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https://www.readbyqxmd.com/read/29036135/negative-optical-radiation-force-and-spin-torques-on-subwavelength-prolate-and-oblate-spheroids-in-fractional-bessel-gauss-pincers-light-sheets
#1
F G Mitri
Fractional Bessel-Gauss light-sheets [J. Opt.19, 055602 (2017)JOOPDB0150-536X10.1088/2040-8986/aa649a], which correspond to finite optical "slices" in 2D and possess asymmetric slit openings and bending characteristics, are examined from the standpoint of optical radiation force and spin torque theories for a subwavelength spheroid with arbitrary orientation in space. The vector angular spectrum decomposition method in addition to the Lorenz gauge condition and Maxwell's equations are used to determine the Cartesian components of the incident radiated electric field of the Bessel-Gauss light-sheets...
July 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/29035047/electrocatalytic-water-oxidation-by-a-water-soluble-copper-ii-complex-with-a-copper-bound-carbonate-group-acting-as-a-potential-proton-shuttle
#2
Fangfang Chen, Ni Wang, Haitao Lei, Dingyi Guo, Hongfei Liu, Zongyao Zhang, Wei Zhang, Wenzhen Lai, Rui Cao
Water-soluble copper(II) complexes of the dianionic tridentate pincer ligand N,N'-2,6-dimethylphenyl-2,6-pyridinedicarboxamidate (L) are catalysts for water oxidation. In [L-Cu(II)-DMF] (1, DMF = dimethylformamide) and [L-Cu(II)-OAc](-) (2, OAc = acetate), ligand L binds Cu(II) through three N atoms, which define an equatorial plane. The fourth coordination site of the equatorial plane is occupied by DMF in 1 and by OAc(-) in 2. These two complexes can electrocatalyze water oxidation to evolve O2 in 0.1 M pH 10 carbonate buffer...
October 16, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/29028330/ambient-stable-bis-azoaromatic-centered-diradical-l-%C3%A2-m-l-%C3%A2-complexes-of-rh-iii-synthesis-structure-redox-and-spin-spin-interaction
#3
Sima Roy, Shuvam Pramanik, Sarat Chandra Patra, Basab Adhikari, Abhishake Mondal, Sanjib Ganguly, Kausikisankar Pramanik
Bis-azoaromatic electron traps, viz. 2-(2-pyridylazo)azoarene 1, have been synthesized by colligating electron-deficient pyridine and azoarene moieties, and they act as apposite proradical templates for the formation of stable open-shell diradical complexes [(1(•-))Rh(III)(1(•-))](+) ([2](+)), starting from the low-valent electron reservoir [Rh(I)]. The less stable monoradical [Rh(III)(1(•-))Cl2(PPh3)3] (3) has also been isolated as a minor product. These π-radical complexes are multiredox systems, and the electron transfer processes occur exclusively within the pincer-type NNN ligand backbone 1...
October 13, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/29024801/population-based-prevalence-of-multiple-radiographically-defined-hip-morphologies-the-johnston-county-osteoarthritis-project
#4
Reshmi Raveendran, Jamie L Stiller, Carolina Alvarez, Jordan B Renner, Todd A Schwartz, Nigel K Arden, Joanne M Jordan, Amanda E Nelson
OBJECTIVE: To provide the first prevalence estimates of different radiographic hip morphologies relevant to dysplasia and femoroacetabular impingement in a well-characterized U.S. population-based cohort. METHODS: Cross-sectional data were from the baseline examination (1991-1997) of a large population-based prospective longitudinal cohort study (The Johnston County Osteoarthritis Project). HipMorf software (Oxford, UK) was used to assess hip morphology on AP pelvis radiographs...
October 9, 2017: Osteoarthritis and Cartilage
https://www.readbyqxmd.com/read/29019358/protonation-and-electrochemical-reduction-of-rhodium-and-iridium-dinitrogen-complexes-in-organic-solution
#5
Gannon P Connor, Nicholas Lease, Andrea Casuras, Alan S Goldman, Patrick L Holland, James M Mayer
Protonation and reduction of pincer-ligated Rh- and Ir-N2 complexes have been studied by NMR spectroscopy and cyclic voltammetry to assess the capability of these complexes to activate or reduce N2. Protonation, which is a prerequisite to electrochemical reduction, results in a cationic metal-hydride that loses N2 under an atmosphere of Ar. Reduction of the metal-hydride results in fast disproportionation of an unobserved transient Ir(2+) species. These studies suggest that the regioselectivity of initial protonation is a strong determinant for the ability of a system to facilitate the reduction of N2...
October 11, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28991392/ambireactive-r%C3%A2-p-%C3%A2-bh%C3%A2-groups-facilitating-temperature-switchable-bond-activation-by-an-iron-complex
#6
Lisa Vondung, Lars Erik Sattler, Robert Langer
An iron pincer complex containing a hemi-labile (R₃P)₂BH₂-group exhibits temperature-switchable reactivity patterns: a reversible B-H-activation concomitant with a P-B-bond cleavage is observed at room temperature. Below 4 °C intra- and inter-molecular C-H-activation pathways are becoming faster and dominating. Mechanistic investigations reveal that the lability of the (R₃P)₂BH₂-group in combination with the exothermic formation of σ-bonded complexes are responsible for the switchable bond activation...
October 9, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28985067/nickel-pincer-complexes-with-frequent-aliphatic-alkoxo-ligands-ipr-pcp-ni-or-r-et-nbu-ipr-2-hydroxyethyl-an-assessment-of-the-hydrolytic-stability-of-nickel-and-palladium-alkoxides
#7
Luis M Martínez-Prieto, Pilar Palma, Eleuterio Álvarez, Juan Cámpora
A series of nickel pincer complexes with terminal alkoxo ligands [((iPr)PCP)Ni-OR] (R = Et, nBu, iPr, CH2CH2OH; (iPr)PCP is the 2,6-bis(diisopropylphosphinomethyl)phenyl pincer ligand) was synthesized and fully characterized. Together with the previously reported methoxo analogues of Ni and Pd, these complexes constitute a unique series of isostructural late transition-metal alkoxides. Spectroscopic and X-ray diffraction data provide direct indications of the strong polarization of their covalent Ni-OR bonds...
October 6, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28984321/the-cytotoxicity-and-mechanism-of-action-of-new-multinuclear-scaffold-au-iii-pd-ii-pincer-complexes-containing-a-bis-diphenylphosphino-ferrocene-non-ferrocene-ligand
#8
Leila Tabrizi, Hossein Chiniforoshan
New multinuclear gold(iii), palladium(ii) pincer complexes containing bis(diphenylphosphino) ferrocene/non-ferrocene ligands of formula [(L)Au(μ(2)-η(2)-CS3)Pd(dppf)](PF6)2, 1, and [(L)Au(μ(2)-η(2)-CS3)Pd(dppe)](PF6)2, 2 (HL = 5-methoxy-1,3-bis (1-methyl-1H-benzo[d]imidazol-2-yl)benzene, dppf = 1,1'-bis(diphenylphosphino)ferrocene, and dppe = bis(diphenylphosphino)ethane) have been synthesized and fully characterized. Both complexes are more cytotoxic to a number of human cancer cell lines than cisplatin...
October 6, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28981000/non-order-disorder-allotwinning-of-the-rhenium-pincer-complex-cis-re-pnp-ch2-ipr-co-2cl
#9
Mathias Glatz, Berthold Stöger, Karl Kirchner
Crystals of cis-Re[(PNP(CH2)-iPr)(CO)2Cl] (1) are made up of two geometrically non-equivalent polytypes with respective symmetries of P21/c and I2/a. The structures were determined in a concurrent refinement, taking into account overlap of diffraction spots. The polytypes are composed of layers with px121/c1 symmetry and are of the non-order-disorder (OD) type (the layer interfaces are non-equivalent). Whereas the molecules of (1) differ in both polytypes, the Re atoms are located at nearly identical positions...
October 1, 2017: Acta Crystallographica Section B, Structural Science, Crystal Engineering and Materials
https://www.readbyqxmd.com/read/28975164/a-bio-inspired-design-and-computational-prediction-of-scorpion-like-scs-nickel-pincer-complexes-for-lactate-racemization
#10
Bing Qiu, Xinzheng Yang
Inspired by the structures of the active site of lactate racemase and recent reported SCS nickel pincer complexes, we built a series of scorpion-like SCS nickel pincer complexes with an imidazole tail and computationally predicted their catalytic activities for the racemization of lactic acid. Density functional theory calculations reveal a proton coupled hydride transfer mechanism for the dehydrogenation of l-lactate and the formation of d-lactate with a free energy barrier as low as 25.9 kcal mol(-1).
October 4, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28972751/tridentate-directing-groups-stabilize-6-membered-palladacycles-in-catalytic-alkene-hydrofunctionalization
#11
Miriam L O'Duill, Rei Matsuura, Yanyan Wang, Joshua L Turnbull, John A Gurak, De-Wei Gao, Gang Lu, Peng Liu, Keary M Engle
Removable tridentate directing groups inspired by pincer ligands have been designed to stabilize otherwise kinetically and thermodynamically disfavored 6-membered alkyl palladacycle intermediates. This family of directing groups enables regioselective remote hydrocarbofunctionalization of several synthetically useful alkene-containing substrate classes, including 4-pentenoic acids, allylic alcohols, homoallyl amines, and bis-homoallylamines, under Pd(II) catalysis. In conjunction with previous findings, we demonstrate regiodivergent hydrofunctionalization of 3-butenoic acid derivatives to afford either Markovnikov or anti-Markovnikov addition products depending on directing group choice...
October 3, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28971081/prevalence-of-femoroacetabular-impingement-morphology-in-asymptomatic-youth-soccer-players-magnetic-resonance-imaging-study-with-clinical-correlation
#12
Anthony Kerbes Yépez, Marcelo Abreu, Bruno Germani, Carlos Roberto Galia
OBJECTIVE: To determine the prevalence of femoroacetabular impingement morphology (FAIM), cam- or pincer-type, by magnetic resonance imaging (MRI) in asymptomatic adolescent soccer players, and to evaluate the possible correlation between alterations on MRI and clinical examination findings. METHODS: A cross-sectional study was conducted to determine the prevalence of FAIM in asymptomatic youth soccer players aged 13-18 years. A total of 112 hips in 56 players (mean age 15...
2017: Revista Brasileira de Ortopedia
https://www.readbyqxmd.com/read/28970988/arthroscopic-focal-subspinal-decompression-and-management-of-pincer-type-femoroacetabular-impingement
#13
Renato Locks, Hajime Utsunomiya, Ioanna Bolia, Sandeep Mannava, Jorge Chahla, Marc J Philippon
Femoroacetabular impingement syndrome is a common hip pathology significantly affecting not only the intra- and extra-articular structures but also the biomechanical function of the joint. Cam and pincer bony lesions have been extensively studied. However, during recent years, other types of extra-articular impingement between the pelvic and femoral bone have been investigated. When a prominent or morphologically abnormal anterior-inferior iliac spine (AIIS) impinges repetitively on the femoral side during motion, the subspinal acetabular region becomes prominent and extends toward the intra-articular part of the joint...
August 2017: Arthroscopy Techniques
https://www.readbyqxmd.com/read/28970986/tenosuspension-of-the-reflected-head-of-the-rectus-femoris-in-hip-arthroscopy-description-of-a-portal-and-a-surgical-maneuver
#14
Bernardo Aguilera-Bohorquez, Eduardo Gil, John Fonseca, Miguel Fernandez, Miguel Sánchez
Arthroscopy is a surgical technique useful in the treatment of intra- and extra-articular hip pathologies, including femoroacetabular impingement (FAI). In the arthroscopic treatment of pincer-type FAI, tendon interposition of the reflected head of the rectus femoris frequently hinders acetabular edge resection in the anterior-superior region (acetabuloplasty) and labrum repositioning, even causing tendon injury during the surgical procedure. Many surgeons do not give importance to the reflected head of the rectus femoris, and during the procedure they try to avoid it, giving 30° of flexion to the hip...
August 2017: Arthroscopy Techniques
https://www.readbyqxmd.com/read/28970919/rapid-reversible-borane-to-boryl-hydride-exchange-by-metal-shuttling-on-the-carborane-cluster-surface
#15
Bennett J Eleazer, Mark D Smith, Alexey A Popov, Dmitry V Peryshkov
In this work, we introduce a novel concept of a borane group vicinal to a metal boryl bond acting as a supporting hemilabile ligand in exohedrally metalated three-dimensional carborane clusters. The (POBOP)Ru(Cl)(PPh3) pincer complex (POBOP = 1,7-OP(i-Pr)2-m-2-carboranyl) features extreme distortion of the two-center-two-electron Ru-B bond due to the presence of a strong three-center-two-electron B-H···Ru vicinal interaction. Replacement of the chloride ligand with a hydride afforded the (POBOP)Ru(H)(PPh3) pincer complex, which possesses B-Ru, B-H···Ru, and Ru-H bonds...
August 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28970889/carbon-dioxide-hydrogenation-catalysed-by-well-defined-mn-i-pnp-pincer-hydride-complexes
#16
Federica Bertini, Mathias Glatz, Nikolaus Gorgas, Berthold Stöger, Maurizio Peruzzini, Luis F Veiros, Karl Kirchner, Luca Gonsalvi
The catalytic reduction of carbon dioxide is of great interest for its potential as a hydrogen storage method and to use carbon dioxide as C-1 feedstock. In an effort to replace expensive noble metal-based catalysts with efficient and cheap earth-abundant counterparts, we report the first example of Mn(i)-catalysed hydrogenation of CO2 to HCOOH. The hydride Mn(i) catalyst [Mn(PNP(NH)-iPr)(H)(CO)2] showed higher stability and activity than its Fe(ii) analogue. TONs up to 10 000 and quantitative yields were obtained after 24 h using DBU as the base at 80 °C and 80 bar total pressure...
July 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28969816/fluoroscopy-learning-curve-in-hip-arthroscopy-a-single-surgeon-s-experience
#17
Kevin M Smith, Neil L Duplantier, Kimbelyn H Crump, Domenica A Delgado, Stephanie L Sullivan, Patrick C McCulloch, Joshua D Harris
PURPOSE: To determine if (1) absorbed radiation dose and (2) fluoroscopy time decreased with experience over the first 100 cases of a single surgeon's hip arthroscopy practice. METHODS: Subjects who underwent hip arthroscopy for symptomatic femoroacetabular impingement and labral injury were eligible for analysis. Inclusion criteria included the first 100 subjects who underwent hip arthroscopy by a single surgeon (December 2013 to December 2014). Subject demographics, procedure details, fluoroscopy absorbed dose (milligray [mGy]), and time were recorded...
October 2017: Arthroscopy: the Journal of Arthroscopic & related Surgery
https://www.readbyqxmd.com/read/28968088/redox-active-bis-phenolate-n-heterocyclic-carbene-oco-pincer-ligands-support-cobalt-electron-transfer-series-spanning-four-oxidation-states
#18
Caleb F Harris, Michael B Bayless, Nicolaas P van Leest, Quinton J Bruch, Brooke N Livesay, John Bacsa, Kenneth I Hardcastle, Matthew P Shores, Bas de Bruin, Jake D Soper
A new family of low-coordinate Co complexes supported by three redox-noninnocent tridentate [OCO] pincer-type bis(phenolate) N-heterocyclic carbene (NHC) ligands are described. Combined experimental and computational data suggest that the charge-neutral four-coordinate complexes are best formulated as Co(II) centers bound to closed-shell [OCO](2-) dianions, of the general formula [(OCO)Co(II)L] (where L is a solvent-derived MeCN or THF). Cyclic voltammograms of the [(OCO)Co(II)L] complexes reveal three oxidations accessible at potentials below 1...
October 2, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28967992/direct-synthesis-of-amides-by-dehydrogenative-coupling-of-amines-with-alcohols-or-esters-catalysed-by-a-manganese-pincer-complex
#19
David Milstein, Amit Kumar, Noel-Angel Espinosa-Jalapa, Gregory Leitus, Yael Diskin-Posner, Liat Avram
The first example of base-metal-catalyzed synthesis of amides from the dehydrogenative coupling of primary amines with alcohols or esters is reported. The reactions are catalyzed by a new manganese pincer complex and generate hydrogen gas as the sole by-product, making the overall process atom economical and sustainable.
October 2, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28967700/single-and-twofold-metal-and-reagent-free-anodic-c-c-cross-coupling-of-phenols-with-thiophenes
#20
Siegfried R Waldvogel, Anton Wiebe, Sebastian Lips, Dieter Schollmeyer, Robert Franke
The first electrochemical dehydrogenative C,C cross-coupling of thiophenes with phenols was realized. This sustainable and very simple to perform anodic coupling reaction enables access to two classes of compounds of significant interest. The scope for electrochemical C,H activating cross-coupling reaction was expanded to sulfur heterocycles. Previously, only various benzoid aromatic systems could be converted, whereas the application of heterocycles was not successful in the C,H activating electrochemical cross-coupling reaction...
October 2, 2017: Angewandte Chemie
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