Silver Coordination Polymers Based on Neutral Trinitrile Ligand: Topology and the Role of Anion

One flexible star-shaped bridging molecule tris-(4-cyanophenyl)amine (TCPA) is synthesized from tris-(4-iodophenyl)amine by treatment with CuCN in hexamethylphosphorotriamide (HMPA) as a catalyst in high yield. Anion-template-controlled reactions of TCPA and silver salts give a series of coordination polymers (CPs) with various topological patterns. The complex [Ag(TCPA)(ClO4)](n)center dot nC(6)H(6) (1) forms an undulating 4.8(2) network, which displays unusual net entanglement. Two 4.82 nets interweave each other to give rise to 2-fold interpenetrating basic layers, which link together via double mu-O-perchlorate bridging interactions. The complex [Ag(TCPA)(CF3SO3)](n)center dot 2nC(6)H(6) (2) forms noninterpenetrating (6,3) nets. The solid state structure of [Ag-3(TCPA)(CF3CO2)(3)](n)center dot nCH(2)Cl(2) (3) also is a (6,3) honeycomb network, differently, including a sphere-type Ag-4(CF3CO2)(6)(2-) cluster-anion in the host frameworks, which is a rare example of the host cationic network containing a guest cluster-anion. The complexes [Ag(TCPA)(BF4)center dot 0.5H(2)O](n)center dot 1.5(n)C(6)H(6) (4), [Ag(TCPA)(ClO4)center dot 0.5H(2)O](n center dot)nC(7)H(8 center dot) nH(2)O (5), and [Ag(TCPA)(CF3SO3)center dot 0.5H(2)O](n)center dot 1.5nC(6)H(6) (6) exhibit three similar (10,3) networks which form rare net entanglements. Four (10,3) nets interweave to generate a 4-fold interpenetrating assemble, which are closely united together via specific mu(2)-O-water bridging interactions. The complex [Ag-4(TCPA)(2)(CF3CO2)(3)(CF3SO3)](n)center dot nC(6)H(6)center dot nCH(2)Cl(2) (7) is a three-dimensional (3D) structure formed via multiple "zigzag" Ag-4 chains. In this Ag-1-TCPA system, the structural diversities and topological differences of these networks result from the flexibilities of the bridging ligand TCPA and the template-effect of anions. The free rotation of three Ph-CN "arms" around the central N moiety results in TCPA adopting different conformation in the self-assembly process by using variational solvent system and/or counterions.