Solvatomorphs of (Bu4N)2[{Ag(N2-py)}2Mo8O26]: structure, colouration and phase transition. Issue 48 (1st December 2021)

• Record Type: Journal Article
• Authors: Abramov, Pavel A.; Komarov, Vladislav Yu.; Pischur, Denis A.; Sulyaeva, Veronica S.; Benassi, Enrico; Sokolov, Maxim N.
• Is Part Of: CrystEngComm. Volume 23:Issue 48(2021)
• Page Start: 8527
• Page End: 8537
• Publication Date: 2021-12-01
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/d1ce01152a
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : (Bu4 N)2 [β-{Ag(N2 -py)}2 Mo8 O26 ] demonstrates monomer/polymer dualism and a colouration phenomenon. The polymeric phase reveals a Ag assisted phase transition. Such complexes can act as precursors for catalytically active materials. Abstract : Self-assembly of (Bu4 N)4 [β-Mo8 O26 ], AgNO3 and N2 -py (N2 -py = 2, 6-diaminopyridine) in DMF solution results in a (Bu4 N)2 [β-{Ag(N2 -py)}2 Mo8 O26 ] complex which crystallises as two phases: one (OP ) is orange in colour and consists of [β-{Ag(N2 -py)}2 Mo8 O26 ] 2− monomers and [β-{Ag(N2 -py)}2 Mo8 O26 ] n 2 n − polymeric chains in the crystal structure; the other (YP ) is yellow in colour and built only with [β-{Ag(N2 -py)}2 Mo8 O26 ] 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 Ag2 Mo4 O13 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.