ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrochemical reduction of protonated cyclopentadienylcobalt phosphine complexesU. Koelle and S. PaulCite this: Inorg. Chem. 1986, 25, 16, 2689–2694Publication Date (Print):July 1, 1986Publication History Published online1 May 2002Published inissue 1 July 1986https://pubs.acs.org/doi/10.1021/ic00236a007https://doi.org/10.1021/ic00236a007research-articleACS PublicationsRequest reuse permissionsArticle Views1220Altmetric-Citations106LEARN ABOUT...

Recent developments on structural mimics for the oxygen-evolving complex of photosystem II are reviewed and discussed.

X-ray diffraction studies on oriented samples of 4-cyanophenyl-4′-n-heptylbenzoate in the nematic phase are reported at different temperatures. The orientational distribution function f(β) has been calculated from angular intensities. order parameters 2 and 4 have determined f(β). is found to be slightly greater than value predicted by Maier-Saupe molecular field theory, whereas values much smaller those given theory. An approximate expression for potential obtained temperature variation...

A recently reported synthetic complex with a Mn4CaO4 core represents remarkable structural mimic of the Mn4CaO5 cluster in oxygen-evolving (OEC) photosystem II (Zhang et al., Science 2015, 348, 690). Oxidized samples show electron paramagnetic resonance (EPR) signals at g ≈ 4.9 and 2, similar to those associated OEC its S2 state (g 4.1 from an S = 5/2 form 2 1/2 form), suggesting similarities electronic as well geometric structure. We use quantum-chemical methods characterize various...

Controlling the selectivity of 4e–/4H+ reduction oxygen over 2e–/2H+ is a key challenge in making efficient catalysts for fuel cell cathodes. A tyrosine residue poised active site cytochrome c oxidase (CcO) has been demonstrated to control hydrogen atom transfer reactions and cleavage O–O bond Fe–O–O–Cu moiety yield water. In couple small-molecule iron complexes supported by porphyrin derivatives, it was shown that presence protonation sites at secondary coordination sphere plays an...

Abstract The crystal and molecular structure of nematogen 4′-n-Pentyloxy-4-Biphenylcarbonitrile has been determined by direct methods. crystals belong to the monoclinic system with space group P21/n. a = 21.378(5), b 5.695(3), c 12.789(2) Å, β 106.074(17)° four molecules per unit cell. Least-squares refinement leads R 0.050 (Rw 0.038) for 1773 observed reflections. are in their most extended conformation, rigid part lies parallel a-axis while chain is inclined it. Rigid also highly planar...

Abstract Refractive indices of bis-(4′-n-alkyloxy benzal)-2-chloro-1,4 phenylene diamine (alkyl = hexyl, octyl and decyl), RO-TN-101 RO-CE-154 have been measured over the whole nematic ranges for different wave lengths. A prism method has employed these measurements. The samples were aligned by surface rubbing application magnetic field. For all samples, refractive index extra-ordinary ray (ne ) decreases that ordinary (no) increases with increasing temperature. At isotropic transition there...

A copper complex, [Cu(dpaq)](ClO4) (1), of a monoanionic pentadentate amidate ligand (dpaq) has been isolated and characterized to study its efficacy toward electrocatalytic reduction oxygen in neutral aqueous medium. The Cu(II) mononuclear poised distorted trigonal bipyramidal structure, reduces at an onset potential 0.50 V vs RHE. Kinetics by hydrodynamic voltammetry chronoamperometry suggests stepwise mechanism for sequential O2 H2O2 H2O single-site Cu-catalyst. foot-of-the-wave analysis...

A systematic characterization of Cu2O nanoclusters using classical electrodynamics and time-dependent density functional theory (TDDFT) is performed to investigate their response light with the alteration size symmetry. Absorption scattering play a crucial role in tuning surface plasmon resonance (SPR), which focal feature optoelectronic properties. In larger dimensions SPR found be strongly influenced by smaller NPs it dominated absorption. blue shift peak observed decreasing cluster size....

This work develops a formalism to quantify the interaction among unpaired spins from ground state spin topology. Magnetic systems where are coupled through direct exchange and superexchange chosen as references. Starting general Hamiltonian, an effective Hamiltonian is obtained in terms of density which utilized compute coupling constants magnetic executing exchange. The high-spin-low-spin energy gap, required extract constant, broken symmetry approach within framework functional theory. On...

All-metal aromatic molecules are the latest inclusion in family of systems. Two different classes all-metal clusters primarily identified: one is only low spin state, and other shows aromaticity even high-spin situations. This observation prompts us to investigate effect multiplicity on aromaticity, taking Al(4)(2-), Te(2)As(2)(2-), their copper complexes as reference Among these clusters, it has been found that singlet state manifest antiaromaticity triplet state. The characterized by...

The oxomanganese(IV) complex [(dpaq)MnIV(O)]+-Mn+ (1-Mn+, Mn+ = redox-inactive metal ion, H-dpaq 2-[bis(pyridin-2-ylmethyl)]amino-N-quinolin-8-ylacetamide), generated in the reaction of precursor hydroxomanganese(III) 1 with iodosylbenzene (PhIO) presence triflates, has recently been reported. Herein generation same species from using various combinations protic acids and oxidants at 293 K is triflic acid one-electron-oxidizing agent [RuIII(bpy)3]3+ leads to formation complex. putative...

A mononuclear manganese(V) oxo complex of a bis(amidate)bis(alkoxide) ligand, (NMe4)[MnV(HMPAB)(O)] [2; H4HMPAB = 1,2-bis(2-hydroxy-2-methylpropanamido)benzene], was synthesized and structurally characterized. Mn-Oterm distance 1.566(4) Å observed in the solid-state structure 2, consistent with Mn≡O formulation. The reaction redox-inactive metal ions (Mn+ Li+, Ca2+, Mg2+, Y3+, Sc3+) 2 resulted formation 2-Mn+ species, which were characterized by UV-vis, 1H NMR, cyclic voltammetry, situ IR...

Abstract It is now well established that for a proper understanding and interpretation of several physical properties liquid crystalline phases, knowledge the molecular arrangement in state very useful. A preliminary survey present solid-mesophase relationships has been given by Bryan1. The classical view typical nematogen crystals long narrow molecules lie more or less parallel are interleaved giving what was described Bernal Crowfoot2 as an imbricated packing transformation from solid to...

Abstract The hexyl, octyl and decyl members of the homologous series bis-(4′-n-alkoxybenzal)-2-chloro-1,4-phenylinediamine have been studied by X-ray diffraction at different temperatures under various magnetic fields. intermolecular distance tilt angle, orientational distribution function order parameters calculated. distance, angle ‘degree ordering’ is found to depend on field strength. Order ⟨P 2⟩ 4⟩ are be slightly lower for BHeCP, more or less equal BOCP, higher BDeCP than those...

Nonequivalent magnetic interactions in systems with multiple centers can be explored through a proper description of exchange coupling. The coupling constant (J) two sites is reliably estimated using Heisenberg-Dirac-van Vleck (HDVV) model broken symmetry approach (BS) within density functional theory (DFT) framework. However, case centers, constants, evaluated state-of-the-art techniques, are often found to inadequate produce correct fingerprint the nature therein. This work suggests new...

Explanation of the ferromagnetic anomaly in two recently synthesized mixed-stack charge-transfer (CT) complexes (1) (HMTTF)[Ni(mnt)2] (HMTTF = bis(trimethylene)-tetrathiafulvalene, mnt maleonitrile dithiolate) and (2) (ChSTF)[Ni(mnt)2] (ChSTF 2,3-cyclohexylenedithio-1,4-dithia-5,8-diselenafulvalene) is cornerstone this investigation. Because these systems are reported to achieve magnetic properties through charge transfer from neutral organic donor organometallic acceptor stack, their...

Abstract The construction of a charge transfer (CT) organic material with important electrical properties is demonstrated where the state generated via delocalization through H‐bonding interaction pathway. reaction simple molecule pyromellitic acid orthophenylene diamine in 1:2 ratios gives colorless cocrystal 1’ . rare transition phenomena to an orange 1 take place methanol water media over several days. isolated as single crystals which show semiconducting well fluorescent properties....

A new metal-organic hybrid complex [Cu(5,5′-dmbipy) (D-cam) (H2O)]n (1), (5,5′-dmbipy = 5,5′-dimethyl-2,2′-bipyridine, D-cam D-camphoric acid anion) was hydrothermally synthesized. This characterized by FTIR spectroscopy, TGA, and single-crystal X-ray diffraction. Crystallographic studies show that the title 1 crystallizes in an orthorhombic system with a P212121 space group 06.9518(05) Ǻ, b 13.5516(13) c 22.6380(02)Ǻ; V 2132.7(3) Ǻ3. The CuII adopts square pyramidal configuration. DFT study...

Spin ordering in (La/Ba) 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3− δ with substitution at A-site enables them to be excellent electrocatalyst for OER and ORR reversible SOC wherein catalysis & spin originate from exchange interaction.

Abstract We have measured the refractive indices (no , ne ) and densities of four members (nonyl, decyl, undecyl dodecyl) a homologous series cyanobiphenyl alkyl ether over their entire mesomorphic range in isotropic phases. The molecular polarizabilities been calculated from using both Vuks' Neugebauer's relations. additive rule bond has also employed to calculate compounds assuming two different configurations chains. orientational order parameter values at temperatures for each compound...

Aromaticity is a multidimensional concept and not directly observable. These facts have always stood in the way of developing an appropriate theoretical framework for scaling aromaticity. In present work, quantitative account aromaticity developed on basis cyclic delocalization π-electrons, which phenomenon leading to unique features aromatic molecules. The stabilization molecular energy, caused by π-electrons obtained as second order perturbation energy archetypal systems. final expression...