Anion-recognition of an ionic cyclodimeric Pd(II) complex

Abstract

Ionic macrocyclodimeric palladium(II) complex, [(dppp)Pd(m-pmps)]2(CF3SO3)4 (dppp = 1,3-bis(diphenylphosphino)propane; m-pmps = 1,3-bis(3-pyridyl)-1,3-dimethyl-1,3-diphenyldisiloxane), was synthesized and its molecular structure determined by X-ray single crystallography. The complex has 19 rings consisting of one 20-membered metallamacrocycle, 2 six-membered metallacycles, 4 pyridyl groups, and 12 phenyl groups. The local geometry around palladium(II) approximates to a typical square planar arrangement with two cis phosphines (P-Pd-P = 90.54(7)degrees; N-Pd-N = 84.6(2)degrees; Pd-P = 2.259(2) angstrom, 2.270(2) angstrom; Pd-N = 2.100(5) angstrom, 2.112(5) angstrom). The triflates were smoothly exchanged to produce [(dppp)Pd(m-pmps)]2(X)4 (X- = [image omitted], [image omitted], [image omitted], [image omitted], and [image omitted]; (X)2 = [image omitted] and [image omitted]). According to 1H-NMR chemical shifts and conductivity measurements, the macrocyclodimer was sensitive to the Hoffmeister series of anions.