Bi2S3 nanotubes and nanoparticle in the form of thin films were deposited on fluorine doped SnO2 (FTO) coated conducting glass substrates by Aerosol Assisted Chemical Vapor Deposition (AACVD) using tris-(N,N-diethyldithiocarbamato)bismuth(III), [Bi(S2CN(C2H5)2)3]2 (1) as a precursor. Thin films were deposited from solutions of (1) in either chloroform, dichloromethane, or a 1:1 mixture of chloroform and toluene at temperature between 350 to 450 °C and characterized by X-ray diffraction (XRD), UV−vis spectroscopy, field emission gun scanning electron microscopy (FEGSEM), and energy dispersive X-ray (EDX) analysis. FEGSEM images of films deposited from chloroform or dichloromethane exhibit well-defined and evenly distributed nanotubes with an average internal diameter of 40 nm. Films deposited from chloroform/toluene, on the other hand, have compact nanostuctured morphology. Bandgaps of 1.85 and 1.8 eV were estimated for nanotubes and nanoparticles, respectively, by extrapolating the linear part of the Tauc plot recorded for the films. The n-type Bi2S3 thin films display a reasonable photoactivity under illumination and are thus promising candidates for photoelectrochemical applications. The photoelectrochemical characteristics recorded under AM 1.5 illumination indicated photocurrent density of 1.9 mA/cm2 and 1.0 mA/cm2 at 0.23 V versus Ag/AgCl/3 M KCl for the films deposited from chloroform and chloroform/toluene, respectively. The photocurrent is among the highest reported for any Bi2S3 photoelectrode to date. Repeated illumination cycles show that the Bi2S3 thin films display a reasonable photosensitivity and response indicating their potential to be used in photodetector and optoelectronic nanodevice applications.

The rational design of triplet-state sensitizers for the photodynamic therapy of cancers [1][2][3] and other diseases [4] remains an obdurate challenge. A prominent strategy [5][6][7] is the modification of existing photosensitizers with bromine (Z = 35) or iodine (Z = 53); the resulting heavy-atom effects potentiate the generation of therapeutic 1 D g O 2 . The (phosphane)gold(I) fragment is s-isolobal with the proton. Terminal substitution of aromatic organic molecules with gold (Z = 79) has clear desirability for developing phototherapy mediators. What is missing are mild means of carbon-gold bond formation in the presence of sensitive functional groups. We describe here a selective protocol that installs gold(I)-carbon bonds along the peripheries of organic molecules. Reducible, polar moieties are tolerated, including nitro groups, aldehydes, ketones, and esters. The organometallic compounds described here withstand air and water indefinitely. The ability to modify organic fluorophores with gold raises immediate opportunities in metallopharmaceuticals design. [8][9][10] Finally, the new protocol affords organogold(I) compounds more rapidly and in higher yield than by traditional methods [11] of arylating gold. In the palladium-catalyzed Suzuki-Miyaura cross-coupling, [12,13] carbon-carbon bond formation is believed to follow transmetalation from boron to palladium. The reaction often requires an auxiliary base, which is thought to quaternize boron and promote transmetalation.[14] Related precedents include observations by the groups of Schmidbaur [15] and Fackler [16] of phenyl-group transfer from BPh 4 À to gold(I) in aqueous and non-aqueous media.[*] Dr.

Phosphine)-and (N-heterocyclic carbene)gold(I) derivatives of naphthalene and pyrene are reported, containing one or two gold atoms per hydrocarbon. The new complexes are prepared by arylation of gold(I) substrates by arylboronic acids or aryl pinacolboronate esters in the presence of cesium carbonate. Isolated yields range from 52% to 98%. The boron precursors themselves derive from the parent hydrocarbon, where boron is installed in an iridium-catalyzed reaction, or from the aromatic bromides, which are borylated with palladium catalysis. Most of the new gold(I) complexes are air-and moisture-stable colorless solids; they are characterized by multinuclear NMR and optical spectroscopy, combustion analysis, and high-resolution mass spectrometry. X-ray diffraction crystal structures are reported for seven. Gold binding red-shifts optical absorption profiles, which are characteristic of the aromatic skeleton. All compounds show triplet-state luminescence, and dual singlet and triplet emission occurs in some instances. Phosphorescence persists for milliseconds at 77 K and for hundreds of microseconds at room temperature. The compounds' photophysical characteristics, along with time-dependent density-functional theory calculations, suggest emission from ππ* states of the aromatic core. Triplet-state geometry optimization finds minimal geometric rearrangement upon one-electron promotion from the (singlet) ground state.

This work builds on the recently developed hardÀsoft approach, as is embodied in the carboxylÀthioether combination, for functionalizing metalÀorganic frameworks (MOFs), and it aims to further demonstrate its efficacy and generality in connection with the prototypic MOF-5 system [i.e., Zn 4 O(bdc) 3 , where bdc is 1,4-benzene dicarboxylate]. Specifically, the thioether side chain CH 3 SCH 2 CH 2 SÀ (methylthioethylenethio, or MSES) is placed at the 2,5-positions of bdc, and the resultant molecule (L) was crystallized with Zn(II) ions into a porous, cubic network [Zn 4 O(L) 3 ] topologically equivalent to MOF-5. Compared with the previously used methylthio (CH 3 SÀ) group, the MSES side chain is more flexible, has more S atoms as the binding sites (per chain), and extends further into the channel region; therefore, this side chain is predisposed for more-efficient binding to soft metal species when installed in a porous MOF matrix. Here, we report the significantly improved properties, with regard to stability to moisture, fluorescence intensity, and capability of metal uptake. For example, activated solid samples of 1 feature long-term stability (more than 3 weeks) in air, have a notable sensing response to nitrobenzene (in the form of fluorescence quenching), and are capable of taking up HgCl 2 from an ethanol solution at a concentration as low as 84 mg/L.

We describe a white emitting coordination network solid that can be conveniently applied as a thin film onto a commercial UV-LED lamp for practical white lighting applications. The solid state material was discovered in an exercise of exploring molecular building blocks equipped with secondary groups for fine-tuning the structures and properties of coordination nets. Specifically, CH(3)SCH(2)CH(2)S- and (S)-CH(3)(OH)CHCH(2)S- (2-hydroxylpropyl) were each attached as secondary groups to the 2,5- positions of 1,4-benzenedicarboxylic acid (bdc), and the resultant molecules (L1 and L2, respectively) were crystallized with Pb(II) into the topologically similar 3D nets of PbL1 and PbL2, both consisting of interlinked Pb-carboxyl chains. While the CH(3)S- groups in PbL1 are not bonded to the Pb(II) centers, the hydroxy groups in PbL2 participate in coordinating to Pb(II) and thus modify the bonding features around the Pb(II), but only to a slight and subtle degree (e.g., Pb-O distances 2.941-3.116 Å). Interestingly, the subtle change in structure significantly impacts the properties, i.e., while the photoluminescence of PbL1 is yellowish green, PbL2 features bright white emission. Also, the homochiral side group in PbL2 imparts significant second harmonic generation, in spite of its seemingly weak association with the main framework (the NLO-phore). In a broad perspective, this work showcases the idea of secondary group participation (SGP) in the construction of coordination networks, an idea that parallels that of hemilabile ligands in organometallics and points to an effective strategy in developing advanced functions in solid state framework materials.

A highly specific, distinct color change in the crystals of a metal-organic framework with pendant allyl thioether units in response to Pd species was discovered. The color change (from light yellow to orange/brick red) can be triggered by Pd species at concentrations of a few parts per million and points to the potential use of these crystals in colorimetric detection and quantification of Pd(II) ions. The swift color change is likely due to the combined effects of the multiple functions built into the porous framework: the carboxyl groups for bonding with Zn(II) ions to assemble the host network and the thioether and alkene functions for effective uptake of the Pd(II) analytes (e.g., via the alkene-Pd interaction). The resultant loading of Pd (and other noble metal) species into the porous solid also offers rich potential for catalysis applications, and the alkene side chains are amenable to wide-ranging chemical transformations (e.g., bromination and polymerization), enabling further functionalization of the porous networks.

·14H 2 O (2). Molecules in the structures of 1, 1a and 2 are held together by noncovalent interactions, and the lattices contain voids filled with water molecules. Compounds 1 and 1a differ in the mode of mphthalate coordination, solvent type, and crystal lattice content. Desolvated 1 and 2 sorb gaseous MeOH and EtOH. Whereas the MeOH sorption capacity was very similar for 1 and 2 (about 0.14 cm 3 /g at PP S -1 = 0.9, where P is the current methanol pressure and P S the saturation vapor pressure of

Benzil has been identified as a potent selective inhibitor of carboxylesterases (CEs). Essential components of the molecule required for inhibitory activity include the dione moiety and the benzene rings, and substitution within the rings affords increased selectivity toward CEs from different species. Replacement of the benzene rings with heterocyclic substituents increased the K(i) values for the compounds toward three mammalian CEs when using o-nitrophenyl acetate as a substrate. Logarithmic plots of the K(i) values versus the empirical resonance energy, the heat of union of formation energy, or the aromatic stabilization energy determined from molecular orbital calculations for the ring structures yielded linear relationships that allowed prediction of the efficacy of the diones toward CE inhibition. Using these data, we predicted that 2,2'-naphthil would be an excellent inhibitor of mammalian CEs. This was demonstrated to be correct with a K(i) value of 1 nM being observed for a rabbit liver CE. In addition, molecular simulations of the movement of the ring structures around the dione dihedral indicated that the ability of the compounds to inhibit CEs was due, in part, to rotational constraints enforced by the dione moiety. Overall, these studies identify subdomains within the aromatic ethane-1,2-diones, that are responsible for CE inhibition.