SYNTHESIS AND NMR CHARACTERIZATION OF P-VINYL SUBSTITUTED PHOSPHAZENE PRECURSORS1

Abstract

The reactions of either PhPCl₂ or PCl₃ with (Me₃Si)₂NLi followed by H₂C[dbnd]CHMgBr were used to prepare the new P-vinyl substituted [bis(trimethylsilyl)amino]phosphines, (Me₃Si)₂NP(R)CH[dbnd]CH₂ [1: R=Ph, 2: CH[dbnd]CH₂, 3: R=Me, and 4: R=N(SiMe₃)₂]. Oxidative bromination of phosphines 3–1 afforded the P-bromo-P-vinyl-N-(trimethylsilyl)phosphoranimines, Me₃SiN[dbnd]P(CH[dbnd]CH₂)(R)Br [5: R=Ph, 6: R=CH[dbnd]CH₂, 7: R=Me], which, upon treatment with CF₃CH₂OH/Et₃N, were subsequently converted to the P-trifluoroethoxy derivatives, Me₃SiN[dbnd]P(CH[dbnd]CH₂)(R)OCH₂CF₃ [8: R=Ph, 9: R=CH[dbnd]CH₂, 10: R=Me]. Compounds 1–10, which are of interest as potential precursors to P-vinyl substituted poly(phosphazenes), were fully characterized by elemental analyses (except for the thermally unstable P-Br derivatives 5–7) and NMR spectroscopy (¹H, ¹³C, and ³¹P) including complete analysis of the vinylic proton splitting patterns via HOM2DJ experiments.     

Synthesis of S-Sulfonyl-Phosphinothioates and Phosphinodithioates,a Novel Organophosphorus-sulphur Structure

Abstract

Racemic and optically active S-sulphonylphosphinothioates R-SO₂-S-P(O)Bu'Ph and dithioates R-SO₂-S-P(S)Bu'Ph (R [dbnd] Me, p-tolyl) have been prepared for the first time by the reaction of the corresponding acids Bu'PhP(S)SH (X [dbnd] O,S) of their salts with sulphonylating reagents RSO₂-Y (Y [dbnd] Cl, O-SO₂R, triazolide).     

Imides of 2-Trifluoroacetylphenol and other Trifluoracetic acid Esters: Novel Reactions with Phosphorus(III) Derivates

Abstract

The imido derivates of 2-trifluoroacetylphenol, 1 (R¹=H, Me, iPr) react with the isocyanatophosphites (R²O)₂PNCO, 2 (R²[dbnd]Et, R²-R²[dbnd]CMe₂-CMe₂) to yield the bicyclic compounds 3, wheras in case of 1 (R¹[dbnd](CH₂)₂NMe2) the λ³σ³P compounds 4 are found. The phosphorus(III) chlorides R3PC12 (R³[dbnd]Ph, OEt) and 1 (R¹[dbnd]H, Me) give rise to furnish the tricyclic phosphoranes 5. However with 1 (R¹[dbnd]iPr) phosphite 6 is obtained, which adds hexafluoracetone to give the 1,3,2λ⁵σ⁵-dioxaphospholane 7. 2-(Trifluoracetoxy)pyridine 8. reacts with Tris(trimethylsily1)phosphite to yield the bis(phosph0nate) 10. Some molecular structures are discussed on the basis of x-ray diffraction results.     

REACTIONS OF A PHOSPHORANIMINE ANION WITH SOME ORGANIC ELECTROPHILES

Abstract

The reactions of a variety of electrophiles with the N-silyl-P-trifluoroethoxyphosphoranimine anion Me₃Sin°P(Me)(OCH₂CF₃)CH^? ₂ (1a), prepared by the deprotonation of the dimethyl precursor Me₃SiN[dbnd]P(OCH₂CF₃)Me₂ (1) with n-BuLi in Et₂O at-78°C, were studied. Thus, treatment of 1a with alkyl halides, ethyl chloroformate, or bromine afforded the new N-silylphosphoranimine derivatives Me₃SiN[dbnd]P(Me)(OCH₂CF₃)CH₂R [2: R = Me, 3: R = CH₂Ph, 4: R = CH[sbnd]CH₂, 5: R = C(O)OEt, and 6: R = Br]. In another series, when 1a was allowed to react with various carbonyl compounds, 1,2-addition of the anion to the carbonyl group was observed. Quenching with Me₃SiCl gave the O-silylated products Me₃SiN[dbnd]P(Me)(OCH₂CF₃)CH₂°C(OSiMe₃)R¹R² [7: R ¹ = R ² = Me; 8: R ¹ = Me, R ² = Ph; 9: R¹ = Me, R ² = CH[sbnd]CH₂; and 10: R ¹ = H, R ² = Ph]. Compounds 2–10 were obtained as distillable, thermally stable liquids and were characterized by NMR spectroscopy (¹H, ¹³C, and ³¹P) and elemental analysis.     

Pt(II) ASSISTED DEOXYGENATION OF COORDINATED SULFOXIDES BY HYDROCHLORIC- OR HYDROBROMIC ACID

Abstract

The interaction of the complexes (Et₄ N)[Pt(R₂ SO)X₃] (R = Me, Et, CH₂ Ph, X [dbnd] C1; R [dbnd] Me, X [dbnd] Br) and cis-[Pt(Me₂ SO)₂ Cl₂] with concentrated HX (X [dbnd] Cl. Br) results in the reduction of the coordinated sulfoxides and oxidation of Pt(II) to Pt(IV). As a result [Pt(R₂ S)X₅ and [Pt(R₂S)₂ X₄] are formed. Ligands R₂ S can be removed from the complexes and isolated in a free state.     

Transition Metal Substituted Phosphanes: Synthesis,Reactivity and Pyramidal Inversion

Abstract

The synthesis of transition metal substituted phosphanes C₅H₅(CO)₂M-PPh₂, C₅H₅(CO)₂(Me₃P)M-PPh₂ (M [dbnd] Mo, W) and C₅H₅(CO)(Me₃P)FePPhR (R [dbnd] Me, Ph) is described as well as their reactivity towards a series of electrophilic and oxidizing reagents.     

PHOSPHORORGANISCHE VERBINDUNGEN 921

Abstract

Optisch aktive Phosphinigsäureamide R¹R²PNR₂ 4 (R¹ [dbnd] Ph, R² [dbnd] Me bzw. Et, R [dbnd] Et) sind durch kathodische Spaltung bzw.Cyanolyse optisch aktiver Amidophosphoniumsalze [R¹R²R³PNR₂]X (R¹ [dbnd] Ph. R² [dbnd] Me bzw. Et. R³ [dbnd] Bz bzw. All, R [dbnd] Et) unter Erhaltung der Konfiguration in hohen Ausbeuten zugänglich.

Optisch aktive Amidophosphoniumverbindungen, z.B. Ethyl-methyl-phenyl-diethylamido-phosphoniumiodid 10 oder Benzyl-ethyl-phenyl-diethylamido-phosphoniumbromid 12 werden erhalten:

a) aus den optisch aktiven tertiären Phosphinen, z.B. R-(+)Benzyl-methyl-phenyl-phosphin 6 bzw. S-(-)Ethyl-methyl-phenyl-phosphin 13 durch Umsetzung mit Alkyl- oder Arylaziden über die Phosphinimine 7 mit anschließender Alkylierung.

b) durch Alkylierung der optisch aktiven Phosphinigsäureamide 4. Die unter a) und b) genannten Umsetzungen verlaufen unter Erhaltung der Konfiguration.

c) Bei der Umsetzung optisch aktiver tertiärer Phosphine mit N-Halogenaminen entstehen nur racemische Amidophosphoniumsalze.

Optisch aktive Amidophosphoniumsalze, z.B. S(+)-Benzyl-methyl-phenyl-diethylamido-phosphoniumbromid 8 oder R-(-)-Ethyl-methyl-phenyl-diethylamido-phosphoniumiodid 10 werden bei der Einwirkung wäßriger Alkalien unter Inversion zu den entsprechenden Phosphinoxiden 9 bzw. 11 abgebaut. Optisch aktive Amidophosphoniumsalze, z.B. S(+)-Benzyl-ethyl-phenyl-diethylamido-phosphoniumbromid 12, werden mit LiAlH₄ retentiv unter Abspaltung des Aminliganden in die zugrundeliegenden optisch aktiven tertiären Phosphine übergeführt. Die Olefinierung von Benzaldehyd mit S(+)-Benzyl-ethyl-phenyl-diethylamido-phosphoniumbromid 5 ergibt unter Retention Stilben und optisch aktives Ethyl-phenyl-phosphinsäure-diethylamid 17, das auch durch Oxidation von R(-)-4 mit H₂O₂ erhalten wird. Schwefelung von R(-)-4 liefert das optisch aktive Ethyl-phenyl-thiophosphinsäure-diethylamid 18.

Das optisch aktive Phosphinigsäure-diethylamid 4 racemisiert allein und in Kohlenwasserstoffen gelöst bei 130°C nach einer Reaktion nullter Ordnung. Die Racemisierung wird durch Austausch der sekundären Aminogruppe über cyclische Assoziate verursacht. Beweis: Verbindungen mit unterschiedlichen. Substituenten am Phosphor- und Stickstoff tauschen beim dreistündigen Erhitzen auf 200°C die sekundären Aminogruppen aus. Es entstehen neue Phosphinigsäureamide in annähernd äquivalenten Mengen.

In Nitrobenzol bildet sich mit Phosphinigsäureamiden ein Charge-Transfer-Komplex, der im Falle des optisch aktiven Ethyl-phenyl-phosphinigsäure-diethylamids 4 bereits bei Zimmertemperatur eine schnelle Racemisierung bewirkt.

Optisch aktives Ethyl-phenyl-phosphinigsäure-diethylamid 4 liefert als Co-Katalysator bei der Homogenhydrierung von α-Ethylstyrol mit (RhCl-Hexadien-1,5)₂ 2-Phenylbutan mit einer optischen Ausbeute von 34%.     

Syntheses and Reactions of Dimolybdenum Alkyne Compounds Containing Functionally Substituted Ligands. The Crystal Structure of [Co2Mo2(μ4-CHCH)(μ-CO)4(CO)4-(η5-C5H4C(O)Me)2]

Abstract

Three dimolybdenum alkyne complexes containing functionally substituted ligands [Mo₂(μ-CHCH)(CO)₄(η⁵?C₅H₄C(O)R)₂] [R ? OEt, (1a); R ? Me, (1b); R ? Ph, (1c)] were synthesized by reactions of acetylene with in situ generated metal-metal triply bonded complexes [Mo(CO)₂(η⁵?C₅H₄C(O)R)]₂ (R ? OEt, Me, Ph). Further reaction of (1a), (1b) or (1c) with Co₂(CO)₈ in refluxing toluene gave another three new butterfly compounds [Co₂Mo₂-(μ₄-CHCH)(μ-CO)₄(CO)₄(η⁵-C₅H₄C(O)R)₂] [R ? OEt, (2a); R ? Me, (2b); R ? Ph, (2c)]. The resulting compounds were characterized by elemental analyses, IR, ¹H NMR and MS. The crystal structure of (2b) was determined by single-crystal X-ray analysis. The results indicate that the existence of functional groups on the cyclopentadienyl ring has an influence on the reactivity of this type of complex.     

SYNTHESIS AND CHARACTERISATION OF DIORGANOANTIMONY(III) COMPLEXES OF THIOSEMICARBAZONES

Abstract

The interaction of the sodium salts of thiosemicarbazones with diphenylantimony chloride in 1:1 molar ratio in benzene solution lead to the formation of derivatives, Ph₂Sb[SC(NH₂)NN: C(R)R′] where R = H; R′ [dbnd] C₆H₅, CH₃OC₆H₄, C₆H₅CH[dbnd]CH, and R′ [dbnd] CH₃; R′[dbnd]C₆H₅, CH₃OC₆H₄, C₆H₄CH₃, respectively. The resulting complexes have been characterised on the basis of elemental analyses and molecular weight determination. The mode of bonding of the ligands with the metal atom has been proposed on the basis of I.R., ¹H and ¹³C NMR studies. All these ligands are found to behave as monofunctional bidentate moiety in these complexes.     

SYNTHETIC,N.M.R. SPECTROSCOPIC AND X-RAY CRYSTALLOGRAPHIC INVESTIGATIONS ON THE PRODUCTS OF THE REACTIONS OF PHENYL (METHYL) PHOSPHONOTHIOIC DICHLORIDE AND THIOPHOSPHORYL CHLORIDE AND PSCL3 WITH PRIMARY AMINES

Abstract

The syntheses in solution of (i) 2,4-dialkylamino-, (ii) 2,4-dimethyl-, and (iii) 2,4-diphenyl-2,4-dithio-cyclodiphosph(V)azanes, [R′P(S)NR]₂ (R′ = NHR, Ph, or Me; R = alkyl), derived from thiophosphoryl trichloride, methylphosphonothioic and phenylphosphonothioic dichlorides and primary alkylamines are described. N.m.r. spectroscopic properties for these cyclodiphosph(V)azanes and their monomeric precursors, R′P(S)(NHR)₂ (R′ = NHR, Ph, or Me; R = alkyl), are presented and structural inferences are drawn from this data. The X-ray crystal structure of [PhP(S)NBuⁱ]₂ is reported.     

Enol ethers and acetals: acylation with dichloroacetyl,acetyl and benzoyl chloride in ionic liquid medium

Synthesis of 4-alkoxy-1,1-dichloro-3-alken-2-ones [CHCl₂C(O)C(R²)C(R¹)-OR, where R, R¹, R² = Et, H, H; Me, Me, H; Et, H, Me; Me, –(CH₂)₂–; Me, –(CH₂)₃–; Et, Et, H; Et, Bu, H; Et, i-Pr, H; Et, i-Bu, H; Me, Ph, H; Me, thien-2-yl, H] from acylation of enol ethers and acetals with dichloroacetyl chloride, in ionic liquid ([BMIM][BF₄] or [BMIM][PF₆]) is reported. The synthesis of alkenones [R³–C(O)C(R²)C(R¹)-OR], where R/R¹/R²/R³ = Et/H/H/Ph, t-Bu/H/H/Ph, Me/-(CH₂)₄/Ph, Me/-(CH₂)₄/Me] from the reaction of enol ethers with benzoyl chloride or acetyl chloride, in ionic liquid [BMIM][BF₄], is also reported. Last products are described for the first time.     

Synthesis,characterization, and antibacterial activity of organotin(IV) complexes with 2-hydroxyacetophenone thiocarbohydrazone

Six new organotin(IV) complexes were synthesized by direct reaction of RSnCl₃ (R?=?Me, Bu and Ph) or R₂SnCl₂ (R?=?Me, Bu and Ph) and 2-hydroxyacetophenone thiocarbohydrazone [H₂APTC] under purified nitrogen in the presence of base in 1?:?2?:?1 molar ratio (metal: base: ligand). Complexes 2–7 have been characterized by elemental analyses, molar conductivity, UV-Visible, IR and ¹H NMR spectral studies. Complexes 2–7 are non-electrolytes. The molecular structure of [Me₂Sn(APTC)]?·?(C₂H₅OH) (5) has been determined by X-ray diffraction analysis. The thiocarbohydrazone ligand (1) and 2–7 have been tested for antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi and Enterococci aeruginosa.     

A PETERSON OLEFINATION REACTION USING SILYL-SUBSTITUTED SULFONAMIDE CARBANIONS. SYNTHESIS OF VINYLIC SULFONAMIDES

Abstract

α-Trimethylsilyl-substituted sulfonamides RCH(SiMe₃)SO₂N(CH₃)₂ (3), (R[dbnd]H, CH₃ and C₆H₅) are synthetized in almost quantitative yields. Their lithium derivatives 4 undergo a smooth Peterson olefination reaction with nonenolisable carbonyl compounds to give good to excellent yields of vinylsulfonamides 6. With R[dbnd]H, the reaction is highly E-stereoselective. Moderate stereoselectivity is obtained in the cases of R[dbnd]CH₃ and R[dbnd]C₆H₅.     

Synthesis of new water soluble diorganotin(IV) complexes with hydrazones derived from Girard-T reagent as antibacterial and anticancer agents

Three new water-soluble organotin complexes R₂Sn(5-BrSalGT)Cl [R = Ph, Me] and Ph₂Sn(2-OHNaphGT)Cl have been synthesized by the reaction of R₂SnCl₂ (R = Ph or Me) with Schiff bases derived from condensation of Girard-T reagent with 5-bromosalicylaldehyde and 2-naphthaldehyde, (5-BrH₂SalGT)Cl (1) and (2-OHH₂NaphGT)Cl (2). The synthesized compounds have been investigated by elemental analysis, conductometric measurements, IR, ¹H NMR, and ¹¹⁹Sn NMR spectroscopy. These data show that the deporotonated ligand is coordinated to Sn(IV) via ONO atoms and six-coordinate zwitterionic complexes are formed. The ligands and their complexes were investigated for their in vitro toxicity against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The results show remarkable antibacterial activity against the studied bacteria. All complexes exhibit more inhibitory effects than the parent ligand. The anticancer activity of all compounds were also performed on HN5 cell line and (2-OHH₂NaphGT)Cl with concentration of 1 mg mL^?1 was found to show higher anticancer activity than other compounds.     

The preparation and characterisation of a series of cationic bimetallic linear triphos-bridged complexes of the type [Mo (CO) (L,L′ or L″–P) (η2-RC2R′)Cp] [BF4] {L,L′ or L″= [WI2 (CO){PhP(CH2CH2PPh2)2–P,P′} (η2-RC2R′)] (L,R=R′=Me; L′,R=R′=Ph; L″,R=Me,R′=Ph}

Equimolar quantities of [Mo (CO) (η²-RC₂R′)₂Cp] [BF₄] (R=R′=Me Ph R=Me R′=Ph) and L L′ or L″ {L L′ or L″= [WI₂ (CO){PhP(CH₂CH₂PPh₂)₂-PP′} (η²-RC₂R′)]} (L R=R′=Me L′ R=R′=Ph L″ R=Me R′=Ph) react in CH₂Cl₂ at room temperature to give the new bimetallic complexes[Mo (CO) (L L′ or L″–P) (η²-RC₂R′)Cp] [BF₄] (1–9) via displacement of the alkyne ligand on the molybdenum centre The complexes have been characterised by elemental analysis IR and ¹ H NMR spectroscopy and in selected cases by ³¹ P NMR spectroscopy.     

O-Alkyl Trithiophosphate Derivatives of Triorganotin(IV) and S-Alkyl Trithiophosphate Derivatives of Diorganotin(IV) Chloride

Reactions of triorganotin chlorides with potassium salt of O-alkyl trithiophosphate [ROP(S)(SK)₂; R = Me, Prⁱ, Ph] in 2:1 molar ratio in anhydrous benzene yield triorganotin O-alkyl trithiophosphate of the type ROP(S) [SSnR′₃]₂ R = Me, Prⁱ; Ph, R′ = Prⁿ, Buⁿ, Ph] which are found to be monomeric in nature. These complexes are soluble in common organic solvents. Similar reactions of diorganotin chloride with dipotassium salt of S-alkyl trithiophosphate yield diorganotin-S-alkyl trithiophosphate of the type [(RS)P(O)S₂]₂SnR′₂; R = Me, Prⁱ; R′ = Me, Et, Ph, which also are found to be monomeric in nature and are soluble in common organic solvents. The newly synthesized derivatives have been characterized by physicochemical and spectroscopic techniques, IR, NMR (¹H, ³¹P, and ¹¹⁹Sn).     

Reaction of Methylene Bridged Diphosphines R2P-CH2-PRH AND RHP-CH2-PRH (R [dbnd] Me,Pri, But,CH2-Ph) with Transition Metal Carbonyls

Abstract

The PH-functional methylene bridged diphosphines R₂P-CH₂-PRH and RHP-CH₂-PHR have been synthesized using Cl₂P-CH₂-PCl₂ as a starting material. On reaction with Fe₂(CO)₉ oxidative addition and cleavage of the P-C-P-skeleton occur yielding cluster compounds, e. g. (CO)₉Fe₃(RR 'P-CH₂-PR)H (R [dbnd] Me, Prⁱ, Bu^t, CH₂-Ph, R' [dbnd] R or H) or (CO)₉Fe₃(μ₃PR)(μ₂PMeR)H.     

Vinyl polymerization of norbornene by mono‐ and trinuclear nickel complexes with indanimine ligands

A series of new indanimine ligands [ArN?CC₂H₃(CH₃)C₆H₂(R)OH] (Ar = Ph, R = Me ( 1 ), R = H ( 2 ), and R = Cl ( 3 ); Ar = 2,6‐i‐Pr₂C₆H₃, R = Me ( 4 ), R = H ( 5 ), and R = Cl ( 6 )) were synthesized and characterized. Reaction of indanimines with Ni(OAc)₂·4H₂O results in the formation of the trinuclear hexa(indaniminato)tri (nickel(II)) complexes Ni₃[ArN = CC₂H₃(CH₃)C₆H₂(R)O]₆ (Ar = Ph, R = Me ( 7 ), R = H ( 8 ), and R = Cl ( 9 )) and the mononuclear bis(indaniminato)nickel (II) complexes Ni[ArN?CC₂H₃(CH₃)C₆H₂(R)O]₂ (Ar = 2,6‐i‐Pr₂C₆H₃, R = Me ( 10 ), R = H ( 11 ), and R = Cl ( 12 )). All nickel complexes were characterized by their IR, NMR spectra, and elemental analyses. In addition, X‐ray structure analyses were performed for complexes 7 , 10 , 11 , and 12 . After being activated with methylaluminoxane (MAO), these nickel(II) complexes can polymerize norbornene to produce addition‐type polynorbornene (PNB) with high molecular weight M_v (10⁶ g mol^?1), highly catalytic activities up to 2.18 × 10⁷ gPNB mol^?1 Ni h^?1. Catalytic activities and the molecular weight of PNB have been investigated for various reaction conditions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 489–500, 2008     

VERBINDUNGEN MIT DEM 1,3-DIMETHYL-1,3- DIAZA-2-PHOSPHETIDIN-4-ON GRUNDGERüST: SYNTHESE VON 1,3-DIMETHYL-2-PHENYLIMINO- 1,3-DIAZA-2λ4-PHOSPHETIDIN-4-ON-DERIVATEN. RÖNTGENSTRUKTURANALYSE VON 4,6- DIMETHOXY -5,10-DIPHENYL-1,3,7,9- TETRAMETHYL-l,3,5,7,9,10-HEXAAZA- 4λ5,6λ55-DIPHOSPHADISPIRO[3.1.3.1]DECAN-2,8-DION

Abstract

Die Umsetzung einer Reihe von λ³P-Diazaphosphetidinonen, MeNC(:O)N(Me)PY (Y [dbnd] NEt₂: 1, N(CH₂)₄; 2, NPh₂; 3, OMe; 4, N(cyc)₂; 5), mit Phenylazid wird beschrieben. Die dabei primär entstandenen 2-Phenylimino-λ⁴P-diazaphosphetidinone, MeNC(:O)N(Me)P(:NPh)Y sind mit Ausnahme des sterisch anspruchsvollen Dicyclohexylderivats, Y [dbnd] N(cyc)₂; 12, unbeständig und dimerisieren rasch zu den entsprechenden Diazadiphosphetidinen, 7 und 9–11. Aus 7 bildet sich in Lösung unter Abspaltung von MeN[dbnd]C[dbnd]NMe das A4P, λ⁴P,λ⁵P-Diazadiphosphetidin 8. Die neuen Verbindungen 8–12 wurden analytisch, ₁H-, ₁₃C- und ³¹P-NMR-spektroskopisch sowie durch ihre Massenspektren charakterisiert. Darüber hinaus wurde von Verbindung 11 eine Röntgenstrukturanalyse durchgeführt. Das Molekül besitzt kristallographische zweizählige Symmetric. Die Geometrie am Phosphor ist verzerrt trigonal bipyramidal, mit P—N-Bindungslängen 173.9. 179.2 pm (axial) sowie 168.3, 168.7 pm (äquatorial).

Compounds involving the 1,3-dimethyl-1,3-diaza-2-phosphetidin-4-one framework: Synthesis of 1,3- dimethyl-2-phenylimino-l,3-diaza-2λ⁴-phosphetidin-4-one derivatives. X-ray crystal structure analysis of 4,6-dimethoxy-5,10-diphenyl-l,3,7,9-tetramethyl- 1,3,5,7,9,10-hexaaza-4λ⁵,6λ⁵-diphosphadispiro- [3.1.3.l]decan-2,8-dione.

The reactions of a series of λ³P-diazaphosphetidinones MeNC(:O)N(Me)PY (Y [dbnd] NEt₂,; ₁, N(CH₂)₄; 2, NPh2,; 3, OMe; 4, N(cyc)₂; 5), with phenyl azide are described. The initially formed 2-phenylimino-λ⁴P-diazaphosphetidinones, MeNC(:O)N(Me)P(:NPh)Y, are. except for the bulky dicyclohexyl derivative 12, unstable and dimerize rapidly to the corresponding diazadiphosphetidines, 7 and 9–11. The λ⁴P,λ⁴P-diazadiphosphetidine 8 is formed from 7 in solution by elimination of MeN[dbnd]C[dbnd]NMe. The novel compounds 8–12 were characterized by analysis, n.m.r. and mass spectroscopy; additionally, an X-ray crystal structure analysis of 11 was carried out. The molecule possesses crystallographic twofold symmetry. The P-N bond lengths are 173.9, 179.2 pm (axial) and 168.3, 168.7 pm (equatorial).     

Cationic tris(pyrazolyl)borate bipyrimidine complexes

The cationic complexes, [Tp^RNi(bpym)]⁺ {Tp^R = tris(3,5-diphenylpyrazolyl)borate, R = Ph₂ 1; tris(3-phenyl-5-methylpyrazolyl)borate, R = Ph,Me 2} were synthesized by reacting [Tp^RNiBr] (R = Ph₂; Ph,Me) with bipyrimidine followed by subsequent addition of KPF₆ in CH₂Cl₂. The green solids have been characterized by IR, UV–Vis and ¹H NMR spectroscopy. Crystallographic studies of [Tp^Ph,MeNi(bpym)]PF₆ reveal a five-coordinate square pyramidal nickel centre with a κ³-coordinated Tp^Ph,Me ligand and a chelating bipyrimidine ligand. Cyclic voltammetric studies show irreversible reduction with the degree of reversibility dependent on the type of Tp^R ligand.