Tris(dialkylamino)benzylphosphoniumbromide – Phosphoniumsalze mit drei nahezu planar konfigurierten N‐Atomen

Tris(dialkylamino)benzylphosphonium Bromides – Phosphonium Salts with three N Atoms configurated nearly planar Tris(dialkylamino)benzylphosphonium bromides [(R₂N)₃PCH₂C₆H₅]⁺Br^– (R: Me, Et, n‐Pr, n‐Bu) have been obtained by the reaction of the corresponding tris(dialkylamino)phosphines with benzylbromide in good yields. The compounds crystallize as colorless solids from acetonitrile or methylene chloride after addition of diethylether. The corresponding tris(dialkylamino)‐benzylphosphonium tribromides have been prepared by treating of the simple bromides with equimolar quantities of elemental bromine. The orange‐red precipitates have been recrystallized from the same solvents by addition of diethylether. In all compounds investigated the crystal structure analyses showing three N atoms with a nearly planar configuration.     

Supramolecular organotin(IV) dithiocarboxylates as potential antimicrobial agents

A series of tri-, chlorodi-, and diorganotin(IV) derivatives of 4-(2-methoxyphenyl)piperazine-1-carbodithioate (L) {R?=?n-C₄H₉ (1), C₆H₁₁ (2), CH₃ (3) and C₆H₅ (4)}, (n-C₄H₉)₂SnClL (5) and R₂SnL₂ {R?=?n-C₄H₉ (6), C₂H₅ (7), CH₃ (8)} have been synthesized by refluxing organotin(IV) chlorides with the ligand-salt in the appropriate molar ratio. Elemental analysis, Raman, IR, multinuclear NMR (¹H, ¹³C and ¹¹⁹Sn), mass spectroscopic, and single-crystal X-ray crystallographic studies were undertaken to elucidate the structures of the new compounds both in solution and in the solid state. The X-ray diffraction work reveals supramolecular structures for 4 and 6, with distorted trigonal-bipyramidal and distorted octahedral geometries around Sn, respectively. The ligand and several of the new compounds are good antimicrobial agents.     

Synthesis of 1-(alkylamino)- and 1-(dialkylamino)benzimidazoline-2-thiones

Unlike 1-aminobenzimidazoles, 1-alkylaminobenzimidazoles are thiolated on fusing with sulfur without elimination of theN-amino group, yielding the previously unknown 1-(alkylamino)benzimidazoline-2-thiones. These compounds can be more conveniently obtained on a preparative scale by thiolation of 1-alkylacetamidobenzimidazoles with subsequent hydrolytic elimination of the acetyl group. When 1-(dialkylamino)benzimidazoles are fused with sulfur, they are converted into 1-(dialkylamino)benzimidazoline-2-thiones. By alkylation of 1-(methylamino)- and 1-(diethylamino)benzimidazoline-2-thiones with methyl iodide in alkaline media the corresponding 2-(methylthio)benzimidazoles were prepared.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2231–2235, November, 1995.The authors are grateful to the Contest Center of Basic Natural Science at St. Petersburg University for financial support of this study.     

Synthese,Struktur und Reaktivität von Bis(dialkylamino)diphosphanen

Synthesis, Structure, and Reactivity of Bis(dialkylamino)diphosphines Starting with the aminochlorophosphines ⁱPr₂N? PCl₂ 1 and (ⁱPr₂N)₂P? Cl 2 , the synthesis of some new functionalized aminophosphines (ⁱPr₂N)₂P? SiMe₃ 3a , (ⁱPr₂N)₂P? SnMe₃ 3b , (ⁱPr₂N)(DMP)P? Cl 4 , ⁱPr₂N? P(SiMe₃)₂ 5 and ⁱPr₂N? P(SiMe₃)Cl 6 is reported. Reactions of 2 with different phosphides yield the aminodiphosphines (ⁱPr₂N)₂P? P(SiMe₃)₂ 7a , (ⁱPr₂N)₂P? P(SiMe₂^tBu)₂ 7b , (ⁱPr₂N)₂P? PPh₂ 8 and (ⁱPr₂N)₂P? PH₂ 9 . The phosphines 3a/b react with halogenophosphines to the aminohalogenodiphosphines (ⁱPr₂N)₂P? PCl₂ 10 , (ⁱPr₂N)₂P? P^tBuCl 11 and (ⁱPr₂N)₂P? P(NⁱPr₂)Cl 12 . The ambivalente aminophosphine 6 gives the aminotrichlorodiphosphine Cl(ⁱPr₂N)P? PCl₂ 13 after condensation with PCl₃, while the reactions with the corresponding lithiumphosphides yield the aminosilyldiphosphines (ⁱPr₂N)(SiMe₃)P? P(SiMe₃)₂ 14a and (ⁱPr₂N)(SiMe₃)P? P(SiMe₂^tBu)₂ 14b . The aminochlorophosphines 2/4 are reductively coupled with magnesium leading to the symmetrically substituted tetraaminodiphosphines (ⁱPr₂N)₂P? P(ⁱPr₂N)₂ 15a and DMP(ⁱPr₂N)P? P(ⁱPr₂N)DMP 15b . The functionalized aminosilyldiphosphine 7a is treated with methanol to yield the diphosphine (ⁱPr₂N)₂P? PH(SiMe₃) 16 and gives the lithium phosphinophosphide (ⁱPr₂N)₂P? PLi(SiMe₃) 17 after metallation with n-BuLi. The compounds are characterized by their NMR and mass spectra and the ³¹P-NMR values of the diphosphines are discussed according to their substituents. The crystal structures of 7b, 8 and 15b showing significantly differing conformations are presented.     

Synthesis and characterization of new platinum(II) phosphinate complexes

The syntheses of platinum(II) complexes of bis(dimethylphosphinylmethylene)amine and bis(aminomethyl)phosphinic acid were investigated. In the case of bis(dimethyl-phosphinylmethylene)amine the reaction with K₂[PtCl₄] yields the potassium amino-trichloroplatinate K[PtCl₃L] (L?=?bis(dimethylphosphinylmethylene)amine), which was characterized by multinuclear (¹H, ¹³C, ³¹P, and ¹⁹⁵Pt) NMR spectroscopy in solution. Bis(aminomethyl)phosphinic acid reacts with K₂[PtCl₄] under strictly controlled pH conditions to give colorless crystals of the cisplatin analog K[PtCl₂L′] (L′?=?bis(aminomethyl)phosphinate). This complex was characterized by multinuclear NMR spectroscopy in solution as well as by single-crystal X-ray diffraction in the solid state. The bis(aminomethyl)phosphinate coordinates to platinum via both amino functions, thus acting as a chelating ligand.     

Catalytic activity of bis(dialkylamino)carbenium salts in hydrosilylation reactions

Bis(dialkylamino)carbenium salts {[(Me₂N)₂CCl]⁺}₂MCl₄ ²⁻ (M=Ni, Pd) and {[Me₂NC(X)NR₂]⁺}₂PtCl₆ ²⁻ (R=Me, All; X=H, Cl, Me) are efficient catalysts for hydrosilylation of allyl phenyl ether, triallylamine, allyl chloride, allylamine, and 1-octene with various hydrosilanes. The catalytic activity is dependent on the salt composition and the nature of the metal M, the saturated compound, and the hydrosilane used. The catalysts used are usually insoluble in the reaction mixture, active, and stable. In some cases, carbenium salts are more selective than Speier's catalyst. Novel catalysts, silica-immobilized dialkylaminocarbenium salts, have been prepared. The kinetics of the reaction have been considered. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1041–1044, May, 1997.     

Two conformers in the solid state for a novel organotin(IV) complex of a phosphoramidate: Syntheses, spectroscopic study and crystal structures of several new organotin(IV) complexes of N-benzoylphosphoric triamides

Several novel organotin(IV) complexes with formula SnCl₂(CH₃)₂(X)₂, X = C₆H₅C(O)NHP(O)(NC₄H₈)₂ (1), C₆H₅C(O)NHP(O)(NC₅H₁₀)₂ (2), C₆H₅C(O)NHP(O)[N(CH₃)(C₆H₁₁)]₂ (3), C₆H₅C(O)NHP(O)[NH-C(CH₃)₃]₂ (4) were synthesized and characterized by ¹H, ¹³C, ³¹P NMR, IR spectroscopy and elemental analysis. The structures have been determined for each of the four compounds. Compound 1 exists in the form of two symmetrically independent molecules in the crystalline state due to differences in their similar torsion angles. In all of the four structures there are intramolecular -Sn-Cl?H-N- hydrogen bonds, in addition to weak C-H?O and C-H?Cl hydrogen bonds. Both ¹H and ¹³C NMR spectra show the coupling of ^119/117Sn nuclei with methyl proton and carbon atoms. The δ(³¹P) of these complexes are in upfields with respect to their corresponding reported ligands. The spectroscopic and structural properties of these complexes were compared with those corresponding ligands.     

EXAFS studies on the methanol and ethanol solutions of cobalt(II) bromides

The results of an EXAFS investigation of methanol and ethanol solutions of CoBr₂ are reported. The curve fitting analysis gives the coordination numbers and the Co–Br and Co-solvent distances. The results for both 0.2M and 3.8M CoBr₂ in ethanol show the existence of [CoBr₂(C₂H₅OH)₂] as the dominant species, although a considerable amount of octahedral species also exists in the solutions. In 0.2 and 3.3M CoBr₂ methanol solutions, the dominant species are [Co(CH₃OH)₆]²⁺ and [CoBr(CH₃OH)₅]⁺, respectively.     

Synthesis and Spectroscopic Characterization of Two New Thiosaccharinate Salts. Molecular Structure of Bis(triphenylphosphine)iminium thiosaccharinate, PNP(tsac)

Summary. We report the synthesis, FTIR, Raman and NMR spectroscopic features of bis(triphenylphosphine)iminium and tetrabutylammonium thiosaccharinates, PNP(tsac) and NBu ₄ (tsac) (tsac: thiosaccharinate anion, PNP: bis(triphenylphosphine)iminium). The molecular structure of the former compound was determined by X-ray diffraction methods. The salt crystallizes in the monoclinic P2₁/n space group with a = 9.6481(9), b = 29.258(3), c = 13.177(2) ?, β = 97.53(1)°, and Z = 4 molecules per unit cell. Slight but significant changes in the bonding structure of the thiosaccharinate anion as compared with those reported for the neutral molecule are observed.     

Single-crystal structures of uranium and neptunium oxychalcogenides AnOQ (An=U, Np; Q=S, Se)

The compounds UOS, UOSe, NpOS, and NpOSe have been synthesized and their structures determined by means of single-crystal X-ray diffraction methods. The results provide more detailed crystallographic information, including more precise interatomic distances, than earlier determinations from powder diffraction data. These isostructural compounds adopt the PbFCl structure type. Each An atom is surrounded by four O and five Q atoms in a distorted monocapped square-antiprismatic arrangement.     

Synthesis and Characterisation of N,N′-Disubstituted 1,2-phenylenebis(amido)tin(II) Compounds; X-Ray structures of 1,2- and of [1,2- (tmeda)

Cyclic bis(amido)tin(II) compounds 1,2- [R = SiMe₃] ( 4 ), SiMe₂Bu^t ( 5 ) and CH₂Bu^t ( 6 )], as well as ( 4 )₂(μ-tmeda) 7 have been obtained either from (i) the corresponding dilithium compound 1,2-C₆H₄[N(R)Li]₂ 1–3 and SnCl₂ for 4–6 , respectively, (or for 4 ) 2 1 + [Sn(μ-Cl){N(SiMe₃)₂}]₂; or (ii) 1,2-C₆H₄[N(H)R]₂ + Sn[N(SiMe₃)₂]₂ for 4–6 ; or for 7 from 4 and tmeda. Compounds 4–6 are monomeric, yellow, thermochromic (becoming redder on heating), diamagnetic, crystalline and are lipophilic and sublimable in vacuo. Compound 7 is colourless. The molecular structures of 6 and 7 have been determined from single crystal X-ray diffraction data. Compound 6 crystallises in bimolecular aggregates, in which there is a weak η-C₆ … Sn contact.     

Molecular Structure of Diperchloratotetraphenylporphinatotin(IV)

X-ray diffraction data and NMR spectra of diperchloratotetraphenylporphinatotin(IV), Sn(tpp)(ClO₄)₂ provide evidence for a monodentate perchlorato group coordinated to the Sn(IV) atom. The molecule Sn(tpp)(ClO₄)₂ displays an octahedral coordination geometry for the tin atom and its crystal belongs to the monoclinic space group P2₁/n with a = 11.241(3), b = 14.644(3), c = 12.173(3) Å,β = 111.18(2)°, and Z = 2. The structure was solved by direct method, 3996 unique reflections having I > 3σ(I) measured with an automated diffractometer were used to refine the crystal structure to a conventional R factor 0.0431. The tin(IV) ion is centered on a planar tpp moiety. The geometry at the octahedral coordination centre of the Sn(tpp) (ClO₄)₂ molecule has Sn-O(perchlorate) = 2.181 Å and Sn-N = 2.073 Å.     

Thermochemistry of adducts of some transition metals(II) bromides with pyridine N-oxide

The compounds [MBr₂(pyNO)_n] (where M: Mn, Fe, Co, Ni, Cu or Zn; pyNO is pyridine N-oxide and n=2, 3 or 6) were synthesized and characterized by melting points, elemental analysis, thermal analysis and electronic and IR spectroscopy. The enthalpies of dissolution of the adducts, metal(II) bromides and pyNo in methanol were measured and by using thermochemical cycles, the following thermochemical parameters for the adducts have been determined: the standard enthalpies for the Lewis acid/base reactions (Δ_rH^θ), the standard enthalpies of formation (Δ_fH^θ), the standard enthalpies of decomposition (Δ_DH^θ), the lattice standard enthalpies (Δ_MH^θ) and the standard enthalpies of the Lewis acid/base reactions in the gaseous phase (Δ_rH^θ(g)). The mean bond dissociation enthalpies of the M(II)-oxygen bonds () have been estimated.     

Benzyl(triphenyl)phosphonium Dichloroiodate: A New Reagent for Coiodination of Alkenes

A mild, efficient, and regio‐ and stereoselective method for iodoalkoxylation and iodohydroxylation of olefins has been developed using benzyl(triphenyl)phosphonium dichloroiodate as iodine source. This procedure led to the corresponding iodoalkoxylated and iodohydroxylated products in moderate to excellent yields.     

Precise Molecular Weight Determination and Structure Characterization of End-functionalized Polymers: An NMR Approach via Combination of One-dimensional and Two-dimensional Techniques

We present here the application of one-dimensional and two-dimensional NMR techniques to characterize the structure of methoxyl end-functionalized polystyrenes (PS).The peaks in 1H-NMR spectra corresponding to main-chain,side-chain and chain-end groups are assigned by 1H-1H gCOSY,1H-13C gHSQC and gHMBC spectra.For the first time,the spin-lattice relaxation time (T1) of protons of the chain-ends is revealed to be affected more by polymer molecular weight (MW) than by the protons of the main-chains and the side-chains (almost independent from MW).As a result,a much higher delay time (d1) for chain-ends (d1 ＞ 20T1) is needed for quantitative NMR measurement when using end-group estimation method to obtain the MW of PS,which is in accordance with the value estimated by GPC.An improved method for the polymer MW determination is established,by combination of different NMR techniques to distinguish the peaks,and a large dl setting to achieve quantitative NMR analysis.     

The syntheses and structures of bis(alkylimino)isoindolines

In this Letter, we present a synthetic and structural study into bis-imino substituted diiminoisoindolines, which can be synthesized either via CaCl₂ mediated reaction of phthalonitrile with primary amines, or via direct reaction of these amines with unsubstituted diiminoisoindoline. The preferred synthesis does depend on the methodology, and in two cases singly substituted adducts were formed. The single crystal X-ray structures show that, with the exception of the bis-naphthyl compound, the anti conformation is preferred, and that the ionizable hydrogen atom resides on an exocyclic nitrogen rather than the central isoindoline nitrogen atom.     

Synthesis,characterization and antimicrobial activities of triorganotin(IV) complexes with azo-azomethine carboxylate ligands: crystal structure of a tributyltin(IV) and a trimethyltin(IV) complex

Triorganotin(IV) complexes with polyaromatic azo-azomethine carboxylate ligands viz. 2-{4-hydroxy-3-[(2/4-hydroxyphenylimino)methyl]phenylazo}benzoic acids [H₃L¹/H₃L²] were synthesized by reacting the ligands with either bis-tri-n-butyltin(IV) oxide (for 1 and 4) or trimethyltin(IV) chloride in presence of triethylamine (for 2 and 5) or triphenyltin(IV) hydroxide (for 3 and 6). The complexes were characterized by elemental analysis, UV, IR, NMR, and mass spectrometry. NMR spectroscopic studies of the compounds suggested that the complexes adopt four-coordinate tetrahedral geometry around tin in solution. Molecular structures of 1 and 2 were determined by single-crystal X-ray diffraction. Both complexes have distorted trigonal bipyramidal geometry around tin in the solid state. Compound 1 is a one-dimensional (1-D) double chain coordination polymer which can be described as two different 24- and 30-membered non-porous macrocyclic rings constructed from two tributyltin units and two ligand moieties. The structure of 2 comprises a discrete cyclic centrosymmetric dimer with two lattice water molecules per formula unit. In the dimer, two trimethyltin entities are bridged by two ligand moieties. The dimers are further interconnected with lattice water molecules by multiple O–H?O hydrogen bonds to form a 1-D H-bonded network. The complexes were also screened for their antimicrobial activities.     

Syntheses, structures, and vibrational spectroscopy of the two-dimensional iodates Ln(IO3)3 and Ln(IO3)3(H2O) (LnYb, Lu)

The reaction of Lu³⁺ or Yb³⁺ and H₅IO₆ in aqueous media at 180 °C leads to the formation of Yb(IO₃)₃(H₂O) or Lu(IO₃)₃(H₂O), respectively, while the reaction of Yb metal with H₅IO₆ under similar reaction conditions gives rise to the anhydrous iodate, Yb(IO₃)₃. Under supercritical conditions Lu³⁺ reacts with HIO₃ and KIO₄ to yield the isostructural Lu(IO₃)₃. The structures have been determined by single-crystal X-ray diffraction. Crystallographic data are (MoKα, λ=0.71073 Å): Yb(IO₃)₃, monoclinic, space group P2₁/n, a=8.6664(9) Å, b=5.9904(6) Å, c=14.8826(15) Å, β=96.931(2)°, V=766.99(13), Z=4, R(F)=4.23% for 114 parameters with 1880 reflections with I>2σ(I); Lu(IO₃)₃, monoclinic, space group P2₁/n, a=8.6410(9), b=5.9961(6), c=14.8782(16) Å, β=97.028(2)°, V=765.08(14), Z=4, R(F)=2.65% for 119 parameters with 1756 reflections with I>2σ(I); Yb(IO₃)₃(H₂O), monoclinic, space group C2/c, a=27.2476(15), b=5.6296(3), c=12.0157(7) Å, β=98.636(1)°, V=1822.2(2), Z=8, R(F)=1.51% for 128 parameters with 2250 reflections with I>2σ(I); Lu(IO₃)₃(H₂O), monoclinic, space group C2/c, a=27.258(4), b=5.6251(7), c=12.0006(16) Å, β=98.704(2)°, V=1818.8(4), Z=8, R(F)=1.98% for 128 parameters with 2242 reflections with I>2σ(I). The f elements in all of the compounds are found in seven-coordinate environments and bridged with monodentate, bidentate, or tridentate iodate anions. Both Lu(IO₃)₃(H₂O) and Yb(IO₃)₃(H₂O) display distinctively different vibrational profiles from their respective anhydrous analogs. Hence, the Raman profile can be used as a complementary diagnostic tool to discern the different structural motifs of the compounds.     

Intramolecularly coordinated organotin(IV) sulphides and their reactivity to iodine

Organotin(IV) sulphides (LSnPhS)₂ (3) and (LSnPh₂)₂S (4) containing O,C,O chelating ligand (L = 2,6-(t BuOCH₂)₂C₆H₃⁻) were prepared by the reaction of parent organotin chlorides LSnPhCl₂ (1) and LSnPh₂Cl (2) with Na₂S · 9H₂O in toluene/water. Both sulphides were characterized by the help of elemental analysis, ESI-mass spectrometry, ¹H, ¹³C ¹¹⁹Sn NMR spectroscopy and the molecular structure of 3 was determined by X-ray diffraction techniques. Compounds 3 and 4 react with I₂ to organotin iodides LSnPhI₂ (5) and LSnPh₂I (6), instead of intended iodolysis of phenyl groups. Triorganotin iodide 6 reacts with the additional molecule of I₂ forming an ionic organotin compound [ LSnPh₂]⁺ I₃⁻ (7), which is unstable in solution and decomposes to Ph₂SnI₂ and 2,6-(tBuOCH₂)₂C₆H₃I (8).