N , N ‐Dialkylcarbamato Complexes of the d 10 cations of copper, silver, and gold

The reaction of CuO'Bu with CO 2 , and i Pr 2 NH in the presence of PPh 3 , gives the dialkylcarbamato complex [Cu(O 2 CN i Pr 2 )(PPh 3 ) 2 ] ( 1 ). The CO 2 /R 2 NH system (R = Me, Et) in an appropriate organic medium reacts with Ag 2 O giving the corresponding N , N ‐dialkylcarbamato complexes of analytical formula [Ag(C 2 CNR 2 )] (R = Me, 2 ; R = Et, 3 ). The methyl derivative 2 was characterized by X‐ray diffraction methods. Crystal data of 2 : for [Ag 2 (O 2 CNMe 2 ) 2 ], C 6 H 12 Ag 2 N 2 O 4 , mol. wt. 391.9; monoclinic, space group P 2 1 / c , a = 12.08(1), b = 3.797(2), c = 11.316(7) Å, β = 113.37(6)°, V = 476.3 Å 3 , Z = 2, D c = 2.732 g cm −3 ; μ(Mo K α ) = 40.64 cm −1 , F (000) = 376.0; R = 0.059, R w = 0.067; g.o.f. 1.27. The structure consists of dinuclear [(Ag 2 OCNMe 2 ) 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 2.837(2) Å; the dinuclear units are further joined by AgO 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 3 , giving the mononuclear triphenylphosphine derivative [Ag(O 2 CNEt 2 )(PPh 3 ) 2 ] ( 4 ). The amine‐catalyzed conversion of Ag 2 O into Ag 2 CO 3 , in the presence of the i Pr 2 NH/CO 2 system, is also reported. Cl‐Exchange from [AuCl(PPh 3 )] with [Ag(O 2 CNEt 2 )] ( 3 ) gives the first N , N ‐dialkylcarbamato complex of gold, namely [Au(O 2 CNEt 2 )(PPh 3 )] ( 5 ), which crystallizes in the monoclinic system: C 23 H 25 AuNO 2 P · 0.5 C 7 H 16 , mol. wt. 625.5, space group P 2 1 / c ; a = 13.212(5), b = 12.25(1), c = 16.795(6) Å, β = 109.09(2)°, V = 2568(2) Å 3 , Z = 4, D c , = 1.618 g cm −3 ; μ(Ag K α ) = 31.40 cm −1 , F (000) = 1236.0; R = 0.058; R w = 0.064; g.o.f. 2.121. The compound contains two‐coordinated Au‐atom, namely to the P‐atom and to the O‐atom of the monodentate carbamato group, the PAuO bond angle being 174.7(3)°. The reaction with MeI showed these compounds to react predominantly at the carbamato O‐atom giving the corresponding urethanes R 2 NCO 2 Me. Evidence was gathered for the transient coordination of CO to Ag in 3 .