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Key indicators: single-crystal X-ray study; T = 293 K; mean (C-C) = 0.008 Å; disorder in main residue; R factor = 0.044; wR factor = 0.111; data-to-parameter ratio = 5.9.

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Le présent article s’intéresse au traitement informationnel d’une radio, Radio-Dakar et de trois organes de presse écrite que sont Dakar-Matin, Afrique Nouvelle et Le Monde dans une période charnière de développement économique et social et de crise des institutions gouvernementales au Sénégal en décembre 1962. La crise qui opposa Léopold Sédar Senghor, président de la République, à Mamadou Dia, président du Conseil, place les médias dans une posture délicate et parfois ambivalente au moment où l’État sénégalais s’employait à élaborer un cadre juridique et réglementaire des médias devenus un enjeu indiscutable de pouvoir et de construction nationale.

The tetranuclear nickel(II) complex [Ni 4 (HL) 4 ]Cl 4 ·4H 2 O {H 2 L = 1,5-bis[1-(pyridin-2-yl)ethylidene]carbono hydrazone} has been prepared by reaction in methanol of nickel(II) chloride and H 2 L in 2:1, M:L molar ratio. The single crystal Xray diffraction analysis revealed a 2 × 2 square grid of tetramer units with the metal ions joined in pairs by the alkoxide oxygen atom in the μ 2 mode with octahedral geometry around each nickel ion. The supramolecular structure shows that the tetramer units are linked through edge-to-face (T shape) C−H···π interactions, forming sheets with hydrophobic-(occupied by infinite 2D water−chlorine chains) and hydrophilic-(occupied by chlorine anions) channels. Variable temperature magnetic studies suggest an antiferromagnetic coupling between the adjacent Ni(II) centers with a coupling constant of J = −6.6 cm −1 .T he binding of transition metal ions to properly designed multifunctional organic ligands for the construction of original metallosupramolecular architectures 1 continue to attract scientific attention for several reasons, such as magnetic, electronic, catalytic, or biological properties. 2 For example, the packing of some compounds can give rise to diverse nature channels, similar to those present in natural proteins as aquaporins involved in water transport. 3 It might seem that hydrophobic channels should repel water; however, they can be hydrated and their nature promoted rapid water flow. 4 It is well-known that if discrete metallo-supramolecular species contain additional peripheral binding sites, they can assemble to give polymeric structures. 5 Similarly, aggregation to give polymers can be supported by additional bridging ligands 6 or counterions. 7 A knowledge of the principles of structure formation through polymerization is important not only from the viewpoint of coordination chemistry but also for the future development of increasingly intricate and functional coordination networks. In this sense, noncovalent interactions such as hydrogen bonds and π,π-stacking are the main driving forces behind this self-assembly process. 8 One of the main targets in this field is the design and synthesis of new polytopic ligands that can be used for synthesis of molecular metal grids. Thompson and cowokers have successfully produced many tetranuclear [n × n] grids using directed self-assembly polydentate ligands with transition metal ions. 9 They have synthesized tetranuclear complexes using templated cyclization methods, where the bridging arrays among the metal ions involve oxygen donor atoms. 10 In this way, self-assembly of transition metal ions with designed Schiff bases allow for the synthesis of stable metal complexes with interest and potential applications in many fields. 11 On the other hand, owing to its ability to adopt various geometries, the coordination chemistry of nickel(II) ions was widely explored in this past decade 12 and complexes with esthetical architectures were synthesized. 13 The use of the nickel compounds in development of new magnetic ...