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Reaction of diethylenetriamine with phenol derivatives possessing a phenyl ester function yields a ligand corresponding to the monocondensation of diethylenetriamine with the phenol derivative. In a following step, its coordination to copper ions gives a neutral complex that is able to react with orthovanillin in order to yield an original complex made of a non symmetric ligand possessing three nitrogen, amide, imine and secondary amine, and four oxygen, amide, phenol (2) and methoxy donor atoms, thanks to the kinetic template effect. In our example, the copper center brings the three reactive functions (first primary amine and aldehyde, then amide) in close vicinity so that the formation of an imine function and the protonation of the amide function can occur. The structural determination of the resulting complex confirms an unexpected copper coordination. [ABSTRACT FROM AUTHOR]

Depending on the ligands involved in the coordination sphere of the Ln ion present in the outer coordination site of the main tripodal ligand, hetero-dinuclear or tetranuclear Ln complexes can be isolated. [Display omitted] Two families of homo- and heterodinuclear complexes are prepared and structurally characterized, thus demonstrating that genuine complexes involving two lanthanide ions closely located in the lanthanide series can be obtained, taking into account a simple rule that necessitates introduction of the better Lewis acid Ln ion (the smallest Ln ion) into the inner coordination site of the main ligand used in this synthesis. In the first family, the presence of a deprotonated orthovanillin ligand (ovan) around the Ln ion positioned in the outer coordination site of the main ligand allows a good isolation of the dinuclear complexes. These complexes behave as SMSs when a Dy ion is coordinated in the outer site but a weak magnetic magnetic Ln-Dy interaction is needed to create a weak magnetic field able to suppress collapsing of the hysteresis loops in zero external applied field at very low temperature. In the second family, the ovan ligand is replaced by a chloride ligand, so that two dinuclear units are linked together by two Cl...HOMe hydrogen bonds to yield tetranuclear complexes that are not SMMs. Eventually these two preparation pathways are expected to give novel and genuine examples of homo or hetero-dinuclear and tetranuclear lanthanide complexes likely to furnish in future coordination complexes useful in quantum computing. [ABSTRACT FROM AUTHOR]

The reaction of neutral “half-unit” copper azido complexes, made of “half-unit ligands” resulting from a monocondensation of different diamines with an aldehyde function and of end-on azido ligands, with diverse gadolinium or sodium salts, is not straightforward. The resulting complexes are mainly homodinuclear copper complexes. Heterodinuclear Cu–Gd complexes devoid of azido bridges necessitate use of gadolinium nitrate or gadolinium hexafluoroacetylacetonate. A heterotrinuclear Cu–Na–Cu by-product in which the Cu and Na ions are linked by double phenoxo-end-on azido bridges has also been structurally characterized. The decrease of the acidic character of positive ions in protic solvents in going from naked gadolinium to gadolinium nitrate, gadolinium complex and to sodium ions can explain the diverse reaction pathways and formation of the different final products. [ABSTRACT FROM AUTHOR]

Two new heterodinuclear Ni–Gd complexes with Ni–(O 2 )–Gd cores, a practically planar one and a highly distorted one, are reported and structurally characterized. DFT calculations allow calculation of the J NiGd interaction parameters, in good agreement with the experimental data. It has been previously shown in such dinuclear complexes with double-phenoxo bridges that the hinge angle, defined as the angle between the O Ni O and O Gd O planes and the Ni–O–Gd angles, involving the bridging oxygen atoms and the metal ions, play a major role in the value of the resulting magnetic interaction. We demonstrate with help of DFT calculations that these parameters are not sufficient to understand the magnetic interaction change observed in the distorted Ni–(O 2 )–Gd core. This work allows to explain why tripodal ligands yielding face-sharing 3d–Gd complexes with three phenoxo bridges give J NiGd values lower than in planar edge-sharing 3d–Gd complexes. Eventually these geometric changes do not favor the SMM properties of the corresponding Ni–Dy dinuclear complex. [ABSTRACT FROM AUTHOR]

1 H and 13 C NMR studies demonstrate that in a reaction involving a Zn–La complex and piperidine as an organic base, a 1-piperidinecarboxylate unit is formed in situ and assimilated by the complex as a ligand. Existence of this ligand is confirmed by structural determinations of two related Ni–Gd and Ni–Tb complexes. We highlight that the observed capture of the CO 2 derivative is not metal or ligand dependent but that the presence of a base in the reaction medium is the key parameter of the assimilation of CO 2 by 3d–4f bimetallic complexes. The propensity of amines for carbonatation is responsible for the formation of these anionic ligands, while the 3d–4f complexes act only as trapping entities. [ABSTRACT FROM AUTHOR]

Abstract: The cutting forces are often modelled using edge discretisation methodology. In finish turning, due to the smaller corner radii, the use of a local cutting force model identified from orthogonal cutting tests poses a significant challenge. In this paper, the local effect of the corner radius r ɛ on the forces is investigated using a new experimental configuration: corner cutting tests involving the tool nose. The results are compared with inverse identifications based on cylindrical turning tests and elementary cutting tests on tubes. The results obtained from these methods consistently show the significant influence of the corner radius r ɛ on the cutting forces. [Copyright &y& Elsevier]

Abstract: The template effect involves two main effects, first the “kinetic template effect”, in which a metal ion is able to hold two reactive functions in a position that allows a reaction to occur, followed by the “thermodynamic template effect” that favours the formation of a thermodynamically more stable product resulting from the reaction. Through the preparation of a non symmetric Schiff base, we highlight the primordial role of the “kinetic template effect”. Very often, this kinetic effect is not easy to evidence, the resulting complex being too reactive to be isolated. In the present example, the use of an ambidentate ligand, pyrrole carboxaldehyde, has been quite interesting. Reaction of a cationic copper complex possessing a primary amine function coordinated to the copper ion with pyrrole carboxaldehyde can yield two different complexes, depending on the reaction conditions. In absence of a base, the structural determination shows that the copper ion is linked in apical position to the carbonyl oxygen atom of pyrrole carboxaldehyde and the two reactive aldehyde and amine functions are unable to react, as a consequence of their mutual coordination to copper. On the contrary, addition of a base to the reaction mixture induces deprotonation of the pyrrole function followed by its coordination to copper ion, leaving free the carbonyl carbon atom that can be positioned in the vicinity of the primary amine function, thus facilitating the formation of a new imine function. The resulting thermodynamically stable complex is characterized by X-ray diffraction. [Copyright &y& Elsevier]

Abstract: The synthesis of two mononuclear precursor copper complexes, [(HL2)2Cu], 1, and [(HL3)2Cu]·H2O, 2, and three dinuclear Cu–Ln complexes, [(HL1)2Cu(CH3CN)2Gd(NO3)3], 3, [(HL3)2CuGd(NO3)3]·2(H2O), 4, and [(HL3)2CuTb(NO3)3]·2(H2O), 5, based on the ligands H2L1 (4-bromo-2-[1-(5-bromo-2-hydroxy-3-methoxybenzyl)-1H-benzimidazol-2-yl]-6-methoxyphenol), H2L2 (2-(1H-benzimidazol-2-yl)-4-bromo-6-methoxyphenol) and H2L3 (2-(1H-benzimidazol-2-yl)-6-methoxyphenol) are described in this contribution. The X-ray crystal structures of H2L2, 1, 3, 4, and 5 have been solved. The novel ligand H2L2 crystallizes with two independent molecules in the asymmetric unit; several intermolecular hydrogen contacts connect alternate independent H2L2 molecules into chains developing along c. In complex 1, two (HL2)− ligands chelate the copper ion through their imidazolyl nitrogen and phenoxo oxygen atoms, in a relative head to tail arrangement. The molecular structure of 3 is similar to those of the previously reported Cu–Ln complexes of H2L1. In the isostructural complexes 4 and 5, two HL3 ligands sandwich one Cu2+ ion through their N,O sites and one Ln3+ ion through their O2 site, implying a relative head to head arrangement, at variance with the relative head to tail arrangement of HL2 in the mononuclear copper precursor 1. The magnetic properties of 1, 3, 4, and 5 have been investigated. Extended intermolecular antiferromagnetic interactions operate in complex 1 ((J Chain =−0.8(1)cm−1). Ferromagnetic interactions between Gd (S =7/2) and Cu (S =1/2) centers operate in complexes 3 and 4, leading to an S =4 ground state (J CuGd =7.2(2)cm−1 for 3 and J CuGd =6.5(2)cm−1 for 4). Depopulation of the Tb Stark levels, preclude obtaining reliable information on the presence and sign of the Cu–Tb interaction in 5. These new complexes are complementary to those previously reported: the Cu–O2–Gd core is planar while deformations are borne by the ligands at variance with previous examples where the constraints were located at the Cu–O2–Gd core. The presence of two independent ligands in the Cu,Gd coordination spheres confers a degree of freedom greater than that allowed by a unique tetradentate ligand. As a result, the strength of the magnetic interaction is not solely related to the dihedral angle between the CuOO and GdOO planes in the central core. [Copyright &y& Elsevier]

Abstract: Salen-type Schiff base ligands possess a N2O2 coordination site able to chelate transition metal ions. Reaction of such a ligand with FeCl3·6H2O leads to the formation of a genuine dinuclear L3Fe2 complex in which the ligand plays a double role. The structural determination confirms that each iron ion is wrapped up by a chelating tetradentate ligand while the third one ensures a bridge in between the two Fe ions and completes to six the metal coordination sphere. Such a bridge implies a non planar coordination of the chelating ligands and induces helicity around each metal ion. Crystals are true racemates made of homochiral Λ–Λ and Δ–Δ pairs. The magnetic study confirms the absence of a spin exchange interaction through the saturated diamino chain and the presence of an axial single ion zero field splitting (ZFS) D equal to −0.7cm−1. The Mössbauer spectra show a unique asymmetric quadrupole-split doublet with isomer shift values, δ, of 0.342(2), 0.438(2) and 0.450(2)mms−1, and quadrupole splittings, ΔE Q, of 0.826(4), 0.836(4) and 0.827(4)mms−1 at 293, 80 and 4.5K, respectively. These values are in agreement with a high-spin iron(III) site in a N3O3 ligand environment. [Copyright &y& Elsevier]

Abstract: We demonstrate with the help of structural determinations and spectroscopic data that the nuclearity of Cu–Ca complexes derived from compartmental Schiff base ligands does not depend on the ionic radius of calcium. The main factors governing these reactions are the different affinities of the calcium ions for the anionic species present in solution: the tetradentate O2O2 coordination site of the ligand and the nitrato ions. Because these affinities do vary upon going from calcium to lanthanide ions, it is not possible to use the template effect of the trinuclear Cu–Ca–Cu complexes in order to prepare the corresponding Cu–Ln–Cu complexes. [Copyright &y& Elsevier]

155Gd Mössbauer spectra highlight existence of a pure and unique heterodinuclear Gd–Eu complex involving two consecutive Ln ions of the periodic table. Use of 155Gd Mössbauer spectroscopy allows a straightforward characterization of heterodinuclear Ln-Ln′ complexes (LLnLn′ (NO 3) 3 ·(H 2 O) 2) with a tripodal ligand L, possessing two different N 4 O 3 and O 3 O 3 coordination sites. Thanks to the isomer shift value, the location of the GdIII ion is confirmed; the Gd atom in the Gd–Ln′ series (Ln′ = Ce, Nd, Eu) occupies the inner N 4 O 3 site with a eight-coordination (N 4 O 3 + O), but on the other hand the Gd atom in the Ln–Gd series (Ln = Dy, Er, Yb) resides in the outer O 3 O 3 site with a ten-coordination (O 3 O 3 + O 2 + O 2). The smaller isomer shift values for the former indicate that coordination of the basic nitrogen atoms enhances the 6s orbital population. With the help of 151Eu Mössbauer spectroscopy, we demonstrate that the Gd–Eu entity is a genuine heterodinuclear complex, in which the GdIII ion is located in the inner site and the EuIII ion in the outer oxygenated site. This result highlights the feasibility of our synthetic process described earlier to introduce in a heterodinuclear complex two consecutive ions of the periodic table. And the slow paramagnetic relaxation observed in the 166Er Mössbauer spectrum of the Er–Gd complex confirms presence of a magnetic interaction in the genuine Er–Gd complex. [ABSTRACT FROM AUTHOR]

• There are differences in risk factors for problem gambling between Polish and French gamblers. • Tthe subjective experience of the importance of winning in gambling is significantly related to the gambling patterns / behaviors. • The significant win experience contributed to problem gambling over other factors. We examined the role of significant win experiences alongside psychosocial factors in the risk of problem gambling. The study involved adult pure-chance gamblers from representative Polish (n = 3143) and French samples (n = 5692). The questionnaire encompassed socio-demographic details, gambling behaviours, significant win experiences, gambling motivation, and problem gambling. Logistic regression analyses unveiled universal and country-specific factors significantly linked to problem-gambling risk. Universal factors comprised gender (lower risk among females), age (higher risk for ages 35+), household income (negative association), current and past debt (positive association), type of gambling game (higher risk for games other than lotteries), and gambling frequency (positive association). Risk factors also encompassed heightened coping and social motivations to gamble, while the financial motivation inversely correlated with risk. Inter-country differences featured significant wins in the player's environment, associated with problem-gambling risk only among the French. Then, only the highest amounts spent on gambling in the French group correlated with problem gambling, while lower amounts in the Polish group also did. Notably, a higher problem-gambling risk was observed in the Polish group compared to the French. A crucial finding was that significant wins were associated with problem gambling, even when controlling for other essential factors. Our study highlights the role of significant wins, construed as subjective gambler experiences, in fostering problem gambling. This insight suggests the need for a paradigm shift in understanding the role of winning in gambling, representing a risky experience regardless of the objective amount gambled. [ABSTRACT FROM AUTHOR]

Abstract: A simple and easy preparation of the hydrogen oxalate ligand (HOOCCOO)−, with only one deprotonated carboxylic function, is described. 13C NMR spectroscopy furnishes a straightforward characterization of this interesting ligand. This ligand coordinates in its monodeprotonated form to a CuII complex with a free coordination position, yielding a complex that presents a very weak antiferromagnetic interaction. In a subsequent step, the second deprotonation allows the isolation of an oxalato-bridged dinuclear CuII complex, which is characterized by structural determination, the copper ions being pentacoordinate in an equivalent centrosymmetry-related environment. DFT calculations show that the magnetic interaction through the oxalato bridge is strictly equal to 0cm−1, demonstrating that the singlet and triplet states of this oxalato-bridged dinuclear CuII complex have the same energy. This dinuclear complex presents a rhombic EPR spectrum, with three well-defined g values, at room temperature as well as at 100K. [Copyright &y& Elsevier]

Abstract: A 1D heterometallic Cr2/Ag2 polymer formulated as {[Ag(μ-H2O)Ag(nta)Cr(μ-OH)(μ-AcO,O′)Cr(nta)]·H2O} n (1) (H3 nta =nitrilotriacetic acid) has been prepared and structurally characterized. {Cr(μ-OH)(μ-OAc)Cr} dimeric units containing two different bridging ligands, hydroxo and acetate groups are coordinated to six Ag atoms forming the 1D network. The temperature dependence of magnetic susceptibility for 1 which was fitted with an isotropic Hamiltonian including biquadratic exchange parameters, yielded antiferromagnetic interaction parameters (J =−8.5(1), j =−0.50(7)cm−1 g=2.0). [Copyright &y& Elsevier]

The reaction of FeCl3 and HL, where HL=C7H8N4S, pyridine-2-carbaldehyde thiosemicarbazone, at physiological pH values in air gives rise to a powder of composition C14H16Cl0.3FeN8O1.2S2 which contains iron(II)– and iron(III)–thiosemicarbazone species. This fact confirms the reducing character of the ligand in neutral and basic media. The [Fe(C7H7N4S)2]·1.25H2O compound has been isolated. The crystal structure consists of discrete monomeric cationic entities containing low-spin iron(II) ions in a distorted octahedral environment. The metal ion is bonded to one sulfur and two nitrogen atoms of each thiosemicarbazone molecule. The powdered X-band EPR spectra of C14H16Cl0.3FeN8O1.2S2 show a significant variation with temperature which can be explained considering an ‘exchange narrowing’ phenomenon, in good accordance with the presence of antiferromagnetic interactions. The Mo¨ssbauer measurements are in good agreement with the existence of one iron(II) and two iron(III) low-spin species, with relative areas of 69, 17 and 14%, respectively. [Copyright &y& Elsevier]

• A constitutive model including the most relevant parameters affecting the mechanical behavior (plasticity and damage) of Ti6Al4V titanium alloy in metal cutting (i.e. the state of stress and the strain-rate) is proposed. • Special specimens' design to generate a wide range of states of stress (i.e. triaxiality and Lode angle) in mechanical testing, which are representative of metal cutting process. • Higher accuracy of the determination of the coefficients of the constitutive model using the developed optimization-based procedure. • The accuracy of the proposed model to represented mechanical behavior of the Ti6Al4V titanium alloy under different state of stresses was confirmed when its results were compared with those obtained experimentally. The predictability of manufacturing process simulation is highly dependent on the accuracy of the constitutive model to describe the mechanical behavior of the work material. The model should consider the most relevant parameters affecting this behavior. In this study, a constitutive model for Ti6Al4V titanium alloy is proposed that considers both material plasticity and damage. It includes the effects of strain hardening, strain-rate and the state of stress to represent the mechanical behavior of Ti6Al4V titanium alloy in metal cutting simulation. To generate states of stress and strain rates representative of this process, mechanical tests were performed using a specific experimental setup. This included a specimen geometry designed to generate different states of stress, as well as a digital image correlation technique to obtain the strains during the mechanical tests. For the determination of the coefficients of the constitutive model, the yield stress and fracture locus obtained from these tests were used in an optimization-based procedure. To verify the accuracy of the proposed constitutive model to represent the mechanical behavior of the Ti6Al4V alloy under different states of stress, force–displacement curves obtained using this model and the Johnson-Cook model are compared with the curves obtained experimentally. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Carbon Fiber-Reinforced by Plastic (CFRP) is now commonly used in the aircraft industry. The main challenge is to manufacture this difficult-to-cut work material, considering its quality criteria and economical aspects. Drilling is the main machining operation required for the assembly of the aircraft structure. In this paper, results are presented and discussed regarding exit delamination studied at a local scale. Because of the anisotropic properties of CFRP, the fiber cutting modes change with the composite sequence combined with the drill revolution parameters. The local feed forces generated by the cutting edge on the hole bottom may be correlated with delaminating aspects. A posttreatment method is proposed to analyze precisely these feed force and cutting torque distributions. Appropriate ply sequences are identified in order to limit the mechanical load concentration and the risk of delamination or uncut fibers [ABSTRACT FROM AUTHOR]

Reaction of the present complex with GdIII ions yields a tetranuclear [Cu-Gd] 2 entity but does not allow to keep the stereogenic Cu centre present in the starting CuII complex. [Display omitted] The present work confirms the difficulty to prepare main ligands able to coordinate 3d and 4f ions and to bring asymmetric centres in the vicinity of the Ln ions. Although our two first examples were not realized with pure enantiomers, we have shown that introduction of 3d ions in these ligands was possible but problems arise with the complexation of the LnIII ions. Due to these difficulties, we used an original reaction pathway. A trianionic ligand possessing one amide, one imine, two phenol functions reacts with CuII ions to yield an anionic complex that crystallizes in a non-centrosymmetric space group, due to the presence of a stereogenic CuII centre. Further reaction with LnIII ions in presence of ancillary ligands yields tetranuclear complexes made of two LCuGd units in a head-to-tail arrangement. Ferromagnetic Cu-Ln interactions, resulting from an alternate distribution of the CuII and LnIII ions, are the only ones to be active. But this tetranuclear complex is no more chiral, the conformation change of the ligand diamino chain around one CuII ion yielding two CuII ions of opposite chiralities. [ABSTRACT FROM AUTHOR]

Abstract: Two heterometallic complexes [{Cu(phen)2}2{Cr2(μ-OH)2(nta)2}][Cr2(μ-OH)2(nta)2]·8H2O (I) and [{Cu(phen)2}2{Ga2(μ-OH)2(nta)2}][Ga2(μ-OH)2(nta)2]·dmf·16H2O (III), where nta is the nitrilotriacetate ligand and dmf is dimethylfomamide, phen is ο,ο′-phenanthroline, have been prepared and structurally characterized by single-crystal X-ray crystallography. Both compounds display an ionic type structure, with close geometric parameters, containing {Cr2(μ-OH)2(nta)2} and {Ga2(μ-OH)2(nta)2} entyties for I and III, respectively. These dimeric di-μ-hydroxy units exhibit different coordination functions. In the tetranuclear Cu2Cr2 and Cu2Ga2 complex cations they are involved in a bidentate bridging form being linked to the cooper atoms through two symmetrically related oxygen atoms of the carboxylate groups. The anionic forms [Cr2(μ-OH)2(nta)2]2− and [Ga2(μ-OH)2(nta)2]2− are non-coordinating and only involved in a multiple hydrogen bonds architecture. Comparative analysis of the temperature dependence of EPR spectrum and magnetic susceptibility of compound I and III, showed that the magnetic properties of tetranuclear cluster [{Cu(phen)}2Cr2(OH)2(nta)2] are dominated by strong antiferromagnetic interaction between chromium ions (Jiso CrCr =−13.4cm−1). The interaction between chromium(III) and copper(II) ions via syn–anti carboxylic groups has a small antiferromagnetic values (Jiso CrCu =−0.23cm−1). The small anisotropy of the exchange interaction between chromium ions manifests itself only in the EPR spectra. [Copyright &y& Elsevier]