[NiL2X2] oder [HL][NiLX3] – Reaktion sterisch anspruchsvoller Trialkylphosphine L mit NiX2 (X = Cl,Br) in Ethanol

[NiL₂X₂] or [HL][NiLX₃] – Reaction of Sterically Demanding Trialkylphosphines L with NiX₂ (X = Cl, Br) in Ethanol The reaction of some sterically demanding trialkylphosphines L = PR₂R′ (R = ⁱPr, R′ = ^tBu; R = ^tBu, R′ = ⁱPr, Me) with NiX₂ (X = Cl, Br) in ethanol affords instead of the expected non-electrolytes [NiL₂X₂] tertiary phosphonium nickelates [HL][NiLX₃] due to participation of the solvent. In case of the less bulky P^tBu₂Me both complex types were obtained. [Ni(P^tBu₂Me)₂Cl₂] is tetrahedral and therefore one of the two examples of paramagnetic bis(trialkylphosphine)dihalogenonickel(II) complexes known so far. In solution the latter compound undergoes an equilibrium of tetrahedral (paramagnetic) and planar (diamagnetic) conformer. Vis spectra as well as the results of magnetic measurements and ¹H and ³¹P NMR investigations are reported.     

Reactivity of [Mo(NHNRPh)(NNRPh)(acac)X2] (R=Ph,Me; X=Br,I) toward tertiary phosphines

The reactivity of mixed [organohydrazido(1-)][organohydrazido(2-)]molybdenum(VI) complexes [Mo(NHNRPh)(NNRPh)(acac)X₂] {R?=?Ph, X?=?Br (1); R?=?Ph, X?=?I (2) and R?=?Me; X?=?I (3)} with tertiary phosphines as PPh₃, PMePh₂ and PMe₂Ph are examined. The syntheses of [Mo(NNPh₂)₂Br₂(PPh₃)] (4), [Mo(NNPh₂)₂Br₂(PMePh₂)₂] (5), [Mo(NNPh₂)₂Br₂(PMe₂Ph)₂] (6), [Mo(NNPh₂)₂(acac)I(PPh₃)] (7), [Mo(NNPh₂)₂(acac)(PMePh₂)₂]⁺I^? (8) and [Mo(NNMePh)₂(acac)(PMePh₂)₂]⁺I^? (9) are reported. All complexes were characterized by elemental analysis, UV-visible, IR, ¹H and ³¹P{H} NMR spectroscopy.     

Barriers to Internal Rotation and Conformational Behaviour of the MESO and D,L Isomers of Pt(II) Complexes with Antitumour Activity

Abstract

The conformational behaviour of a series of ring substituted (ortho-Cl, F and meta or para OH) Pt(II) complexes of general formula [(1,2-hydroxyphenyl)ethylenediamine]PtL₂ [L ? Cl, 1] has been studied by molecular mechanics (MM) methods. Preferred orientations of the phenyl rings, which are important for the complexes′ biological activity, were obtained by calculations of rotational energies about C_sp3?C_ar bonds for all theoretically possible isomers and conformers, meso-λ (R,S/S,R-λ), meso-δ (R,S/S,R-δ), d,l-δ (S,S/R,R-λ) and d,l-λ (S,S/R, R-δ). The influence of the ring substituents and the conformation type on the positions of the energy minima and barriers to rotations about C_sp3?C_ar and C_ar-O(H) bonds were investigated in detail. Theoretical predictions were compared with the experimental results where appropriate.     

31P N.M.R. studies of some pseudo-halogeno-derivatives of phosphorus

Abstract

Several new pseudo-halogeno phosphorus species, including isomeric N- and O-bonded cyanato-derivatives of the PCl₆ ^? ion, cyano-derivatives of RPCl₅ ^? ions (R [dbnd] Ph or Me), and organo-phosphorus (III) cyanide adducts RP(CN)₂X^? (R [dbnd] Me, Et, Ph or C₆F₅; X [dbnd] Cl, Br or I) have been prepared in solution, and identified by means of ³¹P n.m.r. spectroscopy. Isomeric configurations in the six-coordinate species have been assigned by the method of pairwise interactions.     

A new amino alcohol NpyNimineNamineOalcohol-donor ligand: coordination toward zinc(II) and cadmium(II) halides and enantioselective products

In the present work a new ligand, 2-(2-(phenyl(pyridin-2-yl)methyleneamino)ethylamino)ethanol (L), and its Zn(II) and Cd(II) complexes, [Zn(L)Br₂] (1), [Cd(L)Br₂] (2) and [Cd(L)I₂] (3), have been synthesized and characterized by elemental analysis, FT-IR, Raman and ¹H NMR spectroscopies as well as X-ray crystallography. All complexes are isostructural and their metal ions have distorted square pyramidal geometry with an MN₃X₂ (X: Br, I) environment. During the complexation process, the amine group of the ligand becomes a chiral center. In the solid-state, an R-configuration was observed in all three complexes. Furthermore, the molecules form intermolecular C–H?O, C–H?X and O–H?X (X: Br, I) hydrogen bonds in the solid-state.     

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%.     

Metal Complexes of Aniline: Infrared and Raman Spectra

Abstract

The literature for the years 1965–1987 has been searched for all significant papers which refer to the vibrational spectra of metal complexes of aniline and substituted anilines. These papers have been reviewed with particular reference to isotopic labelling and metal ion substitution studies as assignment techniques and to the structural and bonding information which can be derived from the spectra. Compounds of the following classes are included: [M(an)₂X₂] (M = Mn, Co, Ni, Cu, Zn, Cd, Hg; an = aniline, X - Cl, Br, I, NCS); cis- and trans-[Pt(an)₂X₂] (X = Cl, Br, I, NO₂); [M(R-an)₂X₂] (M = Mn, Co, Ni, Cu, Zn; R-an = o-, m- and p-toluidine and other substituted anilines; X = Cl, Br, I); aniline adducts of metal β-ketoenolates; the complexes trans-[PtL(R-an)X₂] (L = CH₂?CH₂ or CO, R-an = aniline or a substtuted aniline, X = Cl, Br); and other miscellaneous systems comprising aniline as a ligand.     

Synthesis and characterization of Ru(III), Rh(III), Pt(IV) and Ir(III) thiosemicarbazone complexes

Ru(III), Rh(III), Pt(IV) and Ir(III) complexes of 2-furfural thiosemicarbazone as ligand have been synthesised. These complexes have the composition [M(ligand)₂X₂]X (M = Ru(III) Rh(III) and Ir(III) X = Cl and Br) and [Pt(ligand)₂ X₂] X₂ (X = Cl, Br and 1/2SO₄). The deprotonated ligand forms the complexes of the formulae M(ligand-H)₃ and Pt(ligand-H)₃Cl. All these complexes have been characterized by elemental analysis, magnetic measurements, electronic and infrared spectral studies. All the complexes are six-coordinate octahedral.     

Zur Reaktion von Halomethylphosphoniumhalogeniden, [R3PCYnX3–n]X,mit Phosphanen,R′3P

On the Reaction of Halomethylphosphonium Halides, [R₃PCY_nX_3–n]X, with Phosphanes, R′₃P The results of the reaction of 19 different halomethylphosphonium halides, [R₃PCY_nX_3–n]X (R = Ph, n-Bu, Me₂N, Et₂N; Y = H, F; X = Cl, Br, I; n = 0–2), with Ph₃P, n-Bu₃P, and (R₂N)₃P are presented. As reaction products bisphosphonium salts, [R₃P? CY_nX_2–n? PR′₃]X₂, and phosphoranylphosphonium salts, [R₃P=CY? PR′₃]X, or reduced (halo)methyl-phosphonium salts, [R₃PCHY_nX_2–n]X, are obtained. [Ph₃PCBrF₂]Br and [Bu₃PCBrF₂]Br react with R′₃P by trans-alkylation forming [R′₃PCBrF₂]Br. The factors influencing the course of the reaction are discussed.     

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).     

Four- and Six-Membered Inorganic Rings in the “Butterfly”-Like [Mn{(OPPh2)N}2]2

Abstract

Manganese(II) compounds of the type Mn[(XPR₂)(YPR'₂)N]₂ (X, Y = O, S; R, R' = Me, Ph) were prepared and characterized by IR spectroscopy. The X-ray molecular structure of the [Mn{(OPPh₂)₂N}₂]₂ is discussed.     

Darstellung und Charakterisierung von [Pt(mal)2]2− und von trans-[Pt(mal)2X2]2− (X = Cl,Br, I,SCN)

Preparation and Characterization of [Pt(mal)₂]^2? and trans-[Pt(mal)₂X₂]^2? (X = Cl, Br, I, SCN) By twofold treatment of K₂[PtCl₄] with potassium hydrogen malonate in a queous solution the yellow K₂[Pt(mal)₂] · H₂O is obtained. After extraction with tetrabutylammonium ions into dichloromethane by oxidative addition at ?90°C the Pt^IV complexes [Pt(mal)₂X₂]^2?, X = Cl, Br, I, SCN, are formed. The SCN ligands are coordinated to Pt via S. The IR and Raman spectra are discussed and assigned.     

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.     

Novel platinum(II) and (IV) complexes of naphthaldimine schiff bases

Naphthaldimines containing N₂O₂ donor centers react with platinum(II) and (IV) chlorides to give two types of complexes depending on the valence of the platinum ion. For [Pt(II)], the ligand is neutral, [(H₂L¹)PtCl₂]·3H₂O (1) and [(H₂L³)₂Pt₂Cl₄]·5H₂O (3), or monobasic [(HL²)₂Pt₂Cl₂]·2H₂O (2) and [(HL⁴)₂Pt]·2H₂O (4). These complexes are all diamagnetic having square-planar geometry. For [Pt(IV)], the ligand is dibasic, [(L¹)Pt₂Cl₄(OH)₂]·2H₂O (5), [(L²)Pt₃Cl₁₀]·3H₂O (6), [(L³)Pt₂Cl₄(OH)₂]·C₂H₅OH (7) and [(L⁴)Pt₂Cl₆]·H₂O (8). The Pt(IV) complexes are diamagnetic and exhibit octahedral configuration around the platinum ion. The complexes were characterized by elemental analysis, UV-Vis and IR spectra, electrical conductivity and thermal analyses (DTA and TGA). The molar conductances in DMF solutions indicate that the complexes are non-ionic. The complexes were tested for their catalytic activities towards cathodic reduction of oxygen.     

Rhodium(1) carbonyl complexes with alkyl sulphoxides and sulphides

Summary Rhodium(I) carbonyl complexes, namely Rh(CO)X(R₂SO)₂ (R = Me, n-Pr or n-Bu) and Rh(CO)X(R₂S)₂ (R = Me, Et or i-Pr) and X = CI or Br, have been prepared and characterized. The compounds Rh(CO)X[P(OPh)₃]₂ X = Cl or Br, have also been isolated. In the R₂SO and R₂S complexes, the carbonyl stretching frequencies occur atca. 2020–2025 cm^–1 andca. 1950–1980 cm^–1 respectively. In the R₂SO ligand containing complexes v(S-O) occurs atca. 1100–1125 cm^–1 indicative of metal-sulphur coordination. In presence of HBF₄, the addition of an excess of Me₂SO to (OC)₂Rh(-Cl)₂Rh(CO)₂ gives [Rh(Me₂SO)₆]³⁺ in which the central metal atom undergoes spontaneous oxidation from Rh¹(d⁸) to Rh^III(d⁶). The complexes have been characterized additionally by u.v.vis. spectra, conductivity measurements and by elemental analyses.     

Synthesis,characterization, DNA binding studies and in vitro cytotoxicity of platinum(II)-dihalogenido complexes containing bidentate chelating N-donor ligands

Platinum(II) complexes, [Pt(L_x)X₂] (1–6), where X = Br or I and L_x = 2,2′-bipyridine or 1,10-phenanthroline derivatives (5,5′-dimethyl-2,2′-bipyridine (5-Mebpy), 4,4′-dimethyl-2,2′-bipyridine (4-Mebpy), and 5-amino-1,10-phenanthroline (5-NH₂phen)) were prepared. The complexes were characterized by the elemental analysis, mass spectrometry, infrared, and multinuclear (¹H, ¹³C and ¹⁹⁵Pt) 1-D and 2-D NMR spectroscopies, and by single-crystal X-ray analysis of [Pt(4-Mebpy)I₂] (4). All the platinum(II) complexes (1–6) were evaluated for in vitro cytotoxicity against human cancer cell lines A2780 and A2780R, and against non-malignant MRC5 cell line. All the complexes were nontoxic up to the 50 μM concentration, although they were found to readily bind to calf-thymus DNA (CT-DNA), as determined by spectrophotometric titration (K_b ≈ 10⁷ M^?1) and ethidium bromide displacement assay.     

Tetrakis(thione)platinum(II) complexes: synthesis,spectroscopic characterization,crystal structures,and in vitro cytotoxicity

A new series of platinum(II) complexes based on thione ligands with general formula [Pt(thione)₄]X₂ (X^??=?Cl^?, NO₃^?) has been synthesized and characterized using CHNS elemental analysis, infrared, ¹H and ¹³C solution-state NMR as well as ¹³C and ¹⁵N solid-state NMR spectroscopy, and X-ray crystallography. The spectroscopic methods confirm the coordination of Pt(II) with thiocarbonyl groups via sulfur of the thione ligands. The X-ray structures showed a distorted square planar geometry for 1, [Pt(MeImt)₄]Cl₂ (MeImt = N-Methylimidazolidine-2-thione) while the hydrogen bonding interactions in 7, [Pt(iPrImt)₄](NO₃)₂·0.6(H₂O) induce a bent see-saw distortion relative to the ideal square planar geometry. The in vitro cytotoxicity studies showed that 2, [Pt(EtImt)₄]Cl₂ is generally the most effective, a two-fold better cytotoxic agent than cisplatin and carboplatin against MCF7 (human breast cancer).     

Binuclear platinum(I) complexes with bis(dimethylphosphino)methane ligands: evidence for both short- and long-range NMR trans-influences

The diplatinum(I) complexes or complex ions [Pt₂X₂(μ-dmpm)₂] (X = Cl or I), [Pt₂X(PPh₃)(μ-dmpm)₂]⁺] (X = I, Br or Me), and [Pt₂(PPh₃)₂(μ-dmpm)₂]²⁺, where dmpm = Me₂PCH₂PMe₂, have been prepared and characterized by ¹H and ³¹P NMR spectroscopy. In the linear X-Pt-Pt-Y unit the trans-influence of X is felt primarily at the PtPt bond, but groups X having a very high trans-influence (X = H or Me) can also exert a weaker long-range trans-influence on the PtY bond.     

Alkyl and cyclic substituted thiuram disulphides as ligands. titanium(iv), vanadium(iv), and oxovanadium(iv) complexes

Summary Titanium(IV) hexacoordinate thiuram disulphide complexes of the type [TiX₄R₂NC(S)SSC(S)NR₂}] (X=Cl or Br; R=Me, Et, piperidinyl or morpholinyl) have been prepared by reaction between TiX₄ (X=Cl or Br) and the thiuram disulphide. Similar reactions with VOCl₃ lead to reduction of vanadium(V) and give rise to the oxovanadium(IV) pentacoordinate complexes [VOCl₂{R₂NC(S)SSC(S)NR₂}]. However, the reactions of these same thiuram disulphide ligands with [VCl₂(THF)₂] (THF=tetrahydrofuran) cause oxidation of vanadium and to the reduction of the disulphide to the corresponding dithiocarbamate [R₂NCS₂]^–, resulting in new dichlorobis (dithiocarbamate)vanadium(IV) complexes [VCl₂-(R₂NCS₂)₂]. All the compounds have been characterized by elemental analyses, i.r., visible and e.p.r. spectra. Both thiuram disulphides and dithiocarbamate ligands exhibit bidentate