SYNTHESIS AND X-RAY MOLECULAR-STRUCTURES OF THE SILVER(I) AMIDES [(AG[MU-N(SIME(3))(2)])(4)] AND [(AG[MU-NCME(2)(CH2)(3)CME(2)])(4)]

The thermally stable silver(I) amides [(Ag(mu-NR(2)))(4)] (R = SiMe(3) ) 1 and [{Ag(mu-NR'(2))}(4)] [NR'(2) = NCMe(2)(CH2)(3)CMe(2)] 2, prepa red from AgNCO and Sn(NR(2))(2) or Sn(NR'(2))(2), or for 1 also from M (NR(2))(2) (M = Pb or Yb) or [{Sn(mu-F)NR(2)}(2)], are centrosymmetric , tetranuclear clusters comprising a square of Ag atoms [mean Ag ... A g 3.001(2) Angstrom for 1 and 2.995(2) Angstrom for 2] linked by singl y bridging amido groups [mean Ag-N 2.148(5) Angstrom for 1 and ranging from 2.126(7) to 2.184(7) Angstrom for 2], the (AgN)(4) macrocycle be ing planar for 1 but puckered for 2, and the N-Ag-N' and Ag-N-Ag' arra ngements being essentially linear and rectangular, respectively.