The adsorption of CO on Pt nanoclusters grown in a regular array on a template provided by the graphene/Ir(111) Moiré was investigated by means of infrared-visible sum frequency generation vibronic spectroscopy, scanning tunneling microscopy, X-ray photoelectron spectroscopy from ultrahigh vacuum to near-ambient pressure, and ab initio simulations. Both terminally and bridge bonded CO species populate nonequivalent sites of the clusters, spanning from first to second-layer terraces to borders and edges, depending on the particle size and morphology and on the adsorption conditions. By combining experimental information and the results of the simulations, we observe a significant restructuring of the clusters. Additionally, above room temperature and at 0.1 mbar, Pt clusters catalyze the spillover of CO to the underlying graphene/Ir(111) interface.

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Shoot regeneration from Rubus leaves was obtained on a medium containing MS salts, vitamins and sugars, Staba vitamins, casein hydrolysate (100 mgl-~) and 10 #M thidiazuron. Shoot regeneration from Malus leaves was obtained on N 6 rice anther medium with 5 #M thidiazuron. In vitro pretreatment of source shoots with either colchicine or thidiazuron enhanced the organogenic potential of detached leaves of two Rubus hybrids. The response to colchicine was quadratic and occurred at non-mutagenic concentrations (75-250 #M). The response to thidiazuron was exponential between 0 and 5 #M. When applied as a pretreatment, the effectiveness of several different cytokinins (benzyladenine, thidiazuron, zeatin) at enhancing Malus and Rubus organogenesis was related to the shoot proliferation activity of the cytokinin and to treatment-induced variation in leaf and petiole size.

Nature determines selectivity and activity in biological reactive centers, based on single metal atom macrocycles, by properly tuning the primary coordination sphere and the surrounding protein scaffold. In a biomimetic approach, we show that activation of carbon dioxide at a 2D crystal of phthalocyanines supported by graphene can be controlled by chemical tuning of the position of the Dirac cones of the support through oxygen adsorption. The room temperature stabilization of the CO2–Fe chemical bond, detected in situ and confirmed by computational density-functional theory simulations, is obtained by governing the charge transfer across the graphene–metallorganic layer interface upon oxidation of graphene at close-to-ambient conditions. In this way, we can turn a weakly binding site into a strong one in an artificial structure that mimics many features of complex biological systems.