Polyatomic anion versus acetonitrile in coordinating ability: Structural properties of AgX-bearing 1,4-bis(2-isonicotinoyloxyethyl)piperazine (X - = NO3-, CF3SO3-, ClO4-, BF4-, and PF6-)

Abstract

Type studies on competitive polyatomic anion versus acetonitrile coordination in the self-assembly of a series of [Ag2(X) m (bip)(NCCH3) n ](X)2-m (X- = NO3-, CF3SO3-, ClO 4-, BF4-, and PF6-; m = 0, 2; n = 0, 2, 4; bip = 1,4-bis(2-isonicotinoyloxyethyl) piperazine) were carried out. Each bip spacer acts as an N4 tetradentate ligand and is linked to four silver(I) centers through two pyridine and two piperazine moieties, producing a double strand consisting of two 20-membered ring units. The coordinating environment around the silver(I) center is subtly determined by the competition of the polyatomic anions with acetonitrile, that is, by the Ag•••NCCH3 versus Ag•••X interactions. The coordinating ability of acetonitrile is inversely proportional to the order of the coordination ability of the Hoffmeister series of polyatomic anions, NO3- ≫ CF3SO3- > ClO4- > BF4- ≫ PF6-. © 2011 The Author(s).