Rafał Grubba

A new synthetic entry to phosphinophosphinidene complexes. Synthesis and structural characterisation of the first side-on bonded and the first terminally bonded phosphinophosphinidene zirconium complexes [μ-(1,2∶2-η-tBu2PP){Zr(Cl)Cp2}2] and [{Zr(PPhMe2)Cp2}(η1-P–PtBu2)]

The reactions of lithiated diphosphanes with transition metal chlorides constitute a new general entry to phosphinophosphinidene complexes: the reaction of Cp2ZrCl2(Cp = C5H5) with tBu2P-P(SiMe3)Li (molar ratio approximately 1:1) yields [mu-(1,2:2-eta-tBu2P=P)[Zr(Cl)Cp2]2]; the reaction of Cp2ZrCl2 with tBu2P-P(SiMe3)Li (molar ratio approximately 1:2) and an excess of PPhMe2 in DME yields the first terminally bonded phosphinophosphinidene complex, [[Zr(PPhMe2)Cp2](eta1-P-PtBu2)].

Syntheses and structures of the first terminal phosphanylphosphido complex of hafnium [Cp2Hf(Cl){η1-(Me3Si)P–P(NEt2)2}] and the first zirconocene-phosphanylphosphinidene dimer [Cp2Zr{μ2-P–P(NEt2)2}2ZrCp2]

Reactions of (Et(2)N)(2)P-P(SiMe(3))Li with [Cp(2)MCl(2)] (M = Zr, Hf) in toluene or pentane yield the related terminal phosphanylphosphido complexes [Cp(2)M(Cl){η(1)-(Me(3)Si)P-P(NEt(2))(2)}]. The solid state structure of [Cp(2)Hf(Cl){η(1)-(Me(3)Si)P-P(NEt(2))(2)}] was established by single crystal X-ray diffraction. The reaction of (Et(2)N)(2)P-P(SiMe(3))Li with [Cp(2)ZrCl(2)] in THF or DME solutions leads to the formation of deep red crystals of the first neutral diamagnetic zirconocene-phosphanylphosphinidene dimer [Cp(2)Zr{μ(2)-P-P(NEt(2))(2)}(2)ZrCp(2)]. The molecular structure of this compound was confirmed by X-ray diffraction. The reactions of (R(2)N)(2)P-P(SiMe(3))Li with [CpZrCl(3)] yield the related tetraphosphetanes R(2)NP(μ(2)-PSiMe(3))(2)PNR(2), which apparently are formed as a result of a transfer of NR(2) groups from a P atom to the Zr atom.

Reactivity of Phosphanylphosphinidene Complex of Tungsten(VI) toward Phosphines: A New Method of Synthesis of catena-Polyphosphorus Ligands.

The reactivity of an anionic phosphanylphosphinidene complex of tungsten(VI), [(2,6-i-Pr2C6H3N)2(Cl)W(η(2)-t-Bu2P═P)]Li·3DME toward PMe3, halogenophosphines, and iodine was investigated. Reaction of the starting complex with Me3P led to formation of a new neutral phosphanylphosphinidene complex, [(2,6-i-Pr2C6H3N)2(Me3P)W(η(2)-t-Bu2P═P)]. Reactions with halogenophosphines yielded new catena-phosphorus complexes. From reaction with Ph2PCl and Ph2PBr, a complex with an anionic triphosphorus ligand t-Bu2P-P((-))-PPh2 was isolated. The main product of reaction with PhPCl2 was a tungsten(VI) complex with a pentaphosphorus ligand, t-Bu2P-P((-))-P(Ph)-P((-))-P-t-Bu2. Iodine reacted with the starting complex as an electrophile under splitting of the P-P bond in the t-Bu2P═P unit to yield [(1,2-η-t-Bu2P-P-P-t-Bu2)W(2,6-i-Pr2C6H3N)2Cl], t-Bu2PI, and phosphorus polymers. The molecular structures of the isolated products in the solid state and in solution were established by single crystal X-ray diffraction and NMR spectroscopy.

1,1,2,2-Tetra-kis(diisopropyl-amino)diphosphane.

In the title compound, C24H56N4P2, the distance between the P atoms [2.2988 (8) and 2.3013 (13) Å in the major and minor occupancy components, respectively] is one of the longest reported for uncoordinated diphosphanes. The whole molecule is disordered over two positions with site-occupation factors of 0.6447 (8) and 0.3553 (8). The structure adopts the synperiplanar conformation in the solid state [N—P—P—N torsion angle = 14.7 (5)°].

Synthetic, Structural, and Spectroscopic Characterization of a Novel Family of High-Spin Iron(II) [(β-Diketiminate)(phosphanylphosphido)] Complexes

This work describes a series of iron(II) phosphanylphosphido complexes. These compounds were obtained by reacting lithiated diphosphanes R2PP(SiMe3)Li (R = t-Bu, i-Pr) with an iron(II) β-diketiminate complex, [LFe(μ2-Cl)2Li(DME)2] (1), where DME = 1,2-dimethoxyethane and L = Dippnacnac (β-diketiminate). While the reaction of 1 with t-Bu2PP(SiMe3)Li yields [LFe(η1-Me3SiPP-t-Bu2)] (2), that of 1 with equimolar amounts of i-Pr2PP(SiMe3)Li, in DME, leads to [LFe(η2-i-Pr2PPSiMe3)] (3). In contrast, the reaction of 1 with (i-Pr2N)2PP(SiMe3)Li provides not an iron-containing complex but 1-[(diisopropylamino)phosphine]-2,4-bis(diisopropylamino)-3-(trimethylsilyl)tetraphosphetane (4). The structures of 2-4 were determined using diffractometry. Thus, 2 exhibits a three-coordinate iron site and 3 a four-coordinate iron site. The increase in the coordination number is induced by the change from an anticlinal to a synclinal conformation of the phoshpanylphosphido ligands. The electronic structures of 2 and 3 were assessed through a combined field-dependent 57Fe Mössbauer and high-frequency and -field electron paramagnetic resonance spectroscopic investigation in conjunction with analysis of their magnetic susceptibility and magnetization data. These studies revealed two high-spin iron(II) sites with S = 2 ground states that have different properties. While 2 exhibits a zero-field splitting described by a positive D parameter (D = +17.4 cm-1; E/D = 0.11) for 3, this parameter is negative [D = -25(5) cm-1; E/D = 0.15(5)]. Density functional theory (DFT) and time-dependent DFT (TDDFT) calculations provide insights into the origin of these differences and allow us to rationalize the fine and hyperfine structure parameters of 2 and 3. Thus, for 2, the spin-orbit coupling mixes a z2-type ground state with two low-lying {xz/yz} orbital states. These interactions lead to an easy plane of magnetization, which is essentially parallel to the plane defined by the N-Fe-N atoms. For 3, we find a yz-type ground state that is strongly mixed with a low-lying z2-type orbital state. In this case, the spin-orbit interaction leads to a partial unquenching of the orbital momentum along the x axis, that is, to an easy axis of magnetization oriented roughly along the Fe-P bond of the phosphido moiety.

The reactivity of 1,1-dichloro-2,2-di-tert-butyldiphosphane towards lithiated metal carbonyls: a new entry to phosphanylphosphinidene dimers

Reactions of [Cp*(OC)3M]Li (Cp* = C5Me5, M = Mo, W) towards t-Bu2P-PCl2 lead to the formation of phosphanylphosphinidene dimers [Cp*(OC)3M(η(2)-t-Bu2P-P)]2 in fairly good yields. The formation of a tetraphosphorus ligand proceeds via reductive dimerization of t-Bu2P-P units. NMR, X-ray investigations and DFT calculations show that the resulting tetraphosphorus ligand has a structure of dication t-Bu2P(+)=P-P=P(+)t-Bu2.

[N,N'-Bis(2,6-diisopropyl-phen-yl)pentane-2,4-diamine-(1-)-2κN,N']-μ(2)-chlorido-1:2κCl:Cl-chlorido-2κCl-bis-(1,2-di-methoxy-ethane-1κO,O')iron(II)lithium.

In the title compound, [FeLi(C29H41N2)Cl2(C4H10O2)2], the FeII atom is coordinated by two N and two Cl atoms, generating a distorted FeN2Cl2 tetrahedral geometry. Additionally, one of the chloride atoms bridges to a lithium ion, which is solvated by two dimethoxyethane molecules and is coordinated in a distorted trigonal-bipyramidal environment. The central Fe, Cl (× 2) and Li atoms are coplanar with a maximum deviation of 0.034 Å.

Bis(diethyl-amido-κN)(diethyl-amine-κN)bis-(2,6-diisopropyl-phenyl-amido-κN)zirconium(IV).

In the title compound, [Zr(C12H18N)2(C4H10N)2(C4H11N)] or [Zr(HNC6H3 iPr2)2(NEt2)2(HNEt2)], which was obtained by the reaction of Zr(NEt)4 with iPr2C6H3NH2, the ZrIV atom is in a trigonal–bipiramidal geometry in which the N atoms from two iPr2C6H3NH and one NEt2 ligand occupy the equatorial positions, and the N atoms of an NEt2 and an Et2NH ligand occupy the apical positions. An intramolecular N—H⋯N contact occurs. There are two independent molecules in the asymmetric unit.

catena-Poly[{μ-η:η-1-[2-(dimethyl-amino)-ethyl-κN]cyclo-penta-dien-yl}-lithium(I)-(μ-1,1,3,3-tetra-tert-butyl-triphosphane-κP:P,P)lithium(I)].

The title compound, [Li2(C9H14N)(C16H36P3)]n, is a by-product of the reaction of [Cp(C5H4CH2CH2NMe2)ZrCl2]n with tBu2P–P(SiMe3)Li in toluene. It is a coordination polymer composed of infinite chains running along [010]. One Li(I) atom is chelated by the cyclopentadienyl ring and and the N atom of the scorpionate ligand and a P atom, whereas the other Li(I) atom is coordinated by the backside of the cyclopentadienyl ring and two P atoms. Both Li(I) atoms adopt a distorted trigonal coordination. The structure was determined from a twinned crystal, but only the data from the main twin component was used. The fraction of components in the crystal was 0.555:0.445 and the twin matrix corresponds to twofold rotation about the c axis (00/00/001).

Dispiro­[cyclo­propane-1,5′-endo-tricyclo­[5.2.1.02,6]deca-3,8-diene-10′,1′′-cyclo­propane]

The title compound, C14H16, is built up from three five-membered rings. Two of the five-membered rings display an envelope conformation and the third one is almost planar (r.m.s. deviation = 0.014 Å).