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International audience; The iridium tetrahydride complex Cp*IrH 4 reacts with a range of isobutylaluminum derivatives of general formula Al(iBu) x (OAr) 3−x (x = 1, 2) to give the unusual iridium aluminum species [Cp*IrH 3 Al(i Bu)(OAr)] (1) via a reductive elimination route. The Lewis acidity of the Al atom in complex 1 is confirmed by the coordination of pyridine, leading to the adduct [Cp*IrH 3 Al(i Bu)-(OAr)(Py)] (2). Spectroscopic, crystallographic, and computational data support the description of these heterobimetallic complexes 1 and 2 as featuring strongly polarized Al(III) δ+ −Ir(III) δ− interactions. Reactivity studies demonstrate that the binding of a Lewis base to Al does not quench the reactivity of the Ir−Al motif and that both species 1 and 2 promote the cooperative reductive cleavage of a range of heteroallenes. Specifically, complex 2 promotes the decarbonylation of CO 2 and AdNCO, leading to CO (trapped as Cp*IrH 2 (CO)) and the alkylaluminum oxo ([(iBu)(OAr)Al(Py)] 2 (μ-O) (3)) and ureate ({Al(OAr)(i Bu)[κ 2-(N,O)AdNC(O)-NHAd]} (4)) species, respectively. The bridged amidinate species Cp*IrH 2 (μ-CyNC(H)NCy)Al(i Bu)(OAr) (5) is formed in the reaction of 2 with dicyclohexylcarbodiimine. Mechanistic investigations via DFT support cooperative heterobimetallic bond activation processes.

International audience; Utilizing the osmotic swelling of Layered Double Hydroxides (LDHs, [Mg1-xAlx(OH)(2)](x+)(NO3-)(x)) in formamide, the anionic luminescent complex [(ThiaSO(2))(2)(Mn-II)(4)F](-) (ThiaSO(2) = p-tert-butylsulfonylcalixarene) is introduced between the positive layers, leading to doping of LDH. In the recovered LDH layers, the hexagonal prism morphology of the precursor is well retained. The formula of the resulting compound (Mg0.71Al0.29(OH)(2)(NO3)(0.288)((ThiaSO(2))(2)(Mn)(4)F)(0.002)(H2O)(0.5)) (1) was determined by elemental and thermogravimetric analysis. The low doping rate is attributed to the low negative charge density (e angstrom(-2)) of the complex. The basal spacing of 12.02 angstrom indicates that [(ThiaSO(2))(2)(Mn-II)(4)F](-) is sandwiched across the width by positive LDH layers. The photophysical properties of compound 1 were studied in the solid state. 1 presents luminescence properties upon UV excitation, with the emission maximum centered at 630 nm and 650 nm in the presence and the absence of atmospheric O-2, respectively. Photophysical studies have been carried out under different atmospheres and using various excitation wavelengths. The relationship of the extinction of emission with the presence of molecular oxygen is reported, and demonstrates the very high sensitivity of this compound to oxygen. Finally, incorporation of the luminescent complex within the LDH host allows the O-2-sensitivity to remain similar to that observed in solution whilst avoiding photo-degradation, thereby opening perspectives for use in oxygen sensing or singlet oxygen generation.

International audience; In the present work, a combined experimental and computational study of three new DHA chelates namely [Co(DHA)2.2DMSO] (1), [Ni(DHA)2.2DMF] (2) and [Zn (DHA)2.2DMF] (3), (DHA = 3-Acetyl-4-hydroxy-6-methyl-2-oxo-2H-pyran) is reported. Synthesized compounds are characterized by FT-IR which indicates the metal coordination via both oxygen atom, while single-crystal X-ray crystallography confirms the chelates structure as mononuclear complexes having a distorted octahedral coordination geometry of type MO6 with intermolecular C–H⋯O bonds. Structures and electronic properties investigated in the framework of the density functional theory (DFT) are in good agreement with experimental results. Besides, a comparative evaluation of in vitro antibacterial potential of DHA and derivatives exhibits better results for DHA free ligand, even close to the effect of antibiotics used as references, highlighting the role of hydroxyl function in case of this application.

The new compounds 4-decyloxy-2-fluorobenzoic acid and 4-dodecyloxy-2-fluorobenzoic acid display hydrogen-bonded liquid crystals (HBLC) of smectic and nematic phases. Their phase behavior established using polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) consistently occurs as the sequence upon cooling: Isotropic liquid – Nematic – SmC – crystalline solid. The dielectric study in the nematic phase shows a single relaxation process at low frequency characteristic of a cybotactic nematic phase. The optical properties of the nematic phase show a decrease of birefringence as alkyl chain length increases in the high-temperature part of the nematic domain, which reveals a decrease of order parameter for longer chains.

International audience; Whereas the synthesis of the $anti$-cryptophane-A (1) derivative is known for nearly 40 years, the preparation of its diastereomer (cryptophane-B according to Collet's nomenclature) has never been reported. Thus, the synthesis of the cryptophane-B derivative represents a real challenge for chemists interested in the preparation of these hollow molecules. Herein, we describe a synthetic route that allows us to prepare cryptophane-B (2), however in low yield. The X-ray crystallographic structure of this compound is described and it reveals the presence of an ethanol molecule inside the cavity of the host. Finally, the ability of cryptophane-B to bind xenon in 1,1,2,2-tetrachloroethane-$d_2$ is also studied via hyperpolarized $^{129}$Xe NMR

Two new organic-inorganic hybrid compounds, 3-chloroanilinium nitrate (I) and 3-chloanilinium perchlorate (II), have been synthesized by an acid/base reaction at room temperature in the presence of 3-chloroaniline as an organic-structure directing agent and their structures were determined by single crystal X-ray diffraction. Compound I, [C6H7ClN]NO3, crystallizes in the orthorhombic space group Pbca with a = 10.4137(16), b = 9.6232(11), c = 16.059(2) A, V = 1609.3(4) and z = 8. Full-matrix least-squares refinement converged at R = 0.041 and Rw = 0.121. Compound II, [C6H7ClN]ClO4, belongs to the monoclinic system, space group P21/n with the following parameters: a = 10.684(2), b = 7.2667(12), c = 12.229(2) A, β = 104.27(2)°, V = 920.1(3) and z = 4. The structure was refined to R = 0.054 and Rw = 0.102. Both salts form anionic parallel layers alternating with thick slabs of [C6H7NCl]+ organic molecules. Charge balance is achieved by the protonated amine which interacts with the inorganic framework through hydrogen bonding. Solid-state 13C CP-MAS NMR spectroscopy is in agreement with the X-ray structures. Ab initio calculations allow the partial attribution of carbon signals to the various atoms of the organic groups. Electronic properties such as HOMO and LUMO energies were studied by Quantum mechanical evaluation by using the B3LYP/6-31+G* method.

Treatment of 1-(2,5-dimethylphenyl)piperazine and 1-(2,3-dimethylphenyl)piperazine with H2SO4 in 2:1 molar ratio at RT affords the corresponding sulfate salts [C12H20N2][HSO4]2·H2O (SI) and [C12H20N2][HSO4]2 (SII). These compounds have been characterized by X-ray diffraction, thermal analysis and spectroscopic investigations (IR and NMR). In the atomic arrangement of (SI) the HSO4− anions are associated by pairs linked to the water molecules forming corrugated ribbons, while in the (SII) structure, the pairs of the HSO4− anions form corrugated chains. Solid-state 13C and 15N CP-MAS NMR spectroscopies are in agreement with the X-ray structure. The vibrational absorption bands were identified by infrared spectroscopy. NMR peaks were attributed with the aid of DFT calculations. The electronic properties such as HOMO and LUMO energies were determined.

The synthesis, crystal structure and spectroscopic characterization of a new chlorocadmate template by the 1-(2-hydroxyethyl)piperazine ligand are reported. In the atomic arrangement, the CdCl5O entities are deployed in corrugated rows along the a-axis at y = 1/4 and y = 3/4 to form layers parallel to the (a,b) plane. In these crystals, piperazinediium cations are in a chair conformation and are inserted between these layers through N H⋯Cl, C H⋯Cl, O H⋯Cl and N H⋯O hydrogen bonds to form infinite three-dimensional network. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that H⋯Cl and C H⋯H C intermolecular interactions are the most abundant contacts of the organic cation in the crystal packing. The crystal contacts enrichments reveals that, the Cd++ … Cl− salt bridges, the Cd⋯O complexation and O H⋯Cl- and N H⋯Cl-strong H-bonds are the driving forces in the packing formation. The presence of twelve independent chloride anions and four organic cation in the asymmetric unit allowed comparing their contact propensities. The 13C and 15N CP-MAS NMR spectra are in agreement with the X-ray structure. Additional characterization of this compound has also been performed by IR spectroscopy.

International audience; The synthesis, crystal structure and spectroscopic characterization of the novel 1-(2-hydroxyethyl)piperaziniumtrichlorozincate(lI) zwitterionic complex are reported. In the atomic arrangement, the ZnCl3N entities, grouped in pairs, are deployed in rows along the a-axis to form layers parallel to the (a,c) plane. The organic molecules are inserted between these layers through N-H center dot center dot center dot Cl, C-H center dot center dot center dot Cl, O-H center dot center dot center dot Cl and N-H center dot center dot center dot O hydrogen bonds to form infinite three-dimensional networks. Intermolecular interactions were investigated by Hirshfeld surfaces. The C-13 and N-15 CP-MAS NMR spectra are in agreement with the X-ray structure. The vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the NMR peaks and of the IR bands.

A novel organic–inorganic hybrid material, C6H15N2CdCl3.H2O, was synthesized, and its structure was determined at room temperature in the monoclinic space group P21/n with the following parameters: a = 10.3829 (17), b = 7.7459 (12), c = 14.905 (2) A, β = 98.801 (15), and Z = 4. Its crystal structure is characterized by one-dimensional polymeric chains of edge-sharing CdCl5N distorted octahedra. These chains are linked to the water molecules via O H … Cl hydrogen bonds to form layers parallel to the (b, a + c) plane. The crystal structure was stabilized by an extensive network of N H … Cl, O H … Cl and N H … O hydrogen bonds. The differential scanning calorimetry (DSC) reveals that the title compound is stable until 101.6 °C. The optimized geometry parameters, normal mode frequencies, and corresponding vibrational assignments of the present compound were theoretically examined by DFT/B3LYP method with the Lanl2dz basis set. The FT-IR spectrum of the polycrystalline sample was examined and compared to the calculated spectrum. The calculated results showed that the optimized geometry could well reproduce the crystal structure and that the theoretical vibrational frequency values were in good agreement with their experimental counterparts.

The physicochemical properties of a new cyclohexaphosphate, (C9H14N)4(H3O)2(P6O18), prepared by an acid-base reaction between cyclohexaphosphoric acid H6P6O18 and 2,4,6-trimethylaniline, are discussed on the basis of X-ray crystal structure investigation. The crystal structure determination reveals that the complete cyclohexaphosphate anion, with chair conformation, is generated by crystallographic inversion symmetry. The asymmetric unit consists of two organic cations, one half-anion and one hydronium cation. The atomic arrangement can be described by thick layers built by P6O18 anions and H3O+ cations parallel to the (a, b) plane. Each cyclohexaphosphate group is connected to its adjacent neighbors by six hydronium ions through strong O-H...O hydrogen bonds. The protonated amines are located between these successive inorganic layers, in order to balance the negative charge of the inorganic framework by establishing N–H...O hydrogen bonds with the O atoms of the P6O18 anions. The three-dimensional cohesion is assured by different interactions (electrostatic, H-bonds, van der Waals) established between the various molecular components. This compound is also characterized by infrared spectroscopy and solid state MAS-NMR.

A new cyclohexaphosphate with the composition (C 6 H 7 ClN) 6 P 6 O 18 ·0.5(H 2 O) has been synthesized at room temperature in the presence of 4-chloroaniline as organic template and investigated by various physicochemical techniques. Its unit cell is triclinic P-1 with parameters a = 9.0054(8), b = 10.1053(9), c = 16.4454(14) A, α = 100.476(7), β = 93.485(7), γ = 115.407(9) °, Z = 2 and V = 1313.0(2)A 3 . The structure involves a network of inorganic parallel layers built up by P 6 O 18 6 − ring anions, NH 3 groups and water molecules. Charge balance is achieved by the protonated amine which is trapped in the interlayer space and interacts with the organic framework through strong hydrogen bonding. The 13 C, 15 N and 31 P CP-MAS NMR spectra are in agreement with the X-ray structure. The vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the NMR peaks.

A novel functionalized Schiff base derivative, (E)-3-(1-(2-(9H-fluoren-9-ylidene)hydrazineyl)ethylidene)-6-methyl-2H-pyran-2,4(3H)-dione, was synthesized via subsequent condensation/tautomerization processes in a high yield. The product was fully characterized using NMR, FT-IR, and single-crystal XRD; the results of DFT simulations were in respectable agreement with crystallographic data. To elucidate the isomerization, the enol↔hydrazinium tautomerism has been pursued theoretically, suggesting an intramolecular single proton transfer (SPT) from enol (O ….H) to the closest NC unit, giving the hydrazine (N–H) via [N+—H ….O−] S (6) zwitterionic intermediate. The results of Hirshfeld surface analysis (HSA) and Molecular electronic potential (MEP) were matching the experimental XRD results. Since a number of hydrogen bonding groups, C–H …. π, and π …. π-stacking interactions were detected experimentally. The optical properties of the desired compound were experimentally and theoretically figure out. The authors acknowledge the Algerian Directorate General for Scientific Research and Technological Development and the Algerian Ministry of Higher Education and Scientific Research, for support of this work. Researchers Supporting Project (RSP-2020/78), King Saud University, Riyadh, Saudi Arabia.

A series of Ti(IV) and Nb(V) complexes with new asymmetric triazine ligands HN3tBuR (R = Et, iPr, tBu) featuring different alkyl substituents at 1,3-N centers was synthesized and characterized by FTIR, 1H and 13C NMR spectroscopy as well as single crystal X-ray structure on a representative titanium complex and then tested for volatility and thermal stability relevant to vapor-phase film growth processes. The niobium complex [Nb(N3tBuEt)(NMe2)4] shows better mass transport properties than the starting reactant [Nb(NMe2)5]2 and thus emerges as a promising precursor for the growth of nitrogen-doped metal oxide films via vapor-phase growth processes.

A new Zn(II) complex with the monodentate ligand methyl-(2-pyridin-2-yl-ethyl)-ammonium, ZnCl3C8H13N2, has been prepared and characterized by single crystal X-ray diffraction. The Zn(II) ion is tetracoordinated by one nitrogen atom of organic ligand and three chlorine ligands. In the atomic arrangement, the ZnNCl3 tetrahedra form corrugated chains extending along the b-axis. The organic entities are located between these chains through N-H···Cl, C-H···Cl and C-H···N hydrogen bonds to form layers parallel to (b, c) plan. Among these hydrogen bonds two are bifurcated.

The synthesis crystal structure and photophysical properties of the new compound {[}Mn 4(ThiaSO(2))(2)F]{[}K(18 crown 6)] ThiaSO(2) = p tert butylsulphonylcalix{[}4]arene are presented and compared to the ones of {[}Mn 4(ThiaSO(2))(2)F]K. The strong orange luminescence is attributed to the Mn2+ centred T 4(1) >(6)A(1) transition. Its temperature and pressure dependence and quenching by molecular dioxygen are reported. The latter is attributed to energy transfer from the T 4(1) state exciting dioxygen to its (1)Sigma(+)(g) state. In the solid state the quenching is much more efficient in {[}Mn 4(ThiaSO(2))(2)F]{[}K(18 crown 6)] than in {[}Mn 4(ThiaSO(2))(2)F]K. This is attributed to the open pore structure of the former allowing fast diffusion of dioxygen into the crystal lattice.}}}}}}}

The effect of phthalocyanine macrocycle distortion on its spectroscopic and packing properties is studied, by comparing two phthalocyanines octa-non-peripherally substituted by alkanethiols of different bulkiness (n-hexyl and tert-butyl). Their X-ray structures evidence their core shape, respectively planar and strongly distorted, inducing a 55 nm shift of their maximum absorption wavelength. Comparison of frontier orbital energies revealed that this distortion decreases the conjugation potency of the benzo rings to the central pyrrolic rings. Also the tert-butyl derivative presents a MOF-like porous crystalline assembly with 22.2% void.

International audience; The synthesis and the X-ray structure of the Zn(II) zwitterionic complex:1-ethylpiperaziniumtrichlorozincate (II) are described. In the atomic arrangement, the ZnCl3N entities, grouped in pairs, are deployed along the b-axis to form layers. The organic entities are inserted between these layers through Nsingle bondH⋯Cl and Csingle bondH⋯Cl hydrogen bonds to form infinite three-dimensional network. The 3D Hirshfeld surfaces were investigated for intermolecular interactions. The optimized geometry, Mulliken charge distribution, molecular electrostatic potential (MEP) maps and thermodynamic properties have been calculated using the Lee-Yang-Parr correlation functional B3LYP with the LanL2DZ basis set. The HOMO and LUMO energy gap and chemical reactivity parameters were made. The 13C and 15N CP-MAS NMR spectra are in agreement with the X-ray crystal structure. The vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the NMR peaks and of the IR bands.

International audience; We report the laser-polarized 129 Xe and 1 H NMR spectra of a series of cryptophane derivatives that differ only by the number of methoxy groups attached on their benzene rings and the arrangement syn or anti of the linkers (compounds 6a-s, 9a-s, 12a-s). All these compounds bind xenon even though the characteristic signal of the gas encapsulated in the cavity of the cage-molecule cannot be always detected. Interestingly, the exchange dynamics of xenon strongly depends on the degree of substitution and is different from that of the cryptophane derivatives studied previously. In solution, the 1 H NMR spectra of these derivatives show the presence of different conformations in a slow exchange regime that can be explained by a decrease of the flexibility of their skeleton. Thanks to 129 Xe-1 H dipolar cross-relaxation (SPINOE) spectra we demonstrate that a single conformation present in solution can bind xenon.

The chemical preparation, crystal structure and spectroscopic characterization of [C 9 H 28 N 4 ][Bi 2 Cl 10 ].H 2 O have been reported. This compound crystallizes in the monoclinic system in space group P21/c and cell parameters a = 12.2385 (6), b = 17.3062 (7), c = 13.0772 (6) A, β = 104.475 (5)°, Z = 4 and V = 2681.9 (2) A 3 . Its crystal structure has been determined and refined to R = 0.049, using 5848 independent reflections. The atomic arrangement can be described by an alternation of organic and inorganic layers. The inorganic layer built up of [Bi 2 Cl 10 ] 4– bioctahedra arranged in sandwich between the organic layer. The organic groups are interconnected by the water molecules through N-H…O(W) hydrogen bonds to form infinite zig-zag chains spreading along the b -axis. These Chains are themselves interconnected by means of the N–H…Cl hydrogen bonds originating from [Bi 2 Cl 10 ] 4– anions, to form a three-dimensional network. Intermolecular Cl…Cl interactions between adjacent dimeric [Bi 2 Cl 10 ] 4– anions have been observed . The compound was also characterized by FT-IR and Raman spectrscopies.

The octupolar cube, a T-d symmetry cube presenting alternating charges at its corners, is the generic point charge template of any octupolar molecule. So far, transposition into real molecular structures has yet to be achieved. We report here a first step toward the elaboration of fully cubic octupolar architectures. A series of octupolar bis(2,3,16,17-tetra(hexylthio)phthalocyaninato)lanthanide double-decker complexes [Pc(2)Ln], Ln = Nd (1), Eu (2), Dy (3), Y (4), and Lu (5), are described, whose original three-dimensional structures display the required alternation of ABAB type for one face of the cube and the delocalization between the two rings approximating to the electronic interaction along the edges of the cube. Synthesis, X-ray crystal structure, and study of the optical properties and of the first molecular hyperpolarizability beta are reported. The size of the lanthanide (III) central ion modulates the ring-to-ring distance and the degree of coupling between the two phthalocyanine rings. As a consequence, the optical properties of these octupolar chromophores and in particular the strong near-infrared absorption due to the intervalence transition between the two rings also depend on the central lanthanide (III) ion. The first oxidized and reduced states of the complexes, while keeping a similar octupolar structure, display considerably changed optical properties compared to the neutral states. Second-order nonlinear properties were determined by nonpolarized harmonic light scattering in solution at 1907 nm. Exceptionally large dynamic molecular first hyperpolarizabilities root (1907), among the highest ever reported, were found that showed a strong dependence on the number of 4f electrons.

In this paper, we report the synthesis and description of a new family of polynuclear cobalt(II) complexes. Starting from the same initial compounds but varying the reaction time results in the formation of several new clusters, an original structure based on [Co14][Co4] clusters was obtained, representing the first one-pot synthesis of a cobalt aggregate salt reported in the literature. The synthesis and magnetic properties of these cobalt compounds are discussed. Three of them display a binuclear molecular structure (1–3) with two encapsulated CoII ions and show slow relaxation of magnetization at small applied magnetic field (Ueff = 10.7 K for 2 and Ueff = 20.3 K for 3), a characteristic of single-molecule-magnet materials.

The crystal structure of {aquaimidazole[2-(2-carbamoylhydrazone)-propionato]}copper(II) nitrate [Cu(L)Im(H2O)]NO3 (I), where HL is the semicarbazone of pyruvic acid, Im is imidazole, is dtermined. The crystal structure of I contains two independent complexes IA and IB in which copper atoms coordinate once deprotonated tridentate HL, imidazole, and water molecules. Outer spheres of the complexes contain nitrate ions. In the compounds studied the coordination polyhedron of the copper atom is a distorted tetragonal pyramid. Its base is composed of carboxyl and carbamide oxygen atoms, azomethine nitrogen of monodeprotonated HL molecules, and the imidazole nitrogen atom. In the crystal, nitrate ions and imidazole molecules link the complexes via hydrogen bonds into 2D networks parallel to the (010) plane. These networks in turn are in pairs arranged into layers along the [010] direction due to hydrogen bonds between water molecules and oxygen atoms of nitrate ions, and also by water molecules and O3 atoms of the neighboring 2D networks. In the crystal, the π-π stacking interaction is observed between the imidazole rings from different layers and there is also a N-O…Cg (π ring) interaction inside the layers.

The title compound crystallized with two independent mol­ecules in the asymmetric unit. Each mol­ecule has three stereogenic centres with configurations 2(S), 3(S) and 4(R), confirmed by resonant scattering., The title compound, C15H18ClN5O2, crystallizes with two independent mol­ecules (A and B) in the asymmetric unit. In both mol­ecules, the isoxazolidine rings have an envelope conformation with the O atoms at the flap positions. Each mol­ecule has three stereogenic centres with configurations 2(S), 3(S) and 4(R), confirmed by resonant scattering. Their conformations are significantly different, for example in mol­ecule A the phenyl ring is inclined to the triazole ring by 32.5 (2)°, while in mol­ecule B the corresponding dihedral angle is 10.7 (2)°. In the crystal, the A and B mol­ecules are linked via an N—H⋯O and a C—H⋯O hydrogen bond. These units are linked by C—H⋯O and C—H⋯N hydrogen bonds, forming slabs parallel to the ab plane. There are C—H⋯π inter­actions present within the slabs.

The synthesis and characterization of two new binuclear compounds [{Fe(dpia)(NCS)2}2(bpac)]·nCH3OH [n = 0 (1) and 2 (2), dpia = bis(2-picolyl)amine, bpac = 1,2-bis(4-pyridyl)ethyne] are reported. The magnetic susceptibility measurements of the compounds revealed different types of magnetic behavior. Complex 1 displays a two-step spin crossover (SCO) that suggests the occurrence of a mixed [HS–LS] (HS = high spin, LS = low spin) pair at the plateau temperature (145 K), at which about 50 % of the complexes undergo a thermal spin conversion. The high-temperature step is very gradual, whereas the low-temperature step shows a first-order spin transition with a hysteresis width equal to 17 K. Compound 2 manifests a relatively abrupt one-step spin change with a narrow hysteresis of 4 K. The single-crystal X-ray structure of 1 was solved for the [HS–HS] complex at room temperature. Compound 2 was structurally characterized in both [HS–HS] and [LS–LS] spin states at 290 and 110 K. The magnetic and structural characteristics of 1 and 2 were compared with previously reported related binuclear compounds with 4,4′-bipyridine and 1,2-bis(4-pyridyl)ethene spacer ligands. This analysis confirms a recently proposed idea about the key role of the [FeN6] core structural distortions, which are caused by crystal packing and strain effects of terminal and/or bridging ligands, in the spin-crossover behavior of binuclear complexes. This study also revealed the predominant role of inter- vs. intramolecular interactions in the spin transition cooperativity.

Ternary iron silicide aluminide γ-Al3FeSi crystals were grown from two Al—Fe—Si melts quenched in cold water. The crystal structures were determined from single-crystal X-ray data: trigonal symmetry, space group R-3 (n°148), unit cell parameters a = 10.2223(2) Å, c = 19.6791(4) Å (V = 1781 Å3) for the Si-poorer crystal and a = 10.1987(2) Å, c = 19.5320(3) Å (V = 1759 Å3) for the Si-richer one. The structure of γ-Al3FeSi may be described in terms of Al-cubes connected together by Al—Al pairs. The structure contains also Al cuboctaedra with one Fe—Al mixed atom in the center. The average chemical formula obtained from the refinements is Al3FeSi. This phase shows a partial disorder on the aluminium network because of the substitution of aluminum atoms by silicon. This substitution mechanism is at the origin of the large homogeneity range of this phase.

Hydrated alkaline earth metal salts of 5-amino-1H-tetrazole (B) were synthesized by reaction of B with a suitable metal hydroxide in water. All compounds were fully characterized by analytical (elemental analysis and mass spectrometry) and spectroscopic (IR, Raman, 1H and 13C NMR) methods. Additionally, the crystal structures of the magnesium [1·4H2O: triclinic, P, a = 5.940(1) A, b = 7.326(1) A,c = 7.383(1) A, α = 106.10(1)°, β = 106.51(1)°, γ = 111.85(1)°, V = 258.0(1) A3], calcium [2·6H2O: monoclinic, P21/m, a = 6.904(1) A,b = 6.828(1) A, c = 10.952(2) A, β = 94.50(2)°, V = 514.6(1) A3], and strontium [3·6H2O: orthorhombic, Cmcm, a = 6.987(1) A, b = 28.394(2) A, c = 7.007(1) A, V = 1390.3(2) A3] were determined by low temperature X-ray diffraction. Additionally, the (gas phase) structure of the 5-amino-1H-tetrazole anion ([B]–) was also studied by natural bond orbital (NBO) analysis [B3LYP/6-31+G(d,p)]. Lastly, standard tests were used to determine the sensitivity towards impact, friction, and electrostatic discharge of the compounds and the thermal stability was assessed by differential scanning calorimetry (DSC) analysis.

The preparation of a new trisodium triborate, Na(3)[B(3)O(4)(OH)(4)], and its complete characterization in terms of molecular structure and thermal behavior are reported. Synthesis of this compound was achieved either by NaBH(4) hydrolysis or by thermal treatment of Na[B(OH)(4)].2H(2)O. The crystal structure was determined by single-crystal X-ray diffraction. The trisodium triborate crystallized in the monoclinic system (a = 12.8274(6) A, b = 7.7276(4) A, c = 6.9690(3) A, and beta = 98.161(3) degrees ), space group Cc, Z = 2. The structure of Na(3)[B(3)O(4)(OH)(4)] comprised [B(3)O(4)(OH)(4)](3-) polyanions, based on B-O-containing rings with two tetracoordinated boron atoms and one tricoordinated boron atom in the fragments BO(2)(OH)(2) and BO(3), respectively. These polyanions are interconnected by four intermolecular hydrogen bonds and presented a tilt of 10.470(4) degrees compared to the a axis. Thus, they are stacked by rotation of about 180 degrees around an axis defined by the three-coordinated boron atoms and parallel to the c axis. Such polyanions were only observed previously in two synthetic compounds, M(3)[B(3)O(4)(OH)(4)].2H(2)O with M = K and Rb, which were isostructural. The originality of the present work was the synthesis and the description of a different crystallographic structure containing this polyanion. Characteristic peaks ranging from 500 to 1500 cm(-1) and around 3300 cm(-1) highlighted the presence of the B-O rings and hydroxyl groups, respectively. The decomposition temperature T = 155 degrees C was obtained by thermogravimetric analysis, and the following equivalent formula in terms of hydration degree was proposed: NaBO(2).(2)/(3)H(2)O. Na(3)[B(3)O(4)(OH)(4)] decomposed into Na(3)[B(3)O(5)(OH)(2)] in equilibrium with its vapor.

The new complex of Zn(II) with 4-ammino-2,2,6,6-tetramethylpiperidine, [C9H22N2]ZnCl4, has been prepared and characterized by various physicochemical studies. This compound crystallizes in the monoclinic system, with the space group P21/c and the following cell parameters: a = 9.8682(7), b = 7.5164(5), c = 21.019(2) Å, β = 99.003 (7)°, V = 1539.8(2) Å3and Z = 4. The crystal structure was solved and refined to R = 0.024 using 3070 reflections. The atomic arrangement can be described by slightly distorted tetrahedral ZnCl42-anions and 4-ammmonio-2,2,6,6-tetramethylpiperidinium cations holding together by different interactions. The four chlorine atoms of the ZnCl42-tetrahedron are acting as acceptors of hydrogen bonds. The crystal packing is influenced by cation-to-anion N-H…Cl and C-H…Cl hydrogen bonds leading to open framework architecture.

In order to obtain a better anhydrous precursor for various applications in materials science and catalysis, thermal dehydration reactions of Y(TFA)3(H2O)3 (TFA = trifluoroacetate) (A) were investigated. Thermal treatment of A at different temperatures under vacuum (5 × 10−2 mm) for several hours failed to give totally anhydrous yttrium trifluoroacetate (as indicated by IR). Two different complexes, a partially dehydrated [Y(μ,η1:η1-TFA)3(THF)(H2O)]1∞·THF (1) and a partially hydrolyzed [Y4(μ3-OH)4(μ,η1:η1-TFA)6(η1-TFA)(η2-TFA)(THF)3(DMSO)(H2O)] · 6THF (2), were obtained with good and moderate yield, respectively, by crystallization of two different thermally treated batches of A from THF (or THF + DMSO) at room temperature. More efficient dehydration of A could be achieved at 200 °C in a furnace, the obtained anhydrous yttrium tris-trifluoroacetate giving Y(TFA)3(THF)2 (3) on crystallization from THF. All the products were characterized by elemental analyses, FT-IR and 1H NMR spectroscopy as well as thermo-gravimetric analysis. In addition, single crystal X-ray structures are reported for 1 and 2, which show either a terminal (η1 and η2) or bridging (μ,η1:η1) bonding behavior of the TFA ligand.

The atomic arrangement of the title compound, (4-NH2-6-OCH3-C4H3N2)2(H2PO4)2.H2O, can be described by inorganic layers of H2PO4 - anions and water molecules parallel to ab-plane at z = � and z = �, between which organic cations (4-NH2-6-OCH3-C4H3N2) + are located. The crystal packing is influenced by O-H…O, N-H…O, N-H…N and C- H…O hydrogen bonds. All ring atoms of the organic entity are coplanar. The exocyclic N atoms are electron receiving centers, which is consistent with features of imino resonance evidenced by bond lengths.

The crystal structures of chloro-(2-formylpyridinethiosemicarbazono)copper dimethyl sulfoxide solvate (I), bromo-(2-formylpyridinethiosemicarbazono)copper (II), and (2-formylpyridinethiosemicarbazono)copper(II) nitrate dimethyl sulfoxide solvate (III) are determined using X-ray diffraction. In the crystals, complexes I and II form centrosymmetric dimers in which the thiosemicarbazone sulfur atom serves as a bridge and occupies the fifth coordination site of the copper atom of the neighboring complex related to the initial complex through the center of symmetry. In both cases, the coordination polyhedron of the complexing ion is a distorted tetragonal bipyramid. Complex III in the crystal structure forms polymer chains in which the copper atom of one complex forms the coordination bond with the thicarbamide nitrogen atom of the neighboring complex. In this structure, the coordination polyhedron of the central atom is an elongated tetragonal bipyramid. It is established that complexes I–III at a concentration of 10−5 mol/l selectively inhibit the growth of 60 to 90 percent of the cancer tumor cells of the human myeloid leukemia (HL-60).

A series of layered compounds of the formula { [ Mn 2 II ( NITBzIm ) 3 ] ( X ) } n [X = ClO4 (1) or CnH2n+1SO4 with n = 10 (2), 11 (3), 12 (4), 13 (5), 14 (6), 18 (7)] were obtained by the reaction of the 2-(2-benzimidazolyl)-4,4,5,5-tetramethylimidazolidinyl-1-oxy-3-oxide nitronyl nitroxide radical (NITBzImH) with manganese(II) acetate in methanol and by the successive addition of sodium perchlorate or n-alkylsulfate. The crystal structures of all compounds have been established by Rietveld refinement of their X-ray powder diffraction patterns using the previously reported analogue compound { [ Mn 2 II ( NITIm ) 3 ] ( ClO 4 ) } n obtained with 2-(2-imidazolyl)-4,4,5,5-tetramethylimidazolidinyl-1-oxy-3-oxide (NITImH) as model. Accordingly, all compounds contain the 2D cationic framework of the formula { [ Mn 2 II ( NITBzIm ) 3 ] + } n exhibiting a honeycomb-like structure with alternating manganese(II) ions and radicals and crystallizing in the form of layered compound with perchlorate or n-alkylsulfate anions in between. The series of compounds with n-alkylsulfate anions evidence a linear dependence of the spacing between the layers in respect to the length of the alkyl chain. The variation is small because the chains are almost parallel to the mean plane of the layers. The study of the magnetic behaviors shows that the spacing between the layers deeply influences the magnetic properties. Compounds 1–6 behave as magnets with Curie temperature decreasing when the interlayer spacing increases [52K (1)–30 K (6)]. No 3D ordering was evidenced for compound 7 with larger spacing. A close examination of the magnetization versus magnetic field indicate that compounds 1–6 are a case of weak ferromagnetism due to spin canting within the 2D framework layers. Interestingly, it is found that the canting as well as the interlayers magnetic coupling of dipolar origin increases when the layers come closer. One explanation is that an increase in the dipolar magnetic interaction causes a more accented canting. Alternatively, it may be that when the layers come closer this induces stronger anisotropy through crystal packing effects.

N,N′-Bis[allylamino]glyoxime, N,N′-bis[anilino]glyoxime, and N,N′-bis[1,2,3,4-tetrahydro-5-naphthalenamino]glyoxime have been prepared from corresponding amines and (E,E)-dichloroglyoxime. These ligands gave orange-red compound with NiCl2 in less acidic medium (pH ∼ 5) that are bis(E,E-dioximato)nickel(II) complexes {[(E,E)-Ni(HL)2]} (1a–3a) and green compounds in acidic medium (pH ∼ 2) that are tris(E,E-dioximato)nickel(II) dichloride complexes {[(E,E)-Ni(LH2)3]Cl2} (1b–3b). The crystal structures of all complexes have been determined by X-ray diffraction on a single crystal. The study of absorption spectra of these two types of complexes shows that they may be converted to each other by addition of acids (1a–3a) or bases (1b–3b) and there is no way for the amphi form.

We report here on the synthesis and characterisation of a first iron(II) spin-crossover coordination polymer with the dca spacer ligand, having the formula [Fe(aqin)2(dca)]ClO4.MeOH (aqin=8-aminoquinoline, dca=dicyanamide), which displays a two-step complete spin transition. Variable-temperature magnetic susceptibility measurements and Mössbauer spectroscopy have revealed that the two relatively gradual steps are centred at 215 and 186 K and are separated by an inflection point at about 201 K, at which 50 % of the complex molecules undergo a spin transition. The two steps are related to the existence of two crystallographically inequivalent metal sites, as confirmed by the structural and Mössbauer studies. The crystal structure was resolved at 293 K (HS form) and 130 K (LS form). Both spin-state structures belong to the triclinic P1 space group (Z=2). The complex assumes a linear chain structure, in which the active iron(II) sites are linked to each other by anionic dicyanamide ligands acting as chemical bridges. The Fe-Fe distances through the dca ligand are 8.119(1) and 7.835(1) A in the high-spin and low-spin structures, respectively. The polymeric chains extend along a (1, 0, -1) axis and are packed in sheets, between which the perchlorate anions and methanol molecules are inserted. The complex molecules are linked together by pi-stacking interactions and H-bonding between the H-donor aqin ligands and the perchlorate ions. These structural features provide a basis for cooperative interactions in the crystal lattice. Analysis of the two-step spin-crossover character in this compound suggests that covalent interactions through the spacer ligand do not provide the main mechanism of cooperativity.