Reactions between ethylenediamine (en) solutions of the intermetallic Zintl phases K(3)E(7) (E = P, As) and a series of homoleptic post-transition metal organometallics such as Cu(5)(Mes)(5), M(C(6)H(5))(2) (M = Zn, Cd) and In(C(6)H(5))(3) have yielded a family of novel bimetallic cluster anions. These new species were isolated as [K(2, 2,2-crypt)](+) salts in [K(2,2,2-crypt)](4)Cu(2)E(14) (E = P (1), As (2)), [K(2,2,2-crypt)](4)ZnE(14) (E = P (3), As (4)), [K(2,2,2-crypt)](4)CdP(14) x 6py (5) and [K(2,2,2-crypt)](2)E(7)InPh(2) (E = P (6), As (7)). Species 2, 3, 5 and 6 were crystallographically characterised by single-crystal X-ray diffraction. The stability of all of the cluster anions in solution was confirmed by electrospray mass-spectrometry and by (1)H, (13)C{(1)H} and (31)P{(1)H} NMR spectroscopy when possible.

Salt metathesis reactions between ethylenediamine (en) solutions of the K(3)E(7) (E = P, As) Zintl phases and post-transition metal halides (InCl(3), TlCl, SnI(2) and PbI(2)) have yielded a family of novel heteroatomic cluster anions, [In(E(7))(2)](3-), [TlE(7)](2-) and [E'E(15)](3-) (E' = Sn, Pb; E = P, As). Several of these new species have been characterized by single-crystal X-ray diffraction as salts of sequestered potassium cations in [K(2,2,2-crypt)](3)[In(P(7))(2)]·3.5py (1), [K(2,2,2-crypt)](2)[TlP(7)]·py (3), [K(18-crown-6)](2)[TlAs(7)] (4b), [K(2,2,2-crypt)](3)[E'P(15)]·en (E' = Sn (5), Pb (6)) and [K(2,2,2-crypt)](3)[SnAs(15)]·2en (7). The presence of all of the cluster anions in solution was confirmed by electrospray mass-spectrometry and by (1)H and (31)P{(1)H} NMR spectroscopy when pertinent.

Reaction of K(3)P(7), FeCl(2), [NH(4)][B(C(6)H(5))(4)] and 2,2,2-crypt yielded the unprecedented cluster dianion [Fe(HP(7))(2)](2-). This species was characterized by single crystal X-ray diffraction, multielement NMR spectroscopy and electrospray mass-spectrometry. DFT calculations on the dianion were also conducted.

Ethylenediamine (en) solutions of K(3)P(7) and 2,2,2-crypt (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane) were reacted with the homoleptic group 11 complexes [M(nbe)(3)][SbF(6)] (M = Ag, Au; nbe = norbornene) yielding two novel cluster anions, [M(2)(HP(7))(2)](2-), both of which were isolated in low crystalline yields as [K(2,2,2-crypt)](2)[M(2)(HP(7))(2)] (M = Ag (1) and Au (2)). Optimization of the reaction conditions by incorporation of a proton source (ammonium tetraphenylborate) and the replacement of the light-sensitive nbe adducts of silver and gold with the chloride salts MCl (M = Ag, Au) was found to greatly increase the yield and purity in which 1 and 2 were isolated. Compounds 1 and 2 were characterized by single crystal X-ray diffraction, electrospray ionization mass-spectrometry (ESI- MS), elemental analysis, and (1)H and (31)P NMR spectroscopy. Density functional theory (DFT) calculations on the cluster anions were also conducted.

A carbon copy: The chemical activation of the heptaphosphide trianion with [Co(PEt(2)Ph)(2)(mes)(2)] (see picture; 1) yields the novel phospha-organometallic complex [Co(η(5)-P(5)){η(2)-P(2)H(mes)}](2-) (2). The reaction product maintains the nuclearity of the parent cluster, but extensive cage fragmentation takes place to yield a diamagnetic "inorganometallic" cobalt complex.