Chi Won Kim

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

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)°; N–Pd–N = 84.6(2)°; Pd–P = 2.259(2) Å, 2.270(2) Å; Pd–N = 2.100(5) Å, 2.112(5) Å). The triflates were smoothly exchanged to produce [(dppp)Pd(m-pmps)]2(X)4 (X− =  , , , , and ; (X)2 =  and ). According to 1H-NMR chemical shifts and conductivity measurements, the macrocyclodimer was sensitive to the Hoffmeister series of anions.