, novel symmetrically alkyl-substituted imidazolium-based ionic liquids have been synthesized featuring either iodide (I^–) or selenocyanate (SeCN^–) as counteranions. Physicochemical assays based on spectroscopy and electrochemistry techniques have been performed to identify the best ionic liquid for application as electrolytes in <i>quasi</i>-solid-state dye-sensitized solar cells (qssDSSC). The latter were mixed with additives such as 4-<i>tert</i>-butylpyridine (4tbpy) and guanidinium thiocyanate (GuSCN) to optimize electrode surface coverage, ionic diffusion, and dye regeneration. In addition, we demonstrate that electrolytes containing a mixture of I₂ and (SeCN)₂ enhance the open-circuit voltage of the final <i>quasi</i>-solid-state device by up to 70 mV. As such, iodine-pseudohalogen electrolytes reveal in qssDSSCs a good balance between dye regeneration and hole transport and, in turn, enhance the overall solar energy conversion efficiency by 70% with respect to reference qssDSSCs with iodine-based electrolytes. Finally, devices with the iodine-pseudohalogen electrolyte show a 1000 h stable efficiency of 7–8% under outdoor temperature operation conditions and 1 sun illumination

Theoretical and Experimental Insights into the Surface Chemistry of Semiconductor Quantum Dots

We present a series of non-stoichiometric cadmium sulfide quantum-dot (QD) models. Using density functional theory (DFT) and semi-empirical molecular orbital (MO) calculations, we explore the ligand binding and exchange chemistry of these models. Their surface morphology allows for these processes to be rationalized on the atomic scale. This is corroborated by ultraviolet–visible (UV–vis), infrared (IR), and inductively coupled plasma–optical emission spectroscopy (ICP–OES)

Polyhydrogenated Graphene: Excited State Dynamics in Photo- and Electroactive Two-Dimensional Domains

Understanding the phenomenon of intense photoluminescence in carbon materials such as hydrogenated graphene, graphene nanoribbons, and so forth is at the forefront of investigations. In this study, six different types of hydrogenated graphene (phG) produced from different starting materials were fully characterized in terms of structure and optical spectroscopy. Comprehensive photoluminescence lifetime analyses of phGs were conducted by combining time-correlated single-photon counting with steady-state fluorescence spectroscopy and femtosecond transient absorption spectroscopy. The conclusion drawn from these assays is that graphene islands with diameters in the range from 1.1 to 1.75 nm reveal band gap photoluminescence between 450 and 800 nm. As a complement, phGs were implemented in hybrids with water-soluble electron accepting perylenediimides (PDIs). By virtue of mutual π-stacking and charge transfer interactions with graphene islands, PDIs assisted in stabilizing aqueous dispersion of phG. Implicit in these ground state interactions is the formation of 300 ps lived charge separated states once photoexcited

Quantum-Dot-Sensitized Solar Cells: Understanding Linker Molecules through Theory and Experiment

We have investigated the role of linker molecules in quantum-dot-sensitized solar cells (QDSSCs) using density-functional theory (DFT) and experiments. Linkers not only govern the number of attached QDs but also influence charge separation, recombination, and transport. Understanding their behavior is therefore not straightforward. DFT calculations show that mercaptopropionic acid (MPA) and cysteine (Cys) exhibit characteristic binding configurations on TiO₂ surfaces. This information is used to optimize the cell assembly process, yielding Cys-based cells that significantly outperform MPA cells, and reach power conversion efficiencies (PCE) as high as 2.7% under AM 1.5 illumination. Importantly, the structural information from theory also helps understand the cause for this improved performance

A Metallofullerene Electron Donor that Powers an Efficient Spin Flip in a Linear Electron Donor–Acceptor Conjugate

The dream target of artificial photosynthesis is the realization of long-lived radical ion pair states that power catalytic centers and, consequently, the production of solar fuels. Notably, magnetic field effects, especially internal magnetic field effects, are rarely employed in this context. Here, we report on a linear Lu₃N@<i>I</i>_<i>h</i>-C₈₀–PDI electron donor–acceptor conjugate, in which the presence of the Lu₃N cluster exerts an appreciable electron nuclear hyperfine coupling on the charge transfer dynamics. As such, a fairly efficient radical ion pair intersystem crossing converts the initially formed singlet radical ion pair state, ¹[(Lu₃N@<i>I</i>_<i>h</i>-C₈₀)^•+–PDI^•–], to the corresponding triplet radical ion pair state, ³[(Lu₃N@<i>I</i>_<i>h</i>-C₈₀)^•+–PDI^•–]. Most notably, the radical ion pair state lifetime of the latter is nearly 1000 times longer than that of the former

Enhancing Molecular Recognition in Electron Donor–Acceptor Hybrids via Cooperativity

Herein, we report the synthesis of guanidinium bis-porphyrin tweezers <b>1</b> and fullerene carboxylate <b>3</b>, their assembly into a novel supramolecular <b>1@3</b> electron donor–acceptor hybrid, and its characterization. In solution, the binding constant affording <b>1@3</b> is exceptionally high. <b>1@3</b>, which features a highly confined topography, builds up from a combination of guanidinium-carboxylate hydrogen bonding and π–π stacking/charge-transfer motifs. The latter is governed by interactions between the electron-donating porphyrin and the electron-accepting fullerene. Importantly, positive cooperativity between the applied binding motifs is corroborated by a number of experimental techniques, such as NMR, absorption, fluorescence, etc. In addition, transient absorption experiments shed light onto electron-transfer processes taking place in the ground state and upon photoexcitation. In fact, porphyrin excitation powers an electron transfer to the fullerene yielding charge separated state lifetimes in the nanosecond regime