ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplication of the multiple scattering X.alpha. molecular orbital method to determination electronic structure metallocene compounds. 1. Dibenzenechromium and its cationJacques Weber, Michel Geoffroy, Annick Goursot, Edouard PenigaultCite this: J. Am. Chem. Soc. 1978, 100, 13, 3995–4003Publication Date (Print):June 1, 1978Publication History Published online1 May 2002Published inissue 1 June...

Chemical and electrochemical reductions of the macrocycle 1 lead to formation a radical monoanion anion [1](*)(-) whose structure has been studied by EPR in liquid frozen solutions. In accord with experimental (31)P hyperfine tensors, DFT calculations indicate that, this species, unpaired electron is mainly localized bonding sigma P-P orbital. Clearly, one-electron bond (2.763 A) was formed between two phosphorus atoms which, neutral molecule, were 3.256 A apart (crystal structure)....

For a version of Newton's method applied to generalized equation with parameter, we extend the paradigm Lyusternik–Graves theorem framework mapping acting from pair “parameter-starting point” set corresponding convergent Newton sequences. Under ample parameterization, metric regularity associated sequences becomes equivalent equation. We also discuss an inexact and present application discretized optimal control.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Benzodiphosphaalkene Ligand and Its PdII PtII Complexes: Their Synthesis, Structure, an ESR Study of Reduction ProductsAbdelaziz Jouaiti, Michel Geoffroy, Gustavo Terron, Gerald BernardinelliCite this: J. Am. Chem. Soc. 1995, 117, 8, 2251–2258Publication Date (Print):March 1, 1995Publication History Published online1 May 2002Published inissue 1 March...

The reduction products of two diphosphaalkenes (1 and 2) a bis(diphosphene) (3) containing sterically encumbered ligands corresponding to the general formulas Ar-X=Y-Ar'-Y=X-Ar, have been investigated by EPR spectroscopy. Due steric constraints in these molecules, at least one dihedral angles between CXYC plane either Ar or Ar' is largely nonzero and, hence, discourages conformations that are optimal for maximal conjugation P=X (or P=Y) aromatic pi systems. Comparison experimental hyperfine...

A "CO-like matrix", showing coordination analogous to that of carbonyl groups, is provided by silacalix[4]phosphinine macrocycles. Reaction with AuI leads the first gold(I) complexes macrocycles, which can be reduced sodium or potassium paramagnetic gold(0) (an example shown), as evidenced cyclic voltammetry and EPR spectroscopy.

In [2] we characterized in terms of a quadratic growth condition various metric regularity properties the subdifferential lower semicontinuous convex function acting Hilbert space. Motivated by some recent results [16] where authors extend to Banach spaces characterization strong regularity, as well characterizations for subregularity and given spaces. We also notice that at least one implication these remains valid limiting without assuming convexity Asplund Additionally, show direct...

Various preparations of the neutral radical [CpNi(dddt)] complex (dddt = 5,6-dihydro-1,4-dithiin-2,3-dithiolate) were investigated with CpNi sources, [Cp2Ni], [Cp2Ni](BF4), [CpNi(CO)]2, and [CpNi(cod)](BF4), dithiolene transfer OC(dddt), naked dithiolate (dddt2-), monoanion square-planar Ni (NBu4)[Ni(dddt)2], [Ni(dddt)2]. The reaction [CpNi(cod)](BF4) (NBu4)[Ni(dddt)2] gave highest yield for preparation (86%). [CpNi(ddds)] (ddds 5,6-dihydro-1,4-dithiin-2,3-diselenolate), [CpNi(dsdt)] (dsdt...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhosphaalkene radical anions: electrochemical generation, ab initio predictions, and ESR studyMichel Geoffroy, Abdelaziz Jouaiti, Gustavo Terron, Maria Cattani-Lorente, Yves EllingerCite this: J. Phys. Chem. 1992, 96, 21, 8241–8245Publication Date (Print):October 1, 1992Publication History Published online1 May 2002Published inissue 1 October 1992https://pubs.acs.org/doi/10.1021/j100200a008https://doi.org/10.1021/j100200a008research-articleACS...

SummaryHydroxyapatite is used as a model for studying radical formation in the mineral compartment of irradiated calcified tissues. Treating this material with 13C-enriched CO2 confirms that radiogenic long-lived radicals correspond to carbon centred species. It shown, however, these are not located on carbonate ions which substitute either phosphate or hydroxyl groups. The conditions allow and trapping investigated (role humidity, temperature) paramagnetic species identified CO−2 adsorbed...

In this paper we consider the following general version of proximal point algorithm for solving inclusion , where T is a set-valued mapping acting from Banach space X to Y. First, choose any sequence functions with that are Lipschitz continuous in neighborhood origin. Then pick an initial guess x0 and find xn by applying iteration We prove if constants gn bounded half reciprocal modulus regularity T, then there exists O ( being solution ) such each one can generated which linearly convergent...

Reaction of 2,4,6-trichloro-1,3,5-triazine with lithiated tetrathiafulvalene (TTF) in stoichiometric conditions, followed by treatment sodium methanolate, provides mono- and bis(TTF)-triazines as new covalently linked (multi)donor-acceptor systems. Single-crystal X-ray analyses reveal planar structures for both compounds, formation peculiar segregated donor acceptor stacks the mono(TTF)-triazine compound, while mixed TTF-triazine establish case bis(TTF) derivative. Cyclic voltammetry...

We describe the preparation of a helicate containing four closely spaced, linearly arrayed copper(I) ions. This product may be prepared either directly by mixing with set precursor amine and aldehyde subcomponents, or indirectly through dimerization dicopper(I) upon addition 1,2-phenylenediamine. A notable feature this is that its length not limited lengths subcomponents: each two ligands wrapped around centers contains one diamine, dialdehyde, monoamine residues. work thus paves way for...

The diphenylphosphino radical, (C6H5)2P, has been observed at room temperature in X-irradiated single crystals of triphenylphosphine oxide and diphenylphosphine sulphide ultra-violet irradiated polycrystalline 77 K. isotropic 31P coupling constant is deduced to be +252 MHz the anisotropic components are approximately 504, -252, -252 MHz. largest value g tensor lies perpendicularly direction hyperfine constant, values being 2·0094, 2·0035 2·0021. also contains (C6H5)2PO radical.

X-irradiation of single crystals yields the (C6H5)2PO radical, phosphorus analogue diphenyl nitroxide. The principal values 31P hyperfine coupling constants are 1439 MHz, 929 MHz and 908 which may be resolved into an isotropic component 1092 anisotropic components 347 -163 -184 MHz. This implies that unlike nitroxide, this radical is nonplanar (s/p ratio = 0·18, s-character 0·11, p-character 0·60).

In this paper we study local convergence of inexact Newton methods the form $ {\big(}f(x_k)+ A_k(x_{k+1}-x_k)+F(x_{k+1}){\big)}\cap R_k(x_k) \neq \emptyset \ {with} A_k \in {\cal H}(x_k)$ for solving generalized equation $f(x) +F(x) \ni 0$ in Banach spaces, where function $f$ is continuous but not necessarily smooth and $F$ a set-valued mapping with closed graph. The $\cal H$ plays role derivative which finite dimensions may be represented by Clarke's Jacobian, while spaces it identified...

Stable for at least one week below −30°C: crystals of 1, the first highly persistent diphosphanyl radical, have been isolated and characterized. This phosphorus-centered radical exhibits hyperfine coupling whose anisotropy is considerably larger than that well-established nitrogen radicals (hydrazyls, nitroxides). feature potential interest studies fast molecular movements. Mes*=2,4,6-tBu3C6H2.

A novel ligand containing two phosphaalkene moieties has been synthesized, which forms a palladium(II) complex whose crystal structure determined and reduction shown, by EPR spectroscopy, to take place on the rather than metal.

Abstract The synthesis and characterization of two ortho ‐dimethyltetrathiafulvalene ( o ‐DMTTF)‐based rigid dimers containing dimethylsilicon (Me 2 Si) or dimethylgermanium Ge) linkers are described. Single‐crystal X‐ray analysis reveals planar geometry for the central 1,4‐disilicon 1,4‐digermanium six‐membered rings. DFT calculations provide optimized conformations in agreement with experimental ones, also emphasize role heteroatomic conjugation between redox active units. Cyclic...

Cyclic voltammetry of Mes*PC(NMe2)2 (1) and Mes*PC(CH3)NMe2 (2) shows that, in solution DME, these compounds are reversibly oxidized at 395 553 mV, respectively. Electrochemical oxidation or reaction 1 (or 2) with [Cp2Fe]PF6 leads to the formation corresponding radical cation, which was characterized by its electron paramagnetic resonance (EPR) spectra. Experimental 31P 13C isotropic anisotropic coupling constants agree density functional theory (DFT) calculations showing that unpaired is...