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Self-assembly of (Bu4N)4[β-Mo8O26], AgNO3 and N2-py (N2-py = 2,6-diaminopyridine) in DMF solution results in a (Bu4N)2[β-{Ag(N2-py)}2Mo8O26] complex which crystallises as two phases: one (OP) is orange in colour and consists of [β-{Ag(N2-py)}2Mo8O26]2− monomers and [β-{Ag(N2-py)}2Mo8O26]n2n− polymeric chains in the crystal structure; the other (YP) is yellow in colour and built only with [β-{Ag(N2-py)}2Mo8O26]2− monomers. Both complexes were characterised by single crystal X-ray diffraction (SCXRD), X-ray powder diffraction (XRPD), diffuse reflectance (DR), infrared spectroscopy (IR), elemental analysis, and quantum chemical calculations. According to differential scanning calorimetry (DSC) and DR, OP demonstrates a complicated phase transition at 130 K. Comprehensive SCXRD studies of the crystal structure change show rearrangement of the Ag+ coordination sphere related with the dominant Ag–N bond distance change. TGA of both complexes confirms formation of silver nanoparticles (Ag-NPs), MoO3 and Ag2Mo4O13 upon thermal decomposition. The Ag-NPs were studied by SEM. Exfoliation of the resulting mixture in water gives a Ag-NP and MoO3 mixed colloid system studied by TEM. |
