Preparation and characterization of the argentates: [Ag[P(CF(3))(2)](2)](-), [Ag[(micro-P(CF(3))(2))M(CO)(5)](2)](-) (M = Cr, W), and [Ag[(micro-P(C(6)F(5))(2))W(CO)(5)](2)](-): X-ray crystal structure of [K(18-crown-6)][Ag[(micro-P(CF(3))(2))Cr(CO)(5)](2)

The first example of a mononuclear diphosphanidoargentate, bisbis(trifluoromethyl)phosphanido]argentate, AgP(CF(3))(2)](2)](-), is obtained via the reaction of HP(CF(3))(2) with Ag(CN)(2)](-) and isolated as its K(18-crown-6)] salt. When the cyclic phosphane (PCF(3))(4) is reacted with a slight excess of K(18-crown-6)]AgP(CF(3))(2)](2)], selective insertion of one PCF(3) unit into each silver phosphorus bond is observed, which on the basis of NMR spectroscopic evidence suggests the AgP(CF(3))P(CF(3))(2)](2)](-) ion. On treatment of the phosphane complexes M(CO)(5)PH(CF(3))(2)] (M = Cr, W) with K(18-crown-6)]Ag(CN)(2)], the analogous trinuclear argentates, Ag(micro-P(CF(3))(2))M(CO)(5)](2)](-), are formed. The chromium compound K(18-crown-6)]Ag(micro-P(CF(3))(2))Cr(CO)(5)](2)] crystallizes in a noncentrosymmetric space group Fdd2 (No. 43), a = 2970.2(6) pm, b = 1584.5(3) pm, c = 1787.0(4), V = 8.410(3) nm(3), Z = 8. The C(2) symmetric anion, Ag(micro-P(CF(3))(2))Cr(CO)(5)](2)](-), shows a nearly linear arrangement of the P-Ag-P unit. Although the bis(pentafluorophenyl)phosphanido compound AgP(C(6)F(5))(2)](2)](-) has not been obtained so far, the synthesis of its trinuclear counterpart, K(18-crown-6)]Ag(micro-P(C(6)F(5))(2))W(CO)(5)](2)], was successful.