The tungsten-oxo moiety in a simple monomeric tungstate, TBA2[WO4] (I, TBA = tetrabutylammonium), showed bifunctional activation of both CO2 and 1,2-phenylenediamine (II). It was confirmed by 1H, 13C, and 183W NMR spectroscopies that adducts I-II and I-(CO)n (n = 1 and 2) were formed by the reactions of I with II and CO2, resp. These adducts played important roles in formation of the corresponding carbamic acid intermediates. The present bifunctionality could be applied to chem. fixation of CO2 even at atm. pressure with various kinds of structurally diverse aryl diamines, primary monoamines, propargylic alcs., and propargylic amines into cyclic urea derivs., 1,3-disubstituted urea derivs., cyclic carbonates, and cyclic carbamates, resp. [on SciFinder(R)]