Graham R. Lief

BIS(DIAZASILAPHOSPHETIDINES) AND THEIR METAL COMPLEXES

The syntheses and solid-state structures of bis(diazasilaphosphetidines) of the type [Me 2 Si(μ-N t Bu) 2 P] 2 NR, R = Ph, i Pr, t Bu, of the P-chiral analogue [Me 2 Si(μ-N t Bu)(μ-N-2,6- i PrPh)P] 2 (C 2 H 4 ), and of some of their metal complexes are reported. The highly electron-rich, modular bis(phosphines) are easy to synthesize and may have applications in catalysis.

Mono- and Bimetallic Cyclodiphosph(V)Azane Complexes

The 2,4-bis(amino)cyclodiphosph(V)azanes cis-[R(H)N(E=PNtBu)2N(H)R] (R = Ph, E = S(2), Se(3); R = tBu, E = p-Tol (4)) were synthesized and X-ray structurally characterized. Treatment of 4 or cis-[tBu(H)N(E=PNtBu)2N(H)tBu] with TiCl4 afforded monometallic complexes of the type {[tBu(H)N(E=PNtBu)2NtBu]TiCl3] E = S(5), Se(6), NPh. Deprotonation of 2 and cis-[tBu(H)N(E=PNtBu)2N(H)tBu] with nBuLi, afforded dilithium complexes of the general formula {[(THF2·LiRN)(E=PNtBu)2(NRLi·THF2)]} R = Ph(7), R = tBu(8). Treatment of [tBu(H)N(E=PNtBu)2N(H)tBu] with trimethylaluminum produced {(Me2AI)[(tBuN)(E=PNtBu)2(NtBu)](AlMe2)}, E = O(9), S(10), p-Tol(11). Single-crystal X-ray analyses demonstrated that the monometallic 5 and 6 are bispirocyclic complexes, while the bimetallic 7–11 were shown to be trispirocyclic complexes.

Reversal of polarization in amidophosphines: neutral- and anionic-κP coordination vs. anionic-κP,N coordination and the formation of nickelaazaphosphiranes

Nickel(II) chloride reacts with the bis(tert-butylamino)diazadiphosphetidine {But(H)NP(μ-NBut)2PN(H)But} to form trans-[{But(H)NP(μ-NBut)2PN(H)But}2NiCl2]. In solution and the solid-state each heterocyclic ligand coordinates nickel through one phosphorus atom only. For comparison the solid-state structure of the known trans-[NiCl2(PEt3)2] was also determined and it was found that the two complexes have almost identical bond parameters about nickel. The nickel–amidophosphine complexes [{ButOP(μ-NBut)2PNBut}NiCl(PBun3)], [(PBun3)ClNi{ButNP(μ-NBut)2PNBut}NiCl(PBun3)], and [{Me2Si(μ-NBut)2PNBut}NiCl(PBun3)] were synthesized and X-ray structurally characterized. In these mono- and di-nuclear nickel complexes the nickel ions are coordinated in pseudo square-planar fashions, by one trialkylphosphine ligand, one chloride ligand and one κP,N-coordinated amidophosphine moiety from tert-butylamido-substituted heterocycles. Attempts to create nickel complexes chelated in a κ2P fashion by the o-phenylenediamine-tethered mono- and di-anionic 1-{Me2Si(μ-NBut)2PN} 2-{Me2Si(μ-NBut)2PNH}C6H4 and 1,2-{Me2Si(μ-NBut)2PN}C6H4, respectively, afforded instead [1,2-{Me2Si(μ-NBut)2PN}{Me2Si(μ-NBut)2PN}C6H4NiCl] and [1,2-{Me2Si(μ-NBut)2PN}{Me2Si(μ-NBut)2PN}C6H4Ni{PEt3}], each complex having κP,N and κP coordinated amidophosphine ligands.

Mono- and di-nickellaazaphosphiranes of mono- and bis-(amido)cyclodiphosph(III)azanes

The syntheses and solid-state structures of the first three-membered nickel-phosphorus-nitrogen ring compounds, having anionic four-electron P=N moieties are reported.