Synthesis,characterization, electrochromic properties,and electrochromic device application of a novel star polymer consisting of thiophene end‐capped poly(ε‐caprolactone) arms emanating from a hexafunctional cyclotriphosphazene core

Hexa‐armed and thiophene (Thi) end‐capped poly(ε‐caprolactone) star polymer (N₃P₃‐(PCL‐Thi)₆), containing cyclotriphosphazene core, was prepared in a four‐step reaction sequence. Ring‐opening polymerization (ROP) and “click chemistry” techniques were employed in the first and final steps, respectively. Hexa‐armed PCL star polymer (N₃P₃‐(PCL‐OH)₆) was successfully synthesized via ROP of ε‐caprolactone (ε‐CL) by using hekzakis(p‐(hydroxymethyl)phenoxy) cyclotriphosphazene as the multisite initiator and tin(II) 2‐ethylhexanoate (Sn(Oct₂)) as the catalyst in bulk at 115 °C. Further modifications of the N₃P₃‐(PCL‐OH)₆ were accomplished by derivatization of the hydroxyl‐functional chain ends. The obtained N₃P₃‐(PCL‐OH)₆ was then reacted with 2‐bromo‐2‐methylpropanoyl bromide, and this led to a star polymer with bromide end groups, N₃P₃‐(PCL‐Br)₆. In the third step, N₃P₃‐(PCL‐Br)₆ was azidified with sodium azide (NaN₃) in DMF affording N₃P₃‐(PCL‐N₃)₆. Conversion of the azide chain end groups into Thi was quantitatively accomplished via the “click reaction” between N₃P₃‐(PCL‐N₃)₆ and prop‐2‐yn‐1‐yl 3‐thienyl acetate in the final step. Subsequently, the star polymer with six Thi chain ends (N₃P₃‐(PCL‐Thi)₆) was employed in electrochemical copolymerization with both pyrrole and Thi. Electrochromic properties and electrochromic device application of N₃P₃‐(PCL‐Thi)₆/PThi were also investigated. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3668–3682, 2010     

The reaction of hexachlorocyclotriphosphazatriene with P-aminophenol

The reaction of hexachlorocyclotriphosphazatriene (1) with p-aminophenol (2) produced two new products: the open chain compound N₃P₃Cl₅(NHC₆H₄OH) (3), and the bridged compound N₃P₃Cl₅(NHC₆H₄O)N₃P₃Cl₅(4). The compounds 3 and 4 were separated and characterized by elemental analysis, massspectrometry and NMR spectroscopy. The molecular structures of compounds 3 and 4 were determined by X-ray crystallography. Compound 3 is the first example of cyclotriphosphazene including (p-hydroxyphenyl) amino group and compound 4 was the first example of the N-substituted p-aminophenoxy group with cyclotriphosphazene.     

A ferrocene dendrimer based on a cyclotriphosphazene core

A ferrocene dendrimer based on a cyclotriphosphazene core was prepared via a sixfold substitution reaction of N₃P₃Cl₆ with a diferrocenyl benzyl alcohol dendron. All twelve ferrocene units in the dendrimer were found to be electrochemically equivalent.     

Optimized synthesis of selected 4-oxybenzaldehyde and 2,2-dioxybiphenyl cyclotriphosphazene derivatives

Abstract

Selected 4-oxybenzaldehyde and 2,2-dioxybiphenyl cyclotriphosphazene derivatives were synthesized via substitution reactions through tailored control. The reactions of cyclotriphosphazene with 4-oxybenzaldehyde and 2,2-dioxybiphenyl gave the following synthesized derivatives: one mono-substituted open-chain compound, N₃P₃Cl₅(O₂C₇H₅) (1, 69%); mono spiro, N₃P₃Cl₄(O₂C1₂H₈) (2, 91.1%); non-gem tri-substituted, N₃P₃Cl₃ (O₆C₂₁H₁₅) (3, 17%); dispiro, N₃P₃Cl₂(O₄C₂₄H₁₆) (4, 92.3%); penta-substituted, N₃P₃Cl(O₁₀C₃₅H₂₅) (5, 92%);hexa-substituted, N₃P₃(O₁₂C₄₂H₃₀). Most of these derivatives (1–6) are obtained with good yield (up to 97%), This work provides a simple and available approach to obtain versatile cyclotriphosphazene derivatives, which is expected to further promote the use of HCCP as phosphorus platform for the construction of multi-functional materials.     

Synthesis of pyrene end‐capped A6 dendrimer and star polymer with phosphazene core via “click chemistry”

Novel hexa‐armed and pyrene (Pyr) end‐capped phosphazene dendrimer [N₃P₃‐(Pyr)₆] and star polymer with poly(ε‐caprolactone) (PCL) arms [N₃P₃‐(PCL‐Pyr)₆] were prepared via two series of reactions. In these series, core‐first approach was used starting from a hexa‐hydroxy functional phosphazene derivative (N₃P₃‐(OH)₆). It was used as an initiator in the ring‐opening polymerization of ε‐caprolactone to prepare a hexa‐armed PCL star polymer (N₃P₃‐(PCL‐OH)₆). Hydroxyl functionalities of N₃P₃‐(OH)₆ and N₃P₃‐(PCL‐OH)₆ were then successfully converted into bromide and azide, in turn. Further end‐group modifications of azide functional dendrimer precursor (N₃P₃‐(N₃)₆) and star polymer (N₃P₃‐(PCL‐N₃)₆) were achieved quantitatively via the Cu(I) catalyzed click reaction between azide functional groups and 1‐ethynyl pyrene in the final step. Moreover, the pyrene end‐capped phosphazene dendrimer and star polymer were used in noncovalent functionalization of multiwalled carbon nanotubes. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Single-crystal micro/nanostructures and thin films of lamellar molybdenum oxide by solid-state pyrolysis of organometallic derivatives of a cyclotriphosphazene

The solid-state pyrolysis of organometallic derivatives of a cyclotriphosphazene is demonstrated to be a new, simple and versatile solid-state templating method for obtaining single-crystal micro- and nanocrystals of transition and valve metal oxides. The technique, when applied to Mo-containing organometallics N₃P₃[OC₆H₄CH₂CN·Mo(CO)₅]₆ and N₃P₃[OC₆H₄CH₂CN·Mo(CO)₄ py]₆, results in stand-alone and surface-deposited lamellar MoO₃ single crystals, as determined by electron and atomic force microscopies and X-ray diffraction. The size and morphology of the resulting crystals can be tuned by the composition of the precursor. X-ray photoelectron and infrared spectroscopies indicate that the deposition of highly lamellar MoO₃ directly on an oxidized (400 nm SiO₂) surface or (100) single-crystal silicon surfaces yields a layered uniphasic single-crystal film formed by cluster diffusion on the surface during pyrolysis of the metal-carbonyl derivatives. For MoO₃ in its layered form, this provides a new route to an important intercalation material for high energy density battery materials.     

Kristallstruktur von Hexamincyclotriphosphazen,P3N3(NH2)6

Crystal Structure of Hexamine Cyclotriphosphazene, P₃N₃(NH₂)₆ In the presence of KNH₂ hexamine cyclotriphosphazene semi ammoniate (molar ratio 12:1) in NH₃ gives crystals of solvent free P₃N₃(NH₂)₆ within 5 d at 130°C and p(NH₃) = 110 bar. The structure was solved by X-rax methods: P₃N₃(NH₂)₆: P2₁/c, Z = 4, a = 10.889(6) Å, b = 5.9531(6) Å, c = 13.744(8) Å, β = 97.83(3)°, Z(F_o) = 1 721 with (F_o)² ≥ 3σ(F_o)², Z(var.) = 157, R/R_w = 0,036/0,041 The structure contains columns of molecules P₃N₃(NH₂)₆ all in the same orientation. The six-membered rings within one molecule have boat conformation. The columns are stacked together in a way that one is surrounded by four others shifted by half a lattice constant in direction [010]. Strong hydrogen bridge-bonds N? H…?N connect molecules within the columns and between them.     

Hexamethylhydrazinocyclotriphosphazene N3P3(NMeNH2)6: Starting reagent for the synthesis of multifunctionalized species,macrocycles, and small dendrimers

Hexamethylhydrazinocyclotriphosphazene N₃P₃ (NMe-NH₂)₆ 1 is a useful precursor for the synthesis of functionalized hexahydrazones ( 3a-f ), multicyclic ( 5 ) and multimacrocyclic ( 7 ) species, and small dendrimers ( 8 and 10 ). © 1996 John Wiley & Sons, Inc.     

Mono-and diphenoxy-substituted cyclotriphosphazenes: The molecular structure and interatomic interactions

The geometric structure of monophenoxy-substituted cyclotriphosphazene P₃N₃Cl₅OC₆H₅ conformers and nongeminally substituted cis, nongeminally substituted trans, and geminally substituted trans-P₃N₃Cl₄(OC₆H₅)₂ diphenoxy derivatives of cyclotriphosphazene was determined by the nonempirical Hartree-Fock and Kohn-Sham methods. These compounds can be used as templates for valence and programmed supramolecular synthesis. Secondary interactions between phenoxy groups stabilizing the molecular structure of the template were revealed and quantitatively analyzed in terms of electron and electron energy densities for nongeminally substituted cis-P₃N₃Cl₄(OC₆H₅)₂.     

Supramolecular inclusion complexes of a star polymer containing cholesterol end‐capped poly(ε‐caprolactone) arms with β‐cyclodextrin

A novel hexa‐armed and star‐shaped polymer containing cholesterol end‐capped poly(ε‐caprolactone) arms emanating from a phosphazene core (N₃P₃‐(PCL‐Chol)₆) was synthesized by a combination of ring‐opening polymerization and “click” chemistry techniques. For this purpose, the terminal ? OH groups of the synthesized precursor (N₃P₃‐(PCL‐OH)₆) were converted into –Chol through a series of reaction. Both N₃P₃‐(PCL‐OH)₆ and N₃P₃‐(PCL‐Chol)₆ were then employed in the preparation of supramolecular inclusion complexes (ICs) with β‐cyclodextrin (β‐CD). The latter formed ICs with β‐CD in higher yield. The host–guest stoichiometry (ε‐CL:β‐CD, mol:mol) in the ICs of N₃P₃‐(PCL‐Chol)₆ was found to be 1.2. The formation of supramolecular ICs of N₃P₃‐(PCL‐Chol)₆ with β‐CD was confirmed by using Fourier transform infrared (FTIR) and ¹H nuclear magnetic resonance (NMR) spectroscopic methods, wide‐angle X‐ray diffraction (WAXD), and thermal analysis techniques. WAXD data showed that the obtained ICs with N₃P₃‐(PCL‐Chol)₆ had a channel‐type crystalline structure, indicating the suppression of the original crystallization of N₃P₃‐(PCL‐Chol)₆ in β‐CD cavities. Moreover, the thermal stabilities of ICs were found to be higher than those of the free star polymer and β‐CD. Furthermore, the surface properties of N₃P₃‐(PCL‐Chol)₆ and its ICs with β‐CD were investigated by static contact angle measurements. The obtained results proved that the wettability of N₃P₃‐(PCL‐Chol)₆ successfully increased with the formation of its ICs with β‐CD. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3406–3420     

Single-, double- and triple-bridged derivatives of cyclotriphosphazenes with an octafluorohexane-1,6-diol

Reaction of hexachlorocyclotriphosphazene, N₃P₃Cl₆ (1), with the sodium derivative of the fluorinated diol, 2,2,3,3,4,4,5,5-octafluorohexane-1,6-diol, (2), in THF solution at room temperature afforded five products, whose structures have been characterised by ¹H, ¹⁹F and ³¹P NMR spectroscopy: the mono-ansa compound N₃P₃Cl₄[OCH₂(CF₂)₄CH₂O] (3); the single-bridged compound N₃P₃Cl₅[OCH₂(CF₂)₄CH₂O]N₃P₃Cl₅ (4), two double-bridged compounds N₃P₃Cl₄(OCH₂(CF₂)₄CH₂O)₂N₃P₃Cl₄, (5-anti, 5-syn) and the triple-bridged compound N₃P₃Cl₃(OCH₂(CF₂)₄CH₂O)₃N₃P₃Cl₃ (6). X-ray crystallographic studies confirmed the structures of the ansa compound (3), the double-bridged compound (5-anti) and the first example of a triple-bridged cyclotriphosphazene derivative (6). The results were also compared with those for reactions of (1) with analogous fluorinated shorter diols (1,4-butane- and 1,5-pentane-diols). It is found that on increasing the chain length of the diol, there is a decrease in the relative proportion of intramolecular reactions giving spiro and ansa derivatives and an increase in the amount of bridged cyclophosphazene derivatives via intermolecular reactions.     

Syntheses and Structures of Trilithium Cyclotriphosphazenates Equipped with 2‐Halo‐aryl Substituents

Hexakis (2‐halo‐anilino) cyclotriphosphazenes (2‐X‐C₆H₄NH)₆P₃N₃ {X = F ( 1d ), Cl ( 1e ), Br ( 1f )} were prepared by refluxing mixtures of hexachloro cyclotriphosphazene, 2‐haloaniline and triethylamine in toluene and characterized by single crystal X‐ray diffraction. 1d , 1e and 1f were reacted with ⁿBuLi in thf. Reactions were monitored with ³¹P NMR. Addition of three equivalents of ⁿBuLi yields lithium complexes of trianionic phosphazenates [{(thf)₂Li}₃{(2‐X‐C₆H₄N)₃(2‐X‐C₆H₄NH)₃P₃N₃}] {X= F ( 2d ), Cl ( 2e ) and Br ( 2f )}. 2d , 2e and 2f were structurally characterized by X‐ray diffraction, which reveals monomeric cis‐metalated phosphazenates featuring central P₃N₃ ring systems of chair conformation. Lithium ions reside in three N(eq)‐P‐N(endo) chelation sites at one face of the P₃N₃ ring system. Li…X distances are rather long (> 3Å) indicating no Li‐X interactions.     

35Cl NQR in N3P3Cl4Ph2 and N3P3Cl4(NMe2)2

³⁵Cl NQR has been investigated in two cyclotriphosphazene derivatives N₃P₃Cl₄Ph₂ and N₃P₃Cl₄(NMe₂)₂. The observed frequencies are assigned to the various chlorines and the temperature variation of the NQR frequencies studied in the range from 77 K to 300 K. The results are analysed using the Bayer-Kushida-Brown approach. Torsional (librational) frequencies are found to fall in the range 10–25 cm^?1 and are found to be only slightly temperature dependent.     

Synthesis,Crystal Structure and Characterization of Hexakis[2‐methoxy‐4‐formylphenoxy]cyclotriphosphazene

The new cyclotriphosphazene derivative N₃P₃(OC₆H₃OCH₃COH)₆ ( 1 ) was synthesized from hexachlorocyclotriphosphazene, N₃P₃Cl₆, and 4‐hydroxy‐3‐methoxybenzaldehyde in acetonitrile in the presence of K₂CO₃. The structure of 1 was verified by means of elemental analysis, IR, ¹H NMR, ¹³C NMR, ³¹P NMR spectra, thermal analysis and X‐ray diffraction.     

Highly Efficient Four‐Component Synthesis of 4(3H)‐Quinazolinones: Palladium‐Catalyzed Carbonylative Coupling Reactions

Given the importance of quinazolinones and carbonylative transformations, a palladium‐catalyzed four‐component carbonylative coupling system for the synthesis of diverse 4(3H)‐quinazolinone in a concise and convergent fashion has been developed. Starting from 2‐bromoanilines (1 mmol), trimethyl orthoformate (2 mmol), and amines (1.1 mmol), under 10 bar of CO, the desired products were isolated in good yields in the presence of Pd(OAc)₂ (2 mol %), BuPAd₂ (6 mol %) in 1,4‐dioxane (2 mL) at 100 °C, using N,N‐diisopropylethylamine (2 mmol) as the base. Notably, the process tolerates the presence of various reactive functional groups and is very selective for quinazolinones, and was used in the synthesis of the precursor to the bioactive dihydrorutaempine.     

N7-DNA: Synthesis and Base Pairing of Oligonucleotides containing 7-(2-Deoxy-β -D-erythro-pentofuranosyl)adenine (N7Ad)

The synthesis of oligonucleotides containing 7-(2-deoxy-β -D -erythro-pentofuranosyl)adenine (N⁷A_d; 1 ) is described. Compound 1 was obtained from the precursor 4-amino-1H -imidazole-5-carbonitrile 2-deoxyribonucleoside 6 and was found to be much more labile than A_d. The N⁶-benzoyl protecting group (see 8 ) destabilized the N-glycosylic bond further and was difficult to remove by NH₃-catalyzed hydrolysis. Therefore, a (dimethyl-amino)methylidene residue was introduced (→ 9 ). Amidine 9 was blocked at OH? C(5′) with the dimethoxytrityl residue ((MeO)₂Tr), and phosphonate 4 as well as phosphoramidite 5 were prepared under standard conditions. Phosphonate 4 was employed in solid-phase oligonucleotide synthesis. Homooligonucleotides as well as self-complementary oligonucleotides were prepared. The oligomer d[(N⁷A)₁₁-A] ( 11 ) formed a duplex with d(T₁₂) ( 13 ). Antiparallel chain polarity and reverse Watson-Crick base pairing was deduced from duplex formation of the self-complementary d[(N⁷A)₈-T₈] ( 14 ).     

Sr3P3N7: Complementary Approach by Ammonothermal and High-Pressure Syntheses

Nitridophosphates exhibit an intriguing structural diversity with different structural motifs, for example, chains, layers or frameworks. In this contribution the novel nitridophosphate Sr₃P₃N₇ with unprecedented dreier double chains is presented. Crystalline powders were synthesized using the ammonothermal method, while single crystals were obtained by a high-pressure multianvil technique. The crystal structure of Sr₃P₃N₇ was solved and refined from single-crystal X-ray diffraction and confirmed by powder X-ray methods. Sr₃P₃N₇ crystallizes in monoclinic space group P2/c. Energy-dispersive X-ray and Fourier-transformed infrared spectroscopy were conducted to confirm the chemical composition, as well as the absence of NH_x functionality. The optical band gap was estimated to be 4.4 eV using diffuse reflectance UV/Vis spectroscopy. Upon doping with Eu²⁺, Sr₃P₃N₇ shows a broad deep-red to infrared emission (λ_em=681 nm, fwhm≈3402 cm⁻¹) with an internal quantum efficiency of 42 %.     

Total Synthesis of (±)-3-Deoxy-7,8-dihydromorphine, (±)-4-Methoxy-N-methylmorphinan-6-one and 2,4-Dioxygenated (±)-Congeners

A total synthesis of racemic 3-deoxy-7,8-dihydromorphine ((±)- 2 ) and 4-me-thoxy-ALmethylmorphinan-6-one ((±)- 3 ) is described. The key intermediate was 2,4-dihydroxy-N-formylmorphinan-6-one (11) , obtained from 3,5-dibenzyloxy-phenylacetic acid (4) in 41.8% overall yield. Bromination of 11 , and treatment with aqueous N_aOH-solution afforded, after N-deblocking and reductive N-methylation with concomitant removal of the aromatic bounded Br-atom, the morphinanone 14. Elimination of the HO–C(2) group in 14 was accomplished by hydrogenolysis of its N-phenyltetrazolyl ether 15 , to give 3-deoxy-6,0-didehydro-7,8-dihydromorphine (16). Reduction of 16 with L-Selectride at low temperature provided (±)- 2 in high yield. The ether 15 directly afforded, under more vigorous reduction conditions, 4-hydroxy-N-methylmorphinan-6-one (17). and after O-methylation of 17 , the methyl ether (±)- 3 was obtained. A (1:l)-mixture of 4-hydroxy-2-methoxy-N-methylmor-phinan-6-one (28) and its 2-hydroxy-4-methoxy isomer 30 svere obtained by Grewe-cyclization of a mono-methoxylated aromatic precursor similar to that which afforded 11. The 2,4-dioxygenated N-methylmorphinan-6-ones 29 , 31 and 38 were also prepared and characterized.     

Synthesis and Characterization of Side Group-Modified Tetradentate Cyclotriphosphazene Derivatives

Abstract

A series of novel side group-modified cyclotriphosphazene derivatives were synthesized by the reaction of hexachlorocyclotriphosphazene [N₃P₃Cl₆] with 2,2′-diphenol and the potassium salt of 4-hydroxybenzaldehyde, and subsequent reduction of aldehyde groups to alcohol groups by the use of sodium borohydride. The bromination reaction was carried out with PBr₃ to give N₃P₃(O₂C₁₂H₈) (p-BrCH₂-C₆H₄-O-)₄. This compound was employed in reactions with macrocyclic polyamides, imidazole, or morpholine to produce title compounds. The target compounds were characterized by ¹H NMR, ³¹P NMR, ¹³C NMR, and electrospray ionization mass spectrometry.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

High‐Pressure Synthesis and Structural Investigation of H3P8O8N9: A New Phosphorus(V) Oxonitride Imide with an Interrupted Framework Structure

The first crystalline phosphorus oxonitride imide H₃P₈O₈N₉ (=P₈O₈N₆(NH)₃) has been synthesized under high‐pressure and high‐temperature conditions. To this end, a new, highly reactive phosphorus oxonitride imide precursor compound was prepared and treated at 12 GPa and 750 °C by using a multianvil assembly. H₃P₈O₈N₉ was obtained as a colorless, microcrystalline solid. The crystal structure of H₃P₈O₈N₉ was solved ab initio by powder X‐ray diffraction analysis, applying the charge‐flipping algorithm, and refined by the Rietveld method (C2/c (no. 15), a=1352.11(7), b=479.83(3), c=1820.42(9) pm, β=96.955(4)°, Z=4). H₃P₈O₈N₉ exhibits a highly condensed (κ=0.47), 3D, but interrupted network that is composed of all‐side vertex‐sharing (Q⁴) and only threefold‐linking (Q³) P(O,N)₄ tetrahedra in a Q⁴/Q³ ratio of 3:1. The structure, which includes 4‐ring assemblies as the smallest ring size, can be subdivided into alternating open‐branched zweier double layers {oB,${2{{2\hfill \atop \infty \hfill}}}$ }[²P₃(O,N)₇] and layers containing pairwise‐linked Q³ tetrahedra parallel (001). Information on the hydrogen atoms in H₃P₈O₈N₉ was obtained by 1D ¹H MAS, 2D homo‐ and heteronuclear (together with ³¹P) correlation NMR spectroscopy, and a ¹H spin‐diffusion experiment with a hard‐pulse sequence designed for selective excitation of a single peak. Two hydrogen sites with a multiplicity ratio of 2:1 were identified and thus the formula of H₃P₈O₈N₉ was unambiguously determined. The protons were assigned to Wyckoff positions 8f and 4e, the latter located within the Q³ tetrahedra layers.