Coordination solids derived from Cp*M(CN)3- (M = Rh,Ir)

Solutions of Rh2(OAc)4 and Et4NCp*Ir(CN)3] react to afford crystals of the one-dimensional coordination solid Et4NCp*Ir(CN)3]Rh2(OAc)4]]. This reaction is reversed by coordinating solvents such as MeCN. The structure of the polymer consists of helical anionic chains containing Rh2(OAc)4 units linked via two of the three CN ligands of Cp*Ir(CN)3-. Use of the more Lewis acidic Rh2(O2CCF3)4 in place of Rh2(OAc)4 gave purple (Et4N)2Cp*Ir(CN)3]2Rh2(O2CCF3)4]3], whose insolubility is attributed to stronger Rh-NC bonds as well as the presence of cross-linking. The species Cp*Rh(CN)3]Ni(en)n](PF6)] (n = 2, 3) crystallized from an aqueous solution of Et4NCp*Rh(CN)3] and Ni(en)3](PF6)2; Cp*Rh(CN)3]Ni(en)2](PF6)] consists of helical chains based on cis-Ni(en)(2)2+ units. Aqueous solutions of Et4NCp*Ir(CN)3] and AgNO3 afforded the colorless solid Ag-Cp*Ir(CN)3]. Recrystallization of this polymer from pyridine gave the hemipyridine adduct AgAg(py)]Cp*Ir(CN)3]2]. The 13C cross-polarization magic-angle spinning NMR spectrum of the pyridine derivative reveals two distinct Cp* groups, while in the pyridine-free precursor, the Cp*'s appear equivalent. The solid-state structure of AgAg(py)]Cp*Ir(CN)3]2] reveals a three-dimensional coordination polymer consisting of chains of Cp*Ir(CN)3- units linked to alternating Ag+ and Ag(py)+ units. The network structure arises by the linking of these helices through the third cyanide group on each Ir center.