Polyphosphonates, a class of polymers with the generic formula -[P(R)(X)-OR'O](n)-, exhibit a high degree of modularity due to the range of R, R', and X groups that can be incorporated. As such, these polymers may be designed with a polyethylene oxide (PEO) backbone (R' group) and employed as solid polymer electrolytes (SPEs). Two PEO-containing polyphosphonate analogs (R = Ph; X = S or Se) were doped with LiPF6 and their conductivities were measured. Conductivities were similar (X = S) to or exceeding (X = Se) those of standard PEO systems (just below 10(-4) S/cm at 100 degrees C). Binding models for Li+ were generated using P-31{H-1}NMR titration experiments. Binding of Li+ by these polyphosphonates followed a positive cooperativity model, and varying the X group (S or Se) affected the observed cooperativity (Hill coefficient = 1.73 and 4.16, respectively). The presence of Se also leads to an increase in conductivity as temperature is raised above the T-g, which is likely an effect of reduced Columbic interactions. Because of their modularity and ease with which cation binding can be evaluated using P-31{H-1} NMR titration experiments, polyphosphonates offer a unique approach for the modification of Li+ ion battery technology.

Capstone teaching laboratory activities can serve as a crucial part of the undergraduate learning experience. With this in mind, a laboratory activity that combines synthesis and multiple characterization techniques has been developed for an upper-division, laboratory-based inorganic course. Complexes of Cu(II) and Ni(II) of the amino acid glycine are first synthesized. These complexes are then characterized using a variety of spectroscopic (IR, UV-vis, H-1 NMR) techniques to determine the coordination geometries of the metal centers and thermal (differential scanning calorimetry, thermal gravimetric analysis) techniques to determine the relative stabilities of geometrical isomers. Details of the activity, including procedure, experimental data, and pre/post-test, are provided.

Linear polyphosphonates with the generic formula -[P(Ph)(X)OR ' O](n)- (X = S or Se) have been synthesized by polycondensations of P(Ph)(NEt2)(2)and a diol (HOR ' OH = 1,4-cyclohexanedimethanol, 1,4-benzenedimethanol, tetraethylene glycol, or 1,12-dodecanediol) followed by reaction with a chalcogen. Random copolymers have been synthesized by polycondensations of P(Ph)(NEt2)(2)and mixture of two of the diols in a 2:1:1 mol ratio followed by reaction with a chalcogen. Block copolymers with the generic formula -[P(Ph)(X)OR ' O]((x + 2))-[P(Ph)(X)OR ' O]((x + 3))- (X = S or Se) have been synthesized by the polycondensations of Et2N[P(Ph)(X)OR ' O]((x + 2))P(Ph)NEt(2)oligomers with HOR ' O[P(Ph)(X)OR ' O]((x + 3))H oligomers followed by reaction with a chalcogen. The Et2N[P(Ph)(X)OR ' O]((x + 2))P(Ph)NEt(2)oligomers are prepared by the reaction of an excess of P(Ph)(NEt2)(2)with a diol while the HOR ' O[P(Ph)(X)OR ' O]((x + 3))H oligomers are prepared by the reaction of P(Ph)(NEt2)(2)with an excess of the diol. In each case the excess, x is the same and determines the average block sizes. All of the polymers were characterized using(1)H,C-13{H-1}, and(31)P{H-1} NMR spectroscopy, TGA, DSC, and SEC.P-31{H-1} NMR spectroscopy demonstrates that the random and block copolymers have the expected arrangements of monomers and, in the case of block copolymers, verifies the block sizes. All polymers are thermally stable up to similar to 300 degrees C, and the arrangements of monomers in the copolymers (block vs. random) affect their degradation temperatures andT(g)profiles. The polymers have weight average MWs of up to 3.8 x 10(4) Da.

Abstract This work describes the synthesis and characterization of a series of arenephosphonic acid salts for use as water soluble down-converters in optogenetic assays. Two phosphonate salts based on anthracene and naphthalene were synthesized through cleavage of phosphonate esters. A third amphiphilic salt, developed from a long-alkylchain modified naphthalene, was produced in the same manner to demonstrate micelle formation. Two techniques were used to determine if any of the salts showed micelle behavior: 31P NMR and fluorescence spectroscopy. Interestingly, all three compounds exhibited micelle formation in water. UV-induced fluorescence of NapPONa and AntPONa revealed a secondary emission profile with maximum excitation wavelengths that lie on top of the primary emission profile. This secondary emission can be attributed to the emission of the micellular structure based on solid-state fluorescence experiments. Moderate x-ray induced radioluminescence was observed in the solid forms of each compound. A solution of amphiphilic NapPONa demonstrated both concentrationdependent and micelle-dependent radioluminescence, indicating the positioning of aromatic rings in a micelle is inducive to a radioluminescent response. Furthermore, the emission wavelength of this compounds lies on top of the excitation wavelength of channelrhodopsin-2, a well-studied optogenetic target.

The down-conversion of high energy light with a fluorescentmaterial may provide sufficient emission intensity to invoke a measurableneurological response in optogentically-active neurons. This work describes the use ofanthracene-containing copolymers for use as a fixed emission material inoptogenetic electrophysiology to demonstrate the feasibility of thistechnique. An anthracene-modifiedmethacrylate was synthesized and copolymerized with methyl methacrylate toproduce glassy copolymers with physical properties like those of poly(methyl methacrylate)(PMMA). The fluorescence in bothsolution and solid states are like those of pure anthracene and overlap fullywith the absorption spectrum of channelrhodpsin-2. Scintillation is observed but is weak comparedto fluorescence. The copolymers were found to be non-toxic to neuronalcultures. Whole cell patching measuredthe voltage changes of neurons under UV-irradiation in the absence and presenceof a copolymer film. Increased frequenciesand amplitudes of electrical events were observed in the presence of thepolymers.

TADDOL-derived P-donor ligands are of interest as ligands in transition metal catalyzed transformations; however, few studies have been conducted on the steric and electronic properties of P-donor ligands derived from TADDOL. To gain more insight into these properties four tetracarbonylmolybdenum(0) and two pentacarbonyltungsten(0) complexes of monodentate P-donor ligands derived from TADDOL have been studied. These studies show that exchanging the chloro substituent on the phosphorus for OMe increases the donor ability of the ligand and that the cis-tetracarbonylmolybdenum(0) complex of the ligand having the OMe substituent spontaneously isomerizes in solution. X-ray crystallographic analyses indicate that the orientations of the 1,3,2-dioxaphosphepane ring and the aryl substituents are not always conserved, even within the same complex.

X-ray radiation exhibits diminished scattering and a greater penetration depth in tissue relative to the visible spectrum and has spawned new medical imaging techniques that exploit X-ray luminescence of nanoparticles. The majority of the nanoparticles finding applications in this field incorporate metals with high atomic numbers and pose potential toxicity effects. Here, a general strategy for the preparation of a fully organic X-ray radioluminescent colloidal platform that can be tailored to emit anywhere in the visible spectrum through a judicious choice in donor/acceptor pairing and multiple sequential Forster resonance energy transfers (FRETs) is presented. This is demonstrated with three different types of approximate to 100 nm particles that are doped with anthracene as the scintillating molecule to "pump" subsequent FRET dye pairs that result in emissions from approximate to 400 nm out past 700 nm. The particles can be self-assembled in crystalline colloidal arrays, and the radioluminescence of the particles can be dynamically tuned by coupling the observed rejection wavelength with the dyes' emission.

The field of optogenetics currently relies on invasive means to deliver light to cells and tissue. A novel, non-invasive approach has been identified in the combination of a penetrative light source and a local light-converting material. A methacrylate-functionalized anthracene has been synthesized to provide a polymerizable fluorescent material. Anthracene-methacrylate has a high quantum efficiency and is visibly fluorescent under soft x-ray irradiation. This material was copolymerized with methyl-methacrylate to produce a model system so the scintillating properties could be tuned. Copolymers of varying ratios were characterized. Visible x-ray fluorescence is observed in the polymers. Copolymers are biocompatible with neurons, and the emission profile of the anthracene-methacrylate overlaps the excitation profile of their light-activated ion channel. Future in vitro studies will test the ability of the material to induce a potential change in neurons through the down-conversion of x-rays.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Three novel ligands have been prepared by the reactions of 1,1′‐(chlorophosphinediyl)bis(1 H ‐pyrrole) with either 2‐pyridinemethanol or 2,6‐pyridinedimethanol or the reaction of 1,1′‐biphenyl‐2,2′‐diyl phosphorochloridite with 2‐pyridinemethanol. Measurement of | 1 J P–Se | values demonstrate that the phosphite donor is less basic than the phosphoramidite donors. Coordination preferences of the ligands in octahedral cis ‐tetracarbonylmolybdenum(0) and square planar cis ‐dichloropalladium(II) complexes have been evaluated using multinuclear NMR and X‐ray crystallography. Rhodium(I) complexes of the bidentate ligands have been evaluated as catalysts for styrene hydroformylation, and their activities are nearly double those of catalysts containing traditional phosphites. The regioselectivities of the Rh I complexes of the bidentate ligands are not significantly different at 80 °C and 20 atm and are not affected by the addition of a lithium salt. In contrast, changing reaction conditions causes the % n ‐aldehyde to vary from 15 to 50 %. The regioselectivity of the catalyst containing the bidentate phosphoramidite/pyridine ligand was more sensitive to pressure than temperature with both effects being significant.

t P-31{H-1} nuclear magnetic resonance spectroscopy is a particularly useful tool for studying the reactions of P-donor ligands such as phosphines and phosphites with transition metals and other Lewis bases because the reactions take place on the nonbonding pair of electrons on the phosphorus. In addition, P-31{H-1} has a 100% natural abundance and a high gyromagnetic ratio resulting in a high sensitivity that allows the spectra to be recorded using small amounts of sample. An activity that combines air sensitive synthesis of transition metal complexes of P-donor ligands and the characterization of these complexes with P-31{H-1} NMR spectroscopy has been developed for an upper-division, laboratory-based inorganic course. This laboratory familiarizes students with this useful nucleus for NMR spectroscopy and allows them to study the factors that affect the P-31{H-1} NMR chemical shifts of phosphorus-donor ligands and their transition metal complexes. Details of the activity, including procedure and pretest, are provided. Alternative methods and presentations are also proposed.

The reactions of [RhCl(cod)](2) and Ph2P(CH2CH2O)(n)CH2CH2PPh2P (n = 3, 4, 5) under a CO atmosphere yield [RhCl(CO){(Ph2P(CH2CH2O)(n) CH2CH2Ph2 P,P')}](m) monocarbonyl metallacrown ethers. These complexes are mixtures of cyclic n-mers and monomers with trans coordination geometries at the rhodium. The monocarbonyl rhodium metallacrown ethers reversibly react with CO at atmospheric pressure to form [RhCl(CO)(2){(Ph2P(CH2CH2O)(n)CH2CH2Ph2-P,P')}](m) dicarbonyl metallacrown ethers. These complexes are only stable under a CO atmosphere as demonstrated by P-31{H-1} NMR spectroscopy. Upon prolonged exposure to the atmosphere, all the monocarbonyl metallacrown ethers lose CO and undergo phosphine ligand oxidation to form [RhCl(H2O){Ph2P(O)(CH2CH2O)(n)CH2CH2P(O)Ph-2-O,O'}] metallacrown ethers. These are the first examples of metallacrown ethers in which the transition metal is coordinated via phosphine oxide donors. (C) 2018 Elsevier B.V. All rights reserved.

The synthesis, linear absorption, emission spectra, and third‐order nonlinear optical (NLO) absorptions at 430 nm of two new series of chalcogenophosphonato‐substituted bithiophenes, pdP(X)T2H and pdP(X)T2P(X)pd [pd = OCH2C(CH3)2CH2O; T = 2,5‐C4H2S; X = O, S, Se] are reported. The X‐ray crystal structures of pdP(X)T2H and pdP(X)T2P(X)pd (X = S, Se) have also been determined. The pdP(X)T2P(X)pd compounds show weak intermolecular aromatic π–π interactions while pdP(S)T2H shows S–π interactions. The compounds exhibit emission at wavelengths ranging from 380–400 nm. Some of the quantum yields are significantly larger than that of 2,2′‐bithiophene. The linear absorption spectra, emission spectra, and emission quantum yields show distinct trends with respect to the chalcogen and the number of substituents attached to the 2,2′‐bithiophene ring. NLO transmission measurements of pdP(X)T2P(X)pd (X = S, Se) indicate that saturated solutions of both compounds show significantly greater NLO absorption than saturated solutions of bpP(X)T2P(X)bp (bp = 2,2′‐biphenol, X = S, Se) do. Notably, the fluence at which the transmittance of a 0.27 m CH2Cl2 solution of pdP(Se)T2P(Se)pd falls to 50 % is 0.2 J/cm2. This rivals the best blue nonlinear absorbers in literature. The excellent emission quantum yields and NLO absorptions make these compounds promising candidates for optical power limiting and as host materials for blue OLEDs.

Ring-opening polymerization of anionic polyamide-6 (APA-6) requires both an activator and an initiator for the reaction to occur. Typical processing techniques for liquid-molded thermoplastic composite laminates involve infusion of the reinforcement with a premixed monomer solution containing both activator and initiator species. The technique described here is a step toward simplification and automation of the in situ polymerization process for composite laminates. By depositing the initiation functional group onto the reinforcement, infusion of a single stream of inert monomer solution is possible. The technique simplifies the processing equipment required and reduces the risk of contamination. Two separate methodologies derived from a silane and a diisocyanate were investigated. The soluble diisocyanate method was used to successfully demonstrate the single-stream APA-6 processing technique. Glass fiber surface-initiated polymerization was also demonstrated using the silane-derived initiator. The findings represent the first steps toward a new processing paradigm of APA-6 composites.

The syntheses of a series of substituted polyphosphonates of the type [OP(X)(Ar)O(CH2)(12)](n) (X=O, S, Se; Ar5phenyl, 2,2'-bithienyl-5-yl) are reported. The (M) over bar (n)s for the polyphosphonates range from 1.1 to 4.6 x 10(4) Da and are significantly higher than those previously reported for polyphosphonates synthesized via polycondensation reactions. Thermal characterization indicates that all of the polymers are in the rubbery state at room temperature and have thermal stabilities as high as 290 degrees C. The linear absorption spectra, emission spectra, and emission quantum yields of the 2,2'-bithenyl-5-yl substituted polyphosphonates show distinct trends with respect to the chalcogen attached to the phosphorus. Solutions of these polymers show emission at wavelengths ranging from 380 to 400 nm and, depending on the choice of X, the quantum yields are considerably larger than that of 2,2'-bithiophene. Nonlinear optical measurements of the polyphosphonates with 2,2'-bithenyl-5-yl substituents show that nonlinear absorbance increases with increasing molecular weight of X. (C) 2016 Wiley Periodicals, Inc.

Alkali metal salts can affect both the activities and regioselectivities of alkene hydroformylation catalysts containing polyether-functionalized phosphorus-donor ligands; however, it is unclear whether these effects arise from direct alkali metal cation binding to the active catalysts. To gain more insight into these effects, a series of phosphite-lariat ether ligands derived from the alkali metal cation binding agents 2-hydroxymethyl-12-crown-4 and 2-hydroxymethyl-15-crown-5 have been prepared. Rhodium(I) complexes of these ligands have been evaluated as styrene hydroformylation catalysts in the absence and presence of a variety of alkali metal salts. The activities of catalysts containing phosphites derived from 2,2'-biphenol or 1,1'-binaphthol increased significantly (up to 92%) in the presence of alkali metal cations that are "moderately oversized" for archetypal binding to the crown cavity. When this criterion are not met, a decrease in the catalytic activity is observed upon addition of an alkali metal salt. NMR titrations (P-31{H-1} and H-1) of two model cis-Mo(CO)(4)(phosphite-lariat)(2), complexes in which the phosphite was derived from 2,2'-biphenol were carried out to gain insight into the manner in which the alkali metal cations interact with the ligands. Both model complexes bind Li+ through a 2:1 two-site binding mechanism, and the model complex with the larger crown ether also binds Na+ in this fashion. In contrast, 1:1 complexes are formed upon Na+ and K+ binding to the model complex containing the smaller crown ether and upon K+ binding to the model complex containing the larger crown ether. Correlation between increases in catalyst activity and binding mode in complexes containing cations "moderately oversized" for archetypal binding to the crown cavity strongly suggests that the increases are due to a specific type of alkali metal cation binding by the lariat ether groups in these catalysts.

The cast steel Yielding Brace System (YBS) is a new hysteretic damper that was developed at the University of Toronto to enhance the seismic performance of braced frames. In this system, a ductile, cast steel connector dissipates seismic energy through inelastic, flexural yielding of specially designed, triangular fingers. The cyclic, plastic bending of the yielding fingers replaces the tensile yielding and inelastic buckling of traditional ductile braces. This provides a symmetrical hysteresis with increased energy dissipation. This paper first presents the development stages of the new cast steel YBS system with an overview of the cast steel material characterization tests and prototype component tests. Results are then presented from a test program in which two prototype YBS-brace assemblies were tested in a full-scale braced frame that simulates the in-situ boundary conditions that would be present in a steel braced frame that employed the YBS as its primary lateral force resisting system. The prototypes were designed for the second floor of a six storey sample structure. The prototypes were subjected to displacement protocols that consisted of large, inelastic, quasi-static and pseudo dynamic cycles up to three times the design level brace elongation as calculated in the sample building design. The system exhibited a high initial stiffness, excellent ductility capacity with a very stable hysteretic response and a desirable large deformation stiffening effect. As such, the YBS represents a viable new alternative to existing yielding brace systems.

The metallathiacrown ethers cis-Mo(CO)(4){2,2'-(C12H8O2)PO-(CH2CH2S)(n)CH2CH2OP(2,2'-(O2H8C12))} (n = 2, 3) and cis-Mo(CO)(4){2,2'-(C12H8O2) POCH2CH2S-1-(C6H4)-2-SCH2CH2OP (2,2'-(O2H8C12))} have been prepared as soft metal selective molecular receptors. Multinudear NMR spectroscopy and X-ray crystallography have been used to show that byproducts formed during the syntheses of the metallathiacrown ethers cis-Mo(CO)(4){2,2'-(C12H8O2)PO-(CH2CH2S)(n)CH2CH2OP(2,2'-(O2H8C12))} (n = 2, 3) are homobinudear complexes with cis-Mo(CO)(4)(P-donor)(S-donor) centers. The abilities of the metallathiacrown ethers to bind PdC12 and PtC12 have been assessed using P-31{H-1} NMR spectroscopy and X-ray crystallography. The complexes showed null results with PtCl2; however, the PtCl2 experiments showed that the complexes cis-Mo(CO)(4){2,2'-(C12H8O2)PO-(CH2CH2S)(n)CH2CH2OP(2,2'-(O2H8C12))} (n = 2, 3) formed heterobinudear cis,cis-Mo(CO)(4){2,2'-(C12H8O2)PO-(CH2CH2S)(n)CH2CH2OP(2,2'-(O2H8C12))} (n = 2, 3) complexes. The P-31{H-1} NMR spectra of these complexes suggest a cis-PtS2Cl2 coordination environment in each, which leads to asymmetric binding in the latter complex. Binding of HgCl2 by the complexes cis-Mo(CO)(4){2,2'-(C12H8O2)PO-(CH2CH2S)(n)CH2CH2OP(2,2'-(O2H8C12))} (n = 2, 3) has been studied using (31P){H-1} NMR spectroscopy. Each complex was titrated with HgCl2, and the quantitative shifts in the P-31{H-1} NMR spectra were fit to a binding mechanism. The n = 2 metallathiacrown ether binds HgC12 to form a 1:1 complex with Ka = 12.0(0.2) M-1. In contrast, interaction of HgCl2 with the n = 3 metallathiacrown ether results in isomerization to the trans complex, and HgCl2 binds to both isomers. A model has been adapted to fit the titration data of this complex and to extract equilibrium constants for each step in the cycle: the cis-trans equilibrium of the free,K-free (0.570 (0.004)), and bound, K-bond (0.16 (0.03)), metallathiacrown ethers, as well as the association binding constants for the cis, k(cis), ([4.1(0.3)] X 10(2)M(-1)) and trans, 'cans ([1.1( 0.2)] X 10(2) M-1), metallathiacrown ethers. The equilibrium constants demonstrate that the cis metallathiacrown ether binds more strongly to the HgCl2 than does the trans metallathiacrown ether and that the cis-trans equilibrium favors the cis metallathiacrown ether.