Pentafluorophenyl isocyanate may be used in the preparation of:pentafluorophenyl end-capped poly(ethylene glycol) (PF-PEG-PF)9-O-(pentafluorophenylcarbamoyl)quinine9-O-(tert-butyldimethylsilyl)-10-(pentafluorophenylcarbamoyloxy)-6′-methoxy-11-norcinchonan-9-olsubstituted 2,6-ethynylpyridine bisphenylurea scaffoldsnovelO-xylyl bridged hexaurea receptor for atmospheric CO2uptake