Preparation and Characterization of a Novel Palladium Complex: cis‐Dichloride(1,2‐bis(diphenylphosphino)vinyl‐P,P′,C)palladium(II)‐(bis(diphenylphosphino)methane‐P,P′)cobaltacarbonyl

A novel palladium complex 4, cis‐dichloride(1,2‐bis(diphenylphosphino)vinyl‐P,P′,C)palladium(II)‐(bis(diphenylphosphino)methane‐P,P′)cobaltacarbonyl, was obtained and characterized from the treatment of [(μ‐Ph₂PCH₂PPh₂)Co₂(CO)₄][(Ph₂PC≡CPPh₂)‐PdCl₂] 3 with hydrochloric acid. The framework of 4 can be regarded as a grouping of two metal‐containing fragments: ‐Co(CO)₂(dppm) and PdCl2(μ‐P,P‐Ph₂PCH=C(‐)PPh₂).     

Solution properties of semirigid polyquinolines. I. Size-exclusion chromatography with light-scattering detection of poly[2,2′-(P,P′-oxydi-P-phenylene) 6,6′-oxybis(4-phenylquinoline)]

An aromatic semirigid polyquinoline, poly[2,2′-(p,p′-oxydi-p-phenylene) 6,6′-oxybis(4-phenylquinoline)], has been studied in dilute solution using viscometry, light scattering, and size-exclusion chromatography coupled with low-angle light-scattering detection (SEC/LALS). The SEC/LALS technique permits determination of the intrinsic viscosity and absolute molecular weight for a series of narrow fractions without preparative fractionation. Aggregation that was observed in dilute chloroform solutions was found to be related to protonation of the polyquinoline by HCI present in chloroform. Unperturbed dimensions calculated from the SEC/LALS results show the chain to have nearly freely rotating dimensions, as expected for a chain composed of long (12-Å) rigid segments connected by ether linkages.     

P−P Condensation and P−N/P−P Bond Metathesis: Facile Synthesis of Cationic Tri‐ and Tetraphosphanes

[L_C^RP((PhP)₂C₂H₄)][OTf] ( 4 a,b [OTf]) and [L_C^iPrP(PPh₂)₂][OTf] ( 5 b [OTf]) were prepared from the reaction of imidazoliumyl‐substituted dipyrazolylphosphane triflate salts [L_C^RP(pyr)₂][OTf] ( 3 a,b [OTf]; a : R=Me, b =iPr; L_C^R=1,3‐dialkyl‐4,5‐dimethylimidazol‐2‐yl; pyr=3,5‐dimethylpyrazol‐1‐yl) with the secondary phosphanes PhP(H)C₂H₄P(H)Ph) and Ph₂PH. A stepwise double P?N/P?P bond metathesis to catena‐tetraphosphane‐2,3‐diium triflate salt [(Ph₂P)₂(L_C^MeP)₂][OTf]₂ ( 7 a [OTf]₂) is observed when reacting 3 a [OTf] with diphosphane P₂Ph₄. The coordination ability of 5 b [OTf] was probed with selected coinage metal salts [Cu(CH₃CN)₄]OTf, AgOTf and AuCl(tht) (tht=tetrahydrothiophene). For AuCl(tht), the helical complex [{(Ph₂PPL_C^iPr)Au}₄][OTf]₄ ( 9 [OTf]₄) was unexpectedly formed as a result of a chloride‐induced P?P bond cleavage. The weakly coordinating triflate anion enables the formation of the expected copper(I) and silver(I) complexes [( 5 b )M(CH₃CN)₃][OTf]₂ (M=Cu, Ag) ( 10 [OTf]₂, 11 [OTf]₂).     

Bis­[methyl­enebis­(di­phenyl­phosphine)‐P,P′]­nickel(II) diperchlorate

The title compound, [Ni(Ph₂PCH₂PPh₂)₂](ClO₄)₂, was synthesized and its structure determined crystallographically. The Ni atom lies on an inversion centre and is at the center of a square formed by four P atoms which are necessarily coplanar. The Ni—P distances are 2.2188 (5) and 2.2322 (5) Å, and the P—Ni—P angle is 73.12 (3)°. The unique perchlorate anion is not coordinated to the Ni atom.     

Bis[1,2‐bis(diphenylphosphino)ethane‐κ2P,P′]difluoridoruthenium(II) trichloromethane disolvate

In the crystal structure of the title compound, [RuF₂(C₂₆H₂₄P₂)₂]·2CHCl₃, the Ru atom lies on a centre of symmetry with a trans arrangement of the F atoms. A H...F contact (2.249 Å) suggests weak intramolecular hydrogen bonding. The solvent molecules exhibit hydrogen bonding with the F atoms (H...F = 1.91 Å).     

[Bis(2‐diphenylphosphinoethyl) sulfide‐κ3P,S,P′](triphenylphosphine‐κP)platinum(II) diperchlorate acetone solvate

In the title compound, [Pt(C₁₈H₁₅P)(C₂₈H₂₈P₂S)]­(ClO₄)₂·­C₃H₆O or [Pt(PPh₃)(PSP)](ClO₄)₂·CH₃COCH₃, where PSP is the potentially tridentate chelate ligand bis(2‐di­phenyl­phosphinoethyl) sulfide, all three donor groups of the PSP ligand are coordinated to the central Pt atom, with Pt—P = 2.310 (1) Å and Pt—S = 2.343 (1) Å. The fourth coordination site is occupied by the P donor of the tri­phenyl­phosphine ligand [Pt—P = 2.289 (1) Å]. The complex cation has exact mirror symmetry, with the S atom, the Pt atom and the P atom of the PPh₃ ligand in the mirror plane. The Pt atom has a distorted square‐planar coordination geometry. A π–π interaction is present between the phenyl rings of the PPh₃ ligand and the terminal –PPh₂ group of the PSP chelate.     

Water‐Soluble Phospholo[3,2‐b]phosphole‐P,P′‐Dioxide‐Based Fluorescent Dyes with High Photostability

We recently reported that fluorescent dye PB430, which consisted of a 2‐phenyl‐substituted benzophosphole P‐oxide skeleton that was reinforced by a methylene bridge, showed pronounced photostability and, thus, high utility for applications in super‐resolution stimulated emission depletion (STED) microscopy. Herein, we replaced the methylene bridge with another P=O group to 1) investigate the role of the bridging moieties; and 2) further modulate the fluorescence properties of this skeleton. We synthesized a series of phospholo[3,2‐b]phosphole‐based dyes—trans‐PO‐PB430, cis‐PO‐PB430, and trans‐PO‐PB460—all of which showed sufficient water solubility. Moreover, trans‐PO‐PB430 and trans‐PO‐PB460 exhibited intense green and orange fluorescence, respectively, and a high photostability that was comparable to that of PB430. In contrast, cis‐PO‐PB430 underwent rapid photobleaching upon continuous photoirradiation, which demonstrated the importance of steric shielding of the polycyclic skeleton by the substituents on the bridging moieties. The fluorescence properties of these dyes were insensitive to concentration, pH value, and polarity changes of the environment in solution. In addition, even in the solid state, these dyes showed strong green to orange emissions. These results demonstrate the potential utility of trans‐PO‐PB430 and trans‐PO‐PB460 as highly photostable fluorescent dyes.     

Synthesis,Crystal Structure,and Properties of HfM′P (M′ = Fe,Co, Ni) in comparison to ZrNiP

The new phosphides HfM′P (M′ = Fe, Co, Ni) have been synthesized by arc melting of HfP and the corresponding 3 d metal, and subsequent annealing at 1400°C. The lattice constants vary from a = 6.247(2) Å, b = 3.7177(6) Å, c = 7.137(2) Å, V = 165.74(8) ų for HfFeP, a = 6.295(3) Å, b = 3.668(2) Å, c = 7.175(4) Å, V = 165.7(2) ų for HfCoP to a = 6.240(3) Å, b = 3.716(2) Å, c = 7.135(2) Å, V = 165.4(2) ų (HfNiP) in the orthorhombic space group Pnma. Although ZrNiP occurs only in the Ni₂In structure type, all three Hf phosphides crystallize in the Co₂Si structure type, isotypic to ZrFeP and ZrCoP. The structural differences between HfNiP and ZrNiP can be explained by the preference of Hf for structures with more metal-metal bonds rather than by size effects.     

Selective P–C-Bond Cleavage in P(III)-Triphenylmethyl Compounds

The phosphorus-carbon bond in various P-triphenylmethyl-substituted phosphorus compounds of simple as well as more complex structure can be cleaved selectively by treatment with Lewis acids, halogens (or halogen transfer agents), and hydrogen halides. The course of the reaction can be followed easily by NMR spectroscopy, in certain cases this P–C-bond cleavage can be used as a synthetic principle for phosphorus difluorohalides, F₂PHal (Hal = Cl, Br, F). In the presence of the appropiate structural elements, cleavage of P–P-bonds or rearrangements are observed.     

Reactions of Lithium Salts of Triphosphanes tBu2P–PLi–PtBu2 and tBu2P–PLi–P(NEt2)2 with Metal Complexes [(R3P)2MCl2] (M = Ni,Pd, Pt,R3P = Et3P,pTol3P,Ph2EtP,iPr3P)

tBu₂P–PLi–PtBu₂ · 2THF reacts with [(R₃P)₂MCl₂] (M = Pt, Pd, Ni; R₃P = Et₃P, pTol₃P, Ph₂EtP, iPr₃P) to yield isomers of [(1,2‐η‐tBu₂P=P–PtBu₂)M(PR₃)Cl], in which the tBu₂P–P–PtBu₂ ligand adopts the arrangement of a side‐on bonded 1,1‐di‐tert‐butyl‐2‐(di‐tert‐butylphosphanyl)diphosphenium cation. tBu₂P–PLi–P(NEt₂)₂ · 2THF reacts with [(R₃P)₂MCl₂] but does not form complexes with a tBu₂P–P–P(NEt₂)₂ moiety, however, splitting of a P–P(NEt₂)₂ bond of the parent triphosphane takes place.     

P,P′-(2,5-Dimethoxy-3,6-dimethyl-2,5-dioxo-2λ5,5λ5-[1,4,2,5]dioxadiphosphinan-2,5-diyl)-bis-phosphonsäuretetramethylester

P,P′-(2,5-Dimethoxy-3,6-dimethyl-2,5-dioxo-2λ⁵,5λ⁵-[1,4,2,5]dioxadiphosphinane-2,5-diyl)-bis-phosphonic acid tetramethylester The title compound 1 is formed by reaction of the corresponding phosphonic acid 2 and orthoformicacidmethylester as a mixture of four stereoisomeres. The RRSS isomer was separated. It crystallizes in the triclinic space group P ?1 with a = 649.2 pm, b = 976.1 pm, c = 1 571.7 pm, α = 80.9°, β = 88.1°, γ = 78.6° and Z = 2. The ³¹P and ¹³C NMR spectra (4 and 5 spin systems) are discussed.     

P,P′-(2,5-Dihydroxy-3,6-dimethyl-2,5-dioxo-2λ5,5λ5-[1,4,2,5]-dioxadiphosphinan-2,5-diyl)-bis-phosphonsäure

P,P′-(2,5-Dihydroxy-3,6-dimethyl-2,5-dioxo-2λ⁵,5λ⁵-[1,4,2,5]dioxadiphosphinane-2,5-diyl)-bis-phosphonic Acid The tetrahydrate 1 of the title compound crystallizes in the monoclinic space group P2₁/c with a = 845.8, b = 1 098, c = 981.7 pm, β = 113.02° and Z = 2. The anions of the oxonium compound (H₃O⁺ · H₂O)₂(C₄H₁₀O₁₂P₄^2?) are layered by hydrogen bridges. The ¹H, ¹³C and ³¹P NMR spectra (4 and 5 spin systems) are discussed.     

cis,cis,cis‐(Acetato‐O,O′)­bis­[1,2‐bis­(di­phenyl­phosphino)­ethane‐P,P′]­ruthenium(II) hexa­fluoro­phosphate di­methanol solvate

In the cation of the title complex, cis,cis,cis‐[Ru(η²‐O₂CMe)(dppe)₂]PF₆·2MeOH [dppe is 1,2‐bis­(di­phenyl­phosphino)­ethane, C₂₆H₂₄P₂], the Ru atom is in a pseudo‐octahedral coordination environment with two chelating dppe ligands and one chelating acetate ligand. Intra‐phosphine and intra‐acetate bond lengths and angles are unexceptional. Deviations from idealized octahedral coordination angles at ruthenium [O—Ru—O 59.43 (8)° and P—Ru—P 103.19 (2)°] presumably derive from constraints imposed by the chelate rings. The Ru—P distances for the mutually trans P‐donor atoms [2.3785 (6) Å] are significantly longer than those for the Ru—P linkages trans to the acetate ligand [2.3074 (6) Å]. The Ru1, C1 and C2 atoms lie on a twofold axis, and atom P3 of the anion lies on an inversion centre.