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The Rh(I) carbene precursors [RhCl(COE)(NHC)] 2 , where the N-heterocyclic carbene is 1,3-bis(2,6diisopropylphenyl)imidazol-2-ylidene (IPr) or 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes), were used to synthesize the RhCl(NHC)(P-N) complexes 4 (NHC ) IPr) and 5 (NHC ) IMes), where P-N is P,N-chelated o-(diphenylphosphino)-N,N-dimethylaniline, and the corresponding cis-RhCl(NHC)-(PPh 3 ) 2 complexes 6 and 7. The synthesis of 4 surprisingly requires the reaction to be carried out under a hydrogen atmosphere and occurs via the intermediate dihydride RhCl(H) 2 (IPr)(P-N) (3). Complexes 4-7 in benzene readily undergo irreversible oxidative addition of O 2 to form the corresponding Rh(III) peroxide complexes 9-12. For comparative purposes, RhCl(PPh 3 )(P-N) (8) was synthesized from RhCl-(PPh 3 ) 3 , and this also added O 2 to form a peroxo complex (13). All of the complexes were generally characterized by elemental analysis and 1 H, 31 P{ 1 H}, and 13 C{ 1 H} NMR and IR spectroscopies and, in the cases of 9, 10, and 13, by X-ray crystallography.

The Rh(I) complexes RhCl(diene)(NHC) have been synthesized from Ag(I) carbene precursors, where NHC is one of the N-heterocyclic carbenes 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr), 1,3bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes), 3-methyl-1-phenacylimidazol-2-ylidene (MAI), and 3-methyl-1-picolylimidazol-2-ylidene (MPI), and diene is either NBD or COD. The complexes are characterized by elemental analysis, 1 H NMR and IR spectroscopies, mass spectrometry, and, in the case of RhCl(NBD)(IMes) and RhCl(COD)(MAI), X-ray crystallography. The new Ag(I) carbene complexes [Ag(IPr) 2 ]PF 6 and [Ag(IMes) 2 ]PF 6 are also reported.

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abbreviated as AMX 3 (A is an organic cation, e.g., CH 3 NH 3 + , HN=CHNH 3 + ; M is a metal cation, e.g., Sn 2+ , Pb 2+ ; X is a halide anion, e.g., Cl − , Br − , I −). In their crystal framework, corner-sharing BX 6 octahedrons form the 3D network with the A cations situated in the cuboctahedral interstices. [4,5] The inorganic components of the halide perovskite provide the conductive backbones required by the carrier's ordered transmission and also provide the thermal and mechanical stability of the material. The organic components, on the other hand, function as templates via hydrogen bonds during the perovskite film formation process. Different from 3D perovskites, layer-structured 2D perovskite materials follow the (RNH 3) 2 (A 3) n-1 M n X 3n+1 structure, where R is an alkyl or aromatic moiety larger than A, and n is the number of inorganic layers between the organic chains. [6,7] When n→∞, the structure converts to 3D perovskite. When n is a limited integer, quantum well structures form with layers of AX 4 2− separated and supported by a layer of organic cations via weak van der Waals forces. The inorganic components provide high carrier mobility and wide bandgap tunability. The organic components, being either large aliphatic or aromatic ammonium cations, can enhance hydrophobicity by preventing water molecules from penetrating and destroying the inorganic layers. Thus 2D perovskites usually demonstrate improved environmental stability against moisture. [8-10] Importantly, 2D perovskite crystals also showed unique optical properties such as deep blue emission and strong excitonic effect due to the strong quantum well effect. [11] Furthermore, targeting on the instability issue of hybrid perovskites under high-temperature and humid environments, scientists prompted all-inorganic perovskites (e.g., CsPbX 3) by replacing the organic component with inorganic ions. [12] Besides the rapid development of perovskite-based photovoltaics, [13-16] other perovskite-related devices including lightemitting diodes (LED), [17-20] laser, [21-23] transistors, [24] thermoelectric generators, [25] photodetectors for UV-NIR photons, [26-29] and various sensors for gas, chemical, and pressure have been widely studied. [30-33] Among all these potential applications, detectors and sensors became very active areas of research and even the third-largest application behind photovoltaics and LEDs (Figure 1). This trend could, again, be attributed to the favorable intrinsic properties of hybrid halide perovskites such as direct and tunable bandgaps with significant absorption coefficients, ultralong charge carrier lifetimes/diffusion lengths, high carrier mobilities, low charge carrier recombination, broad Optoelectronic devices based on perovskite materials have shown significant improvement due to the direct and tunable bandgaps, large absorption coefficients, broad absorption spectra, high carrier mobilities, and long carrier diffusion lengths. In addition to the excellent performance in solar cells, scientists have utilized per...

The NHC‐RhI complexes [RhCl(COE)(NHC)]2 1 and 2 [COE = cyclooctene, NHC in 1 = N,N‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (IPr) and, in 2, N,N‐bis(2,4,6‐trimethylphenyl)imidazol‐2‐ylidene (IMes)] react with H2 in hexane to give the dimeric, mono‐carbene dihydrido species [Rh(H)2Cl(NHC)]2 (NHC = IPr (3), IMes (4)). In the presence offurther NHC, the bis‐carbene dihydrido species Rh(H)2Cl(NHC)2 are formed; a crystal structure of the IPr complex 5 is analogous to that of the known IMes analogue. The dihydride‐mixed‐carbene species Rh(H)2Cl(IPr)(IMes) (5a) was also observed but not isolated. A benzene solution of 5 under D2 slowly generates the corresponding dideuteride. Reactions of the mono‐carbenes (1/3, or 2/4) with CO in hexane afford the respective dicarbonyl complexes RhCl(CO)2(NHC) [NHC = IPr (6), IMes (7)], while CO reactions with the bis‐carbene dihydrides give, respectively, the mono‐carbonyl complex RhCl(CO)(IPr)2 (8) and the known IMes analogue. All the complexes are characterized by elemental analysis, 1H and 13C{1H} NMR and IR spectroscopies and, in the case of 5, by X‐ray crystallography. The catalytic activities of 5 and the previously reported Rh(H)2Cl(IMes)2 for hydrogenation of COE and 1‐octene (and isomerization of the latter) are shown to be poor.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

bHepatitis C virus (HCV) core protein is essential for virus assembly. HCV core protein was expressed and purified. Aptamers against core protein were raised through the selective evolution of ligands by the exponential enrichment approach. Detection of HCV infection by core aptamers and the antiviral activities of aptamers were characterized. The mechanism of their anti-HCV activity was determined. The data showed that selected aptamers against core specifically recognize the recombinant core protein but also can detect serum samples from hepatitis C patients. Aptamers have no effect on HCV RNA replication in the infectious cell culture system. However, the aptamers inhibit the production of infectious virus particles. Beta interferon (IFN-␤) and interferon-stimulated genes (ISGs) are not induced in virally infected hepatocytes by aptamers. Domains I and II of core protein are involved in the inhibition of infectious virus production by the aptamers. V31A within core is the major resistance mutation identified. Further study shows that the aptamers disrupt the localization of core with lipid droplets and NS5A and perturb the association of core protein with viral RNA. The data suggest that aptamers against HCV core protein inhibit infectious virus production by disrupting the localization of core with lipid droplets and NS5A and preventing the association of core protein with viral RNA. The aptamers for core protein may be used to understand the mechanisms of virus assembly. Core-specific aptamers may hold promise for development as early diagnostic reagents and potential therapeutic agents for chronic hepatitis C.