Jerzy Pikies

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.

Zum Einfluß der PR3-Liganden auf Bildung und Eigenschaften der Phosphinophosphiniden-Komplexe [{η2-tBu2P–P}Pt(PR3)2] und [{η2-tBu2P1–P2}Pt(P3R3)(P4R′3)]

Die aus (R3P)2PtCl2 und C2H4 gebildeten Verbindungen [{η2-C2H4}Pt(PR3)2] (PR3 = PMe3, PEt3, PPhEt2, PPh2Et, PPh2Me, PPh2iPr, PPh2tBu und P(p-Tol)3) reagieren mit tBu2P–P=PMetBu2 zu den Phosphinophosphiniden-Komplexen [{η2-tBu2P–P}Pt(PMe3)2], [{η2-tBu2P–P}Pt(PEt3)2], [{η2-tBu2P–P}Pt(PPhEt2)2], [{η2-tBu2P–P}Pt(PPh2Et)2], [{η2-tBu2P–P}Pt(PPh2Me)2], [{η2-tBu2P–P}Pt(PPh2iPr], [{η2-tBu2P–P}Pt(PPh2tBu)2] und [{η2-tBu2P–P}Pt(P(p-Tol)3)2]. [{η2-tBu2P–P}Pt(PPh3)2] reagiert mit PMe3 und PEt3 sowie mit tBu2PMe, PiPr3 und P(c-Hex)3 unter Substitution eines PPh3-Liganden zu den Verbindungen [{η2-tBu2P1–P2}Pt(P3Me3)(P4Ph3)], [{η2-tBu2P1–P2}Pt(P3Ph3)(P4Me3)], [{η2-tBu2P1–P2}Pt(P3Et3)(P4Ph3)], [{η2-tBu2P1–P2}Pt(P3MetBu2)(P4Ph3)], [{η2-tBu2P1–P2}Pt(P3iPr3)(P4Ph3)] und [{η2-tBu2P1–P2}Pt(P3(c-Hex)3)(P4Ph3)]. [{η2-tBu2P–P}Pt(P(p-Tol)3)2] bildet mit tBu2PMe das [{η2-tBu2P1–P2}Pt(P3MetBu2)(P4(p-Tol)3)]. Es werden die NMR-Daten der Verbindungen angegeben und im Hinblick auf den Einflus der PR3-Liganden diskutiert.

Hunting for the Magnesium(I) Species: Formation, Structure, and Reactivity of some Donor‐Free Grignard Compounds

Magnesium bromide radicals have to be prepared as high-temperature molecules and trapped as a metastable solution because a seemingly simple reduction of donor-free Grignard compounds failed. However, the essential role of magnesium(I) species during the formation of Grignard compounds could be demonstrated experimentally.

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.

Bildung und Strukturen von [{η2‐tBu2P–P=P–PtBu2}Pt(PR3)2]

tBu2P–P=P(Me)tBu2 reagiert sowohl mit [{η2-C2H4}Pt(PR3)2] als auch mit [{η2-tBu2P–P}Pt(PR3)2] unter Bildung von [{η2-tBu2P–P=P–PtBu2}Pt(PR3)2]; PR3 = PMe33 a, PEtPh23 b, 1/2 dppe 3 c, PPh33 d, P(p-Tol)33 e. Die Verbindungen sind uber 1H- und 31P-NMR-Untersuchungen belegt. Von 3 b und 3 d liegen Einkristallstrukturanalysen vor. 3 b kristallisiert triklin, P1 (Nr. 2) mit a = 1212,58(7), b = 1430,74(8), c = 1629,34(11) pm, α = 77,321(6), β = 70,469(5), γ = 87,312(6)°. 3 d kristallisiert triklin, P1 (Nr. 2) mit a = 1122,60(9), b = 1355,88(11), c = 2025,11(14) pm, α = 83,824(9), β = 82,498(9), γ = 67,214(8)°. Coordination Chemistry of P-rich Phosphanes and Silylphosphanes. XVIII. Syntheses and Structures of [{η2-tBu2P–P=P–PtBu2}Pt(PR3)2] tBu2P–P=P(Me)tBu2 reacts with [{η2-C2H4} · Pt(PR3)2] as well as with [{η2-tBu2P–P}Pt(PR3)2] yielding [{η2-tBu2P–P=P–PtBu2}Pt(PR3)2]; PR3 = PMe33 a, PEtPh23 b, 1/2 dppe 3 c, PPh33 d, P(p-Tol)33 e. All compounds are characterized by 1H and 31P NMR spectra, for 3 b and 3 d also crystal structure determinations were performed. 3 b crystallizes in the triclinic space group P1 (No. 2) with a = 1212.58(7), b = 1430.74(8), c = 1629.34(11) pm, α = 77.321(6), β = 70.469(5), γ = 87.312(6)°. 3 d crystallizes in the triclinic space group P1 (No. 2) with a = 1122.60(9), b = 1355.88(11), c = 2025.11(14) pm, α = 83.824(9), β = 82.498(9), γ = 67.214(8)°.

Reactions of Lithiated Diphosphanes R2P–P(SiMe3)Li (R = tBu and iPr) with [MeNacnacTiCl2·THF] and [MeNacnacTiCl3]. Formation and Structure of TitaniumIII and TitaniumIV β-Diketiminato Complexes Bearing the Side-on Phosphanylphosphido and Phosphanylphosphinidene Functionalities

β-Diketiminate complexes of TiIII-containing phosphanylphosphido ligands [MeNacnacTi(Cl){η2-P(SiMe3)-PR2}] (MeNacnac- = [Ar]NC(Me)CHC(Me)N[Ar]; Ar = 2,6-iPr2C6H3) were prepared by reactions of [MeNacnacTiCl2·THF] with lithium derivatives of diphosphanes R2P-P(SiMe3)Li (R = tBu, iPr) in toluene solutions. Surprisingly, reactions of [MeNacnacTiCl2·THF] with R2P-P(SiMe3)Li in THF solutions led to TiIV complexes containing phosphanylphosphinidene ligands [MeNacnacTi(Cl)(η2-P-PtBu2)] via an autoredox path involving a migration of a nitrene NAr from the Nacnac skeleton to the Ti centers. Solid-state structures of [MeNacnacTi(Cl){η2-P(SiMe3)-PtBu2}] (1a) and [MeNacnacTi(Cl)(η2-P-PtBu2)] (two isomers 2a1, 2a2) together with [MeNacnacTi(Cl){η2-P(SiMe3)-PiPr2}] (1b) and [MeNacnacTi(Cl)(η2-P-PiPr2)] (2b) were established by the single-crystal X-ray diffraction and display clearly side-on geometry of the (Me3Si)P-PR2 and P-PR2 moieties in the solid state. Phosphanylphosphinidene complexes [MeNacnacTi(Cl)(η2-P-PR2)] indicate that the 31P NMR resonances of phosphinidene P atoms appear at a very low field in solution and in the solid state.

[Co4P2(PtBu2)2(CO)8] und [{Co(CO)3}2P4tBu4] aus Co2(CO)8 undtBu2P-P=P(Me)tBu2

Co2(CO)8 bildet mit tBu2P–P=P(Me)tBu2 die Verbindungen [Co4P2(PtBu2)2(CO)8] (1) und [{η2-tBu2P=P–P=PtBu2}{Co(CO)3}2] (2 a) cis, (2 b) trans. In Verbindung 1 bilden vier Co- und zwei P-Atome eine tetragonale Bipyramide, in der je zwei benachbarte Co-Atome uber eine tBu2P-Gruppe μ2-verbruckt sind. An jedes Co-Atom sind noch zwei CO-Gruppen gebunden. In den Verbindungen 2 a und 2 b sind die Co(CO)3-Gruppen an die endstandigen P2-Einheiten jeweils η2-koordiniert, wobei sich die cis- und trans-Anordnungen 2 a und 2 b ausbilden. 1 kristallisiert orthorhombisch in Pnnm (Nr. 58) mit a = 879,41(5), b = 1199,11(8), c = 1773,65(11) pm. 2 a kristallisiert monoklin in P21/n (Nr. 14) mit a = 875,97(5), b = 1625,36(11), c = 2117,86(12) pm, β = 91,714(7)°. 2 b kristallisiert triklin in P 1 (Nr. 2) mit a = 812,00(10), b = 843,40(10), c = 1179,3(2) pm, α = 100,92(2)°, β = 102,31(2)°, γ = 102,25(2)°. Coordination Chemistry of P-rich Phosphanes and Silylphosphanes. XIX. [Co4P2(PtBu2)2(CO)8] and [{Co(CO)3}2P4tBu4] from Co2(CO)8 and tBu2P–P=P(Me)tBu2 Co2(CO)8 reacts with tBu2P–P=P(Me)tBu2 yielding the compounds [Co4P2(PtBu2)2(CO)8] (1) and [{η2tBu2P=P–P=PtBu2}{Co(CO)3}2] (2 a) cis, (2 b) trans. In 1, four Co and two P atoms form a tetragonal bipyramid, in which two adjacent Co atoms are μ2-bridged by tBu2P groups. Additionally, two CO groups are linked to each Co atom. In 2 a and 2 b, each of the Co(CO)3 units is η2-coordinated to the terminal P2 units resulting in the cis- and trans-configurations 2 a and 2 b. 1 crystallizes in the orthorhombic space group Pnnm (No. 58) with a = 879,41(5), b = 1199,11(8), c = 1773,65(11) pm. 2 a crystallizes in the monoclinic space group P21/n (No. 14) with a = 875,97(5), b = 1625,36(11), c = 2117,86(12) pm, β = 91,714(7)°. 2 b crystallizes in the triclinic space group P 1 (No. 2) with a = 812,00(10), b = 843,40(10), c = 1179,3(2) pm, α = 100,92(2)°, β = 102,31(2)°, γ = 102,25(2)°.

Sila-biperiden und endo-Sila-biperiden: Synthesen, Kristallstrukturen und antimuscarinische Eigenschaften

Summary Starting from trichloro(vinyl)silane (Cl 3 SiCH=CH 2 ), the muscarinic antagonists sila- biperiden [ rac -(Si RS ,C2 SR ) -exo - 2 ] and endo -sila-biperiden [ rac -(Si RS ,C2 SR )- endo - 2 ] were prepared by a seven-step synthesis. Both silanols are configurationally stable in inert organic solvents but undergo slow epimerization in aqueous solution (pH 7.4, 32°C) by inversion of the configuration at the silicon atom. The relative configurations of sila-biperiden and endo -sila- biperiden were determined by single-crystal X-ray diffraction. Both compounds form intermolecular O-H ⋯ N hydrogen bonds in the crystal leading to the formation of centrosymmetric dimers (sila-biperiden) and infinite chains ( endo -sila-biperiden), respectively. Sila-biperiden is a silicon analogue (C/Si exchange) of the antiparkinsonian drug biperiden [ rac -(C RS /C2 SR ) -exo - 1 ]. In functional pharmacological experiments, as well as in radioligand competition studies, biperiden, sila-biperiden and endo -sila-biperiden behaved as simple competitive antagonists at muscarinic M1-, M2-, M3- and M4-receptors. The three compounds displayed the highest affinity for M1-receptors (pA 2 values: 8.72–8.80; pK i values: 8.8–9.1), intermediate affinity for M4- and M3-receptors, and lowest affinity for M2-receptors (pA 2 values: 7.57–7.79; pK i values: 7.7–7.8). The affinity profile (M1 ≫ M4 ≫ M3 ≫ M2) of biperiden, sila-biperiden and endo -sila-biperiden is qualitatively similar to that of the M1-selective muscarinic antagonist pirenzepine. The antimuscarinic properties of the C/Si analogues biperiden and sila-biperiden are almost identical.

(Di-tert-butyl­phosphan­yl)bis­(diphenyl­phosphan­yl)phosphane

The title phosphane, C32H38P4 or (Ph2P)2P(PtBu2), has a P atom that is linked to another three P atoms in a pyramidal configuration; the P—P distances in the range 2.2231 (7)–2.2446 (7) Å indicate that the P—P bonds are single bonds.