The structure of benzene deposited on a Cu(111) surface has been investigated by a combination of temperature-programmed desorption (TPD), high-resolution electron energy loss spectroscopy (HREELS), and near-edge x-ray absorption fine structure (NEXAFS) measurements. The results indicate that benzene forms a stable bilayer on Cu(ll1) at 110 K prior to multilayer formation. The TPD studies show that the second layer benzene desorbs with a peak temperature 5 K higher than that for benzene multilayers. HREELS and NEXAFS results indicate that benzene in the first layer bonds with its T ring parallel to the surface. With increasing coverage, benzene forms a second layer with its GT ring significantly tilted away from the surface. The results are consistent with an approximately perpendicular configuration between the first and second layer benzene molecules, which is analogous to the structure of crystalline benzene. Isotope labeling experiments indicate there is almost complete mixing between molecules in different layers during sequential adsorption at 110 K.

The hydroformylation of decene-1 was studied in the presence of the fluorous-soluble P[CH2CH2(CF2)5CF3]3 modified rhodium catalyst at 100 °C and 1.1 MPa of CO/H2 (1:1) in a 50/50 vol % toluene/C6F11CF3 solvent mixture, which forms a homogeneous liquid phase at and above 100 °C. P[CH2CH2(CF2)5CF3]3 was selected on the basis of a semiempirical calculation of the electronic properties of P[(CH2) x (CF2) y CF3]3 (x = 0, y = 2, 4 and x = 0−5, y = 2) and prepared by the reaction of PH3 with CH2CH(CF2)5CF3. The solution structure of HRh(CO){P[CH2CH2(CF2)5CF3]3}3 (1) in C6F11CF3 is similar to that of HRh(CO)(PPh3)3 (2) in toluene and HRh(CO){P(m-C6H4SO3Na)3}3 (3) in water. High-pressure NMR of 1 under 2.1−8.3 MPa of CO/H2 (1:1) revealed that 1 is in equilibrium with HRh(CO)2{P[CH2CH2(CF2)5CF3]3}2 (4). Kinetic studies show that the reaction is first order in both rhodium and decene-1. While the reaction is inhibited by P[CH2CH2(CF2)5CF3]3, the normal/iso (n/i) ratio of the aldehyde increases with increasing phosphine concentration. The catalytic activity of the Rh/P[CH2CH2(CF2)5CF3]3 catalyst is similar to that of the nonfluorous analogue Rh/P[(CH2)7CH3]3 catalyst and is an order of magnitude lower than that of the Rh/PPh3 catalyst. Surprisingly, the n/i product selectivity of Rh/P[CH2CH2(CF2)5CF3]3 is closer to the selectivity of the Rh/PPh3 catalyst than that of the Rh/P[(CH2)7CH3]3 catalyst. The fluorous biphase catalyst recovery concept was tested in a semicontinuous hydroformylation of decene-1 with the Rh/P[CH2CH2(CF2)5CF3]3 catalyst. During 9 consecutive reaction/separation cycles, a total turnover of more than 35 000 was achieved with a loss of 1.18 ppm of Rh/mol of undecanals. The fluorous-soluble Rh/P[CH2CH2(CF2)5CF3]3 catalyst was also tested for the continuous hydroformylation of ethylene using the high-boiling fluorous solvent FC-70, which allows continuous removal of propanal at the reaction temperature of 110 °C. The long-term stability of the Rh/P[CH2CH2(CF2)5CF3]3 catalyst is better than that of the Rh/PPh3 catalyst. Thus, the Rh/P[CH2CH2(CF2)5CF3]3 catalyst is the first catalyst system which can be used for the hydroformylation of both low and high molecular weight olefins and provides facile catalyst separation for both low and high molecular weight aldehydes.

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Microspectroscopic methods were explored to investigate binder effects occurring in ZSM‐5‐containing SiO2‐ and Al2O3‐bound millimetre‐sized extrudates. Using thiophene as a selective probe for Brønsted acidity, coupled with time‐resolved in situ UV/Vis and confocal fluorescence microspectroscopy, variations in reactivity and selectivity between the two distinct binder types were established. It was found that aluminium migration occurs in ZSM‐5‐containing Al2O3‐bound extrudates, forming additional Brønsted acid sites. These sites strongly influence the oligomer selectivity, favouring the formation of thiol‐like species (i.e., ring‐opened species) in contrast to higher oligomers, predominantly formed on SiO2‐bound ZSM‐5‐containing extrudates. Not only were the location and distribution of these oligomers visualised by 3 D analysis, it was also observed that more conjugated species appeared to grow off the surface of the zeolite ZSM‐5 crystals (containing less conjugated species) into the surrounding binder material. Furthermore, a higher binder content resulted in an increasing overall reactivity owing to the greater number of stored thiophene monomers available per Brønsted acid site.

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