Metal complexes of 3-acetamido-5-methylpyrazole

Anion-tuning of supramolecular gel properties

“…14-17, 48,87 The bidentate coordination of 3.10 is similar to the amide pyrazole complexes reported by Kraatz and to complexes of triazole amides. 68,72,88,89 The bidentate coordination is also similar to that of the coordination complexes of 2-pyridylureas. 78,90,91 The observed hydrogen bonding motifs are essential to the understanding of this ligand, its coordination complexes and the gelation possibilities of both.…”

“…The association of these fibres into larger bundles (which branch further through mechanisms such as crystallographic mismatch branching) 44 54 This tuning ability has led to many ideas for applications of LMWGs. 27,38,68 The following paragraphs describe some of the methods used to tune LMWGs' properties and some of the applications that have arisen from them. We will then focus on the tuning of gel properties by anion binding in particular.…”

“…14-17, 48,68,72,87 There is an increasing interest in coordination metal-tuned LMWGs, especially those formed by the first row transition metals because of the interesting properties shown by these metals, such as their redox chemistry, spectroscopic properties, catalytic properties and magnetism, to name but a few.…”

“…The bidentate coordination is similar to that found for amide-derivatised pyrazole. 68,72 The coordination to the metal ion results in the urea group going from the anti conformation seen in the crystal structure of 3.10 (section 3.2) to a syn conformation. The syn conformation suggests that the urea is free from intra-molecular hydrogen bonding and is able to interact with anions and solvent.…”

“…68,72,78,[88][89][90][91] The The coordination chemistry of compound 3.11a was also investigated. They are a five-membered ring involving the deprotonated carboxamide and pyrazole (-Cu1-N5-C13-N1-N2-) and a six-membered ring involving the carbonyl of the urea group and the same pyrazole (-Cu1-O1-C5-N3-C4-N2-).…”