An improved preparation of substituted phosphoryl difluorides. Synthesis of trifluoromethylthiodifluorophosphine and trifluoromethylthiophosphoryl difluoride

Difluorobromophosphine reacts readily with bis(trifluoromethylthio)- mercury to yield the fluorophosphine CF₃SPF₂ in excellent yields. The resulting new phosphine is readily oxidized under very moderate conditions by ClF, Cl₂ and O₂ to give new chlorofluorophosphorane and fluorophosphoryl compounds which contain the CF₃S moiety. CF₃SPF₂Cl₂ and CF₃SPF₂Cl were not characterized because of their tendency to disproportionate. CF₃SP(O)F₂ has, however, been isolated and characterized. All the new compounds are relatively unstable and decompose with a fluoride shift from the methyl group to the phosphorus atom. A new synthetic route to the known difluorophosphoryl compounds OPF₂Cl, OPF₂Br, OPF₂NCS and OPF₂(CH₃)₂, by the direct oxidation of the respective difluorophosphine with oxygen, has been found.     

Two New Crystalline Organogermanate‐Based Inorganic‐Organic Hybrid Compounds

The bifunctional metalloligand bis(carboxyethylgermanium)sesquioxide, (HOOCCH₂CH₂Ge)₂O₃, was employed in the systematic high‐throughput (HT) investigation of the system Zn²⁺/(HOOCCH₂CH₂Ge)₂O₃/H₂O/C₄H₉OH. Two new metal‐organogermanates Zn[(OOCCH₂CH₂Ge)₂O₃] ( 1 ) and Zn₂(O₃GeCH₂CH₂COO) ( 2 ) were discovered that show two new structural motifs for this class of compounds. Whereas in compound 1 a formal intercalation in the structure of (HOOCCH₂CH₂Ge)₂O₃ is observed, 2 exhibits a new layered structure composed of CGeO₃ and ZnO₄ unit linked by μ₃‐oxygen atoms. Both connectivity modes lead to dense three‐dimensional framework structures.     

New members of a family of layered bismuth compounds

Two new compounds, Bi₃Ti₂O₈F and PbBi₃Ti₃O₁₁F, were prepared and identified by X-ray diffraction analysis. These compounds are members of the family called layered bismuth compounds. Thermal properties of the new compounds were also studied. Besides the preparation and identification of these new compounds, a new method for preparing already known members, Bi₂NbO₅F and Bi₂TiO₄F₂, was reported. Moreover, the possibility of the existence of other new members belonging to the family was discussed.     

Fluorinated peroxides derived from hexafluoroacetone. II. Insertion of (CF3) 2CO into alkali-metal peroxides and subsequent reaction with active halogen compounds

The novel alkali metal peroxide derivatives (CH₃) ₃COOC(CF₃) ₂ONa, NaOC(CF₃) ₂OOC(CF₃) ₂ONa and CF₃C(O) OOC(CF₃) ₂ONa have been prepared through reactions of hexafluoroacetone, (CF₃) ₂CO, with the sodium salts of various organic hydroperoxides. These new salts are soluble in water and polar organic solvents and have been used to prepare the new covalent fluorocarbon/hydrocarbon peroxides [(CH₃₃COOC(CF₃) ₂OC(O)C₆H₅, (CH₃) ₃SiOC(CF₃) _2-OOC(CF₃) ₂OSi(CH₃) ₃, and (CH₃₃COOC(CF₃) ₂C(O)CF₃] through reaction with compounds having active halogen. Although the new peroxides are apparently less flammable and explosive than their hydrocarbon analogs, they also exhibit shorter half-lives than the parent compound (i.e., the peroxide without hexafluoroacetone insertion).     

Aerobic alcohol oxidation catalyzed by a new, oxygen-bridged heterometallic compound [PPh4][Ru(N)Me2(μ2-O)2Pd((−)-sparteine)]

The reaction between the new hydroxy compound [PPh₄][Ru(N)(OH)₂Me₂] and Pd(OSiMe₃)₂((−)-sparteine) produces (Me₃Si)₂O, H₂O and a new heterobimetallic compound [PPh₄][Ru(N)Me₂(μ₂-O)₂Pd((−)-sparteine)] in good yield. The Ru/Pd bimetallic compound catalyzes the oxidation of aryl and allyl alcohols to the corresponding carbonyl compound in air and the rearrangement of allylic alcohols unsaturated aldehydes. It also oxidizes PPh₃ to O-PPh₃ under O₂.     

Neuartige Polyanionen in Zintlphasen. Zur Kenntnis von Ca3Si2As4, Ca3Ge2As4, Sr3Si2As4 und Sr3Ge2As4

New Polyanions in Zintl Phases. On Ca₃Si₂As₄, Ca₃Ge₂As₄, Sr₃Si₂As₄, and Sr₃Ge₂As₄ The new compounds Ca₃Si₂As₄, Ca₃Ge₂As₄, Sr₃Si₂As₄ and Sr₃Ge₂As₄ crystallize in the monoclinic system with lattice constants see “Inhaltsübersicht”. There are two new structure types. Both contain Si₂As₆ or Ge₂As₆ groups connected to chains in different ways. These chains are ordered parallel to each other to sheets with the alkaline-earth atoms between them.     

Quantum Chemical Study of Potential Energy Surface in the Formation of Atmospheric Sulfuric Acid?

A new potential energy surface (PES) for the atmospheric formation of sulfuric acid from OH+SO₂ is investigated using density functional theory and high-level ab initio molecular orbital theory. A pathway focused on the new PES assumes the reaction to take place between the radical complex SO₃·HO₂ and H₂O. The unusual stability of SO₃·HO₂ is the principal basis of the new pathway, which has the same final outcome as the current reaction mechanism in the literature but it avoids the production and complete release of SO₃. The entire reaction pathway is composed of three consecutive elementary steps:(1) HOSO₂+O₂→SO₃·HO₂, (2) SO₃·HO₂+H₂O→SO₃·H₂O·HO₂, (3) SO₃·H₂O·HO₂→H₂SO₄+HO₂. All three steps have small energy barriers, under 10 kcal/mol, and are exothermic, and the new pathway is therefore favorable both kinetically and thermodynamically. As a key step of the reactions, step (3), HO₂ serves as a bridge molecule for low-barrier hydrogen transfer in the hydrolysis of SO₃. Two significant atmospheric implications are expected from the present study. First, SO₃ is not released from the oxidation of SO₂ by OH radical in the atmosphere. Second, the conversion of SO₂ into sulfuric acid is weakly dependent on the humidity of air.     

Allyldifluorophosphite-metal chemistry: Ru complexes of F2POC3H5 and the crystal structure of (Ph3P)2(F2POC3H5)Ru(CO)(Cl)H

With several chloro ruthenium phosphine complexes, allyldifluorophosphite, F₂POC₃H₅, displaces triphenylphosphine to form new compounds in which it acts as a phosphorus donor ligand. The new complexes [PPh₃]₂[F₂POC₃H₅]Ru[CO][Cl][H], I, and [(PPh₃)₂(F₂POC₃H₅)₂RuCl₂]_nII, hav characterized by chemical, spectroscopic, and, in the case of I, crystallographic means. This behaviour of F₂POC₃H₅ contrasts to its reactions with several platinum and palladium chloro complexes where it undergoes Arbuzov-type rearrangements.     

Formation of pentagonal tunnels bordered with P2O7 groups in diphosphate tungsten bronzes (P2O4)2(WO3)2m: A HREM investigation

During the investigation of the phosphate bronzes (PO₂)₄(WO₃)_2m [MPTB_P] and K_x(P₂O₄)₂WO₃)_2m [DPTB_H] crystals of a new type were observed. HREM images of these crystals showed twinned ReO₃-type slabs the junction of which was parallel to the (102)_ReO3 plane. The proposed model identified the twin boundary as built from P₂O₇ groups involving the formation of pentagonal tunnels. The structure of this new type of extended defects is quite original: it corresponds to a new structural type named “diphosphate tungsten bronzes with pentagonal tunnels” [DPTB_P], for which no regular member could be synthesized. Image calculations were performed to confirm the junction model. Apart from the disordered stacking of the ReO₃-type slabs, very few defects were observed and shear planes were only obtained in reduced samples. This new structural type takes its place in the large family of phosphate tungsten bronzes where all members (DPTB_H, MPTB_H, MPTB_P) are very closely related.     

A re-interpretation of the crystal structure of ‘(NH4)2(NH3)[Ni(NH3)2Cl4]’ in terms of (NH4)2−2z[Ni(NH3)2]z[Ni(NH3)2Cl4]

A re-interpretation and re-evaluation of single-crystal X-ray diffraction data of a previously reported ‘(NH₄)₂(NH₃)[Ni(NH₃)₂Cl₄]’ (J. Solid State Chem. 162 (2001) 254) give a new formula (NH₄)_2−2z[Ni(NH₃)₂]_z[Ni(NH₃)₂Cl₄] with z=0.152. This new formula results from defects in an idealized ‘(NH₄)₂[Ni(NH₃)₂Cl₄]’ basic structure, where two adjacent NH₄⁺ cations are replaced by one Ni(NH₃)₂²⁺ unit. Cl⁻ anions from the basic structure complete the coordination sphere of the new Ni²⁺ to [Ni(NH₃)₂Cl₄]²⁻.     

Tricarbonyl Derivatives of Manganese(I) with Diphosphinite Chelating Ligands

Reaction of [MnBr(CO)₃L] [L = Ph₂POCH₂CH₂OPPh₂, L¹ , {(CH₃)₂CH}₂POCH₂CH₂OP{CH(CH₃)₂}₂, L² ] with AgO₃SCF₃ and AgO₂CCF₃ in dichloromethane afforded the new complexes [Mn(O₃SCF₃)(CO)₃L] and [Mn(O₂CCF₃)(CO)₃L], respectively. Substitution of O₃SCF₃ resulted in the new species [Mn(SCN)(CO)₃L], [Mn(NCCH₃)(CO)₃L](O₃SCF₃) and, in the case of L² , [Mn(CN)(CO)₃L²]. By contrast, any attempt to displace the O₂CCF₃ ligand in the same way was unsuccessful. After maintaining for some days the complex [Mn(CH₃CN)(CO)₃L¹](O₃SCF₃) in dichloromethane at room temperature, the new complex [MnCl(CO)₃L¹] was formed. All the new complexes were characterized by elemental analysis, mass spectrometry and IR and NMR spectroscopies. In the case of [Mn(O₃SCF₃)(CO)₃L¹], [Mn(O₂CCF₃) (CO)₃L¹], [MnCl(CO)₃L¹], [Mn(CH₃CN) (CO)₃L²] (O₃SCF₃), [Mn(CN)(CO)₃L²] and [Mn(O₂CCF₃)(CO)₃L²], together with the previously synthesized complex [MnBr(CO)₃L²], suitable crystals for X‐ray structural analysis were isolated. In all of them the Mn atom adopts six‐coordination by bonding to the three CO ligands, the two P atoms of L and either one C atom (CN), one oxygen atom (O₂CCF₃, O₃SCF₃), one N atom (CH₃CN, SCN) or the halogen atom (Cl, Br).     

Thermal decomposition of novel rare-earth selenites

TG and DTA have been carried out on new anhydrous rare-earth selenites R₂Se_aO_3+2a (a=3.5,4) in order to establish their stability. Decomposition occurs in three steps attributed to successive losses of SeO₂. The first process gives rise to other new group of selenites of composition R₂Se₃O₉, which crystallize in two different forms depending on the rare-earth element. The second process leads to isomorphous compounds R₂SeO₅. The final product of thermal degradation is R₂O₃. All products were characterized by chemical analysis and X-ray powder diffraction methods.     

Preparation and reactions of nitrosyl-tetrazene derivatives of Rh and Ir

Compounds of formula [M(NO)(PPh₃)(N₄R₂)] (I) (M  Rh, Ir; R  SO_2^? C₆H₄CH₃) have been obtained by the interaction of M(NO)(PPh₃)₃ with p-toluene-sulphonyl azide in benzene. These new compounds are formulated as tetrazene derivatives on the basis of chemical and spectroscopic data. They react with ligands, L, (e.g. CO, PPh₃ to give pentacoordinated species of formula [M(NO)(PPh₃(L)(N₄R₂)].The tetrazene derivatives yield the new nitrosyl compounds, M(NO)(PPh₃)Cl₂ (II) on treatment with HCl, the nitrogen-containing residue being converted into RN₃ and RNH₂ species. The compounds (II) are coordinatively unsaturated, and react with ligands L in the same manner as compounds (I), giving new derivatives of formula M(NO)(PPh₃)(L)Cl₂.IR and NMR spectra of the new compounds are reported and discussed. The presence in solution of a structure in which the chelate tetrazene ring has opened {e.g. [M(NO)(PPh₃)(NR)(N₃R)]} is suggested by NMR studies.     

S6N2O15—A Nitrogen‐Poor Sulfur Nitride Oxide,and the Anhydride of Nitrido‐tris‐Sulfuric Acid

The reaction of hexachlorophosphazene, P₃N₃Cl₆, with SO₃ leads to the new sulfur nitride oxide S₆N₂O₁₅. The compound displays an extraordinarily low nitrogen content and exhibits a bicyclic cage structure according to the formulation N{S(O)₂O(O)₂S}₃N, with both nitrogen atoms in trigonal planar coordination of sulfur atoms. Interestingly, the new nitride oxide can be also seen as the anhydride of nitrido‐tris‐sulfuric acid, N(SO₃H)₃.     

Fluordiazadiphosphetidine. 21. Mitt. Die Photochemische Chlorierung von 2,2,2,4,4,4-Hexafluoro-1,3-diethyl (und dipropyl)-1,3,2λ5,4λ5-diazadiphosphetidin und die Herstellung von 2,2,2,4,4,4-Hexafluoro-1-(cyanometyl)-3-methyl-1,3,2λ5,4λ5-diazadiphosphetidin

Summary The result of the chlorination of (CH₃CH₂NPF₃)₂ and (CH₃CH₂CH₂NPF₃)₂ with chlorine under UV-radiation were the new compounds CH₃CH₂(NPF₃)₂CH₂CH₂Cl and CH₃CH₂CH₂(NPF₃)₂CH₂CH₂CH₂Cl. The reaction of CH₃(NPF₃)₂CH₂Cl with KCN and crown-ether gave the new compound CH₃(NPF₃)₂CH₂CN.

     

Surface modification of semiconductor photoelectrodes for better photoelectrochemical performance

The present paper describes the modification and solar hydrogen production studies employing a new semiconductor-septum (SC-SEP) photoelectrode ns-TiO₂/In₂O₃ based photoelectrochemical solar cell. The current-voltage characteristics of the above SC-SEP cell revealed that an enhancement in short-circuit current (I_SC) up to three times (5 ～ 14.6 mA cm^?2). The optimum hydrogen production rate was found to be 11.8 lh^?1 m^?2 for 5M H₂SO₄ and with a further increase in H₂SO₄ concentration, the hydrogen production rate was found to be invariant. In yet another part of our study instead of using new SC-SEP solar cell design, we used another new oxide material form such as ns-TiO₂/WO₃. The ns-TiO₂/WO₃ exhibited a high photocurrent and photo-voltage of 15.6 mA cm^?2, 960 mV, respectively. The ns-TiO₂/WO₃ electrode exhibited a higher hydrogen gas evolution rate of 13.8 lh^?1 m^?2. Evidences and arguments are put forward to show that, whereas for the bare ns-TiO₂ electrode, the improvement in the performance of this photo-electrode compared with its original form was due to the higher quantum yield. In the case of ns-TiO₂/In₂O₃ and ns-TiO₂/WO₃ photo-electrodes, the improvement is due to the improved spectral response resulting from decrease of energy band gap.     

Trifluoromethylated 3-(Pyrazol-1-yl)propanamide (PPA) Ligands

The new PPA ligands 3-[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]propanamide (CF₃MePPA; 3 ) and 3-[3,5-bis(trifluoromethyl)-1H-pyrazol-1-yl]propanamide ((CF₃)₂PPA; 4 ) were synthesized by Aza-Michael addition of the specific pyrazole derivatives to acrylamide. Both products were characterized by elemental analyses, IR and NMR spectroscopy, and mass spectrometry. X-Ray structure determination of 3 revealed the presence of a one-dimensional hydrogen-bonded structure in the solid state. The ligating ability of the new ligands towards PdCl₂ was studied, showing that 3 behaves similar to Me₂PPA and reacts cleanly with PdCl₂ to afford the sparingly soluble complex PdCl₂(CF₃MePPA-κN)₂. By contrast, the donor ability of pyrazolyl group in 4 was found to be considerably reduced, thus resulting in the formation of the unusual complex PdCl₂{(CF₃)₂PPA-κN}{(CF₃)₂PPA-κO}.     

Ringöffnende acetylierung eines an kobalt koordinierten ringliganden vom divinylboran-typ

(C₅H₅)Co[2–6-η-(CH₃)₂Si(CHCH)₂BC₆H₅(III) is prepared photochemically from (C₅H₅)Co(CO)₂ and (CH₃)₂Si(CHCH)₂BC₆H₅ (II). Acetylation of the new complex III with CH₃COCl/AlCl₃ and subsequent hydrolysis effect ring-opening new complex III with CH₃COCl/AlCl₃ and subsequent hydrolysis effect ring-opening to give (C₅H₅)Co[(1,2-η-(cis-CH₃COCH)CH(η-CH₂CH)Si(CH₃)₂] (IV) which slowly isomerizes (ΔG^≠₂₉₆ 100 ± 2 kJ mol^?1) to the corresponding trans-isomer (V).Pure (CH₃)₂Si(CHCH)₂Sn(CH₃)₂ (I) can be obtained in preparative quantities via the new complex (CH₃)₂Si(CHCH)₂Sn(CH₃)₂ · 2 CuCl.     

Komplexchemie reaktiver organischer Verbindungen,XX

A new convinient route to [Ta(η-C₅H₅)₂Cl₂] is described. The compound [Ta(η-C₅H₅)₂(SCH₃)₂] and hence {[Ta(η-C₅H₅)₂(SCH₃)₂Pt(SCH₃)₂ Ta(η-C₅H₅)₂](PFδ)₂} are derived from it. Monocyclopentadienylniobium halides are shown to be precursors of the new derivative given in the title.     

Chemical vapor transport and solid-state exchange synthesis of new copper selenite bromides

A new dimorphic copper selenite bromide, Cu₅(SeO₃)₄Br₂ was obtained via chemical transport reactions. α-Cu₅(SeO₃)₄Br₂, monoclinic (1m) and β-Cu₅(SeO₃)₄Br₂, triclinic (1a) polymorphs were produced simultaneously upon reaction of amorphous, partially dehydrated copper selenite and copper bromide. 1m is similar to Cu₅(SeO₃)₄Cl₂, whereas 1a is distantly related to Ni₅(SeO₃)₄Br₂ and Co₅(SeO₃)₄Br₂. Attempts to reproduce synthesis of 1a via exchange reaction between Na₂SeO₃ and CuBr₂ resulted in a new Na₂[Cu₇O₂](SeO₃)₄Br₄ (2). Current study demonstrates for the first time, that both chemical vapor and exchange reactions can be employed in preparation of new selenite halides.