Synthesis and ansa substitution of novel examples of aryl hydrido fluorophosphazenes

The first examples of uncharged aryl substituted fluorinated hydridophosphazenes, N₃P₃F₄(Ar)H [Ar=C₆H₅ (1), p-ClC₆H₄ (2)] were obtained in an unprecedented manner upon fluorination of diaryloctachlorobi(cyclophosphazenes) (N₆P₆Cl₈(Ar)₂) [Ar=C₆H₅, p-ClC₆H₄] using KF in acetonitrile. The compounds (1) and (2) were stable to air and moisture, and were characterized by spectral and analytical methods. Compound (1) on reaction with FcCH₂P(S)(CH₂OLi)₂ (Fc=Ferrocenyl) gave endo (3) and exo (4) isomers of ansa substituted hydridophosphazenes. The crystal structure of (4) was determined and the structure shows the ansa substitution on the phosphazene ring, trans to the phenyl group with the hydridophosphazene ring puckered to a partial chair configuration.     

Synthesis and characterization of per-substituted spermine-bridged cyclophosphazene derivatives: the first example of syn/anti conformational polymorphism in a bridged cyclophosphazene

The synthesis and characterization of a series of per-substituted spermine-bridged cyclophosphazene derivatives are reported based on the known compound [N₃P₃X₄(NHCH₂CH₂CH₂N)CH₂CH₂]₂, (1a) (where X = Cl), to give a number of new compounds (1b–1h) in which X = OPh, [spiro-O(CH₂)₃O]_0.5, OCH₂CF₃, NHPh, NC₄H₈, Ph and NHBu^t, respectively. Two synthetic routes were utilized: (i) using the chloro-precursor 1a in nucleophilic substitution reactions with a variety of anionic and neutral nucleophiles to give compounds 1b–1f and (ii) reaction of spermine with the appropriate di-gem tetrasubstituted cyclophosphazene to give compounds 1g and 1h. Bridged compounds such as 1a–1h may exist as syn or anti conformers in the solid state and the first example of syn and anti conformational polymorphism is reported for a bridged cyclophosphazene, viz. for compound 1a.     

Networking chiral coordination polymers through amide hydrogen bond interactions: Thermal stability and optical SHG investigations

Complementary amide H-bond interactions of chiral C₂-symmetric bis(amide) ligand BINDC, (N,N′-bis(isonicotinoyl)-(1R,2R)-diaminocyclohexane) in Zn(BINDC)Cl₂ (1), Zn(BINDC)Br₂ (2) and Ag(BINDC)NO₃ (3) metal-organic frameworks (MOFs) lead to the formation of hierarchical network structures. The strong H-bond interactions coupled with coordinate bond leads to enhanced thermal stability to the materials. Moreover, the MOFs show solid state second harmonic generation (SHG) and good optical transparency in the visible range.     

Calcium-mediated hydrophosphination of diphenylethyne and diphenylbutadiyne as well as crystal structure of 1,4-diphenyl-1,4-bis(diphenylphosphanyl)buta-1,3-diene

Hydrophosphination reactions of phenyl substituted alkynes are catalyzed effectively by [(thf)₄Ca(PPh₂)₂] (1). The reactions of diphenylethyne and diphenylbutadiyne with diphenylphosphane in THF in the presence of catalytic amounts of 1 (approx. 5 mol%) yield quantitatively the cis-addition products trans-1,2-diphenyl-1-diphenylphosphanylethene (2) and 1,4-diphenyl-1,4-bis(diphenylphosphanyl)buta-1,3-diene (3), respectively. The phenyl groups in 3 are oriented nearly perpendicular to the butadiene backbone and therefore, the π-systems of the phenyl groups and the butadiene unit show no interaction with each other.     

Stimuli-responsive conjugated polymers. Synthesis and chiroptical properties of polyacetylene carrying l-glutamic acid and azobenzene in the side chain

A glutamic acid- and azobenzene-containing novel N-propargylamide, (S)-CHCCH₂NHCOCH(CH₂CH₂CO₂CH₂C₆H₅)NHCO₂CH₂CH₂-p-C₆H₄NNC₆H₅ (1) was synthesized and polymerized with (nbd)Rh⁺[η⁶-C₆H₅B⁻(C₆H₅)₃] as a catalyst to obtain the corresponding polymer [poly(1)] with the moderate number-average molecular weight of 12,200 in 93% yield. The chiroptical studies revealed that poly(1) took a helical structure in THF, CHCl₃, CH₂Cl₂ and toluene. Poly(1) underwent solvent and heat-driven helix-helix transition. The trans-azobenzene of the side chain isomerized into cis upon UV-irradiation, accompanying decrease in helicity. The cis-azobenzene moiety reisomerized into trans upon visible-light irradiation, while the polymer did not recover the original helicity.     

Synthesis and gas permeability of new polynorbornene dicarboximide with fluorine pendant groups

The new exo-N-3,5-bis(trifluoromethyl)phenyl-7-oxanorbornene-5,6-dicarboximide (TFmPhONDI, 2), was synthesized and polymerized via ring opening metathesis polymerization (ROMP) using tricyclohexylphosphine [1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazolilydene][benzylidene] ruthenium dichloride (I) to produce the corresponding PTFmPhONDI (3). Gas permeability, diffusion and solubility coefficients of PTFmPhONDI (3) were determined by transient permeation for five gases He, CO₂, O₂, N₂ and CH₄. The larger gas permeability and diffusion coefficients of 3 compared to polynorbornene dicarboximides without fluorine pendant groups were attributed to a lower polymer chain packing due to the effect of the CF₃ groups in the lateral phenyl moiety pending at positions 3 and 5.     

Electrochemical anion recognition by redox-responsive unnatural amino acid derivatives; the X-ray crystal structure of N-ferrocenoyl glycine methyl ester, (η5-C5H5)Fe(η5-C5H4)CONHCH2COOMe

N-Ferrocenoyl glycine ester derivatives FcCONHCH₂COOR (Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄); R=methyl (1), ethyl (2) and benzyl (3)) have been prepared by coupling ferrocene carboxylic acid to a series of glycine esters using 1,3-dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBT) and Et₃N in CH₂Cl₂. The electrochemical anion sensing using a platinum microdisk working electrode of these N-ferrocenoyl glycine ester derivatives is reported. The crystal structure of 1 has been determined; principal dimensions are amide N(H)CO 1.229(3) Å, ester CO 1.183(3) Å with N–H⋯OC(amide) as the primary intermolecular hydrogen bond, N⋯O 2.804(3) Å.     

Polymerization of Cyclophosphazenes with Spriocyclic Methacrylate Containing Substituents

The radical addition polymerization and copolymerization of the cyclophosphazene monomers with spirocyclic methacrylate containing substituents, spiro(2,3-dioxypropylmethacryloyl)tetrachlorocyclotriphosphazene, N₃P₃Cl₄[OCH₂CH(OC(O)=CH₂)O] (1) and spiro((2-methyl-3-oxy-2-(oxymethyl)propyl)methacryloyl)tetrachlorocyclotriphosphazene, N₃P₃Cl₄[OCH₂CMe(CH₂OC(O)=CH₂)CH₂O] (2), has been investigated. In the case of 1, homopolymerization using AIBN as the initiator yielded only cross-linked solids. Copolymerization of 1 with methyl methacrylate was accomplished using VAZO 52 under milder initiation temperature. GPC of copolymer suggested a significant amount of chain transfer. Homopolymerization of 2 gave low isolated yields of the homopolymer but copolymerization with methyl methacrylate yielded the expected copolymers. The reactive chlorine atoms in the copolymers of 2 can be replaced by trifluoroethoxide or methyl amine. Thermal properties of the copolymers were examined by DSC, TGA and pyrolysis mass spectrometry.     

Stereoselective synthesis of trans N/O dispirocyclic cyclotriphosphazenes based on the steric demands of the constrained 2-pyridyl group

Monospiro- and dispirocyclic cyclotriphosphazenes, 2a and 2b, were synthesized by the reaction of hexachlorocyclotriphosphazene, N₃P₃Cl₆ (1), with 2-(2-pyridylamino)phenol in the presence of base. The reactions of phosphazenes 2a and 2b with sodium (4-methyl-2-pyridyl)oxide afforded tetrakis- and bis(4-methyl-2-pyridyloxy)cyclotriphosphazenes, 3a and 3b, respectively. ³¹P NMR spectroscopy of 2b and 3b using d-camphorsulfonic acid as a chiral solvating agent indicated that they were racemates of the trans isomers. The trans configuration of trans-3b could also be elucidated by X-ray crystal structural analysis, which suggested that the steric demand of the 2-pyridyl group was responsible for the stereoselective formation of trans-2b. The steric demand of the 2-pyridyl group was supported by the reaction of N₃P₃Cl₆ (1) with N,N′-bis(2-pyridyl)benzene-1,2-diamine, which only gave monospirocyclic cyclotriphosphazene 4a.     

N-halosuccinimide-mercaptoethanol cohalogenation of olefinic fatty methyl esters: Synthesis of β-halo thioethoxylates

Olefinic fatty methyl esters, undec-10-enoate (1), octadec-Z-9-enoate (2), methyl-12 hydroxy octadec-Z-9-enoate (3), on reaction with N-halosuccinimides (4,5), that is, N-bromosuccinimide (4) or N-chlorosuccinimide (5) and 2-mercaptoethanol (6) in benzene, gave β-bromo- or β-chlorothioethoxylates (8–13). β-Halothioethoxylates so formed were acetylated with acetyl chloride in CH₂Cl₂ to form the respective acetylated products (20–25).     

Synthesis and Properties of 1,1-bis{[3-(<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-Dimethylamino)propyl]amido}alkane-di-<Emphasis Type="Italic">N</Emphasis>-oxides

A homologous series of new surface-active 1,1-bis{[3-(N,N-dimethylamino)propyl]amido}alkane-di-N-oxides were synthesized in the reaction of an appropriate diethyl 2-alkylmalonate with N,N-dimethylamino-1,3-propanediamine followed by oxidation with aqueous hydrogen peroxide. The adsorption isotherms of their aqueous solutions were measured and evaluated to obtain adsorption parameters: critical micelle concentration (CMC), surface excess concentration (Γ_CMC), equilibrium surface tension at the CMC (γ_CMC), cross-sectional area of the adsorbed surfactant molecule (A _CMC), efficiency of surface adsorption (pC₂₀), standard free energies of adsorption (ΔG°_ads), and micellization (ΔG°_CMC). All investigated di-amidoamines and di-N-oxides were practically non-toxic to selected bacteria and yeasts. These compounds are readily biodegradable in the Closed Bottle Test inoculated with activated sludge. Surface and biological properties showed that this group of N-oxide-type compounds has high surface activity and fulfills requirements for environmental acceptance.

Formation of an unusual copper(II) complex from the degradation of a novel tricopper(II) carbohydrazone complex

An unusual copper(II) complex [Cu(L^1a)₂Cl₂] CH₃OH·H₂O·H₃O⁺Cl⁻ (1a) was isolated from a solution of a novel tricopper(II) complex [Cu₃(HL¹)Cl₂]Cl₃·2H₂O (1) in methanol, where L^1a is 3-(2-pyridyl)triazolo[1,5-a]-pyridine, and characterized with single crystal X-ray diffraction study. The tricopper(II) complex of potential ligand 1,5-bis(di-2-pyridyl ketone) carbohydrazone (H₂L¹) was synthesized and physico-chemically characterized, while the formation of the complex 1a was followed by time-dependant monitoring of the UV–visible spectra, which reveals degradation of ligand backbone as intensity loss of bands corresponding to O → Cu(II) charge transfer.     

New (κ-C,N)-palladacyclic complexes with benzimidazol-2-ylidene ligand: Synthesis, crystal structures and characterization

Reaction of unsymmetrical benzimidazolium bromides (1) with Ag₂O and subsequent transmetallation with chloro-bridged dinuclear palladacycle, [Pd(dmba)(μ-Cl)]₂ (dmba: N,N-dimethylbenzylamine) afforded benzannulated monocarbene complexes [Pd(dmba)(NHC)Cl], 2. The palladacycles (2a–c) were characterized by elemental analysis; NMR spectroscopy and the molecular structure of 2a and 2c were determined by X-ray crystallography.     

Structure,Luminescence, and Vapochromism of Bridged Cationic Copper(I) Dimers and Polymers

The dimeric complex of Cu(I) [Cu₂(PPh₃)₄(MeCN)₂(Bpy)](BF₄)₂ (1a, Bpy = 4,4′-dipyridyl) self-assembles in CH₂Cl₂ or acetone and shows intense photoluminescence (excitation λ_max = 356 nm, emission λ_max = 486 nm, ? = 0.47). The MeCN ligands are readily removed from 1a, producing [Cu₂(PPh₃)₄(Bpy)](BF₄)₂ (1b) and altering the photophysical behavior (excitation λ_max = 336 nm, emission λ_max = 568 nm, ? = 0.07). The desolvated compound 1b reversibly absorbs many vapor phase nucleophiles, as revealed by thermogravimetry. Intense luminescence emission is restored for 1b/Nu, Nu = MeCN (1a), acetone, tetrahydrothiophene (THT), and Et₂S. Films of 1b are produced when CH₂Cl₂ solutions of 1a are cast onto glass. The films also react with Nu vapor, again producing intense emission. The pyrazine-bridged dimer [Cu₂(PPh₃)₄(MeCN)₂(Pyz)](BF₄)₂ (2a) is produced in CH₂Cl₂, while [Cu₂(PPh₃)₄(MeCN)(acetone)(Pyz)](BF₄)₂?½[Cu₂(PPh₃)₄(MeCN)₂(Pyz)](BF₄)₂ (2b) is formed in acetone. The crystal structure of the polymer {[Cu(PPh₃)₂(Bpy)](BF₄)?acetone} _n (3) is reported, as is the mixed polymer/dimer structure {[Cu(PPh₃)₂(Pyz)](BF₄)} _n ?½n[Cu₂(PPh₃)₄(BF₄)₂(Pyz)] (4b) in which the dimer units show Cu–FBF₃ coordination. The Pyz dimer and the Pyz and Bpy polymers show much weaker luminescence behavior than that of Bpy dimers 1a and the related 1b/Nu adducts. Nucleophile adduct structures [Cu₂(PPh₃)₄(THT)₂(Bpy)](BF₄)₂?½ethyl ether (5) and [Cu₂(PPh₃)₄(Py)₂(Bpy)](BF₄)₂?CH₂Cl₂ (6) confirmed the coordination of one Nu per Cu to 1b.     

Comparison of HPLC and NMR characterization of the stereogenic properties of cyclotriphosphazene derivatives containing two equivalent centres of chirality: Cis (meso) and trans (racemic) isomers

The di-spiro derivatives of the reaction of gem-disubstituted cyclotriphosphazenes, N₃P₃Cl₄X₂ (X = Ph, PhS, PhNH, PhO) with 3-amino-1-propanol are expected to exist as cis and trans geometric isomers and exist as meso and racemic, respectively. The geometric isomers were separated by column chromatography on silica gel and analyzed by elemental analysis, mass spectrometry, and ³¹P and ¹H NMR spectroscopies. The stereogenic properties of all the compounds (trans, 2a–5a) and (cis, 2b–5b) were investigated by ³¹P NMR spectroscopy on the addition of a chiral solvating agent (CSA), (S)-(+)-2,2,2-trifluoro-1-(9′-anthryl)ethanol; one example of a derivative with the trans configuration (compound 5a, X = PhO) has been found where the ³¹P NMR/CSA method does not lead to the expected separation of the signals of enantiomers, even up to a molar ratio of CSA:compound of 50:1. On the other hand, chiral HPLC methods have been developed in order to characterize the trans (2a–5a) and cis (2b–5b) forms of the cyclotriphosphazene derivatives and give good separation of enantiomers for the trans disubstituted compounds (2a–5a). It is found that chiral HPLC is more reliable than the ³¹P NMR/CSA method for characterising the stereogenic properties of the cis and trans isomers of di-spiro 3-amino-1-propanoxy cyclophosphazene derivatives.     

Synthesis and surface properties of chemodegradable anionic surfactants: Diastereomeric (2-n-alkyl-1,3-dioxan-5-yl) sulfates with monovalent counter-ions

Sodium, potassium and ammonium cis- and trans-(2-n-alkyl-1,3-dioxan-5-yl) sulfates 6–8 (alkyl: n-C₉H₁₉, 6a–8a, and n-C₁₁H₂₃, 6b–8b) were synthesized in a reaction of aliphatic aldehydes 1a,b with glycerol 2 followed by separation in high yields of individual geometric isomers of cis-and trans-2-n-alkyl-5-hydroxy-1,3-dioxanes, cis-3a,b and trans-3a,b, followed by sulfation with sulfur trioxide-pyridine complex, and finally neutralization with NaOH, KOH, and NH₄OH, respectively. Physical data of the compounds and some surface properties of 2-n-nonyl derivatives, such as critical micelle concentration (CMC), effectiveness of aqueous surface tension reduction (Π_CMC), surface excess concentration Γ_CMC, and the surface area demand per molecule (A_CMC), were determined. It was shown that the surface activity of these compounds is influenced both by their geometric structure and by the monovalent counter-ion.     

A novel alanine derivatised phosphine

Reaction of Ph₂PCl with alanine methyl ester affords the chiral aminophosphine Ph₂NHCH(CH₃)C(O)OCH₃ (dppal) which reacts with M(COD)Cl₂ to give Pt(dppal)₂Cl₂ (1) and Cl(dppal)PdCl₂Pd(dppal)Cl (2). The X-ray structures of dppalO, 1 and 2 are reported. The amino acid containing ligand forms intramolecular H bonds with the C–O–C or CO oxygen atoms within the ligand and with the cis chlorides in the complexes.     

New organoplatinum (IV) complex with quaterpyridine ligand: Synthesis,structure and its catalytic activity in the hydrosilylation of styrene and terminal alkynes

The reaction of ligand L with PtCl₂ leads to a novel structural motif of octahedral ortho-metalated complex of formula [Pt(L_-H)Cl₃] 1. This result is a consequence of drastic conditions of reaction and preferred Pt(IV) octahedral coordination geometry. The new compound has been characterised on the basis of the spectroscopic data in solution, and its structure confirmed in the solid state by X-ray crystallography (1a—[Pt(L_-H)Cl₃]∙MeOH, 1b—[Pt(L_-H)Cl₃]∙C₆H₅CH₃). This article reports organoplatinum (IV) complex 1 as effective and highly selective catalyst precursor in the hydrosilylation of styrene and terminal alkynes.     

Synthesis of estolide esters from cis-9-octadecenoic acid estolides

Oleic acid (cis-9-octadecenoic acid) was converted in excellent yield to the estolide, which was then esterified with 2,2-dimethypropan-1-ol (neopentyl alcohol), cis-9-octadence-1-ol (oleyl alcohol), and 2-propanol to generate the corresponding estolide esters. Higher-formula mass estolide esters were synthesized by reaction of the parent estolide with 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, and 1,5-pentanediol to give the corresponding diesters of oleic estolide, thus doubling the molecular size of the parent estolide. Pour points and viscosities were determined in order to evaluate these products for possible industrial application.     

Carbosilane Metallodendrimers with Cyclopentadienyldichlorotitanium(IV) End Groups

Dendritic polyols of the second and third generation 2G-OH₈ (1), 2G-OH₁₆ (2), and 3G-OH₁₆ (3) were prepared by hydroboration/oxidation of allyl-terminated carbosilane dendrimers and used as supports for the immobilization of cyclopentadienyltrichlorotitanium(IV) complexes via alcoholysis. The reaction of 1–3 with CpTiCl₃ gave metallodendrimers 2G-(OTiCpCl₂)₈ (4a), 2G-(OTiCpCl₂)₁₆ (5a), and 3G-(OTiCpCl₂)₁₆ (6a), respectively, whereas the reaction of 1 and 3 with CpSi^FTiCl₃ (CpSi^F = C₅H₄SiMe₂CH₂CH₂C₈F₁₇) yielded peripherally fluorinated metallodendrimers 2G-(OTiCpSi^FCl₂)₈ (4b) and 3G-(OTiCpSi^FCl₂)₁₆ (6b). All metallodendrimers were characterized by multinuclear NMR spectroscopy. The suggested structures were supported by comparison with model 1-propoxycomplexes 10a,b. To identify side products of the alcoholysis reaction, hydrolytic behavior of the starting trichloro complexes was studied both in solid state and in solution. The main products of hydrolysis in solution were identified as μ-oxocomplexes 8a,b whereas hydrolysis in solid state yielded mainly hydroxycomplexes 7a,b.