Pyridyl‐Functionalised 3H‐1,2,3,4‐Triazaphospholes: Synthesis,Coordination Chemistry and Photophysical Properties of Low‐Coordinate Phosphorus Compounds

Novel conjugated, pyridyl‐functionalised triazaphospholes with either tBu or SiMe₃ substituents at the 5‐position of the N₃PC heterocycle have been prepared by a [3+2] cycloaddition reaction and compared with structurally related, triazole‐based systems. Photoexcitation of the 2‐pyridyl‐substituted triazaphosphole gives rise to a significant fluorescence emission with a quantum yield of up to 12 %. In contrast, the all‐nitrogen triazole analogue shows no emission at all. DFT calculations indicate that the 2‐pyridyl substituted systems have a more rigid and planar structure than their 3‐ and 4‐pyridyl isomers. Time‐dependent (TD) DFT calculations show that only the 2‐pyridyl‐substituted triazaphosphole exhibits similar planar geometry, with matching conformational arrangements in the lowest energy excited state and the ground state; this helps to explain the enhanced emission intensity. The chelating P,N‐hybrid ligand forms a Re^I complex of the type [(N^N)Re(CO)₃Br] through the coordination of nitrogen atom N² to the metal centre rather than through the phosphorus donor. Both structural and spectroscopic data indicate substantial π‐accepting character of the triazaphosphole, which is again in contrast to that of the all‐nitrogen‐containing triazoles. The synthesis and photophysical properties of a new class of phosphorus‐containing extended π systems are described.     

Polymerization of olefin oxides and of olefin sulfides

Two new catalyst systems, sulfur–diethylzinc and 98% hydrogen peroxide–diethylzinc, have been investigated for polymerizing propylene oxide. The sulfur–diethylzinc catalyst system has a broad range of sulfur/zinc atomic ratio for polymerizing propylene oxide heterogeneously to high molecular weight materials in high yields. The highest polymer yield is obtained at the sulfur/zinc atomic ratio of 3–3.5. Like the water–diethylzinc system, the hydrogen peroxide–diethylzinc system has a narrow range of hydrogen peroxide/diethylzinc molar ratio in the vicinity of 0.57 for optimum polymer yield. Crystallinity measurements by x-ray diffraction of a few polymers prepared with these three catalyst systems showed that they are fairly similar in the extent of their crystallinity. A plot of the per cent of polymer insoluble in acetone against inherent viscosity of the original polymer also showed that the polymers prepared with sulfur–diethylzinc and hydrogen peroxide–diethylzinc catalyst systems have similar amounts of crystallinity. Data are given for the polymerizability of ethylene oxide, 1,2-butene oxide, styrene oxide, propylene sulfide, 1,2-butene sulfide, and a vulcanizable copolymer of propylene oxide and allyl glycidyl ether with the sulfur–diethylzinc catalyst system. The polymers from the olefin sulfides had lower inherent viscosities than the polymers from the corresponding olefin oxides. Aging of the sulfur–diethylzinc catalyst (S/Zn atomic ratio = 3.5) improved the yield of poly(propylene oxide). The yield was essentially unchanged when propylene oxide was polymerized in six different solvents. The formation of C₂H₅S_xZnSC₂H₅ and C₂H₅S_xZnS_yC₂H₅ (x and y are integers between 2 and 8) and possibly C₂H₅S_xZnC₂H₅ as the catalytically active species is postulated during the reaction of sulfur and diethylzinc.     

Efficient Oxidation of Sulfur Mustard and Its Simulants using N‐tert‐Butyl‐N‐chlorocyanamide

N‐tert‐Butyl‐N‐chlorocyanamide reacts with sulfur mustard instantaneously to give a corresponding nontoxic sulfoxide in quantitative yield. The transformation is selective and takes place in semi‐aqueous medium (CH₃CN/H₂O, 1∶1), even at subzero temperatures.     

Reactions of Aliphatic Diazo Compounds: V. Reaction of Methyl Diazoacetate with Imides of Itaconic Acid

Methyl diazoacetate regioselectively adds to N-substituted imides of itaconic acid to afford 2-pyrazolines, methyl 7-aryl-6,8-dioxo-1,2,7-triazaspiro[4.4]non-2-ene-3-carboxylates that in reaction with halogens (Cl₂, Br₂) yield methyl 5-aryl-1-halo-4,6-dioxo-5-azaspiro[2.4]heptane-1-carboxylates as a mixture of syn- and anti-isomers.     

Bis(tetrahydro-2H-pyran-2-ylmethyl)sulfide and -Sulfoxide from Sulfur Dichloride and 5-Hexen-1-ol

The reaction of sulfur dichloride with 5-hexen-1-ol has given bis(tetrahydro-2H-pyran-2-ylmethyl)-sulfide in 87% yield. Oxidation of the latter with NaIO₄ has afforded bis(tetrahydro-2H-pyran-2-ylmethyl)-sulfoxide in 96% yield.

     

Synthesis of tris(organylthioethyl)phosphines and their derivatives on the basis of the reaction of phosphine with vinyl sulfides

Phosphine generated from the red phosphorus in the system KOH-H₂O-toluene adds regio- and chemoselectively to vinyl sulfides under radical initiation conditions with the formation of tris(2-organylthioethyl)phosphines, which are easily oxidized by elemental sulfur and selenium to the corresponding phosphine sulfides and phosphine selenides in 54–78% yield. The obtained adducts are split when treated with sodium amide in THF to give trivinylphosphine and trivinylphosphine chalcogenides.     

Carbonylation of Methanol with Carbon Monoxide in the Presence of Sulfur-containing Catalysts

Physicochemical features of methanol carbonylation with carbon monoxide catalyzed with sodium sulfides Na_2Sx (x = 1, 2, 4) were studied. The effect of admixtures of sulfur dioxide in the gas phase on the yield of the target product (methyl formate) was revealed.     

Die Bildung von Gallium-Chalkogen-Heterokubanstrukturen durch Umsetzung der Alkylgallium(I)-Verbindung Ga4[C(SiMe3)3]4 mit Schwefel,Selen und Tellur

The Formation of Gallium Chalcogen Heterocubanes by the Reaction of the Alkylgallium(I) Compound Ga₄[C(SiMe₃)₃]₄ with Sulfur, Selenium, and Tellurium The alkylgallium(I) compound Ga₄[C(SiMe₃)₃]₄ 1 , which monomerizes in dilute solutions, reacts with elemental sulfur, selenium, and tellurium in boiling n-hexane to yield the corresponding Ga₄X₄R₄ cage compounds in a high yield. As shown by crystal structure determinations, the products have distorted Ga₄X₄ heterocubanes in their molecular centers with a slightly increasing distortion for the heavier chalcogen atoms. While the selenium and tellurium derivatives show a very low solubility in benzene, the sulfur compound dissolves readily accompanied by the dissociation into the (RGaS)₂ dimer.     

Syntheses and Characterization of Half—Sandwich Zirconium Complexes with Dichalcogenolate o—Carborane Ligands

Metallocene complex Cp2^ttZrCl2(Cp^tt=η^5-1,3-^tBu2C5H3)(1)has been prepared from the reaction of LiCp^tt with ZrCl4 in good yield.Reactions of 1 with dilithium dichalcogenolate o-carboranes afforded new type of half-sandwich compounds with dichalcogenolate o-carboranyl ligands,[Li(THF)4][Cp^ttZr(E2C2B10H10)2](E=S,2a;E=Se,2b)in which only one cyclopentadienyl ring ligand existed.Complexes 1 and 2a were structurally characterized by X-ray analyses.In complex 2a,the Zr(IV)ion is η^5-bound to one 1,3-ditert-cyclopentadienyl ring and σ-bound to four μ2-sulfur atoms of two dithio-carboranes.the zirconium atom and four sulfur atoms form a distorted pyramid.The coordination sphere around the zirconium atom resembles in a piano stool structure with four legs of sulfur stoms and the fulcrum at the zirconium stom.     

Structure and dynamic features of an intramolecular frustrated Lewis pair

Di(mesityl)cyclohexenylphosphine undergoes hydroboration with Piers' borane [HB(C₆F₅)₂] to yield the cyclohexylene‐anellated frustrated Lewis pair 5 . This P/B pair splits H₂ with the formation of the product 4 and adds to the C?O double bond of phenyl isocyanate to yield 6 . In the crystal, compound 5 features a puckered four‐membered heterocyclic core structure with a long P? B bond (av. 2.197(5) Å). The activation energy of the P? B cleavage of the frustrated Lewis pair 5 was determined by dynamic ¹⁹F NMR spectroscopy at ΔG^≠(298 K)=12.1±0.3 kcal mol^?1.     

Silica anchored bis(trialkylphosphine) platinum oxalate. A photogenerated catalyst for olefin hydrosilation

Ultraviolet irradiation of the silica attached complex Pt(C₂O₄)L ₂, [L=(H₃CO)₃Si(CH₂)₂PEt ₂], yields a [SiO₂]-L ₂Pt species that catalyzes olefin hydrosilation or adds 2 CO to yield a surface dicarbonyl complex.Dedicated to Prof. Dr.Kurt L. Komarek on the occasion of his 60th birthday.     

Highly Stereoselective Synthesis of a C2-Symmetric 2,2′-Bipyridine Derived from Glucose

2-Bromo-6-lithiopyridine adds stereoselectively to the β-face of 1,2;5,6-di-O-isopropylidene-α-D-glucofuranos-3-ulose (2) to provide compound 5 in 50% yield as a single diastereomer. Compound 5 can be coupled to form novel C₂-symmetric 2,2′-bipyridine 7, the first example of a C₂-symmetric bipyridine that derives chirality from glucose.     

Synthesis and structure of the first diamagnetic trinuclear cobalt carbonyl sulfur complexes,SCo3(CO)7(μ-R1ĆNR2)

Reaction of primary thioamides with dicobalt octacarbonyl affords in good yield the first diamagnetic monomeric trinuclear cobalt carbonyl sulfur complexes SCO₃(CO)₇(μ-R¹?NR²), which contain a bridging bidentate imino ligand. The structure of the product with R¹  Me, R²  C₆H₁₁ has been determined by X-ray diffraction, and shown to include a very short cobaltcobalt bond distance and a long cobaltsulfur bond distance when compared to other cobaltsulfur clusters.     

High-field NMR of ethylene—sulfur dioxide copolymers

Copolymers of ethylene and sulfur dioxide containing 40–60 wt-% sulfur dioxide have been analyzed by using 220 MHz high-resolution NMR, and it has been shown that they contain structures of the form, ? SO₂? (CH₂? CH₂)_n? SO₂? , where n is 1, 2, 3, 4, … The relative numbers of structures with n = 1, 2, 3, or 4 and above can be calculated from the NMR spectra. The fraction of ethylenes in longer blocks and the sulfur dioxide contents of the polymers can also be determined from the NMR data. The NMR results indicate that the distribution of ethylenes among the different structures is not that expected for a random copolymerization of ethylene and sulfur dioxide but that the arrangement of these structures within the copolymer is random.     

Schwefelmonoxid-komplexe: III. Ein kationischer eisen-so-komplex

The compounds [cpFe(dppe)(SO)]PF₆, the first mononuclear cationic complex of sulfur monoxide, and [cpFe(dppe)(SO₂)]PF₆ were obtained in high yield from the corresponding carbonyl [cpFe(dppe)(CO)]PF₆. From spectroscopic studies the sulfur monoxide was found to be coordinated to iron in the usual bent η¹-fashion; the sulfur dioxide complex, as expected, contains SO₂ in an η¹-planar fashion.     

New Route for the Synthesis of Pyrazole,Triazole, Triazine,and Triazepine Derivatives

N,N′‐Diphenylpiperidine‐1‐carbohydrazonamide 1 was prepared and treated with halo compounds, active nitriles, diethylhy malonate, ketones, CS₂, phenylisocyanate, phenylisothiocyanate, LR, ethyl 2‐cyano‐3,13‐dithiomethylacetate, and benzylidenenitriles to give the corresponding triazines 2–4, pyrazoles 5 and 6, triazoles 7, 8, and 10, triazaphosphole 11, and triazepines 12 – 14, respectively.     

Fluorsulfonylmethylidene sulfur difluoride oxide,FSO2?CH  SF2  O

SO₃ adds across the CS double bond of H₂C  SF₄ with formation of 2-tetrafluoro-4-dioxo-1,2,4-oxadithietane, which rearranges to fluorsulfonylmethylidene sulfur difluoride oxide, F SO₂ CH  SF₂  O in the presence of CsF. © John Wiley & Sons, Inc.     

Addition of chlorofluorocarbene to poly(1-methyl-1-phenyl-1-sila-cis-pent-3-ene) and poly(1,1-dimethyl-1-sila-cis-pent-3-ene): Characterization of chlorofluorocyclopropanated polymer microstructures by 1H-, 13C-, 19F-, and 29Si-NMR spectroscopy

Chlorofluorocarbene, generated by the sodium iodide catalyzed decomposition of phenyl(dichlorofluoromethyl)mercury, adds to the carbon-carbon double bonds of poly(1-methyl-1-phenyl-1-sila-cis-pent-3-ene) (I) and poly(1,1-dimethyl-1-sila-cis-pent-3-ene) (II) to yield poly(3,4-chlorofluoromethylene-1-methyl-1-phenyl-1-sila-cis-pent-3-ene) (CIFC-I) and poly(3,4-chlorofluoromethylene-1,1-dimethyl-1-sila-cis-pent-3-ene) (CIFC-II). Similarly, two series of random partially chlorofluorocyclopropanated polymers have been prepared. The microstructures of these adduct polymers have been determined by ¹H-, ₁₃C-, ¹⁹F-, and ²⁹Si-NMR spectroscopy. The glass transition temperatures (T_g's) depend on the extent of chlorofluoropropanation of these polymers. These copolymers become less thermally stable as the extent of chlorofluorocyclopropanation increases. © 1993 John Wiley & Sons, Inc.     

Synthese von 8-Alkylamino-8-aryl-1,2,3,4,5,6-hexathiocan-7-thionen

Zusammenfassung Durch gemeinsame Einwirkung von primären aliphat. Aminen und Schwefel auf Methylarylketone in Methanol bei Raumtemp. erhält man in meist guten Ausbeuten 8-Alkylamino-8-aryl-1,2,3,4,5,6-hexathiocan-7-thione (1a-h). Die Umsetzung von 1,4-Diacetylbenzol mit n-Propyl-bzw. n-Butylamin und Schwefel liefert Phenylen-1,4-di-hexathiocanderivate (3 a, b).Bei der Reaktion von Acetophenon mit 3-N,N-Diäthylaminopropylamin und Schwefel entstehen neben dem 8-(3-N,N-Diäthylaminopropylamino)-8-phenyl-1,2,3,4,5,6-hexathiocan-7-thion (1e) 51% einer Verbindung der Summenformel C₁₅H₂₂N₂S₂ (2), der die Struktur der (3-N,N-Diäthylaminopropylimino)-phenyldithioglyoxylsäure zugeordnet wird.1 e läßt sich durch Behandlung mit wäßr. Natriumsulfit-Lösung zu2 abbauen,2 durch Reaktion mit Schwefel wieder in1 e überführen.

---

Synthesis of 8-alkylamino-8-aryl-1,2,3,4,5,6-hexathiocan-7-thiones (Joint action of elemental sulfur and gaseous ammonia upon ketones, LXXVIII: Action of sulfur and amines on acetophenone, IX)

8-Alkylamino-8-aryl-1,2,3,4,5,6-hexathiocan-7-thiones (1a toh) are obtained mostly in good yields by the concomitant action of primary aliphatic amines and sulfur upon methyl aryl ketones in methanol at room temperature. Reaction of 1,4-diacetyl benzene and sulfur with n-propylamine or n-butylamine respectively leads to phenylene-1,4-dihexathiocane derivatives (3 a, b).Besides 8-(3-N,N-diethylaminopropylamino)-8-phenyl-1,2,3,4,5,6-hexathiocan-7-thione (1 e), which is obtained by reaction of acetophenone with 3-N,N-diethylaminopropylamine and sulfur, a product with the formula C₁₅H₂₂N₂S₂ (2) is isolated in 51% yield, to which the structure (3-N,N-diethylaminopropylimino)phenyl dithioglyoxylic acid is assigned. By treatment of1 e with aqueous sodium sulfite solution2 is obtained, which can be transformed back into1 e by reaction with sulfur.

---

---

77. Mitt.:F. Asinger, A. Saus, H. Offermanns undP. Scherberich, Ann. Chem.753, 151 (1971).

---

8. Mitt.:F. Asinger, A. Saus, H. Offermanns undF. Abo Dagga, Ann. Chem.723, 119 (1969).

---

Teil der DiplomarbeitJ. Hartig, Techn. Hochschule Aachen, 1969.     

Divalent Ytterbium Iodide Supported by β‐Diketiminato Based Tridentate Ligand: Synthesis,Structure and Small Molecule Activation†

Divalent ytterbium iodide [LYb(μ‐I)(THF)]₂ ( 1 ; L = [MeC(NDIPP)CHC(Me)NCH₂CH₂NMe₂]^?, DIPP = 2,6‐(ⁱPr)₂C₆H₃) was synthesized and its reactivity was studied. Complex 1 was synthesized by salt metathesis of YbI₂(THF)₂ with the potassium salt of ligand (KL) in high yield. In the reactions with trimethylsilyl azide, azobenzene, sulfur and diphenyl disulfide, complex 1 acts as a 2e reductant. In the reaction with CO₂, the central carbon atom of β‐diketiminato backbone in 1 nucleophilically attacks the CO₂ molecule to give a divalent ytterbium carboxylate.