title: Non-covalent interactions at bis(pyrazole)silver(i) or -gold(i) cations.
abstract: The reaction of AgBF(4) with two equivalents of pzH (pyrazole) or dmpzH (3,5-dimethylpyrazole) leads to [Ag(pzH)(2)]BF(4) or [Ag(dmpzH)(2)]BF(4). The reaction of [AuCl(tht)] with an equimolar amount of dmpzH in refluxing hexane leads to [Au(dmpzH)(2)][AuCl(2)]. Similar complexes [Au(dmpzH)(2)]A (A = BF(4) or NO(3)) are obtained from [AuCl(tht)], two equivalents of dmpzH, and AgBF(4) or AgNO(3). The complexes [Ag(dmpzH)(2)]BF(4) and [Au(dmpzH)(2)]A (A = [AuCl(2)], BF(4) or NO(3)) crystallize as ionic pairs where the NH groups of the pyrazoles are involved in short cation-anion interactions. The nitrate complex crystallizes as a dimer, where both molecules are supported by pi-stacking interactions between the pyrazole rings. The crystal structure of [Ag(pzH)(2)]BF(4) reveals a three dimensional array of cations and anions. In solution, [Ag(pzH)(2)]BF(4) and [Ag(dmpzH)(2)]BF(4) undergo intermolecular processes involving pyrazole decoordination, and behave as 1/1 electrolytes; whereas dimethylpyrazole gold complexes do not display any dynamic behavior, and show cation-anion association also in solution.
authors.affiliation: Facultad de Ciencias, Universidad de Valladolid, 47005, Valladolid, Spain.
authors.forename: Vanesa
authors.initials: V
authors.lastname: García-Pacios
authors.forename: Marta
authors.initials: M
authors.lastname: Arroyo
authors.forename: Noelia
authors.initials: N
authors.lastname: Antón
authors.forename: Daniel
authors.initials: D
authors.lastname: Miguel
authors.forename: Fernando
authors.initials: F
authors.lastname: Villafañe