Mechanochemical and thermal formation of 1H-benzotriazole coordination polymers and complexes of 3d-transition metals with intriguing dielectric properties

Abstract

Liquid-assisted grinding (LAG) reactions have been successfully applied to achieve a series of complexes and coordination polymers based on divalent 3d-transition metal chlorides (TM chlorides) and the aromatic ligand 1H-benzotriazole (BtzH). The obtained substances were investigated via single crystal X-ray, powder X-ray determination and simultaneous DTA/TG analysis as model compounds for structural and chemical influences on their dielectric properties. Depending on the synthesis method, different constitutions and structures are observed. Two polymorphous forms of the 1D polymer [MnCl2(BtzH)2] (1 and 2) as well as the complexes [ZnCl2(BtzH)2]·BtzH (3) and [CoCl2(BtzH)2]·BtzH (4) have been obtained as phase-pure bulk substances via the mechanochemical LAG route, and even single crystals are available. For comparison, thermal reactions were also carried out and have led to the formation of the neutral complexes: [CoCl2(BtzH)2] (5) and [CoCl2(BtzH)4]·4BtzH (6), [ZnCl2(BtzH)2] (7) and the anionic complex BtzH2[CoCl3BtzH] (8). In addition, thermal treatment of 3 yields the benzotriazolium salt {(BtzH)2H}Cl (9). The transition metal compounds were additionally analysed regarding their dielectric properties by frequency-dependent as well as temperature-dependent permittivity investigations. It is intriguing that compounds 1 and 3 show remarkably low dielectric constants and loss factors up to 50 °C highlighting them as potential "low-k materials".

Building Manganese Halide Hybrid Materials with 0D, 1D, and 2D Dimensionalities

“…There was an additional emission band at 760 nm observed in the 1D chains that was absent from the 0D units (Figure 5b). the highly symmetrical nature of these 1D chain structures, only three other structures with similar 1D chains were found in the literature: benzotriazole [28], benzo-2,1,3-selenenadiazole [29], and 3-cyanopyridine [23]. As expected, similar IR and Raman spectra were observed in these 1D chains (Figures S2 and S3), indicating the same framework.…”

Syntheses, structures and characterization of isomorphous CoII and NiII coordination polymers based on 2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole and benzene-1,4-dicarboxylate

“…Aromatic polycarboxylates, like benzenedicarboxylate, benzenetricarboxylate, benzenetetracarboxylate and their derivatives, have been widely used in the preparation of metal-organic polymers since they have various coordination modes to form diverse structures and can act as hydrogen-bond acceptors and donors in the assembly of supramolecular structures (Lin et al, 2008;Cui et al, 2009). Nitrogen-heterocyclic organic compounds, like imidazole, benzimidazole and their derivatives, have also been used extensively as ligands for the construction of polymers with intriguing structures and potential applications in fluorescent materials, nonlinear optical (NLO) and ferroelectric materials, dielectric materials and in the pharmaceutical industry (Wang et al, 2010;Dou et al, 2016;Castillo et al, 2016;Brede et al, 2016).…”

Syntheses, structures and properties of two new isostructural zinc(II) complexes based on 1-[(benzotriazol-1-yl)methyl]-1H-imidazole

“…Owing to the strong coordination ability and diversities of their coordination modes, N-heterocyclic organic compounds, such as imidazole, triazole, benzimidazole, benzotriazole and their derivatives, have been used extensively as ligands for the construction of complexes with intriguing structures and potential applications in fluorescent materials, nonlinear optical (NLO) and ferroelectric materials, dielectric materials and the pharmaceutical industry (Wang et al, 2010;Dou et al, 2016;Castillo et al, 2016;Brede et al, 2016). In recent years, many researchers, including our group, have focused their attention on the design and synthesis of metal-organic complexes based on 1-[(benzotriazol-1-yl)methyl]-1H-imidazole (bmi), since it has three potential N-atom donors and can coordinate to metal ions in monodentate or bridging coordination modes in the construction of complexes (An et al, 2008;Zhang et al, 2015).…”