Reactions of TiCl4, VCl4 and VOCl3 with tetraalkyldiphosphine disulphides

Summary The reactions of MCl₄ (M = Ti or V) with R₂P(S)P(S)R₂ (R = Me or Et) yield hexacoordinate complexes MCl₄ · R₂P(S)P(S)R₂ (M = Ti or V; R = Me or Et), whereas similar reactions with VOCl₃ lead to reduction of vanadium and give rise to the vanadium(IV) pentacoordinated complexes: VOCl₂-R₂P(S)P(S)R₂ (R = Me or Et). All the compounds have been characterized by elemental analyses, i.r., visible and e.p.r. spectra, which show thecis-chelate character of these ligands, although in the complexes containing Et₄P₂S₂ the i.r. spectra indicates that thegauche conformation of the ligand is implicated in bonding to the metal. The occupation of the sixth coordination site in pentacoordinate complexes, VOCl₂ · R₂P(S)P(S)R₂, by different donor solvents, has been studied by means of visible and e.p.r. spectra.     

1,3-Digermacyclobutanes with exocyclic C=P and C=P=S double bonds

New 1,3-digermacyclobutanes, with two exocyclic C=PMes* bonds, and the corresponding first bis(methylenethioxo)phosphoranes with C=P(S)Mes* moieties have been synthesized.     

Die Kristallstruktur von [Cl3PNPCl3][VOCl4]

Investigations on Electronically Conducting Oxide Systems. XIV. Solid Solutions and Conductivity in the System MgTiO₃? Ti₂O₃ Solid solution formation and conductivity is reported for the system Mg_1?xTiTiO₃ (0 < x < 1). Ti^III atoms are predominantly substituted in pairs for Mg^II and Ti^IV. In the range of low x values Ti^III? Ti^III bonds typical for Ti₂O₃ in the semiconducting state are very weakened because of the distances preserved in the host lattice of MgTiO₃. Up to x = 0,5 EPR measurements at 77 K indicate magnetic “dimers” with S = 1 at a distance of 550 pm resulting from antiparallel spin orientation of the Ti^III pairs and transfer of the magnetic interaction by super exchange to a next-neighboured Ti^III pair. Electrical conductivity is caused by polaron hopping. The steep increase in the range of small Ti^III concentration is interpreted by a screening field approximation.     

Tetrapnictidotitanate(IV) M4TiX4 (M = Sr,Ba; X = P,As), hierarchische Derivate der KGe-Struktur K4□Ge4

Tetrapnictidotitanates(IV) M₄TiX₄ (M = Sr, Ba; X = P, As), hierarchical Derivatives of the KGe Structure K₄□Ge₄ The four new tetrapnictidotitanates(IV) Sr₄TiP₄, Sr₄TiAs₄, Ba₄TiP₄ and Ba₄TiAs₄ are synthesized from the binary pnictides MX (M = Sr, Ba and X = P, As) and elementary titanium in tantalum ampoules. The compounds are isotypic and isoelectronic with Ba₄SiAs₄ (space group P4 3n (no. 218); cP72; Z = 8; Sr₄TiP₄: a = 1259.0(1) pm; Sr₄TiAs₄: a = 1288.3(4) pm; Ba₄TiP₄: a = 1316.6(2) pm; Ba₄TiAs₄: a = 1346.9(2) pm). The transition metal compounds form cubic, metallic reflecting crystals (Sr₄TiP₄ (green); Sr₄TiAs₄ (silver coloured); Ba₄TiP₄ (silver coloured); Ba₄TiAs₄ (violet). They are semiconducting and very sensitive against air and moisture. The structure is a hierarchical derivative of Cr₃Si (A15) and KGe type: Cr₆Si₂ ? (□Ge₄K₄)₆(□Ge₄K₄)₂ ? (TiX₄M₄)₆(TiX₄M₄)₂, where Ti occupies the positions of the Cr₃Si structure, and the alkaline-earth metal and pnicogen atoms occupy the positions of the KGe structure. Therefore, Ti is surrounded by four X and four more distant M atoms forming a heterocubane. The mean bond lengths are: d (Ti? P) = 238.0(5) pm; 307 ? d(Sr? P) ? 333 pm; d (Ti? As) = 245.9(4); 313 ? d(Sr? As) ? 341 pm; d (Ti? P) = 240.5(5); 324 ? d(Ba? P) ? 348 pm; d (Ti? As) = 248.3(3) pm; 331 ? d(Ba? As) ? 355 pm.     

Multiphoton ionization of VOCl3

VOCl₃ is studied by resonance-enhanced multiphoton ionization in the region 430 to 440 nm. Mass spectrometric detection reveals the production of both V⁺ and VO⁺ with the molecular ion having the larger intensity. The V⁺ ion current spectrum shows sharp atomic resonance peaks while the VO⁺ spectrum is structureless.     

Konzentrationen von Isomeren des Typs P m As4−m X 3 in P4S3-As4S3- und P4Se3-As4Se3-Mischungen

The reactions of P₄S₃ with As₄S₃ and of P₄Se₃ with As₄Se₃ in the molten state yields molecules of the type P _m As_4–m S₃ and P _m As_4–m Se₃, respectively. A method was developed to separate the different components by the HPLC technique, and to determine their concentrations. The identification of the isomers in the HPLC pattern was achieved with the aid of the LC-MS method. In the selenium system, the distribution of the different species is statistical. In the system P₄S₃-As₄S₃, the formation of PAs₃S₃ with one phosphorus atom in the apical position is favoured.

     

Reactions of sterically hindered phenols with P2S5

The direction of the reaction of 2,6-disubstituted phenols with P₂S₅ leading to bis(hydroxyaryl)dithiophosphinic acids orO,O-bis(aryl) dithiophosphates is determined by the degree of shielding of the OH group. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1442–1444, July, 1998.     

Formation of CH3TiX, CH2=TiHX, and (CH3)2TiX2 by reaction of methyl chloride and bromide with laser-ablated titanium atoms: photoreversible alpha-hydrogen migration

The simple methylidene (CH2=TiHX) and Grignard-type (CH3TiX) complexes are produced by reaction of methyl chloride and bromide with laser-ablated Ti atoms and isolated in a solid Ar matrix, and they form a persistent photoreversible system via alpha-hydrogen migration between the carbon and titanium atoms. The Grignard-type product is transformed to the methylidene complex upon UV (240 nm < lambda < 380 nm) irradiation and vice versa with visible (lambda > 530 nm) irradiation. More stable dimethyl dihalide complexes [(CH3)2TiX2] are also identified, whose relative concentration increases upon annealing and at high methyl halide concentration. The reaction products are identified with three different groups of absorptions on the basis of the behaviors upon broadband photolysis and annealing, and the vibrational characteristics are in a good agreement with DFT computation results.     

Vaporisation et dissociation thermique des sulfures de phosphore P4S3, P4S7 et P4S10 a l'etat gazeux

Résumé Nous avons montré par spectrométrie Raman à chaud et mesure des tensions de vapeur que P₄S₃ se vaporise de façon congruente tandis que P₄S₇ et P₄S₁₀ se dissocient dès le début de leur vaporisation. P₄S₇ donne réversiblement P₄S₃ et soufre. P₄S₁₀ se dissocie irréversiblement en P₄S₇ et soufre. A l'état de vapeur non saturante, P₄S₃ se dissocie au-dessus de 600° avec formation de phosphore, de soufre et d'autres espèces non identifiées.Nous avons mesuré expérimentalement la capacité calorifique de P₄S₃ liquide, calculé celle de P₄S₃ gazeux et son entropie standard. Nous avons aussi estimé l'enthalpie standard de vaporisation de P₄S₃ à l'aide des mesures des tensions de vapeur saturante. Nous en avons déduit l'entropie standard de P₄S₃ liquide et son point d'ébullition.

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It is shown by Raman spectroscopy at high temperature and by vapor tensimetric measurements that the vaporisation of P₄S₃ is congruent, whereas P₄S₇ and P₄S₁₀ dissociate at the beginning of vaporisation. P₄S₇ gives P₄S₃ and sulfur reversibly. The dissociation of P₄S₁₀ into P₄S₇ and sulfur is irreversible. Above 600°, in non-saturated vapour the dissociation of P₄S₃ gives phosphorus, sulfur and some unidentified gaseous species. The heat capacity of liquid P₄S₃ has been measured. That of gaseous P₄S₃ and its standard entropy have been calculated. The vaporisation standard enthalpy of P₄S₃ has been estimated from the experimental results on the saturated vapour pressures. The standard entropy of liquid P₄S₃ and its boiling point have been derived from these data.

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Zusammenfassung Mittels Raman-Spektrometrie bei erhöhter Temperatur und durch Messung der Dampfdrucke wurde festgestellt, daß sich P₄S₃ verflüchtigt, während P₄S₇ und P₄S₁₀ mit Beginn der Verflüchtigung dissoziieren. P₄S₇ ergibt reversibel P₄S₃ und Schwefel. Im Zustand ungesättigten Dampfes dissoziiert P₄S₃ oberhalb von 600° unter Bildung von Phosphor, Schwefel und anderer nicht identifizierter Substanzen.Die Wärmekapazität von flüssigem P₄S₃ wurde gemessen, während die vom gasförmigem P₄S₃ sowie seine Standard-Entropie berechnet wurden. Die Standard-Enthalpie der Verflüchtigung des P₄S₃ wurde durch Messungen der Sättigungs-Dampfdrucke ermittelt. Daraus wurden die Standard-Entropie des flüssigen P₄S₃ sowie sein Siedepunkt berechnet.

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- - , P₄S₃ , P₄S₇ P₄S₁₀ . P₄S₇ P₄S₃ , P₄S₁₀ P₄S₇ . 600° P₄S₃ , . P₄S₃, P₄S₃ . P₄S₃. P₄S₃ .

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Nous remercions Monsieur Letoffe du laboratoire du Professeur J. Bousquet, INSA de Lyon, 20 Avenue Albert Einstein 401, 69621 Villeurbanne, qui a r6alis6 pour nous les déterminations expérimentales des capacités calorifiques de P₄S₈ liquide.     

Reactions of dodecacarbonyltriosmium with dienic ligands

Dodecacabonyltriosmium reacts with diene ligands (D) such as 2,4-trans, trans- and 2,4-cis, trans-hexadiene and 1,6- and 1,5-heptadiene to give H₂Os₃D(CO)₉, H₄Os₄(CO)₁₂ and two isomers of molecular formula HOs₃-(D  H)(CO)₉ in addition to Os₂(D  2H)(CO)₆ and OsD(CO)₃. The structures of the trimetal complexes show that dehydrogenation, isomerization and rearrangement of the organic substrates occur before the coordination to the metal cluster. 2,3-Dimethyl-1,3-butadiene and dodecacabonyltriosmium give only the well known bi- and mono-metal complexes. The results are compared with those obtained in the reactions of the some organic molecules with dodecacabonyltriruthenium.     

Reactions of S4N4 with diphosphines,Ph2P(X)PPh2 (X = NC4H8N,CH2CH2)

Reactions of S₄N₄ with diphosphines, Ph₂P(X)PPh₂ (X = NC₄H₈N, CH₂CH₂) have resulted in the isolation of N₃S₃? NPPh₂(X)Ph₂PN? S₃N₃ (X = NC₄H₈N, CH₂CH₂), (S)PPh₂(CH₂CH₂)Ph₂PN? S₃N₃, and (S)PPh₂NC₄H₈NPh₂P(S) as new compounds. These heterocycles have been characterized by analytical and spectroscopic (IR, UV-VIS, ¹H and ³¹P-NMR, and MS) techniques.     

Group 11 complexes with unsymmetrical P,S and P,Se disubstituted ferrocene ligands

The reaction of the unsymmetrical ligands 1-diphenylphosphino-1'-(phenylsulfanyl)ferrocene and 1-diphenylphosphino-1'-(phenylselenyl)ferrocene, Fc(EPh)PPh2(E = S, Se), with several group 11 metal derivatives leads to the synthesis of complexes of the type [MX{Fc(EPh)PPh2}](M = Au, X = Cl, C6F5; M = Ag, X = OTf), (OTf = trifluoromethanesulfonate), [M{Fc(EPh)PPh2}2]X (M = Au, X = ClO4; M = Ag, X = OTf), [M(PPh3){Fc(EPh)PPh2}]OTf (M = Au, Ag), [Au2{Fc(SPh)PPh2}2](ClO4)2, [Au(C6F5)2{Fc(SePh)PPh2}]ClO4, [Au(C6F5)3{Fc(EPh)PPh2}], [Au2(C6F5)6{Fc(SePh)PPh2}] or [Cu{Fc(EPh)PPh2}2]PF6(E = S, Se). In these complexes coordination depends upon the metal centre; with gold it takes place predominantly to the phosphorus atom and with silver and copper to both phosphorus and chalcogen atoms. The treatment of some of the gold complexes with other metal centres affords heterometallic derivatives that in some cases are in equilibrium with the homometallic derivatives. Several compounds have been characterized by X-ray diffraction, four pairs of homologous compounds, yet not a single pair is isotypic. In many of them a three dimensional network is formed through secondary bonds such as hydrogen bonds, Au...Cl or Au...Se interactions. The complex [Ag(OTf){Fc(SePh)PPh2}] forms one-dimensional chains through trifluoromethanesulfonate bridging ligands.     

New ferrocenyl P,S and S,S ligands for asymmetric catalysis

Various new chiral ferrocenyl phosphine-thioethers and thiophosphine-thioethers with planar chirality only have been efficiently synthesized with good overall yields (39–43%) in enantiomerically pure form by a nine-step sequence involving the introduction of the planar chirality by Kagan’s acetal method. These new P,S and S,S ligands have been successfully used in the palladium-catalyzed asymmetric allylic substitution reaction (ee up to 93%).     

Reactions of carbonyl clusters with heterobidentate ligands. Synthesis and structural characterization of H4Ru4(CO)10[k2(P,S)-Ph2P(2-CH3SC6H4)] and Rh6(CO)14[k2(P,S)-Ph2P(2-CH3SC6H4)] clusters

Two new disubstituted derivatives of the clusters Rh₆(CO)₁₆ and H₄Ru₄(CO)₁₂ with the heterobidentate ligand [Ph₂P(2-CH₃SC₆H₄)] were synthesized. Structures of these compounds were completely characterized both in solid phase and solution. The H₄Ru₄(CO)₁₀[k²(P,S)-Ph₂P(2-CH₃SC₆H₄)] cluster is an example of a structure, in which a chelating coordination of a heterobidentate ligand results in the occurrence of a center of asymmetry associated with the substituted metal atom. This type of polynuclear complexes is of interest for obtaining essentially new catalysts for asymmetric synthesis on the basis of cluster compounds.     

First transition-metal complexes of S=P(NHBu t)3

The first transition-metal (Rh(I), Mo(VI), Ni(II)) complexes of S[double bond, length as m-dash]P(NHBu(t))(3) have been synthesized via metathetical reactions of mono-lithiated and [Rh(CO)(2)Cl](2), (Bu(t)N)(2)MoCl(2)(dme) and NiBr(2)(dme). Surprisingly in the molecular structure of the Ni(II)-complex both hard-soft (N,S) and hard-hard (N,N[prime or minute]) chelation modes of are realized.     

Mischkristalle aus A4B3-Molekülen (A = P,As; B = S,Se)

Mixed Crystals from A₄B₃ Molecules (A = P, As; B = S, Se) The system P₄S₃? P₄Se₃? As₄S₃? As₄Se₃ was investigated by thermal and x-ray methods. Five regions of solid solubility with different crystal structures were found at room temperature. The range of existence can be influenced by the temperature of annealing. All these phases transform into a plastic-crystalline modification with complete solid solubility at higher temperature. A decomposition reaction of the A₄B₃ molecules was observed in the P₄Se₃/As₄Se₃/As₄S₃ part of the system. The molecules decompose into A₄B₄ molecules and an amorphous phase. The existence of all molecules of the type P_nAs_4–nS_mSe_3–m (n = 0–4, m = 0–3) and also As₄S_mSe_4–m (m = 1–3) was verified by mass spectrometric measurements. The thermochemical data of the mixed crystals are determined by the type of the constituent A₄B₃ molecules. The temperature and the entropy of the α–β transition are lower for mixed crystals, formed by substituted molecules, than for those of the same structure, consisting of pure A₄B₃ molecules.     

Reactions of diiminopyridine ligands with chalcogen halides

The reactions of the chalcogen halides (Ch = S, Se, Te) with a series of diiminopyridine (DIMPY) ligands were explored. It was determined through these studies that varying both the substitution on the α-carbon and the chalcogen halide reagent afforded different products. If methyl groups were present on the α-carbon, reactivity was observed through the eneamine tautomer to yield N,N',C-bound neutral chalcogen complexes. In the cases where H and C(6)H(5) groups were in the same position, N,N',N″-chelated chalcogen cations or dications were produced. Many of the reactions resulted in complex mixtures postulated to occur by the release of halogen decomposing the product or, for reactions with the CH(3) substituted ligand, uncontrollable reactivity with the eneamine tautomer. This is the first report of reactions of sulfur and selenium halides with the ubiquitous diiminopyridine ligands and only the second example for a tellurium halide.