The reaction of CuO'Bu with CO, and 'Pr,NH in the presence of PPh, gives the dialkylcarbamato complex [Cu(O,CN'Pr,)(PPh,),] (1). The CO,/R,NH system (R = Me, Et) in an appropriate organic medium reacts with Ag,O giving the corresponding N,N-dialkylcarbamato complexes of analytical formula [Ag(O,CNR,)] (R = Me, 2; R = Et, 3). The methyl derivative 2 was characterized by X-ray diffraction methods. Crystal data of 2: for [Ag,(O,CNMe,),], C,H,,Ag,N,O,, mol. wt. 391.9; monoclinic, space group P2,/c, a = 12.08(1), b = 3.797(2), c = 11.316(7) A, p = 113.37(6)", V = 476.3 A3, Z = 2, D, = 2.732 g ~m -~; p(MoK,) = 40.64 cm-', F(OO0) = 376.0; R = 0.059, R, = 0.067; g.0.f. 1.27. The structure consists of dinuclear [Ag,(O,CNMe,),] 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 2.837(2) A; the dinucledr units are further joined by Ag-0 bonds to form an infinite array. Compound 3, which is presumably dinuclear, as suggested by cryoscopic measurements in benzene, undergoes a structural fission with PPh,, giving the mononuclear triphenylphosphine derivative [Ag(O,CNEt,)(PPh,),] (4). The amine-catalyzed conversion of Ag,O into Ag,CO,, in the presence of the 'Pr,NH/CO, system, is also reported. CI-Exchange from [AuCI(PPh,)] with [Ag(O,CNEt,)] (3) gives the first N,N-dialkylcarbamato complex of gold, namely [Au(O,CNEt,)(PPh,)] (5), which crystallizes in the monoclinic system: C,,H,,AuNO,P 0.5 C,H,,, mol. wt. 625.5, space group P2,/c; a = 13.212(5), h = 12.25(1), c = 16.795(6) A, / l = 109.09(2)", V = 2568(2) A3, Z = 4, D, = 1.618 g cm-,; p(AgK,) = 31.40 cm-', F(OO0) = 1236.0; R = 0.058; R , = 0.064; g.0.f. 2.121. The compound contains two-coordinated Au-atom, namely to the P-atom and to the 0-atom of the monodentate carbamato group, the P-Au-0 bond angle being 174.7(3)". The reaction with Me1 showed these compounds to react predominantly at the carbamato 0-atom giving the corresponding urethanes R,NCO,Me. Evidence was gathered for the transient coordination of CO to Ag in 3.
')
2 ,
3,
Throughout this paper, the term homolepttc denotes a compound formed by anionic hgands of the same type. Tetrahydrofuran solutions of CuO'Bu, as prepared from cuprous chloride and KO'Bu [l la], are indefinitely stable at room temperature under exclusion of air and moisture [llb].
No reaction was found to occur between cuprous chloride and the R,NH/CO, system.