N,N-DIALKYLCARBAMATO COMPLEXES OF THE D(10) CATIONS OF COPPER, SILVER, AND GOLD

The reaction of CuO'Bu with CO2 and (Pr2NH)-Pr-i in the presence of PP h3 gives the dialkylcarbamato complex [Cu((O2CNPr2)-Pr-i)(PPh3)(2)] (1 ). The CO2/R2NH system (R = Me, Et) in an appropriate organic medium r eacts with Ag2O giving the corresponding N,N-dialkylcarbamato complexe s of analytical formula [Ag(O2CNR2)] (R = Me, 2; R = Et, 3). The methy l derivative 2 was characterized by X-ray diffraction methods. Crystal data of 2: for [Ag-2(O2CNMe2)(2)], C6H12Ag2N2O4, mol. wt. 391.9; mono clinic, space group P2(1)/c, a = 12.08(1), b = 3.797(2), c = 11.316(7) Angstrom, beta = 113.37(6)degrees, V = 376.3 Angstrom(3), Z = 2, D-c = 2.732 g cm(-3); mu(MOKalpha) = 40.64 cm(-1), F(000) = 376.0; R = 0.0 59, R-w = 0.067; g.o.f. 1.27. The structure consists of dinuclear [Ag- 2(O2CNMe2)(2)] units with slightly distorted linearly two-coordinated Ag-atoms containing bridging carbamato groups to form a substantially planar eight-membered ring with an intra-annular Ag-Ag distance of 2.8 37(2) Angstrom; the dinuclear units are further joined by Ag-O bonds t o form an infinite array. Compound 3, which is presumably dinuclear, a s suggested by cryoscopic measurements in benzene, undergoes a structu ral fission with PPh3, giving the mononuclear triphenylphosphine deriv ative [Ag(O2CNEt2)(PPh3)(2)] (4). The amine-catalyzed conversion of Ag 2O into Ag2CO3, in the presence of the (Pr2NH)-Pr-i/CO2 system, is als o reported. Cl-Exchange from [AuCl(PPh3)] with [Ag(O2CNEt2)] (3) gives the first N,N-dialkylcarbamato complex of gold, namely [Au(O2CNEt2)(P Ph3)] (5), which crystallizes in the monoclinic system: C23H25AuNO2P.0 .5C(7)H(16), mol, wt. 625.5, space group P2(1)/c; a = 13.212(5), b = 1 2.25(1), c = 16.795(6) Angstrom, beta = 109.09(2)degrees, V = 2568(2) Angstrom(3), Z = 4, D-c = 1.618 g cm(-3); mu(AgKalpha) = 31.40 cm(-1), F(000) = 1236.0; R = 0.058; R-w = 0.064; g.o.f. 2.121. The compound c ontains two-coordinated Au-atom, namely to the P-atom and to the O-ato m of the monodentate carbamato group, the P-Au-O bond angle being 174. 7(3)degrees. The reaction with Mel showed these compounds to react pre dominantly at the carbamato O-atom giving the corresponding urethanes R2NCO2Me. Evidence was gathered for the transient coordination of CO t o Ag in 3.