Here we demonstrate high-performance room-temperature NO sensors based on ultrathin ZnO nanorods/reduced graphene oxide (rGO) mesoporous nanocomposites. Ultrathin ZnO nanorods were loaded on rGO nanosheets by a facile two-step additive-free solution synthesis involving anchored seeding followed by oriented growth. The ZnO nanorod diameters were simply controlled by the seed diameters associated with the spatial confinement effects of graphene oxide (GO) nanosheets. Compared to the solely ZnO nanorods and rGO-based sensors, the optimal sensor based on ultrathin ZnO nanorods/rGO nanocomposites exhibited higher sensitivity and quicker p-type response to parts per million level of NO at room temperature, and the sensitivity to 1 ppm of NO was 119% with the response and recovery time being 75 and 132 s. Moreover, the sensor exhibited full reversibility, excellent selectivity, and a low detection limit (50 ppb) to NO at room temperature. In addition to the high transport capability of rGO as well as excellent NO adsorption ability derived from ultrathin ZnO nanorods and mesoporous structures, the superior sensing performance of the nanocomposites was attributed to the synergetic effect of ZnO and rGO, which was realized by the electron transfer across the ZnO-rGO interfaces through band energy alignment.

Chemical reactions involving quantum mechanical tunneling (QMT) increasingly attract the attention of scientists. In contrast to the hydrogen-tunneling as frequently observed in chemistry and biology, tunneling solely by heavy atoms is rare. Herein, we report heavy-atom tunneling in trifluoroacetyl nitrene, CF C(O)N. The carbonyl nitrene CF C(O)N in the triplet ground state was generated in cryogenic matrices by laser (193 or 266 nm) photolysis of CF C(O)N and characterized by IR and EPR spectroscopy. In contrast to the theoretically predicted activation barriers (>10 kcal mol ), CF C(O)N undergoes rapid rearrangement into CF NCO with half-life times of less than 10 min and unprecedentedly large N/ N kinetic isotope effects (1.18-1.33) in solid Ar, Ne, and N matrices even at 2.8 K. The tunneling disappearance of CF C(O)N becomes much slower in the chemically active toluene and in 2-methyltetrahydrofuran at 5 K.

Disulfur dioxide, OSSO, has been proposed as the enigmatic "near-UV absorber" in the yellowish atmosphere of Venus. However, the fundamentally important spectroscopic properties and photochemistry of OSSO are scarcely documented. By either condensing gaseous SO or 266 laser photolysis of an S2O2 complex in Ar or N2 at 15 K, syn-OSSO, anti-OSSO, and cyclic OS([double bond, length as m-dash]O)S were identified by IR and UV/Vis spectroscopy for the first time. The observed absorptions (λmax) for OSSO at 517 and 390 nm coincide with the near-UV absorption (320-400 nm) found in the Venus clouds by photometric measurements with the Pioneer Venus orbiter. Subsequent UV light irradiation (365 nm) depletes syn-OSSO and anti-OSSO and yields a fourth isomer, syn-OSOS, with concomitant dissociation into SO2 and elemental sulfur.

Two simple acylnitrenes, 2-furoylnitrene (2) and 3-furoylnitrene (6), were generated through 266 nm laser photolysis of the corresponding azides. Both are magnetically bistable in cryogenic matrices, as evidenced by the direct observation of the closed-shell singlet state with IR spectroscopy in solid Ne, Ar, Kr, Xe, and N matrices (3-40 K) and the triplet state in toluene (10 K) with EPR spectroscopy (2: |D/hc| = 1.48 cm and |E/hc| = 0.029 cm; 6: |D/hc| = 1.39 cm and |E/hc|c = 0.039 cm). Subsequent visible-light and UV laser irradiations led to the formation of furyl isocyanates (3 and 7) and ring-opening product 3-cyanoacrolein (9-E and 9-Z), respectively, in which the elusive 3-furylnitrene (8) was also identified by IR and EPR spectroscopy (|D/hc| = 1.12 cm and |E/hc| = 0.005 cm).

A new system, consisting of a double channel Fabry Perot etalon and laser diodes emitting around 780 nm is described and proposed to be used for air refractive index measurements. The principle of this refractometer is based on frequency measurements between optical laser sources.It permits quasi-instantaneous measurement with a resolution better than 10

Two hitherto unreported sulfur-centered radicals CF SO and CF OS were generated in the gas phase through high-vacuum flash pyrolyses of sulfoxide CF S(O)X (X=CF , Cl, PhO) precursors. The CF OS molecule is the first experimental example that constitutes an oxathiyl radical. It was isolated and characterized by combining matrix-isolation IR and UV/Vis spectroscopy with quantum chemical computations up to the UCCSD(T)-F12/cc-pVTZ-F12 level of theory. Upon UV light irradiation (254 or 266 nm), sulfinyl radical (CF SO ) isomerizes to oxathiyl radical (CF OS ) in cryogenic noble gas matrices (Ar and Ne). Natural population analyses at the BP86/def2-TZVPP//UCCSD(T)-F12/cc-pVTZ-F12 level suggest that the spin density in CF OS is mainly localized on the sulfur atom (0.86), whereas, in CF SO the spin density is almost equally distributed on the sulfur (0.55) and oxygen (0.43) atoms.

The elusive plumbylone {[SiII(Xant)SiII]Pb0} 3 stabilized by the bis(silylene)xanthene chelating ligand 1, [SiII(Xant)SiII=PhC(NtBu)2Si(Xant)Si(NtBu)2CPh], and its isolable carbonyl iron complex {[SiII(Xant)SiII]Pb0Fe(CO)4} 4 are reported. The compounds 3 and 4 were obtained stepwise via reduction of the lead(II) dibromide complex {[SiII(Xant)SiII]PbBr2} 2, prepared from the bis(silylene)xanthene 1 and PbBr2, employing potassium naphthalenide and K2Fe(CO)4, respectively. While the genuine plumbylone 3 is rather labile even at −60 °C, its Pb0→Fe(CO)4 complex 4 turned out to be relatively stable and bottleable. However, solutions of 4 decompose readily to elemental Pb and {[SiII(Xant)SiII]Fe(CO)3} 5 at 80 °C. Reaction of 4 with [Rh(CO)2Cl]2 leads to the formation of the unusual dimeric [(OC)2RhPb(Cl)Fe(CO)4] complex 6 with trimetallic Rh−Pb−Fe bonds. The molecular and electronic structures of 3 and 4 were established by Density Functional Theory (DFT) calculations.

The homeodomain transcription factor distal-less homeobox 3 gene (DLX3) is required for hair, tooth and skeletal development. DLX3 mutations have been found to be responsible for Tricho-Dento-Osseous (TDO) syndrome, characterized by kinky hair, thin-pitted enamel and increased bone density. Here we show that the DLX3 mutation (c.533 A>G; Q178R) attenuates osteogenic potential and senescence of bone mesenchymal stem cells (BMSCs) isolated from a TDO patient, providing a molecular explanation for abnormal increased bone density. Both DLX3 mutations (c.533 A>G and c.571_574delGGGG) delayed cellular senescence when they were introduced into pre-osteoblastic cells MC3T3-E1. Furthermore, the attenuated skeletal aging and bone loss in DLX3 (Q178R) transgenic mice not only reconfirmed that DLX3 mutation (Q178R) delayed cellular senescence, but also prevented aging-mediated bone loss. Taken together, these results indicate that DLX3 mutations act as a loss of function in senescence. The delayed senescence of BMSCs leads to increased bone formation by compensating decreased osteogenic potentials with more generations and extended functional lifespan. Our findings in the rare human genetic disease unravel a novel mechanism of DLX3 involving the senescence regulation of bone formation.