Formation of a Hexaphosphido Cobalt Complex through P-P Condensation

The reaction between diphosphorus derivatives [(Cl ImDipp )P2 (Dipp)]OTf (1[OTf]) and [(Cl ImDipp )P2 (Dipp)Cl] (1[Cl]) with the cyclotetraphosphido cobalt complex [K(18c-6)][(PHDI)Co(η4 -cyclo-P4 )] (2) leads to the formation of complex [(PHDI)Co{η4 -cyclo-P6 (Dipp)(Cl ImDipp )}] (3), which features an unusual hexaphosphido ligand [Cl ImDipp =4,5-dichloro-1,3-bis(2,6-diisopropylphenyl)imidazol-2-yl, Dipp=2,6-diisopropylphenyl, 18c-6=18-crown-6, PHDI=bis(2,6-diisopropylphenyl)phenanthrene-9,10-diimine]. Complex 3 was obtained as a crystalline material with a moderate yield at low temperature. Upon exposure to ambient temperature, compound 3 slowly transforms into two other compounds, [K(18c-6)][(PHDI)Co(η4 -P7 Dipp)] (4) and [(PHDI)Co{cyclo-P5 (Cl ImDipp )}] (5). The novel complexes 3-5 were characterized using multinuclear NMR spectroscopy and single-crystal X-ray diffraction. To shed light on the formation of these compounds, a proposed mechanism based on 31 P NMR monitoring studies is presented.

Haptotropism in a Nickel Complex with a Neutral, π‐Bridging cyclo ‐P 4 Ligand Analogous to Cyclobutadiene

Dedicated to Professor Manfred Scheer on the occasion of his 65th birthday

The reaction of (1)Ni(η²‐cod), 2, incorporating a chelating bis(N‐heterocyclic carbene) 1, with P₄ in pentane yielded the dinuclear complex [(2)Ni]₂(μ₂,η² : η²‐P₄), 3, formally featuring a cyclobutadiene‐like, neutral, rectangular, π‐bridging P₄‐ring. In toluene, the butterfly‐shaped complex [(1)Ni]₂(μ₂,η² : η²‐P₂), 4, with a formally neutral P₂‐unit was obtained from 2 and either P₄ or 3. Computational studies showed that a haptotropic rearrangement involving two isomers of the μ₂,η² : η²‐P₄ coordination mode and a low‐energy μ₂,η⁴ : η⁴‐P₄ coordination mode, as previously predicted for related nickel cyclobutadiene complexes, could explain the coalescence observed in the low‐temperature NMR spectra of 3. The insertion of the (1)Ni fragment into a P−P bond of P₇(SiMe₃)₃, forming complex 5 with a norbornane‐like P₇ ligand, was also observed.

Inorganic Ferrocene Analogue [Fe(P4)2]2

Inorganic metallocene derivatives containing only cyclo-P_n ligands have been targeted for more than 20 years, but their syntheses have never been achieved by pursuing the conventional route of using P₄ phosphorus except for the generation of [Ti(η⁵-P₅)₂]^2-. Herein, we report a facile one-step method for the synthesis of the homoleptic iron complex [Fe(P₄)₂]^2- by the Zintl-phase-type precursor KP. ³¹P NMR analyses indicate that upon dissolving the KP phase in ethylenediamine P₄^2- was generated only in the presence of 2,2,2-crypt. The amounts of cation-sequestering agents, the type of iron precursor, and their consuming ratio have a decisive impact on the yield of [Fe(P₄)₂]^2-. Both the Fe^II and the Fe^III precursors can oxidize P₄^2- to give a concomitant product [(P₇)Fe(P₄)]^3-, which can be partially inhibited by the addition of potassium to produce relatively pure crystalline [K(2,2,2-crypt)]₂[Fe(P₄)₂].

Incorporation of coinage metal–NHC complexes into heptaphosphide clusters

A Me₃Si-protected P₇ cage reacts with N-heterocyclic-carbene complexes of coinage metals to yield a mononuclear Cu(i) complex featuring a Cu(η⁴-P₇) core and a trinuclear Au(i) complex with linearly coordinated metal ions attached to the P₇ cluster.

[Bi7M3(CO)3]2− (M = Co, Rh): a new architype of 10-vertex deltahedral hybrids by the unprecedented polycyclic η5-coordination addition of Bi73− and trimetallic fragments

A new prototype of 10-vertex deltahedral clusters, [Bi₇M₃(CO)₃]²⁻ (M = Co, 1a; M = Rh, 2a), have been synthesized and characterized, resulting from the unprecedented polycyclic η⁵-coordination addition of a Bi₇³⁻ cage and trimetallic fragments.

Selective Derivatization of a Hexaphosphane from Functionalization of White Phosphorus

The reaction of LGa (L = Dipp(4-(Dipp-imino)pent-2-en-2-yl)amide; Dipp: 2,6-diisopropylphenyl) and white phosphorus was revisited. A plethora of unprecedented polyphosphanes in addition to the known monoinserted product LGaP₄ (1) are observed. An optimized synthesis of the hitherto unknown hexaphosphane (LGa)₂P₆ (3) is presented, and its subsequent selective derivatization with Brønsted acids, MeOTf, Ph₂ECl (E = P, As), and NaOCP provides access to a wealth of functionalized hexa- and heptaphosphanes.

{[CuSn5 Sb3 ](2-) }2 : A Dimer of Inhomogeneous Superatoms

Reaction of the binary Zintl anion (Sn2 Sb2 )(2-) with the β-diketiminato complex [LCu(NCMe)] (L=nacnac=[(N(C6 H3 (i) Pr2 -2,6)C(Me))2 CH](-) ) in ethylenediamine or DMF affords the ternary cluster dimer {[CuSn5 Sb3 ](2-) }2 (1) as its [K(crypt-222)](+) salt. The chemical formulation of 1 is supported by energy-dispersive X-ray spectroscopy (EDX) and quantum chemical calculations. Each monomeric part of the dimer represents a trimetallic "[CuSn5 Sb3 ](2-) " cluster, with an architecture in between a tricapped trigonal prism and a capped square antiprism. As shown by quantum chemical investigations, the presence of Sb atoms and, in particular, of Cu atoms in the cluster skeleton makes the monomeric unit behave like an inhomogeneous superatom, which clearly prefers to dimerize, thereby producing a relatively short, yet virtually non-bonding Cu⋅⋅⋅Cu distance.

Heptaphosphide cluster anions bearing group 14 element amide functionalities

Reactions of the protonated heptaphosphide dianion, [HP7](2-), with one equivalent of E[N(SiMe3)2]2 (E = Ge, Sn, Pb) give rise to novel derivatized cluster anions [P7EN(SiMe3)2](2-) (E = Ge (1), Sn (2) and Pb (3)). All three species were characterized by multi-element solution-phase NMR spectroscopy and electrospray ionization mass spectrometry. In addition, 1 and 2 were structurally authenticated by means of single crystal X-ray diffraction in [K(18-crown-6)]2[P7EN(SiMe3)2]·2py. Interestingly, while 2 appears to be indefinitely stable in solution for prolonged periods of time, the germanium-containing analogue, 1, readily decomposes at room temperature giving rise to the dimeric species [(P7Ge)2N(SiMe3)2](3-) (4) and [K(18-crown-6)][N(SiMe3)2]. A low quality single crystal X-ray structure of the former allowed for the confirmation of its composition and connectivity which is consistent with the (31)P NMR spectrum obtained for the anion.

[Co(η5-P5){η2-P2H(mes)}]2-: a phospha-organometallic complex obtained by the transition-metal-mediated activation of the heptaphosphide trianion

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.