Ethyl (2‐pyridyl­methyl)­phospho­nate

Molecules of the title compound, C₈H₁₂NO₃P, exist as zwitterions. The positive charge formally located on the N atom is spread over the pyridyl ring. A partial delocalization of negative charge within the O—P—O system is observed. The conformational features and hydrogen‐bonding network of the title compound are compared with the structure of (2‐pyridyl­methyl)­phosphonic acid.     

Hydro­gen bonding in 1‐carbamoyl­guanidinium methyl­phospho­nate monohydrate

The title compound, C₂H₇N₄O⁺·CH₄O₃P⁻·H₂O, crystallized with one carbamoyl­guanidinium cation, one methyl­phos­phonate anion and one water mol­ecule in the asymmetric unit. All H atoms of the carbamoyl­guanidinium ion are involved in a hydrogen‐bonded network. The CH₃PO₂(OH) anions, together with the water mol­ecules, build O—H⋯O hydrogen‐bonded ribbons around a 2₁ screw axis parallel to the b axis. Neighbouring ribbons are not directly connected via hydrogen bonding. The carbamoyl­guanidinium cations are linked to these ribbons by N—H⋯O bridges and build a slightly buckled layer structure, the interlayer distance being b/2.     

[(5‐Bromo­pyridinium‐2‐ylamino)(phosphono)meth­yl]phospho­nate

The title compound, C₆H₉BrN₂O₆P₂, a micromolar inhibitor of the farnesyl pyrophosphate synthase, is a Z‐isomer zwitterion with one negative phospho­nate group and a protonated pyridine N atom. Two types of ribbons, both parallel to the a axis, formed by several centrosymmetrically related O—H⋯O and N—H⋯O hydrogen bonds are generated in the crystal structure. The resulting two‐dimensional (001) `double‐layered' networks are joined into a three‐dimensional network via inversion‐related halogen–oxygen inter­actions.     

Diethyl [(Z)‐1‐iodo‐2‐phenyl‐1‐hex­enyl]phospho­nate

The crystal structure of the title compound, C₁₆H₂₄IO₃P, is composed of independent molecules, in which one of the phospho­nate ethoxy groups is disordered over two positions. The other ethoxy group lies sandwiched between two phenyl rings and, as a result, is ordered. This constrained environment also leads to two C—H⋯centroid interactions, one intra‐ and one intermolecular. Examination of the extended structure reveals the presence of chains of molecules held together by I⋯O interactions.     

Hydronium (cyclo­heptyl­ammonio)­methyl­ene‐1,1‐bis­phospho­nate (hydronium incadronate)

The structure of the title compound, H₃O⁺·C₈H₁₈NO₆P₂⁻, adopts a zwitterionic form containing an alkyl­ammonium group, a hydro­nium ion, and two negatively charged phosphon­ate groups. The cyclo­heptyl side chain adopts a twist‐chair conformation. The crystal packing is dominated by an extensive hydrogen‐bonding network.     

Two members of the bis­phospho­nate class of drugs: a zwitterion and a molecular compound

The compounds studied in this paper, viz. (1‐ammonio‐1‐phosphono­propyl)­phospho­nate, C₃H₁₁NO₆P₂, (I), and 1‐(acetyl­amino)­propyl­idene‐1,1‐bis­phospho­nic acid dihydrate, C₅H₁₃NO₇P₂·2H₂O, (II), are members of a commonly used family of therapeutic agents. Compound (I) is an inner salt with separated negative (on the ionized PO₃ group) and positive (on the tetrahedral N atom) charges, while (II) possesses neutral phospho­nyl groups and one amide N atom. Both structures have a C—C—C—N backbone, which has comparable geometric parameters in (I) and (II); the main difference was found in one of the N—C—P bond angles, which is lengthened in (II) because of an intramolecular O_PO3—H⃛O_C=O interaction. The hydrogen‐bonding scheme in the crystal of (I) includes all possible donor atoms, namely all the H atoms of the ammonium group and the phospho­nic acid functions. As a result of these interactions, the zwitterions are organized into a plane running along the crystallographic x axis. In (II), the intermolecular interactions include all possible donor atoms, except for the N atom; the packing differs from that of (I) in that the mol­ecules are arranged in a chain running parallel to the x axis. In the chains, the mol­ecules form head‐to‐head dimers, while the crystallization water mol­ecules contribute to the intra‐ and interchain cohesion.     

rac‐1‐Phenyl­ethyl­ammonium carboxy­methyl­phospho­nate(1–): hydrogen‐bonded anion sheets with pendent cations

In the title compound, C₈H₁₂N⁺·C₂H₄O₅P⁻, the anions are linked by two O—H⋯O hydrogen bonds [H⋯O both 1.75 Å, O⋯O = 2.5781 (15) and 2.5834 (15) Å, and O—H⋯O = 169 and 176°] into sheets built from alternating (8) and (32) rings. Each cation is linked to an anion sheet by three N—H⋯O hydrogen bonds [H⋯O = 1.88–2.04 Å, N⋯O = 2.7603 (16)–2.9334 (17) Å and N—H⋯O = 162–166°], such that all the cations pendent from one face of the sheet are of the R configuration, while all those pendent from the opposite face are of the S configuration.     

Block copolymer materials from the organocatalytic ring‐opening polymerization of a pentaerythritol‐derived cyclic carbonate

9‐Phenyl‐2,4,8,10‐tetraoxaspiro[5,5]undecanone (PTO) was synthesized from pentaerythritol via the acid‐catalyzed acetal formation reaction with benzaldehyde and subsequent ring closure with ethyl chloroformate. The cyclic carbonate monomer was subsequently polymerized by ring‐opening polymerization (ROP) initiated from 1,4‐butanediol (1,4‐BDO) using the 1‐(3,5‐bis(trifluoromethyl)phenyl)‐3‐cyclohexylthiourea and 1,8‐diazabicyclo[5.4.0]undec‐7‐ene dual organocatalytic system. It was found that the organocatalyst allowed for the synthesis of well‐defined polymers with minimal adverse side reactions and low dispersities. This system was then employed in the ROP of PTO initiated from an α,ω‐dihydroxy poly(caprolactone) (PCL) macroinitiator, with varying molecular weights, to yield a series of A‐B‐A block copolymers. These materials were characterized by ¹H NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis and tensile analysis. It was found that the chain extension from PCL with poly(PTO) (PPTO) blocks yielded a thermoplastic material with superior tensile properties (elongation and Young's modulus) to that of the PCL homopolymer. Furthermore, it was noted that the addition of PPTO could be employed to alter the crystallization properties (crystallization temperature (T_c), and percentage crystallization) of the central PCL block. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2279–2286     

Cyano‐stabilized triphenyl­phospho­nium ylids

Crystalline cyano‐stabilized triphenyl­phospho­nium ylids with keto or ester groups give rise to an extended electronic delocalization. In methyl 2‐cyano‐2‐(trimethyl­phospho­nio)­ethenoate, Ph₃P=C(CN)CO₂CH₃ or C₂₂H₁₈NO₂P, (I), and 1‐cyano‐1‐(trimethyl­phospho­nio)prop‐1‐en‐2‐olate, Ph₃P=C(CN)CO—CH₃ or C₂₂H₁₈NOP, (II), the carbonyl groups are oriented toward the cationoid P atom. Bond lengths and angles, torsion angles and P⋯O contact distances are consistent with a dominant coplanar conformation where the mol­ecular structures are the result of a balance between intra‐ and inter­molecular inter­actions. The main inter­actions presented by cyano‐ester (I) and cyano‐keto (II) are intra­molecular inter­actions between the carbonyl O and the P atoms. In addition, both compounds show other less important intra­molecular inter­actions between the carbonyl O and phenyl H atoms, which could contribute to form a preferred conformation in the crystal structure.     

3‐(Triphenyl­phospho­ranyl­idene)pentane‐2,4‐dione and dieth­yl 2‐(triphenyl­phospho­ranyl­idene)malonate

The title ylides, 3‐(triphenyl­phospho­ranyl­idene)pentane‐2,4‐dione, C₂₃H₂₁O₂P, (I), and diethyl 2‐(triphenyl­phospho­ranyl­idene)malonate, C₂₅H₂₅O₄P, (II), differ in the conformations adopted by their extended ylide moieties. In (I), one carbonyl O atom is syn and the other is anti with respect to the P atom, the ylide group is nearly planar, with a maximum P—C—(C=O) angle of 18.2 (2)°, and the P—C, C—C and C=O bond lengths are consistent with electronic delocalization involving the O atoms. In (II), both carbonyl O atoms are anti and the ester groups are twisted out of the plane of the near trigonal ylide C atom, reducing delocalization, the largest P—C—(C=O) angle being 30.2 (2)°.     

The synthesis of phospho­rus heterocycles from tetra‐tert‐butyl­tetraphosphacubane

Tetra‐tert‐butyl­tetraphosphacubane, P₄C₄^tBu₄, reacts with water in the presence of `GaI' to yield two products, namely 4,6,7,8‐tetra‐tert‐butyl‐1,2,3‐triphospha‐5‐phospho­niatetra­cyclo­[3.2.1.0^2,4.0^3,8]­oct‐6‐ene tetra­iodo­gallate(III), (C₂₀H₃₇P₄)[GaI₄], and tri­iodo(3,5,7,8‐tetra‐tert‐butyl‐1,2,4λ⁵,6‐tetra­phos­pha­tetra­cyclo­[4.1.1.0^2,5.0^7,8]­octan‐4‐one)­gallium(III), [GaI₃(C₂₀H₃₈OP₄)], both of which have been structurally characterized. The X‐ray crystal structure determination of the former compound shows it to be an ion‐separated salt, while the latter compound is a neutral phosphinite complex of GaI₃.     

{[(N‐Methyl‐p‐toluidino)­di­phenyl­phospho­ranyl­idene]­methyl}(N‐methyl‐p‐toluidino)­di­phenyl­phospho­nium iodide

The cationic part of the homodifunctional amino­phospho­ranyl ligand, C₄₁H₄₁N₂P₂⁺·I^?, shows interesting features associated with the N—P—C—P—N skeleton. The P—C(H) bond distances [1.696 (3) and 1.697 (3) Å] possess partial double‐bond characteristics. The nature of the P—C(H) and P—N bonds suggests that the positive charge is only distributed around the P—C—P atoms. The structure has near twofold symmetry through the central methyl­ide‐C atom.     

1‐tert‐Butyl‐2‐methyl­phospho­lane–borane and its coupling product 2,2′‐bis(1‐tert‐butyl­phospho­lane–borane)

The title compound, C₉H₂₂BP, and its coupling product, C₁₆H₃₈B₂P₂, were synthesized and their crystal structures analyzed by X‐ray diffraction. The molecular structures clearly explain the stereoselective reaction pathways leading to the products. The average P—B distance and C—P—B angle are 1.929 Å and 114°, respectively.     

4‐Fluoro‐2‐(phospho­no­methyl)­benzene­sulfonic acid monohydrate

The title compound, C₇H₈FO₆PS·H₂O, contains both phospho­nic and sulfonic acid functionalities. An extensive network of O—H?O hydrogen bonds is present in the crystal structure. The three acidic protons are associated with the phospho­nate group. Two protons experience typical hydrogen‐bond contacts with the sulfonate‐O atoms, while the third has a longer covalent bond of 1.05 (3) Å to the phospho­nate‐O atom and a short hydrogen‐bond contact of 1.38 (3) Å to the water O atom (all O—H?O angles are in the range 162–175°). The sulfonate group is positioned so that one S—O bond is nearly coplanar with the phenyl ring [torsion angle O—S—C—C ?8.6 (2)°]. The phospho­nate group is oriented approximately perpendicular to the ring [torsion angle P—C—C—C 99.2 (2)°] with one P—O bond anti to the benzyl C—C bond. The mol­ecules pack in layers in the b–c plane with the water mol­ecules in between adjacent pairs of inverted layers.     

Synthesis,characterization, and thermal properties of a novel pentaerythritol‐initiated star‐shaped poly(p‐dioxanone)

A novel star‐shaped poly(p‐dioxanone) was synthesized by the ring‐opening polymerization of p‐dioxanone initiated by pentaerythritol with stannous octoate as a catalyst in bulk. The effect of the molar ratio of the monomer to the initiator on the polymerization was studied. The polymers were characterized with ¹H NMR and ¹³C NMR spectroscopy. The thermal properties of the polymers were investigated with differential scanning calorimetry and thermogravimetric analysis. The novel star‐shaped poly(p‐dioxanone) has a potential use in biomedical materials. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1245–1251, 2006     

Phase change in tetra­phenyl­phospho­nium perchlorate

The title compound, C₂₄H₂₀P⁺·ClO₄^?, undergoes a sudden reversible phase change in the region of 173–180 K which involves ordering of three quarters of the perchlorate anions.     

Ethyl­tri­phenyl­phospho­nium perrhenate and (iodo­methyl)­tri­phenyl­phospho­nium perrhenate

Ethyl­tri­phenyl­phospho­nium perrhenate, (C₂₀H₂₀P)[ReO₄], and (iodo­methyl)­tri­phenyl­phospho­nium perrhenate, (C₁₉H₁₇IP)[ReO₄], have been crystallized from 2‐propanol. Both crystal structures consist of phospho­nium cations and perrhenate anions. The cations show the typical propeller‐like geometry. In both crystals, the positions of the nearly tetrahedral anions are stabilized by weak C—H⋯O hydrogen bonds, and for the latter compound, I⋯π interactions also occur.     

Lithium phospho­enolpyruvate monohydrate at 85 K

The crystal structure of the title compound, lithium (1‐carboxy­ethenyl­oxy)­phospho­nate monohydrate, Li⁺·C₃H₄O₆P^?·­H₂O, is governed by lithium–oxy­gen interactions and hydrogen bonds. The Li⁺ cation is tetrahedrally coordinated by phosphate and water O atoms. The phospho­enolpyruvate monoanions form carboxyl‐to‐carboxyl and phosphate‐to‐water hydrogen bonds.     

Symmetric hydrogen bonding in dimethyl­ammonium hydrogen diphenyl­diphospho­nate

In the title compound, C₂H₈N⁺·C₁₂H₁₁O₅P₂⁻, pairs of hydrogen diphenyl­diphospho­nate anions form dimers across a twofold axis, with two symmetric O⋯H⋯O hydrogen bonds [O⋯O = 2.406 (3) and 2.418 (3) Å]. The 12‐membered ring thus formed has crystallographic 2 and quasi‐222 symmetry. Cations on either side of the ring form N—H⋯O hydrogen bonds to the four extraannular O atoms, with N⋯O distances of 2.765 (2) and 2.748 (3) Å.     

A green approach toward oleic‐ and undecylenic acid‐derived polyurethanes

Naturally occurring oleic and undecylenic acids were used as raw materials for the synthesis of novel polyurethanes (PUs). The application of environmentally friendly thiol‐ene additions to 10‐undecenoate and oleate derivatives was studied with the goal of obtaining renewable diols. The resulting monomers were then polymerized with 4,4′‐methylenebis (phenylisocyanate), in N,N‐dimethylformamide solution using tin (II) 2‐ethylhexanoate as catalyst, to produce the corresponding thermoplastic PUs (TPUs). Also, ultrasound irradiation has been tested to improve the synthesis of PU. Under these conditions, TPUs were obtained in high yields (80–99%) with weight‐average molecular weights in the 36–83 kDa range. The chemical structures of PUs were assessed by FTIR and NMR spectroscopy. The thermal and mechanical properties of the synthesized TPUs have been studied and they showed a clear dependence on the structure of the parent diol. MTT test was carried out to asses the potential cytotoxicity of the prepared PUs, indicating no cytotoxic response. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011