Gas Sorption and Luminescence Properties of a Terbium(III)-Phosphine Oxide Coordination Material with Two-Dimensional Pore Topology

The structure, stability, gas sorption properties and luminescence behaviour of a new lanthanide-phosphine oxide coordination material are reported. The polymer PCM-15 is based on Tb(III) and tris(p-carboxylated) triphenylphosphine oxide and has a 5,5-connected net topology. It exhibits an infinite three-dimensional structure that incorporates an open, two-dimensional pore structure. The material is thermally robust and remains crystalline under high vacuum at 150 degrees C. When desolvated, the solid has a CO2 BET surface area of 1187 m(2) g(-1) and shows the highest reported uptake of both O-2 and H-2 at 77 K and 1 bar for a lanthanide-based coordination polymer. Isolated Tb(III) centres in the as-synthesized polymer exhibit moderate photoluminescence. However, upon removal of coordinated OH2 ligands, the luminescence intensity was found to approximately double; this process was reversible. Thus, the Tb(III) centre was used as a probe to detect directly the desolvation and resolvation of the polymer.Welch Foundation F-1738, F-1631National Science Foundation 0741973, CHE-0847763Chemistr

Synthesis and Study of Olefin Metathesis Catalysts Supported by Redox-Switchable Diaminocarbene 3 Ferrocenophanes

A redox-switchable ligand, N,N'-dimethyldiaminocarbene[3]ferrocenophane (5), was synthesized and incorporated into a series of Ir- and Ru-based complexes. Electrochemical and spectroscopic analyses of (5) Ir(CO)(2)Cl (15) revealed that 5 displayed a Tolman electronic parameter value of 2050 cm(-1) in the neutral state and 2061 cm(-1) upon oxidation. Moreover, inspection of X-ray crystallography data recorded for (5) Ir(cis,cis-1,5-cyclooctadiene)Cl (13) revealed that 5 was sterically less bulky (%V-Bur = 28.4) than other known diaminocarbene[3]ferrocenophanes, which facilitated the synthesis of (5)(PPh3)Cl2Ru-(3-phenylindenylid-1-ene) (18). Complex 18 exhibited quasi-reversible electrochemical processes at 0.79 and 0.98 V relative to SCE, which were assigned to the Fe and Ru centers in the complex, respectively, based on UV-vis and electron pair resonance spectroscopic measurements. Adding 2,3-dichloro-5,6-dicyanoquinone over the course of a ring-opening metathesis polymerization of cis, cis-1,5-cyclooctadiene catalyzed by 18 ([monomer](0)/[18](0) = 2500) reduced the corresponding rate constant of the reaction by over an order of magnitude (pre-oxidation: k(obs) = 0.045 s(-1); post-oxidation: k(obs) = 0.0012 s(-1)). Subsequent reduction of the oxidized species using decamethylferrocene restored catalytic activity (post-reduction: k(obs) = up to 0.016 s(-1), depending on when the reductant was added). The difference in the polymerization rates was attributed to the relative donating ability of the redox-active ligand (i.e., strongly donating 5 versus weakly donating 5(+)) which ultimately governed the activity displayed by the corresponding catalyst.U. S. Army Research Office W911NF-09-1-0446Chemistr

First Supramolecular Sensors for Phosphonate Anions

Fluorescent tripodal anion sensors with a 1,3,5-triethylbenzene core display a turn-on fluorescence response to phosphonate and phosphate anions and may be used as optical sensors. The properties of the receptors and sensors as well as their anion binding behavior were investigated both in solution and in solid state. The turn-on fluorescence response can be leveraged in sensing of phosphate anions and, most importantly, hydrolysis products of the nerve gas sarin, isopropyl methylphosphonate (IMP), and methylphosphonate (MP). The fluorescence signal amplification in the presence of anions allows for application of these molecules in a sensor microarray suitable for high-throughput screening.NSF CHE 0750303, EXP-LA 0731153BGSU (TIE Grant)Chemistr

Structure Of 18'-Epivinblastine

Methyl {3aR-[3a-alpha,4-beta,5-beta,5a-beta,9(3R*,-5S*,7R*,9R*),10bR,13a-alpha]}-4-(acetyloxy)-3a-ethyl-9-[5-ethyl-1,4,5,6,7,8,9,10-octahydro-5-hydroxy-9-(methoxycarbonyl)-2H-3,7-methanoazacycloundecino[5,4-b]indol-9-yl]-3a,4,5,5a,6,11,12,13a-octahydro-5-hydroxy-8-methoxy-6-methyl-lH-indolizino-[8,1-c,d]carbazole-5-carboxy?? late methanol solvate, C46H58N4O9.2CH3OH (1), M(r) = 875.07, monoclinic, P2(1), a = 10.2759 (12), b = 22.353 (3), c = 10.4051 (12) angstrom, beta = 106.502 (9)-degrees, V = 2291.6 (5) angstrom 3, Z = 2, D(x) = 1.27 g cm-3, Mo K-alpha radiation, lambda = 0.7107 angstrom, mu = 0.8397 cm-1, F(000) = 940, T = 198 K, R = 0.0470 for 2751 reflections, F(o) greater-than-or-equal-to 4-sigma-(F(o)). The C ring of the vindoline moiety is in the boat conformation with the hydroxy group and the tertiary N in the bowsprit positions resulting in a fairly short intramolecular hydrogen-bonding interaction. The relevant parameters for O3-H3...N9 are O...N 2.651 (6), H...N 1.94 (5) angstrom and O-H...N 147 (5)-degrees. The D and E rings are in the sofa and envelope conformations, respectively. The piperidine ring of the catharanthine portion of the molecule assumes the chair conformation while the conformation of the azacyclononene ring is a boat-chair. An intramolecular hydrogen bond between the indolino NH of the catharanthine moiety and methoxy O (O25) of the vindoline moiety is also observed. The relevant parameters for N16'-H16'...O25 are N...O 2.827 (6), H...N2.14 (6) angstrom and O-H...N 136 (5)-degrees.National Institutes of Health (GM 29801)ChemistryBiochemistr

Enthalpy vs Entropy Driven Complexation of Homoallylic Alcohols by Rh(I) Complexes

This document is the Accepted Manuscript version of a Published Work that appeared in final form inOrganometallics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/om200793p.The thermodynamics of binding between several homoallylic alcohols and simple olefinic Rh(I) compounds was examined with 1H NMR spectroscopy and ITC. 1H NMR titrations revealed moderate binding of these alcohols with [Rh(COD)2]+ (1) and [Rh(COD)(CH3CN)2]+ (3), but weaker binding with [Rh(NBD)2]+ (2). ITC indicated that the complexation with [Rh(COD)2]+ is mainly governed by enthalpy whereas binding with [Rh(COD)(CH3CN)2]+ is entirely driven by entropy. The thermodynamic parameters for the homoallylic alcohol binding of Rh(I) complexes 1–3 are consistent with crystallographic data

Synthesis and Recognition Properties of Higher Order Tetrathiafulvalene (Ttf) Calix N Pyrroles (N=4-6)

Two new benzoTTF-annulated calix[n]pyrroles (n = 5 and 6) were synthesized via a one-step acid catalyzed condensation reaction and fully characterized via single crystallographic analyses. As compared to the known tetra-TTF annulated calix[4]pyrrole, which is also produced under the conditions of the condensation reaction, the expanded calix[n]pyrroles (n = 5 and 6) are characterized by a larger cavity size and a higher number of TTF units (albeit the same empirical formula). Analysis of the binding isotherms obtained from UV-Vis spectroscopic titrations carried out in CHCl3 in the presence of both anionic (Cl-, Br-, I-, CH3COO-, H2PO4-, and HSO4-) and neutral (1,3,5-trinitrobenzene (TNB) and 2,4,6-trinitrotoluene (TNT)) substrates revealed that as a general rule the calix[6]pyrrole derivative proved to be the most efficient molecular receptor for anions, while the calix[4]pyrrole congener proves most effective for the recognition of TNB and TNT. These findings are rationalized in terms of the number of electron rich TTF subunits and NH hydrogen bond donor groups within the series, as well as an ability to adopt conformations suitable for substrate recognition, and are supported by solid state structural analyses.National Science Foundation CHE 1057904, 0741973Robert A. Welch Foundation F-1018Danish Natural Science Research Council (FNU) 272-08-0047, 11-106744WCU (World Class University) program of Korea R32-2010-10217-0Villum FoundationChemistr

The Structure At 198 K Of (1R,5R,15R,16R)-5-Isopropenyl-2-Methyl-1(N-(Trans-2-Phenylcyclohexyloxyc Arbonyl)Amino)-2-Cyclohexene

trans-2-Phenylcyclohexyl N-(5-isopropenyl-2-methyl-2-cyclohexan-1-yl)carbamate, C23H31NO2, M(r) = 353.50, orthorhombic, P2(1)2(1)2(1), a = 8.813 (2), b = 9.043 (2), c = 25.643 (5) angstrom, V = 2043.6 (8) angstrom 3, Z = 4, D(x) = 1.15 g cm-3 (198 K), Mo K-alpha radiation, lambda = 0.7107 angstrom, mu = 0.6734 cm-1, F(000) = 768, T = 198 K, R = 0.0547 for 1772 reflections [F(o) greater-than-or-equal-to 4-sigma-(F(o))]. Molecules are H-bonded into infinite columns parallel to a. The H bond involves the NH group and the carbonyl O atom of the carbamate moiety with relevant parameters: N11-H11...O13 (related by 1/2 + x, 1/2 - y, - z); N...O 2.910 (5), H...O 2.11 (5) angstrom, N-H...O 159 (4)-degrees.Robert A. Welch Foundation (F-626)National Institutes of Health (GM 31750)ChemistryBiochemistr

Peptide-directed assembly of functional supramolecular polymers for biomedical applications: electroactive molecular tongue-twisters (oligoalanine-oligoaniline-oligoalanine) for electrochemically enhanced drug delivery

We report the preparation and characterization of films of electroactive supramolecular polymers based on non-electroactive oligoalanines and electroactive oligoanilines. Fibroblasts adhered to and proliferated on the films, and the delivery of the clinically relevant anti-inflammatory drug dexamethasone phosphate could be enhanced upon the application of an electrical stimulus

ASEAN Synergy to Overcome Challenges in Investment Arbitration

Cambodia, Indonesia, Lao, Malaysia, Thailand, and the Philippines, have been sued by foreign investors through International investment arbitrations (IIA). No matter whether the outcome is favorable or not, those countries have spend significant time, energy, and financial resources to arbitrate. ASEAN countries are not in advantageous position in IIA.The first and the most obvious reason is language barrier. Arbitration proceedins are mainly conducted in English. Consequently, the arbitrators and counsels more often than not come from English speaking countries. Not only do they lead to high cost, but also they lack of familiarity with South East Asia\u27s social, politics, economic, culture and customs. This may influence how they treat the cases such as the interpretation of provisions specifically designed to protect foreign investors such as: national treatment; fair and equitable treatment; most favored nation; and also in deciding jurisdictional issues. regional news as a legal basis for foreign investment activities aim to provide protection for foreign investor. On the other hand, it also serves as a mean to facilitate economic development in the host states of investment. Unfortunately, BITs often contain excessive and limitless protection clauses in order to attract foreign investors. This may endanger host states position as it can be used as a weapon by the investors to sue the host states. In responding to this fact, it is necessary to strengthen cooperation among ASEAN members in dealing with foreign investors through BIT. The ideal picture will be that SEA is pro-market and pro-arbitration reform. It is unavoidable that in order to protect themselves from harsh investors as well as intricate arbitration, ASEAN would be better off having its own investment arbitration center run by its experts. Thus, the short-term challenge is to equip legal practitioners, business players and academicians with more knowledge, skills and experiences in dealing with investment disputes. The long-term step will be to negotiate model of investment treaties applicable in the region and to harmonize national investment laws. These efforts are strategic opportunities for ASEAN as single market to keep balance between promoting investment, protecting investors and the host states at the same time

Conference on the Federal Sentencing Guidelines, Panel 3: The Allocation of Discretion Under the Guidelines

The guidelines have shifted the locus of discretion from the judge to the prosecutor. This transfer has drastically changed sentencing because the prosecutor\u27s role is very different from the judge\u27s role. Before the guidelines, the prosecutor\u27s role in sentencing was minimal. The prosecutor could put a cap on the sentence by accepting a plea to a charge with a low maximum, but there was virtually no instance in which the charge would put a floor under the judge\u27s sentence. The judge, on the other hand, could sentence however he liked. Not only was the judge\u27s decision correct because it was final – there was no appellate review of sentences within the statutory maximum – it was correct because there was no law by which it could be called incorrect. Absent a few factors that were statutorily excluded from consideration, the judge could take into account any factor he thought relevant, and weigh it to whatever degree he thought it counted. The judge could be harsh or lenient, a retributivist or a utilitarian, a believer in deterrence or rehabilitation