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)(ClO<sub>4</sub>)]<sub><i>n</i></sub>·<i>n</i>C<sub>6</sub>H<sub>6</sub> (<b>1</b>) forms an undulating 4.8<sup>2</sup> network, which displays unusual net entanglement. Two 4.8<sup>2</sup> nets interweave each other to give rise to 2-fold interpenetrating basic layers, which link together via double μ-O<sub>perchlorate</sub> bridging interactions. The complex [Ag(TCPA)(CF<sub>3</sub>SO<sub>3</sub>)]<sub><i>n</i></sub>·2<i>n</i>C<sub>6</sub>H<sub>6</sub> (<b>2</b>) forms noninterpenetrating (6,3) nets. The solid state structure of [Ag<sub>3</sub>(TCPA)(CF<sub>3</sub>CO<sub>2</sub>)<sub>3</sub>]<sub><i>n</i></sub>·<i>n</i>CH<sub>2</sub>Cl<sub>2</sub> (<b>3</b>) also is a (6,3) honeycomb network, differently, including a sphere-type Ag<sub>4</sub>(CF<sub>3</sub>CO<sub>2</sub>)<sub>6</sub><sup>2−</sup> 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)(BF<sub>4</sub>)·0.5H<sub>2</sub>O]<sub><i>n</i></sub>·1.5<i>n</i>C<sub>6</sub>H<sub>6</sub> (<b>4</b>), [Ag(TCPA)(ClO<sub>4</sub>)·0.5H<sub>2</sub>O]<sub><i>n</i></sub>·<i>n</i>C<sub>7</sub>H<sub>8</sub>·<i>n</i>H<sub>2</sub>O (<b>5</b>), and [Ag(TCPA)(CF<sub>3</sub>SO<sub>3</sub>)·0.5H<sub>2</sub>O]<sub><i>n</i></sub>·1.5<i>n</i>C<sub>6</sub>H<sub>6</sub> (<b>6</b>) 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 μ<sub>2</sub>-O<sub>water</sub> bridging interactions. The complex [Ag<sub>4</sub>(TCPA)<sub>2</sub>(CF<sub>3</sub>CO<sub>2</sub>)<sub>3</sub>(CF<sub>3</sub>SO<sub>3</sub>)]<sub><i>n</i></sub>·<i>n</i>C<sub>6</sub>H<sub>6</sub>·<i>n</i>CH<sub>2</sub>Cl<sub>2</sub> (<b>7</b>) is a three-dimensional (3D) structure formed via multiple “zigzag” Ag<sub>4</sub> chains. In this Ag<sup>I</sup>-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.