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Zusammenfassung: Die Reaktion von 1,5-Bis(trimethylsilyl)-1,3,5-trimethylbiuret mit Di- bzw. Monochlorphosphanen führte unter Bildung von Me3SiCl zu den 1,3,5-Trimethyl-1,3,5-triaza-2σ 3 λ 3-phosphorinan-4,6-dionen 1–4 bzw. zu den 1,5-Bis(phosphano)-1,3,5-trimethylbiuret-Derivativen 5 und 6. Verbindungen 1, 2 und 4 wurden mittels Einkristall-Röntgenstrukturanalyse charakterisiert. Alle Heterozyklen wiesen eine flache Boot-Konfiguration auf, wobei das Phosphoratom und das gegenüberstehende Stickstoffatom außerhalb der Ebene der restlichen Atome lagen. Oxidation der σ 3 λ 3P-Derivative mit dem 1:1-Harnstoff/Wasserstoffperoxid-Addukt lieferte die entsprechenden 2-Oxo-2σ 4 λ 5-phosphorinan-4,6-dionen 8–11 und die 1,5-Bis(phosphoryl)biuret-Derivate 12 und 13. Die Spirophosphorane 15–22 wurden bei der Reaktion von 1–4 mit Tetrachlor-o-benzochinon, und von 1, 3und 4 mit Hexafluoraceton gebildet. Verbindungen 20 und 21 enthalten einen Oxaphosphetanring, der durch die elektronegativen CF3-Gruppen stabilisiert wird. Verbindung 22 wurde aus 21 durch Verlust der Trimethylsilylgruppe gebildet.Außer 21 wurden alle Oxaphosphetane über ihre 1H-, 13C-, 19F- und 31P-NMR-Spektren und mittels E.I.-Massenspektrometrie characterisiert. Auch für 20 wurde eine Einkristall-Röntgenstrukturanalyse durchgeführt; die Koordination am Phosphor ist stark verzerrt trigonal bipyramidal, wobei der Oxetanring eine axiale und eine equatoriale Lage am Phosphor besetzt. Die Reaktion von 1 mit 1-Trifluormethyl-2-(heptafluorisopropyl)-biacetyl lieferte 23 anstatt eines Oxaphosphetans wie 20.

This article summarizes some of our investigations of compounds featuring the structural fragment P‒C‒P. Phosphorus atoms in different oxidation states and coordination numbers display different chemical behaviors. This may lead to unique chemical properties when they are bridged by a methylene group in a P‒CH2‒P system. For example, the PIII‒CH2‒PVunit is able to add different unsaturated compounds to give zwitterionic products with oppositely charged phosphorus atoms. In addition, the two hydrogen atoms in P‒CH2‒P may also take part in different transformations, resulting in the formation of carbodiphosphoranes or in the formation of a direct P-P bond to give three-membered ring diphosphiranes.

The gas-phase structure of 1-adamantylphosphine has been determined by electron diffraction, supplemented with data from ab initio and DFT calculations. The adamantyl fragment was modeled with local C 3v symmetry and the phosphino group was found to be in a position almost bisecting a mirror plane of the adamantyl group, giving the molecule overall approximate C s symmetry. There is a small displacement of the C–P bond from the local threefold axis of the adamantyl group. Geometry optimizations were also performed for bis-(1-adamantyl)phosphine (C 1 point-group symmetry) and tris-(1-adamantyl)phosphine (C 3 symmetry), demonstrating extremely crowded environments around the phosphorus atoms leading to adamantyl groups that were much less symmetric. The adamantyl groups were also found to twist by a significant amount to minimize the strain.

The reaction of linear push–pull enamines bearing a methyl group at the α-position with a set of trifluoromethylated carbonyl compounds was investigated. It has been found that the reaction proceeds at the methyl group of the enamines. The first computational study of the reaction between push–pull enamines and strong electrophilic reagents was reported. Out of three pathways considered DFT and MP2 calculations support ene-mechanism previously suggested based on experimental results only.

2,4-Diphospha-3-thia- and 3-selenapentadienes [(Me 3 Si) 2 C = P] 2 E ( 1a : E = S; 1b : Se) react as bifunctional phosphaalkenes with two equivalents of cyclopentadiene and of tetrachloro-o-benzoquinone (TOB), furnishing 2a and 2b from double [2+4] cycloaddition reactions of the diene and 3a and 3b from the reactions of TOB with the P = C double bonds. The phosphanorbornane-related chalcogenophosphinous anhydrides 2a and 2b are obtained as pairs of isomers, whereas the reactions with TOB proceed diastereoselectively. X-ray crystallographic data confirm that bis-dioxaphospholene-related 3b consists of a mixture of (RR) and (SS) enantiomers. A third equivalent of TOB can be added oxidatively to one phosphorus atom of 3a and 3b , furnishing the spirocyclic compounds 6a and 6b with P(σ λ 5 5 ) connectivity. 3a and 6a are configurationally stable at room temperature, whereas the selenium derivatives 3b and 6b undergo slow isomerisation in solution.

3,4,5,6-Tetrachlorobenzo-3-(2,4,6-tri-tert-butylphenyl)-1,3,2-dioxaphospholane (2) and benzo-3-(2,4,6-tri-tert-butylphenyl)-1,3,2-dioxaphospholane (4), in which the reactive PIII-center lies close to the sterically demanding Mes* group (Mes* = 2,4,6-tri-tert-butylphenyl), were prepared from Mes*–Br and the corresponding P-chloro-phospholane. Compounds 2 and 4 reacted with various oxidants, azides, MeSO3CF3 or [(tht)AuCl] (tht = tetrahydrothiophene) to give the expected products. All crystal structures of the products display a strongly distorted Mes* system with a boat conformation of the phenyl ring and appreciable out-of-plane deviations of phosphorus and the ortho-tert-butyl groups to opposite sides of the ring. Quantum chemical calculations at the DFT (density functional theory) level of theory were used in order to discriminate between intra- and intermolecular forces, which are responsible for these distortions.

The reduction of dimenthyl ketophosphonates with sodium borohydride involves asymmetric induction at the α-carbon atom, resulting in a small excess of the (R)-enantiomer of the α-hydroxyphosphonate formed. A higher ee purity was achieved if the reduction of chiral dimenthyl ketophosphonates was carried out by the chiral complex of NaBH4-L-proline, owing to the double asymmetric induction at the α-carbon atom. The hydroxyphosphonates obtained were isolated in a diastereomerically pure state and were transformed to the optically active, free hydroxyalkylphosphonic acids. The (R)-configuration of one of them was proved by X-ray crystal structure analysis. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:133–139, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20391

The reaction of the title compound 1 with the p-R-aniline derivatives (R═H, F, OCH3, NO2, and NH2) led to the formation of the aza-2σ3,4σ3-diphosphetidines 2a– 2e, whereas 2-trimethylsiloxyaniline furnished the azadiphosphetidine 2f. The reaction of the sterically crowded 2,6-dimethylaniline with 1 furnished the disubstituted derivative 3. The tricyclic compound 5 was formed during the reaction of 1,2-phenylenediamine with 1. Heptamethyldisilazane formed the aza-2σ 3 ,4σ 3 -diphosphetidine 6 on reaction with 1. The bulkier tert.-butylamine formed with 1 a mixture of the aza-2,4-diphosphetidine 7a and the disubstituted derivative 7b, which could not be separated. The reaction of 2b and 6 with tetrachloro-o-benzoquinone resulted in the formation of the bis-spirophosphoranes 8 and 9b, respectively. The formation of the monospirophosphorane 9a was observed in the 31P NMR spectrum. The characterization of compounds is based in particular on NMR investigations (1H, 13C, 31P). 2a was characterized by a single-cr...

19F and 31P NMR spectroscopy were used to study the kinetics of the hydrolysis of LiPF6 in the homogenous solvent system propylene carbonate (PC)—dimethyl carbonate (DMC)—H2O. It was found that the main products of the hydrolysis are HF, LiPO2F2 and Li2PO3F. The content of POF3 and PF5 was negligibly low. We set up a hypothesis that the main factor determining the rate of the process is the so-called ‘secondary’ catalytic effect, caused by solvated H+ ions.

Bis(dimethylphosphino)naphthalene, 1,8-(PMe 2 ) 2 C 10 H 6 (dmpn), reacts readily with Ru 3 (CO) 12 or Ru 3 (μ-dppm)(CO) 10 with replacement of one of the PMe 2 groups by H to give Ru 3 (CO) 12 − n {PMe 2 (nap)} n ( n = 1 2 , 2 3 ) or Ru 3 (μ-dppm)(CO) 9 {PMe 2 (nap)} 4 ; the complex Ru 3 (CO) 10 (dmpn) 1 is obtained only in small amount. Thermolysis of 2 or 4 gives Ru 3 (μ-H) 2 {μ 3 -PMe 2 (C 10 H 5 )}(μ-dppm) n (CO) 8-2n ( n = 0 5 , 1 6 , respectively) containing μ 3 -naphthalyne groups.

Reactions of Os3(CO)12 with 1,8-bis(diphenylphosphino)naphthalene (dppn) are described. Crystallographically characterised complexes isolated from a reaction carried out in refluxing toluene are Os3(μ-H)2{μ-PPh2(nap)PPh(C6H4)}2(CO)6 (1), Os3(μ-H){μ3-PPh2(nap)PPh(C6H4)}(CO)8 (2) and Os2(μ-PPh2){μ-PPh2(nap)}(CO)5 (3) (nap=1,8-C10H6), while at r.t. in the presence of ONMe3, only Os3(CO)11{PPh2(1-C10H7)} (4) was isolated. While 1 and 2 contain ligands formed by metallation of a Ph group of dppn, as found also in complexes obtained from dppn and Ru3(CO)12, ligands in 3 and 4 are formed by cleavage of a P-nap bond, not found in the Ru series.

The phosphoryl compound (O:)P(TMG)3 (TMG = N’,N’,N”,N”-tetramethylguanidyl) (6) was synthesized during attempts to obtain the potentially very basic (but still unknown) compound P(TMG)3 (1). Its reaction with HCl resulted in the triply protonated species 7. The crystal structure of compound 7 was determined; it crystallizes as a bis-dichloromethane solvate. Each protonated nitrogen forms a hydrogen bond to one chloride. A series of protonation experiments was conducted in order to test the behaviour of 6 towards weak acids.

Michael I. Bruce, Paul A. Humphrey, Sakir Okucu, Reinhard Schmutzler, Brian W. Skelton and Allan H. White

The reaction of the symmetric diphosphene 2, 4, 6-(CF3)3-C6H2-P=P-C6H2-2, 4, 6-(CF3)34 with Ru3(CO)12 led to the 50-electron Ru3P2nido-cluster Ru3(CO)9[μ-P-C6H2-2, 4, 6-(CF3)3]25, which in solution at room temperature displays hindered rotation of the aromatic rings about the C(aryl)—P bonds. The structure of 5 was determined by X-ray crystal structure analysis; its Ru3P2 centre forms a distorted square pyramid with one ruthenium atom at the apex. One of the two C6H2(CF3)3 groups is also appreciably distorted. Temperature-dependent 19F NMR studies of the [A3M3X]2 spin system (A = M = CF3, X = 31P) of 5 indicated a rotational barrier ΔG≠ of 82.3 kJ mol-1 at 141 °C. The same Ru3P2 core was obtained by the reaction of the unsymmetric diphosphene Mes*-P=P-Mes 11 with Ru3(CO)12; hindered rotation about the C(aryl)—P bonds was also observed, in this case. Reaktionen von Ru3(CO)12 mit Diphosphenen — Ein neuer Weg zu 50-Elektronen Ru3P2nido-Clustern Die Umsetzung des symmetrischen Diphosphens 2, 4, 6-(CF3)3-C6H2-P=P-C6H2-2, 4, 6-(CF3)34 mit Ru3(CO)12 fuhrte zu dem 50-Elektronen Ru3P2nido-Cluster Ru3(CO)9[μ-P-C6H2-2, 4, 6-(CF3)3]25. Dieser zeigt in Losung bei Raumtemperatur Rotationsbehinderung der aromatischen Ringe um die C(Aryl)-P-Bindungen. Die Struktur von 5 wurde durch Rontgenbeugung ermittelt. Das Ru3P2-Zentrum bildet eine verzerrte quadratische Pyramide mit einem Rutheniumatom in der apikalen Position. Eine der zwei C6H2(CF3)3-Gruppen ist ebenfalls betrachtlich verzerrt. Temperaturabhangige 19F-NMR-Studien des [A3M3X]2 Spinsystems (A = M = CF3, X = 31P) in 5 ergaben eine Rotationsbarriere ΔG≠ von 82.3 kJ mol-1 bei 141 °C. Das gleiche Ru3P2-Zentrum wurde bei der Umsetzung des unsymmetrischen Diphosphens Mes6ast;-P=P-Mes 11 mit Ru3(CO)12 erhalten. Auch in diesem Fall wurde eine Hinderung der Rotation um die C(Aryl)-P-Bindungen beobachtet.

A series of phosphor(III)inanone ligands 4-7, linked by ethylene bridges between the nitrogen atoms of the heterocyclic rings, were synthesized by the reaction of the bis-PCl derivative 3 with the appropriate trimethylsilylamines. The bis-phosphor(V)inanone compounds 8-11 were obtained by the oxidation of 4-7 with hexafluoroacetone (HFA). Oxidation of 4 and 6 with tetrachloro-orthobenzoquinone (TOB) gave the bis-phosphor(V)inanones 12 and 13. The reaction of 4-6 with [Pt(COD)Cl2] led to the platinum complexes 14-16. All the σ3-phosphorinanone compounds 4-7 and the σ5-phosphorinanone compounds 8-10, 12 and 13 exist as a mixture of two conformers, as indicated by two signals in the 31P-NMR spectra. However, compounds 9 and 11 exist as single conformers, both display only one sharp singlet in the 31P-NMR spectra. The Pt-complexes 15 and 16 contain two conformers; one conformer of 16 could be isolated by crystallization. X-ray crystal structure determinations for compounds 8, 14 and 16 were conducted, revealing inversion symmetry for 8 and cis arrangement for 14 and 16. Synthese von ethylen-verbruckten heterocyclischen P(III)N-Liganden — Untersuchungen der Oxidation und Komplexierung Eine Serie von Phosphor(III)-inanon-Liganden 4-7, durch Ethylengruppen zwischen den Stickstoffatomen der heterocyclischen Ringe verknupft, wurden durch Umsetzung der Bis-PCl-Verbindung 3 mit den entsprechenden Trimethylsilylaminen synthetisiert. Die Bis-phosphor(V)-inanon-Verbindungen 8-11 wurden durch Oxidation von 4-7 mit Hexafluoraceton (HFA) erhalten. Die Oxidation von 4 und 6 mit Tetrachlor-o-benzochinon (TOB) fuhrte zu den Bis-phosphor(V)-inanonen 12 und 13. Durch Umsetzung von 4-6 mit [Pt(COD)Cl2] (COD = 1, 5-Cyclooctadien) wurden die Platinkomplexe 14-16 erhalten. Die σ3-Phosphorinanon-Komplexe 4-7 und die σ5-Phosphorinanone 8-10, 12 und 13 liegen als Mischungen von zwei Konformeren vor. Dies wird durch die Beobachtung von zwei Signalen im 31P-NMR-Spektrum belegt. Die Verbindungen 9 und 11 existieren jedoch als einzelne Konformere, sie zeigen im 31P-NMR-Spektrum scharfe Singuletts. Die Platinkomplexe 15 und 16 liegen in jeweils zwei Konformeren vor; ein Konformer von 16 wurde durch Kristallisation isoliert. Einkristall-Rontgenstrukturuntersuchungen wurden fur die Verbindungen 8, 14 und 16 durchgefuhrt. Dabei ergab sich Inversionssymmetrie fur 8 und cis-Geometrie fur 14 und 16.

Studies by 1H NMR spectroscopy and X-ray diffraction analysis revealed hindered rotation of the aromatic substituent about the CAr—N bond in ortho-substituted (except for o-fluorine-substituted) phosphorus-containing carbamates. The energy barriers to rotation (ΔG c ≠) and coalescence temperatures (T c) determined by the coalescence method increase with increasing volume of the ortho substituent. Conformations resulting from rotation of the ortho-substituted aryl group about the CAr—N bond were analyzed by quantum-chemical methods, potential curves were constructed, and differences between the conformational energies and the heights of rotation barriers were estimated. The theoretical rotation barriers change in parallel with the experimental values of ΔG c ≠; however, the theoretical values are much smaller in magnitude.

Chiral racemic 1,8-bis( tert -butylphenylphosphino)naphthalene oxide ( 2a ) was resolved into enantiomers by fractional crystallization of its diastereomeric adducts 3a with (+)-(2 S ,3 S )-di- O -benzoyl tartaric acid (DBTA), followed by neutralization. Racemic 1,8-bis( tert -butylphenylphosphino)naphthalene ( 1a ) was oxidized with sulfur to two isomers of 1,8-bis( tert -butylphenyl-phosphino)naphthalene monosulfide, rac - 4a and rac - 4a ′, or 1,8-bis( tert -butylphenylphosphino)naphthalene disulfide, rac - 5a . The compounds were characterized by NMR spectroscopy ( 1 H, 31 P, 13 C). Crystal structures were determined by the X-ray method for (−)- 3a, rac - 4a , rac - 4a ′ and rac - 5a ; this allowed the determination of the absolute configuration ( S , S ) for the more soluble adduct (−)- 3a . It was found that rac - 1a undergoes partial epimerization in boiling xylene to give the meso form.

Die Umsetzung des 2, 2, 2, 4, 4, 4-hexachlorsubstituierten Diazadiphosphetidins 1 mit unterschiedlichen Mengen Diethylaminotrimethylsilan fuhrte zum Diazadiphosphetidin 2b oder zu der Diphosphonium-Verbindung 3. Wurde 1 mit zwei λquivalenten Aminosilan umgesetzt, wurde das Tetrachlordiazadiphosphetidin 2b isoliert, mit uberschussigem Aminosilan entstand dagegen das Salz 3. Eine Offnung des Vierrings, wie bei der Reaktion mit primaren Aminen, wurde nicht beobachtet. Erst die Hydrolyse von 3 offnete den Ring; da die Hydrolyse jedoch ohne Zusatz einer Base durchgefuhrt wurde, wurde die Phosphonium-Phosphoryl-Verbindung 6 isoliert. Rontgenstrukturanalysen fur 2b, 3 (als Chloridsalz/Dichlormethansolvat), 4 (als HCl2-Salz) und 6 wurden durchgefuhrt. Die Struktur von 2b weist zwei unabhangige Molekule auf. Die Molekule von 2b und die Kationen von 3 und 4 haben kristallographische Inversionssymmetrie. Alle zentralen Vierringe sind also exakt planar. Die Packung von 2b zeigt kurze Chlor-Chlor-Abstande. In 3 und 4 werden Wasserstoffbrucken der Form C-H···Cl beobachtet. Die asymmetrische Einheit von 6 enthalt zwei unabhangige Formeleinheiten und zwei Molekule Kristallwasser; durch klassische Wasserstoffbrucken werden die Formeleinheiten zu endlosen Strangen verknupft. Reactions of a Hexachloro-substituted Diazadiphosphetidine with Diethylaminotrimethylsilane The reaction of the 2, 2, 2, 4, 4, 4-hexachlorosubstituted diazadiphosphetidine 1 with varying amounts of diethylaminotrimethylsilane furnished the diazadiphosphetidine 2 or the diphosphonium compound 3. Reaction of 1 with two equivalents of diethylaminotrimethylsilane led to the tetrachlorodiazadiphosphetidine 2b, while excess of the aminosilane furnished the salt 3. Opening of the four-membered ring, as in the reaction with primary amines, was not observed. The ring was opened only upon hydrolysis of 3, conducted in the absence of base, with formation of the phosphonium-phosphoryl compound 6. Single crystal structure determinations are reported for 2b, 3 (as the chloride salt/dichloromethane solvate), 4 (the corresponding HCl2-salt) and 6. The structure of 2b involves two independent molecules. The molecules of 2b and the cations of 3 and 4 display inversion symmetry, and the central four-membered rings are thus exactly planar. The crystal packing of 2b involves short chlorine-chlorine contacts. In 3 and 4, hydrogen bonds of the form C-H···Cl are observed. The asymmetric unit of 6 contains two independent formula units and two molecules of water; classical hydrogen bonds connect the various residues to form infinite ribbons.

The reaction of the monofunctional closo-silsesquioxane silanol derivative Cy7Si8O12OH (3, Cy = c-C6H11) with tris(dimethylamino)phosphine afforded the novel silsesquioxanyl phosphine ligand Cy7Si8O12OP(NMe2)2 (4) in virtually quantitative yield. The complexes [Cy7Si8O12OP(NMe2)2]2PtCl2 (5) and [Cy7Si8O12OP(NMe2)2]2Mo(CO)4 (6) were obtained in excellent yields upon treatment of 4 with (COD)PtCl2 (COD = 1, 5-cyclooctadiene) and (NBD)Mo(CO)4 (NBD = norbornadiene), respectively. An attempted preparation of the bis(silsesquioxanyl)phosphine (Cy7Si8O12O)2P(NMe2) led to the formation of the known disiloxane derivative (Cy7Si8O12)2O (7), instead. Silsesquioxan-Chemie. 12 [1] Herstellung und Komplexierung eines neuen Silsesquioxanyl-Phosphin-Liganden Die Reaktion des monofunktionellen closo-Silsesquioxansilanol-Derivats Cy7Si8O12OH (3, Cy = c-C6H11) mit Tris(dimethylamino)phosphan lieferte den neuartigen Silsesquioxanylphosphan-Liganden Cy7Si8O12OP(NMe2)2 (4) in praktisch quantitativer Ausbeute. Die Komplexe [Cy7Si8O12OP(NMe2)2]2PtCl2 (5) und [Cy7Si8O12OP(NMe2)2]2Mo(CO)4 (6) wurden in hervorragenden Ausbeuten durch Umsetzung von 4 mit (COD)PtCl2 (COD = 1, 5-Cyclooctadien) bzw. (NBD)Mo(CO)4 (NBD = Norbornadien) erhalten. Ein Versuch, das Bis(silsesquioxanyl)phosphan (Cy7Si8O12O)2P(NMe2) herzustellen, fuhrte lediglich zur Bildung des bekannten Disiloxanderivats (Cy7Si8O12)2O (7).

The conformations and vibrational spectra of 2-benzylphenol have been analysed within the framework of scaled quantum mechanics. It is shown that the solid-state conformation of the 2-benzylphenol molecule corresponds to one of four potential energy minima predicted by non-empirical quantum chemical calculations for the isolated molecule. In the molten state and in diluted CCl4 solutions of the title compound this conformer coexists with another two spectroscopically detected conformations. The presence of several conformers gives rise to the observation of the corresponding number of vsCH2 and vasCH2 bands in the IR spectra, thus providing experimental evidence of the conformational sensitivity of the vCH2 frequencies. It is shown that vCH2 wavenumbers of different kinds of molecules, containing diphenylmethane fragments, are determined by the dihedral angles between the planes of the aromatic rings and the plane of the connecting methylene bridges, except for the case of short intramolecular contacts with the participation of the methylene protons.

The reactions of meta—para-substituted aryl isocyanates with phosphorus-containing 1,3-zwitterions, which proceed with the C→N migration of the CO2Et group to form the corresponding carbamates, were extended to ortho-substituted aryl isocyanates. The influence of the steric and electronic effects of the ortho substituents in the aromatic rings of aryl isocyanates on the ease of this rearrangement is qualitatively considered.

Chlorination of the 4-[chloro(diisopropylamino)phosphino]pyrazole 1 leads to the dichlorophosphonium chloride 2, which immediately after its formation transforms into the dichloro(diisopropylamino)phosphonio[5(4)oxopyrazol-4-ylide-5-one] 3, as a result of dealkylation through loss of ethyl chloride. Reactions of 3 with various nucleophilic reagents were studied. The partial hydrolysis of 3 in the presence of nitriles, resulting in new phosphorus-containing cyclic systems, is of particular interest. It was demonstrated that chlorination of the P-dichloropyrazolylphosphine A leads to the stable tetrachlorophosphorane 12. The CP bond of 12 is broken upon heating. An X-ray structure determination of compound 11b revealed a planar central heterocycle (mean deviation 0.029 A). © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:452–458, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10177

The [1+1] cyclocondensation of the bis-PCl species 1,2-bis(benzo-1-methyl-2-chloro- 1,3,2-diazaphosphorin-4-on-3-yl)ethane 1 and 1,3-bis(benzo-1-methyl-2-chloro-1,3,2-diazaphosphorin- 4-on-3-yl)propane 2 with the 1,2-benzenediol bis(trimethylsilyl) ether 3a and 2,3- naphthalenediol bis(trimethylsilyl) ether 3b gave the symmetrical phosphorus-containing largering systems 4 - 7 in moderate yield. The phosphoryl compounds 8 - 11 were obtained by the oxidation of 4 - 7 with (H2N)2C(:O) H2O2. Oxidation of 6 and 7 with elemental sulfur furnished the thiophosphoryl compounds (12 and 13). All new compounds formed in the reactions were characterized unambiguously by NMR spectroscopy, mass spectrometry, and elemental analysis. For compounds 6, 9, 10, 11 and 12, X-ray crystal structure determinations were conducted. The compounds with ten-membered rings show approximate (6, 12) or exact (10) twofold symmetry. In each of the compounds 9 and 11 the two six-membered heterocycles are appreciably different; one is approximately planar, whereas in the other, phosphorus lies outside the plane of the other five atoms

Chemical shifts, δ( 19 F ), were recorded for solutions of LiBF4 in diethyl carbonate (DEC), dimethyl carbonate (DMC), tetrahydrofuran (THF), 1,2-dimethoxyethane (DME), γ-butyrolactone (GBL), propylene carbonate (PC) and water. The δ( 19 F ) values of the tetrafluoroborate anion were obtained by extrapolation to infinite dilution. A correlation between δF and both dielectric constants and dipole moments of the solvents has been found.

The reactions of the zwitterionic species 1 with ortho -substituted aryl isocyanates proceed in an unusual way, resulting in the formation of the P-containing carbamates 3. In the latter (except for X=F) the CH 2 P protons are anisochronous and give rise to an AB pattern at the corresponding temperatures (1H{31P}). When the temperature is increased, the AB pattern coalesces to a singlet. The j G c # values, together with all pertinent data, are listed.

The conformations and vibrational spectra of the 2,6-dimethylanisole and n-propyl-2,6-dimethylphenyl ether molecules have been analysed within the framework of density functional theory. The calculated force field (B3LYP/6-31G∗) has been transformed to internal coordinates, and the set of 10 different scaling factors has been applied. The scaled quantum mechanical method reproduces the experimental range of the IR and Raman spectra with high accuracy. According to the computations, the conformational behaviour of the alkyl aryl ethers studied is similar to the related dialkyl ether molecules, i.e. the CO–CC bond prefers the anti conformation, while the OC–CC bond prefers the gauche conformation. The major part of the vibrational spectra of the title compounds can be approximated by the sum of the vibrational modes of their constituent groups, these modes being transferable among the related molecules.

The reaction behaviour of 1, 3, 5-triaza-2σ3λ3-phosphorin-4, 6-dionyloxy-substituted calix[4]arenes towards mono- and binuclear rhodium and platinum complexes was investigated. Special attention was directed to structure and dynamic behaviour of the products in solution and in the solid state. Depending on the molar ratio of the reactands, the reaction of the tetrakis(triazaphosphorindionyloxy)-substituted calix[4]arene (4) and its tert-butyl-derivative (1) with [(cod)RhCl]2 yielded the mono- and disubstituted binuclear rhodium complexes 2, 3, and 5. In all cases, a C2-symmetrical structure was proved in solution, apparently caused by a fast intramolecular exchange process between cone conformation and 1, 3-alternating conformation. The X-ray crystal structure determination of 5 confirmed [(calixarene)RhCl]2-coordination through two opposite phosphorus atoms with a P P separation of 345 pm. The complex displays crystallographic inversion symmetry, and the Rh2Cl2 core is thus exactly planar. Reaction of 1 and of the bis(triazaphosphorindionyloxy)-bis(methoxy)-substituted tert-butyl-calix-[4]arene (7) with (cod)Rh(acac) in equimolar ratio and subsequent reaction with HBF4 led to the expected cationic monorhodium complexes 5 and 8, involving 1, 3-alternating P-Rh-P-coordination. The cone conformation in solution was proved by NMR spectroscopy and characteristic values of the 1J(PRh) coupling constants in the 31P-NMR-spectra. Reaction of equimolar amounts of 4 with (cod)Rh(acac) or (nbd)Rh(acac) led, by substitution of the labile coordinated acetylacetonato and after addition of HBF4, to the corresponding mononuclear cationic complexes 9 and 10. Only two of the four phosphorus atoms in 9 and 10 are coordinated to the central metal atom. Displacement of either cycloocta-1, 5-diene or norbornadiene was not observed. For both compounds, the cone conformation was proved by NMR spectroscopy. Reaction of 4 with (cod)PtCl2 led to the PtCl2-complex (11). As for all compounds mentioned above, only two phosphorus atoms of the ligand coordinate to platinum, while two phosphorus atoms remain uncoordinated (proved by δ31P and characteristic values of 1J(PPt)). NMR-spectroscopic evidence was found for the existence of the cone conformation in the cis-configuration of 11. Ein- und zweikernige Komplexe des Rhodiums und Platins von 1, 3, 5-Trimethyl-1, 3, 5-triaza-2σ3λ3-phosphorin-4, 6-dionyloxy-substituierten Calix[4]arenen Das Reaktionsverhalten von 1, 3, 5-Trimethyl-1, 3, 5-triaza-2σ3λ3-phosphorin-4, 6-dionyloxy-substituierten Calix-[4]arenen gegenuber ein- und zweikernigen Rhodium- und Platin-Komplexen wurde untersucht. Besonderes Augenmerk wurde auf die Untersuchung der Struktur und des dynamischen Verhaltens der Produkte im festen Zustand und in Losung gelegt. Abhangig vom molaren Verhaltnis der Reaktanden lieferte die Umsetzung des tetrakis(triazaphosphorindionyloxy)-substituierten Calix[4]-arens (4) und seines tert-Butyl-Analogons (1) mit [(cod)RhCl]2 die mono- und disubstituierten, zweikernigen Rhodiumkomplexe 2, 3 und 5. In allen Fallen wurde eine C2-symmetrische Struktur in Losung nachgewiesen, die anscheinend aus einem schnellen intramo-lekularen Austauschprozes zwischen der Konus- und der 1, 3-alternierenden Konformation resultiert. Die Rontgenstrukturanalyse von 5 bestatigte die [(Calixaren)RhCl]2-Koordination uber zwei gegenuberliegende Phosphoratome mit einem P P-Abstand von 345 pm. Der Komplex zeigt kristallographische Inversionssymmetrie, damit ist die Rh2Cl2-Verbruckungseinheit exakt planar. Die Reaktion von 1 und dem bis(triazaphosphorindionyloxy)-bis(methoxy)-substituierten tert-Butyl-Calix[4]aren (7) mit (cod)-Rh(acac) in aquimolarem Verhaltnis und anschliesender Umsetzung mit HBF4 fuhrte zu den erwarteten Monorhodiumkomplexen 6 und 8 mit 1, 3-alternierender P-Rh-P-Koordination. Die Konus-Konformation wurde in Losung durch NMR-Spektroskopie und charakteristische 1J(PRh)-Kopplungskonstanten in den 31P-NMR-Spektren nachgewiesen. Die Umsetzung aquimolarer Mengen von 4 mit (cod)Rh(acac) und (nbd)Rh(acac) fuhrte durch Substitution des schwachkoordinierten Acetylacetonato-Restes und nach Zugabe von HBF4 zu den entsprechenden einkernigen Komplexen 9 und 10. Nur zwei der vier Phosphoratome von 9 und 10 sind ans Zentralmetallatom koordiniert. Abspaltung von Cycloocta-1, 5-dien oder Norbornadien wurde nicht beobachtet. Fur beide Verbindungen wurde die Konus-Konformation durch NMR-Spektroskopie nachgewiesen. Die Umsetzung von 4 mit (cod)PtCl2 ergab den PtCl2-Komplex (11). Wie bei allen zuvor genannten Verbindungen, koordinieren nur zwei der Phosphoratome an Platin, wahrend zwei Phosphoratome unkoordiniert bleiben (nachgewiesen durch die Signalmuster im 31P-NMR-Spektrum mit charakteristischen Werten fur die 1J(PPt)-Kopplungskonstanten). NMR-spektroskopische Evidenz wurde auch fur die Existenz der Konus-Konformation in der cis-Konfiguration von 11 gefunden.

The reaction of 1, 8-dilithionaphthalene 2, with 2 equivalents of rac-Me(C6F5)PCl, gave a 6 : 1 mixture of rac- and meso-1, 8-di(methyl-pentafluorophenylphosphino)naphthalene (dmfppn, rac-3h and meso-3h), but no reaction was observed when the sterically crowded rac-tBu(C6F5)PCl was used. In 31P NMR experiments, rac-3h and mmeso-3h exhibited characteristic signals (virtual quintets), which indicate that there is significant coupling through space (3JPF + 7JPF ≈ 15 Hz). Compound rac-3h was isolated by fractional crystallisation and treated with aqueous H2O2 to yield the corresponding bis-phosphine dioxide, rac-7h. In contrast to rac-3h, there was no sign of through-space coupling in rac-7h, which again illustrates that the latter operates via the lone pairs at phosphorus. Platinum(II) complexes were prepared from the new, P-chiral chelate rac-3h, and the related ligand 1, 8-di(tert-butylphenylphosphino) naphthalene (rac-dtbppn, rac-3e). All isolated new compounds were characterised by multinuclear NMR and IR spectroscopy, mass spectrometry, and elemental analysis. Single-crystal X-ray structure determinations were performed for rac-dmfppn (rac-3h), rac-[PtCl2(dtbppn)] (rac-17e), and rac-[PtCl2(dmfppn)] (rac-17h). rac-3h displays crystallographic twofold symmetry. In rac-17h, the electron-withdrawing effect of the C6F5 groups causes a shortening of the Pt—P bond to ca. 220 pm (cf. 223 pm in rac-17e). Platin(II)-Komplexe von P-chiralen 1, 8-Bis(diorganophosphino)naphthalinen; Rontgenstrukturanalysen von dmfppn, rac-[PtCl2(dmfppn)] und rac-[PtCl2(dtbppn)] (dmfppn = 1, 8-Di(methyl-pentafluorphenylphosphino)naphthalin und dtbppn = 1, 8-Di(tert-butylphenylphosphino)naphthalin) Die Reaktion von 1, 8-Dilithionaphthalin (2) mit 2 Aquivalenten rac-Me(C6F5)PCl ergab ein 6 : 1 Gemisch von rac-und meso-1, 8-Di(methyl-pentafluorphenylphosphino)naphthalin (dmfppn, rac-3h und meso-3h). Wurde jedoch das sterisch anspruchsvollere rac-tBu(C6F5)PCl verwendet, konnte keine Reaktion beobachtet werden. In den 31P NMR Spektren zeigten rac-3h und meso-3h) charakteristische Signale (virtuelle Quintetts), die auf eine signifikante Kopplung durch den Raum deuten (3JPF + 7JPF ≈ 15 Hz). Die Verbindung rac-3h wurde durch fraktionierende Kristallisation isoliert und ein Teil davon mit wassr. H2O2-Losung versetzt, wodurch das entsprechende Bis-phosphinoxid (rac-7h) erhalten wurde. Anders als rac-3h, zeigte rac-7h keine Anzeichen fur Kopplungen durch den Raum (through-space coupling), was erneut illustriert, das diese Kopplungen durch die nicht-bindenden Elektronenpaare am Phosphor vermittelt werden. Von dem neuen, P-chiralen Chelat-Liganden rac-3h und dem strukturell verwandten Liganden 1, 8-Di(tert-butylphenylphosphino)-naphthalin (rac-dtbppn, rac-3e) wurden Platin(II)-Komplexe hergestellt. Alle neuen Produkte wurden durch NMR und IR Spektroskopie, Massenspektrometrie und Elementaranalysen charakterisiert. Von den Verbindungen rac-dmfppn (rac-3h), rac-[ PtCl2(dtbppn)] (rac-17e) und rac-[PtCl2(dmfppn)] (rac-17h) wurden Einkristall-Rontgenstrukturanalysen angefertigt. rac-3h zeigt kristallographische, zweizahlige Symmetrie. In rac-17h fuhrt der elektronenziehende Effekt der C6F5-Gruppen zu einer Verkurzung der Pt—P Bindung auf ca. 220 pm (vgl. 223 pm in rac-17e).

This paper describes the preparation of 1,8-bis[bis(dimethylamino)phosphino]naphthalene (2a) and the attempted preparation of its isopropyl analogue 2c, which led to the formation of 1-naphthyl-bis(diisopropylamino)phosphine (4), and to other unidentified products. The X-ray structures of 2a and 4 are discussed in comparison to those of 1,8-bis[bis(diethylamino)phosphino]naphthalene (2b) and 1-naphthyl-di-tert-butylphosphine (5), respectively. In the structures of 2a, 2b and 4 the (R2N)2P groups (R=alkyl) are eclipsed with respect to the naphthalene plane, whereas the R2P groups (R=alkyl or aryl) in 5, as in 1,8-bis(diorganophosphino)naphthalenes in general, adopt a conformation between bisecting and eclipsed. Furthermore, the reactions of 2a and 2b with BX3 ether adducts (X=F, Cl) are described, which furnished the heterocyclic [σ3P–σ4P+]-diphosphorus compounds, 1-dimethylamino-2-bis(dimethylamino)-, 1-diethylamino-2-bis(diethylamino)- and 1-chloro-2-bis(diethylamino)-1-phospha-2-phosphonium-acenaphthene (6a, 6b and 7b); the first examples of the 1,2-dihydro-1,2-diphospha-acenaphthene ring system. The X-ray structures of 6a and 7b display a relief of strain compared to the parent bis-aminophosphines 2a and 2b, quantified by negative splay angles [−7.89° (6a) and −9.40° (7b); cf. +12.16° (2a) and +12.0° (2b)] and the bonded [225.38 (6a) and 223.16 (7b) pm] compared to the non-bonded phosphorus–phosphorus distances [311.9 (2a) and 311.7 (2b) pm]. A mechanism is discussed for the formation of 6b and 7b from 2b and gaseous hydrogen chloride.

The conformations and vibrational spectra of bis(2-hydroxyphenyl)methane have been analysed within the framework of density functional theory. The calculated force fields (B3LYP/6-31G*) of seven possible energy minima were transformed to internal coordinates, and a set of ten different scaling factors was applied. The scaled quantum mechanical (SQM) method reproduces the experimental IR and Raman spectra with high accuracy. The dependence of the CH2 stretching vibrations on the conformation and the possibility of its use as a probe for larger systems, e.g., calixarenes or polyphenols, are discussed.

Vinylphosphonsauredichlorid I sowie dessen Thioanalogon 3 wurden mit Dialkylaminotrimethylsilanen Me3SiNR2 (R = Me. Et) zu den entsprechenden Amidchloriden CH2=CHP(:O)CI(NR2) 5 (R = Me) und 6 (R = Et) sowie den Thioamidchloriden CH2=CHP(:S)CI(NR2) 7 (R = Me) und 23 (R = Et) umgesetzt. Analoge Alkoholysereaktionen lieferten die ethoxy- und phenoxysubstituierten Esterchloride CH2=CHP(:O)CI(OR) 10 (R = Et) und 12 (R = Ph); auserdem erhalt man durch Veresterung mil aromatischen Diolen wie Tetrachlorbrenzkatechin oder 1,2-Dihydroxynaphthalin Diester. Sowohl die erwahnten Amidchloride ah auch die Ehterchloride wurden in einem weiteren Schritt durch Chlor-Fluo-raustausch mit SbF3 bzw. AsF3 in die entsprechenden Amidfluoride bzw. Thioamidfluoride CH2=CHP(:X)F(NMe2) 8 (X = O) bzw. 9 (X = S) und die Esterfluoride CH2=CHP(:O)F(OR) 11 (R = Et) bzw. 14 (R = Ph) uberfuhrt. Schlieslich wurden weitere Vinylphosphonsaurederivate, wie z.B. die vinylsubstituierte, cyclophosphamid-analoge Verbindung 21 durch Amino-l...

Verschiedene Diazadiphosphetidine werden aus PCl5 und primaren Aminen, entsprechend einer modifizierten Kirsanov-Reaktion, hergestellt und einer Rontgenstrukturanalyse unterzogen. Die Ergebnisse der Rontgenstrukturanalysen der Hexahalogendiazadiphosphetidine weisen auf eine sterische Hinderung in der cyclohexylsubstituierten Verbindung 4 hin. Im Vergleich zur Struktur der Fluorverbindung 12 wird gezeigt, das die sterische Hinderung nur bei Chlorphosphoranen eine Rolle spielt. Bei der Kirsanov-Reaktion von PCl5 mit aliphatischen Aminen, die in α-Stellung verzweigt sind, wurde eine Folgereaktion beobachtet, wenn das Amin im Uberschus eingesetzt wurde. Das Phosphonium-Salz 11 wird durch 1H-, 13C- und 31P-NMR-Spektren, FAB-Massenspektrum, Elementaranalyse und Rontgenstrukturanalyse zweifelsfrei charakterisiert. X-Ray Structure Analysis of Diazadiphosphetidines Various diazadiphosphetidines are synthesized by a modified Kirsanov reaction and subjected to X-ray crystal structure analysis, the results of which show steric hindrance in the cyclohexyl-substituted compound 4. A comparison of its structure to that of the fluorine compound 12 shows that the steric hindrance occurs only in the case of chlorophosphoranes. During the Kirsanov reaction with aliphatic amines branched at the α-position, a further reaction is observed if the amine is added in excess. The phosphonium salt 11 is characterized by 1H-, 13C- and 31P-NMR-spectra, FAB-mass spectrum, elemental analysis and X-ray crystal structure analysis.

A series of naphthalenediyl-1,8-bis(phosphine oxides) 1-RR′P(:O)(C10H6)-8-P(:O)RR′ (R = R′ = Me (2a), Et (2b), iPr (2c), Cy (2d), Ph (2f) and R = tBu, R′ = Ph (2e) was prepared by oxidation of the corresponding bis(phosphines) 1a–f with molecular oxygen or H2O2·(H2N)2C(:O) and characterized by NMR and IR spectroscopy, mass spectrometry, and elemental analysis (2a, 2b, 2d–f). X-ray crystal structure analyses were performed for 1,8-bis(dimethylphosphinyl)naphthalene (2a), (RR,SS)-1,8-bis(phenyl-tert-butylphosphinyl)naphthalene (2e) and 1,8-bis(diphenylphosphinyl)naphthalene (2f). Treatment of 1,8-bis(diphenylphosphino)naphthalene (dppn, 1f) with an excess of sulfur in hot toluene afforded the bis(phosphine sulfide) 1-Ph2P(:S)(C10H6)-8-P(:S)Ph2 (dppnS2, 3f) the structure of which was elucidated by X-ray crystal structure analysis. The geometries of the compounds 2a, 2e, 2f, and 3f revealed an increase of strain from the corresponding bis(phosphines). In each case, the proximity of the P(:X)R2 groups (X = O, S) led to distortion, the main feature of which was the out-of-plane displacement of the P atoms. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:102–113, 2001

The reactions of the zwitterion derived from triisopropylphosphine and ethyl 2-cyanoacrylate with mercuric chloride and aryl isothiocyanates containing Cl atoms in the ortho positions of the benzene ring follow an unusual pathway because this zwitterion represents “latent” triisopropylphosphine due to the reversibility of the reaction of triisopropylphosphine with ethyl 2-cyanoacrylate. The molecular structures of the adducts of triisopropylphosphine with 2,6-dichloro- and 2,4,6-trichlorophenyl isothiocyanates were confirmed by X-ray diffraction study. Protonation of the adduct of triisopropylphosphine with 2,6-dichlorophenyl isothiocyanate occurred at the nitrogen atom, whereas methylation with methyl trifluoromethanesulfonate afforded an S-methylation product. The results of X-ray diffraction study of the resulting compounds are presented.

The course of the alkaline hydrolysis of (diphenoxyphosphoryl)methyl p-tolyl sulfoxide (8) has been elucidated by a combination of 18O isotopic labelling and mass spectrometric analysis of the hydrolysis products. The hydrolysis of the sulfoxide 8 containing 18O in the sulfinyl group afforded the corresponding phosphonic acid 9, which, upon methylation with diazomethane, was converted into [methoxy(phenoxy)phosphoryl]methyl p-tolyl sulfoxide (10) also containing 18O in the sulfinyl group, as demonstrated by the EI- and CI-mass spectra. The hydrolysis of 8 in 18O-enriched water followed by methylation with diazomethane gave the sulfoxide 10 in which 18O was incorporated into the phosphonic ester moiety. These results do not support a two-step mechanism for the hydrolysis of α-phosphoryl sulfoxides involving participation of the neighbouring sulfinyl group and formation of a cyclic oxathiaphosphetane intermediate. The latter is most probably formed in the mass spectrometric fragmentation process of α-phosphoryl sulfoxides.

Reactions between isocyanates, carbanions with an acetyl group at the carbanion center occurvia rearrangement of the intermediate N-anions into isomeric C-anions by C→N-migration of the MeC(O)group. The acetyl group undergoes migration easier than the ethoxycarbonyl group. The P-zwitterionic rearrangement products were subjected to X-ray diffraction analysis.

The conformational and normal coordinate analysis of vibrational spectra of the diphenylmethane molecule has been realised within the framework of density functional theory. The calculated force field (B3LYP/6-31G∗) was transformed to nonredundant internal coordinates. It is shown that after assignment of two different scaling factors for aromatic and aliphatic C–H coordinates, the scaled quantum mechanical (SQM) method reproduces the complete experimental range of the IR and Raman spectra with high accuracy (mean deviation: 5.5 cm−1). The set of nine different scaling factors will be used in conformational studies of calixarene building blocks.

The synthesis of calix[4]arene-based phosphorus diamides and phosphites is described. These oligocyclic ligands have been tested in the Rh(I)- catalyzed hydroformylation of 1-octene. Depending on the reaction conditions, yields up to 99% and n/iso-selectivities between 0.7 and 2.6 have been observed. tert-Butyl groups on the upper rim of the calix[4]arene template had a beneficial effect on the catalytic reaction. In general biuret-derived P-ligands were superior. For comparison, the corresponding “monomeric” ligands have also been synthesized and were employed in the catalytic reaction. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:577–585, 2001

Treatment of 1,8-bis(diphenylphosphino)naphthalene (dppn, 1) with stoichiometric amounts of sulfur or selenium in toluene at 80 °C selectively afforded the diphosphine monochalcogenides 1-Ph2P(C10H6)-8-P(:S)Ph2 (dppnS, 2 a) and 1-Ph2P(C10H6)-8-P(:Se)Ph2 (dppnSe, 2 b). The 31P{1H} NMR spectrum of 2 b showed an unusually large 5J(P–Se) value, which indicates a significant through-space coupling component. The monosulfide acted as a bidentate P,S-ligand towards platinum(II) (3 a), whereas the corresponding monoselenide complex (3 b′) lost elemental selenium with formation of the previously reported complex [PtCl2(dppn)-P,P′] (3). Treatment of dppnSe with [(nor)Mo(CO)4] (nor = norbornadiene) led to formation of [(dppnSe)Mo(CO)4-P,Se] (3 b). Solutions of the latter slowly deposited Se with formation of [(dppn)Mo(CO)4-P,P′] (4) which was also obtained by independent synthesis from 1 and [(nor)Mo(CO)4]. All isolated new compounds were characterised by a combination of 31P, 1H, 13C and 77Se (2 b) NMR spectroscopy, IR spectroscopy, mass spectrometry and elemental analysis. Single-crystal X-ray structure determinations were performed for dppnSe (2 b), [PtCl2(dppnS)-P,S] (3 a), [(dppnSe)Mo(CO)4-P,Se] (3 b) and [(dppn)Mo(CO)4-P,P′] (4). In 2 b steric effects cause the naphthalene ring to be distorted and force the phosphorus atoms by 65 and 59 pm to opposite sides of the best naphthalene plane. In the metal complexes 3 a, 3 b and 4 the phosphino-phosphinochalcogenyl systems act as bidentate ligands through the P and the chalcogen atoms. The naphthalene systems are again distorted. The two independent molecules of 4 differ in their conformations. Einfach oxidierte Schwefel- und Selen-Derivate von 1,8-Bis(diphenylphosphino)naphthalin: Synthese und Koordinationschemie Die Umsetzung von 1,8-Bis(diphenylphosphino)naphthalin (dppn, 1) mit stochiometrischen Mengen Selen oder Schwefel in Toluol bei 80 °C fuhrte selektiv zu den Diphosphin-Monochalkogeniden 1-Ph2P(C10H6)-8-P(:S)Ph2 (dppnS, 2 a) und 1-Ph2P(C10H6)-8-P(:Se)Ph2 (dppnSe, 2 b). Das 31P{1H} NMR Spektrum von 2 b zeigte einen ungewohnlich grosen Wert fur 5J(P–Se), der auf eine signifikante Wechselwirkung durch den Raum deutet (through-space coupling). Das Monosulfid fungierte als zweizahniger P,S-Ligand gegenuber Platin(II) (3 a), wahrend sich der entsprechende Komplex des Monoselenids (3 b′) unter Abscheidung elementaren Selens schnell in den bekannten Komplex [PtCl2(dppn)-P,P′] (3) umwandelte. Die Umsetzung von dppnSe mit [(nor)Mo(CO)4] (nor = Norbornadien) fuhrte zur Bildung von [(dppnSe)Mo(CO)4-P,Se] (3 b). Aus Losungen dieses Komplexes in Dichlormethan schied sich langsam elementares Selen ab, wobei sich [(dppn)Mo(CO)4-P,P′] (4) bildete. Letzterer Komplex konnte auch durch unabhangige Synthese aus dppn und [(nor)Mo(CO)4] hergestellt werden. Alle isolierten neuen Verbindungen wurden durch eine Kombination von 31P, 1H, 13C und 77Se (2 b) NMR-Spektroskopie, IR-Spektroskopie, Massenspektrometrie und Elementaranalyse charakterisiert. Von den Verbindungen dppnSe (2 b), [PtCl2(dppnS)-P,S] (3 a), [(dppnSe)Mo(CO)4-P,Se] (3 b) und [(dppn)Mo(CO)4P,P′] (4) wurden Einkristall-Rontgenstrukturanalysen angefertigt. In 2 b fuhren sterische Effekte zu einer Verzerrung des Naphthalinrings und zwingen die Phosphoratome um 65 und 59 pm auf gegenuberliegende Seiten der gemittelten Naphthalinebene. In den Metallkomplexen 3 a, 3 b und 4 fungieren die Phosphino-Phosphinochalkogen-Systeme als zweizahnige P-Chalkogen-Liganden. Auch hier sind die Naphthalinringe verzerrt. Die beiden unabhangigen Molekule von 4 unterscheiden sich in ihren Konformationen.

Treatment of the spacer modified glucose derivative 1 with diethylaminotrimethylsilane furnished the bis-silylated molecule 2. Reaction of 2 with two equivalents of the phosphorus compounds 3, 4, and 5 led to the spacer phosphorylated glucosyl derivatives 6, 7 and 8. Complexation of 6 with (COD)PtCl2 gave complex 9; the cis-conformation of 9 could be confirmed by 31P NMR investigations

Although diverse phosphorus-containing heterocycles had been synthe-sized during the late nineteenth century already, work was still sparse in this area as recently as 1950[1,2]. The realization, around 1950, of the importance of phosphorus-containing substances in biological processes resulted in intense activity in preparative organophosphorus chemistry, and in an upsurge of research on structural and mechanistic problems [3–6].

Synthesis, characterization, and solid state X-ray crystallographic structures for 12-Pn-6 complexes derived from carbene 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene and phosphorus, arsenic, or antimony pentafluoride are reported. The adducts show octahedral geometries at the pnictogen centers with C-Pn bond distances of 189.8 (P), 199.9 (As), and 217.5 (Sb) pm. The structures are those of internal zwitterions with imidazolium ion character in the heterocyclic ring and a pentafluoropnictanide anion bonded to C2. Adducts of BF3 with 1,3-dimesitylimidazol-2-ylidene and 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene are also reported for comparison. Although the reactivity of chlorinated and non-chlorinated carbenes varies considerably, the spectroscopic and structural properties of analogous adducts are remarkably similar.