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This work presents a simple synthesis of tetraaza macrocyclic Schiff base ligand (C40H28N4), its complex [(C40H28N4)@Fe(II)], and a novel complex of magnetite Fe3O4NPs incorporated inside tetraaza macrocyclic cavity [(C40H28N4)@Fe3O4NPs] in order to obtain well-dispersed nanoparticles. The characterization and structural identification were carried out by 1H NMR, 13C and DEPT 135 NMR spectroscopy as well by X-ray spectroscopy, FT-IR, and finally by ATG using both experimental and theoretical methods. XRD measurements indicate that the presence of Schiff's bases does not modify the crystal structure of the nanoparticles (approximately 11 nm). FT-IR was used to illuminate the presence of Fe3O4NPs in tetrahedral and octahedral sites as well as their coordination with imine (C=N) of tetraaza macrocyclic. The UV–Vis spectra and frontier molecular orbitals (FMOs) of the title compounds were calculated at TD-DFT/CAM-B3LYP-D3/6-311 G (d, p) level of theory. The corresponding calculated results yield shows a good agreement with the experimental data. The morphological characterization of the nanoparticles was carried out by SEM which revealed that the shape of the NPs was generally spherical. The SEM images also show that the nanoparticles prepared by in-situ with co-precipitation method were able to form stable complexes. Thermal characterization by ATG shows that there is 64% of the magnetite nanoparticles formed in-situ which corresponds to a grafting density of 25 mmol.g−1.

International audience; We report in the present paper the synthesis, the spectroscopic, structural, and electrochemical properties of a new magnesium(II) coordination compound namely the bis(4-dimethylaminopyridine)[meso-tetra(p-tolyl)porphyrinato)]magnesium(II) dichloromethane disolvate complex with the formula [Mg(TTP)(DMAP)2]•2CH2Cl2 (I). This species crystallizes in the triclinic crystal system with the centrosymmetric space group P-1. The crystal lattice of (I) is stabilized by C__H…Cg (Cg is the centroid of a phenyl ring) and C__H…Cl intermolecular interactions. Further insights on these weak intermolecular contacts are provided by the Hirshfeld surface analysis. This new Mg(II) porphyrin species was characterized by 1H NMR, IR, fluorescence, UV/Vis spectroscopy and ESI-HRMS mass spectrometry. A cyclic voltammetry investigation of this new metalloporphyrin was also reported. Furthermore, the bioactivity of the H2TTP free base porphyrin, the [Mg(TTP)] starting material and [Mg(TTP)(DMAP)2]•2CH2Cl2 (I) was evaluated in vitro, by examining their inhibitory effect against three strains of Candida viz. C. albicans, C. glabrata and C. tropicalis with MIC values in the range 2.5 to 10 μg.mL−1. The screening of the susceptibility of M. canis and T. rubrum clinical strains on the three porphyrinic derivatives is also reported.

The azobenzene 1-arylazo-2-naphthol has been synthesized and characterized by elemental analysis, 1H NMR, IR and UV–Vis spectroscopies using both experimental and theoretical methods. The MEP, NPA and FMOs have also been performed at the DFT/B3LYP-D3 level with different solvents in order to investigate the solvent's effect. The energetic behavior of the compound has been examined in the gas phase and in solvent media using the integral equation formalism polarizable continuum model (IEF-PCM). Solvents had sligth significant effect on NPA values whereas both molecules hardness and stability decrease along with increasing of the solvent's polarity. Vibrational and absorption analysis showed no significant azo±hydrazone tautomerism. Theorically, the title molecule calculated in Acetonitrile solvent is the most reactive. The observed red shifts are explained by the large extension of the π conjugated system and the blue shifts confirm the appearance of several tautomeric forms of the studied azo-benzene which lead to a marked improvement in photochemical stability. The cation binding properties of azo benzene as absorption sensor for Cu2+, Mg2+, Ni2+ and Zn2+ cations were reported. The highest adsorption energy in both gas and liquid phase corresponds to the complexes Azoic/Ni2+ then in Azoic/Cu2+ and somewhat in Azoic/Zn2+complex. The lowest adsorption energy is given to Azoic/Mg2+ complex. After cations chemisorption on azoic molecule a bathochromic shift is observed in the optical spectra, particularly for Azoic/Ni2+ complex, which is the proof of interaction between azoic compound and mentioned cations. The electronic proprieties and the vibrational spectra can therefore be used to detect the presence of different cations and the azobenzene shows appropriate properties to constitute good cations (Ni2+ and Cu2+) sensors.

A new metalloporphyrin (4,4′-bipyridine)meso-tetrakis(2,4,6-trimethylphenyl) porphyrinato) zinc(II) ([Zn(TMP)(4,4′-bpy)]) (3) was obtained by reacting meso-tetrakis(2,4,6-trimethylphenyl)porphyrinato) zinc(II) [Zn(TMP)] (2) and 4,4′-bipyridine (4,4′-bpy). The starting material meso-tetrakis(2,4,6-trimethylphenyl)porphyrine (H2TMP, 1) as well as complexes (2 and 3) were characterized by the means of microanalysis, 1H NMR, and ESI-MS techniques. The molecular structure of the final complex (3) was also confirmed by single crystal X-ray crystallography. Detailed photo-physical and electrochemical properties of the complexes were also determined. The oxidative degradation ability of complexes (2 and 3) was evaluated and compared against an organic dye (calmagite). When used as catalyst, complex (2) showed better efficiency ~ 48% than the complex (3) (41%). Overall, this work not only explores the ability of metalloporphyrin to degrade organic dyes in aqueous solution, but also showed that the degradation ability of a metalloporphyrin complex can be fine-tuned by varying axial ligand.

International audience; In this study, we report the design and the synthesis of a Schiff base; Anil and its corresponding Boron Difluoride complexe; Boranil. The synthesis procedure was carried out adopting new, optimized reaction conditions. The Boranil dye presents the advantage to be emissive in solution. 1H and 19F NMR along with FTIR confirmed both compound's structure. To gain a better understanding of the solvatochromic behavior of Anil and Boranil, the dependence of the absorption spectra on the solvent's polarity was studied in depth. Thus, UV–Vis spectroscopy was performed in five selected solvents. In addition to the solvent's polarity effect, the influence of BF2 moiety introduction on the molecule's photophysical properties was also evaluated. When examining different absorption spectra, we found that the title fluorescent dye exhibited weak solvatochromic (11 nm in THF) as well as a slight redshift broader and relatively more structured absorption spectra after complexation. Besides, we investigate the obtained key structure–property relationships through DFT and TD-DFT calculations using a 6–311++ G (d, p) basis set. Quantum chemical calculations allowed confirming proposed structures and understanding their electronic structure in larger details. Theoretical results also showed good agreement with the experimental findings. Finally, the frontier molecular orbitals were investigated to illustrate the pi-conjugation and charge transfer effect.

Understanding the interactions of the cage molecules with a variety of invited molecules is getting very important. But, the hydrogen bonds can also play a crucial role in the interaction phenomenon. In this work, natural population analysis (NPA), chemical shifts, and atom in molecules (AIM) analysis have been used to identify the role of hydrogen bonds in the stability of CX[n] molecules. According to our calculation, the 13C NMR spectra are also sensitive to the nature of hydrogen bonds. We note that the DFT calculations have reproduced with a very good agreement, the experimentally observed chemical shifts of CX[4].

International audience; This work focuses on new materials based on the addition of zinc as specifically metal centers for the capture of NO2 gas with DFT calculations. This study aims at the synthesis and the spectroscopic characterizations of the free base meso-tetrakis-,(3,4,5trimethoxyphenyl)porphyrin (H2TTMP) (I), meso tetrakis(3,4,5trimethoxyphenyl)porphyrinato)zinc(II) complex [Zn(TTMP)] (II) and the (4-cyanopyridine) meso-tetrakis - (3,4,5-trimethoxyphenyl)porphyrinato)zinc(II) [Zn(TTMP)(4-CNpy)] (III). X-ray molecular structure of (III) displays that the crystal lattice of the five-coordinated zinc(II) coordination compound, is made up of two dimensional layers parallel to the [0 0 1] direction sustained by CH⋯Cg and Cg⋯Cg π inter and intra-molecular interactions. Notably, the presence of voids of 1.2 Å and a grid of 0.7 Å are located between the 2D layers. DFT calculations on the three porphyrin derivatives were carried out and results indicated an agreement with both IR and UV-vis experimental data. The adsorption behaviors of the toxic NO2 gas molecules on the porphyrin derivatives were investigated using first-principles density functional theory. Based on the MEP of (I)–(III) molecules and the MEP of NO2 and the calculation of the adsorption energies, we suggest that compound (II) has the best attraction. More importantly, after NO2 chemi-sorption on porphyrin derivatives, a remarkable red-shift is observed in the optical spectra, especially for II/NO2 complex, thus offering a good index to detect the binding of NO2. The optical spectra can therefore be used to detect the presence of NO2 and porphyrin derivatives indicate appropriate properties to establish good NO2 sensors.

International audience; The novel compounds (E)‐2‐(((4‐hydroxyphenyl)imino)methyl)phenol, Tetraphenyl (hydroxyl) imidazole and their corresponding Boron difluoride complexes were synthesized and characterized by spectroscopic techniques. Density functional theory calculations at B3LYP‐D3/6–311++G (d, p) level of theory were performed for the geometric parameters. The MEP surface studies were used to understand the behavior of molecules in terms of charge transfer and to determine how these molecules interact. We used the GIAO and the B3LYP‐D3 with a 6–311++ G (d, p) basis set to simulate the (1H‐NMR and 19F‐NMR) and the IR spectra, respectively. The corresponding calculated results are in good agreement with the experimental data. The stability of the molecule arising from hyperconjugation interaction and charge delocalization were analyzed using NBO analysis. FMOs revealed the occurrence of charge transfer within the molecule. The complexation using BF3.Et2O was also found to have remarkable effects on the electrochemical properties of the studied molecules, where (b) and (d) present lower chemical stability, higher reactivity and higher polarizability than (a) and (c), respectively. Moreover, the energy gap of (a) and (c) decreased after complexation using BF3.Et2O, indicating the reliability of the electrochemical evaluation of LUMO and HOMO energy levels. These values are the factors explaining the possible charge transfer interaction within the molecule. The absorption and emission spectra of the model compound were also simulated and compared to experimental observations in the DMF solvent. The results of DFT calculations supported the structural and spectroscopic data and confirmed the structure modification of frontier molecular orbitals for BF2 complexes as well as tunable potentials and energy levels.

The shape, size and diameter of the cavities are one of the main factors which control the interactions of the calix[n]arene molecules with cation, anion or neutral guests in sensor applications. In this work, vibrational spectroscopy analysis, molecular electrostatic potential (MEP) surface, atom in molecules (AIM) and thermochemical properties were used to check the reorganizations of hydrogen bonds in such cavity shape for the improvement of physical proprieties of CX[n] molecules. We have demonstrated that the hydrogen bonds O···H and the angles O–H···O of CX[n = 4, 6, 8] play the role of the moderator or modifier of the cavity. MEP topography reveals that the cavity form of CX[8] is less hydrophilic as compared to those of CX[4] cavity. The QTAIM theory showed that CX[4] and CX[8] has a more symmetric and well-organized cavity than CX[6]. It was also shown that the hydrogen bond enhanced the topographic parameters in CX[n] at the lower edge levels.

International audience; Zinc-phthalocyanines ZnPc derivatives including quinoleinoxy groups have been studied through DFT calculations. The most stable geometries were characterized for the unsubstituted to the tetra substituted ZnPcs. The energy gap decreased from 2.146 eV for ZnPc to 2.050 eV for ZnPcR4, in agreement with the experimental trend, and indicating the reliability of the electrochemical evaluation of LUMO and HOMO energy levels. Optical transitions computed at the CAM-B3LYP-D3 with triple zeta basis sets were found to be in good agreement with experimental values for both the B and Q bands. Subsequently, structures were also characterized for NO2 adsorbed complexes, in order to assess the potential role of ZnPc as a NO2 sensor. A clear sigma bonding chemisorption of NO2 on Zn atom is observed for all derivatives, followed by a charge transfer from the π Pc conjugated system to the Zn-NO2 moiety. More importantly, after NO2 chemisorption on ZnPc derivative a remarkable red-shift is observed in the optical spectra, particularly for NO2/ZnPcR4 complex, thus offering a good index to detect the binding of NO2. The optical spectra and the vibrational spectra can therefore be used to detect the presence of NO2 and ZnPc derivatives show appropriate properties to constitute good NO2 sensors.

In this work, free base meso-tetratolylporphyrin H2TTP (I), meso-tetratolylporphyrinato zinc(II) [Zn (TTP)] (II), and zinc derivative (4.4′diaminodiphenylmethane) (meso-tetratolylporphyrinato) zinc {[Zn (TTP) (DADMP)2]}n (III) were successfully synthesized and characterized. Density functional theory calculations at B3LYP-D3/6-311+G (d, p) level of theory were carried out for geometric parameters. Structures of compounds (I)-(III) were studied using UV–vis, FT-IR, 1H NMR, fluorescence spectroscopy, and ESI Mass Spectrometry. The experimental data displayed good agreement with DFT-calculations results. Natural bond orbital (NBO) confirmed the stability of the obtained molecules from hyperconjugation interaction and charge delocalization. Molecular electrostatic potential (MEP) demonstrated the charge transfer and the way of interaction for (I)-(III). Frontier molecular orbitals (FMOs) showed the occurrence of charge transfer within the molecule. The optical spectra and interaction energy data confirmed a strong interaction between [Zn (TTP)] and DADMP ligand. The single structure of complex (III) indicated a building block, in solid state. The axial ligand (4.4′diaminodiphenylmethane) present as a bridge between adjacent zinc(II) consisted of 1D polymer chain along the [001] direction. The supramolecular was stabilized by weak intermolecular interactions C69–H69 … Cg7. The porphyrin core structure was practically quasi-plane. The optical spectra and interaction energy data proved the strong interaction between [Zn (TTP)] and DADMP ligand.

This paper presents a new technique for detection of dental caries that is a bacterial disease that destroys the tooth structure. In our approach, we have achieved a new segmentation method that combines the advantages of fuzzy C mean algorithm and level set method. The results obtained by the FCM algorithm will be used by Level sets algorithm to reduce the influence of the noise effect on the working of each of these algorithms, to facilitate level sets manipulation and to lead to more robust segmentation. The sensitivity and specificity confirm the effectiveness of proposed method for caries detection.

International audience; The novel 1D coordination polymer (CP) [{Cu(mu(2)-Br)(2)Cu}(mu-L2)(2)] CP2 has been obtained by reaction of the tetrakisthioether p-MeSC6H4SCH2SC6H4SMe-p (L2) with CuBr in a 1: 2 metal-to ligand ratio. In contrast to the previously described CP [{Cu(mu(2)-Br)(2)Cu}(mu-L1)(2)] CP1 obtained by reaction of the tetrakisthioether p-MeOC6H4SCH2SC6H4OMe-p (L1) with CuBr, the two independent extended 1D ribbons contain bent Cu(mu(2)-Br)(2)Cu units of the butterfly-type with short Cu center dot center dot center dot Cu separations of 2.679(1) and 2.613(1) angstrom. In contrast to the common planar rhomboid Cu(mu(2)-Br)(2)Cu cluster, this butterfly-shaped geometry of the core is without precedent. A luminescent material of composition [(Cu4I4)(mu-L2)](n) CP3 is formed by reaction of L2 with CuI in a 1: 4 ratio. The two-dimensional CP of stoichiometry [Hg2Br4(L2)](n) CP4 results from treatment of HgBr2 with this tetradentate thioether L2. The structure is of the adduct type with two crystallographically different covalently bound HgBr2 bars assembled in the first step into the chains through the weak Hg-S interactions involving one Hg atom and two S atoms. The chains thus constructed are further brought together through a supplementary Hg1-S1 inter-chain interactions leading to the 2D layered structure. Consequently the Hg1 atom may be considered as pentacoordinated, while the second Hg2 atom has a formal coordination number of 4. The nature of bonding in these CPs has been studied by the Quantum Theory of Atoms in Molecules (QT-AIM) approach allowing a clear classification of metal-ligand bonds and detection of pi-pi stacking interactions. (C) 2016 Elsevier B.V. All rights reserved.

The substitution of the aryl group at trans position with respect to the N atom in the imine part of 4,4-dihalogeno-1,1-aryl-2-aza­buta-1,3-dienes [Ar2C=N—C(H)=CX 2] by a CN group allows to get an almost perfectly planar mol­ecule., The title compound, C12H10Br2N2O2, represents an example of a planar π-con­jugated 2-aza­butadiene mol­ecule, which is both an inter­esting starting material for further organic transformations and a potential ligand in organometallic coordination chemistry. Its metric mol­ecular parameters are typical for the family of 2-aza­buta-1,3-dienes not substituted at the (CH) 3-position. In the crystal, the almost planar (r.m.s. deviation = 0.0658 Å) aza­diene mol­ecules form one-dimensional double-wide ribbons through inter­molecular halogen bonds (C—Br⋯O and C—Br⋯Br—C), which then stack in a slipped manner through weak C—H⋯Br and π–π inter­actions to generate a three-dimensional network.