[10]Cycloparaphenylene ([10]CPP) and its tetraalkoxy derivatives were synthesized on the gram scale in 7 steps starting from 1,4-benzoquinone or 2,5-dialkoxy-1,4-benzoquinone. The key steps involve the highly cis-selective bis-addition of 4-bromo-4'-lithiobiphenyl to the quinones to produce a five-ring unit containing cyclohexa-1,4-diene-3,6-diol moiety, the platinum-mediated dimerization of the five-ring unit, and the HSnCl-mediated reductive aromatization of cyclohexadienediol. The tetraalkoxy substituents increased the solubility of [10]CPP in common organic solvents. The carrier-transport properties of thin films of [10]CPP and its derivatives were measured for the first time and indicated that [10]CPP derivatives could rival phenyl-C-butyric acid methyl ester, which is used widely as an n-type active layer in bulk heterojunction photovoltaics.

The Rh-1.5P catalyst exhibited the highest activity among the investigated catalysts. ► Rh2P was easily formed in catalysts with a higher P loading. ► Higher P loadings and higher reduction temperatures led to aggregation of Rh species. ► RhP2 exhibits lower catalytic activity than Rh2P. ► High HDS activity was caused by small Rh2P formation at lower reduction temperature.

In this study, the low-temperature synthesis of rhodium phosphide (Rh2P) on alumina (Al2O3) using triphenylphosphine (TPP) as a phosphorus (P) source and its catal ytic activit y toward 2 hydrodesulfurization (HDS) were investigated to prepare a highl y active HDS catal yst. TPP was more easil y reduced than phosphate, and Rh2P was formed in the P (T)/Rh/Al2O3 catal yst prepared from TTP at lower temperature as compared with the temperature required by Rh-P(A)/Al2O3 catal yst prepared from a phosphate precursor. However, after reduction at a low temperature (450 °C), excess P covered the surface of Rh2P. The optimal reduction temperature for HDS rate of the P(T)/Rh/Al 2 O3 catal yst (650 °C) was lower than that of the Rh-P(A)/Al2O3 catal yst (800 °C). Furthermore, t his temperature was slightly hig her than the optimal reduction temperature for CO uptake (600 °C). These results are explained as follows: HDS rate is increased by both elimination of excess P on the active sites at higher reduction temperature s and enhancement of the crystallinit y of Rh2P. Furthermore, because the particle size of the P(T)/Rh/Al2O3 catal yst (ca. 1.2 nm) was substantiall y smaller than that of the Rh-P(A)/Al2O3 catal yst, the P(T)/Rh/Al2O3 catal yst exhibited greater HDS rate compared with the Rh-P(A)/Al2O3 catal yst.

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