Synthesis and Structure of Coordination Polymers of Ag(I) with Isomeric (Aminomethyl)pyridines. Formation of A Novel Circular Helicate and 2-D Networks via Ag···Ag Contacts and Coordination Shell Expansion under Anion Control

Reaction between Ag(I) salts and the three isomers of (aminomethyl)pyridines, viz., 2-amp, 3-amp, and 4-amp, lead to either discrete or polymeric (1-D and 2-D) structures influenced by anions and closed shell Ag···Ag contacts. Characterization data for Ag(2-amp)BF₄ (<b>1</b>) follow:  monoclinic, space group <i>C</i>2/<i>c</i>, with <i>a</i> = 16.788(2) Å, <i>b</i> = 11.5719(6) Å, <i>c</i> = 11.3864(7) Å, <i>β</i> = 123.671(8)°, and <i>Z</i> = 8. For Ag₂(2-amp)₃(PF₆)₂ (<b>2</b>):  monoclinic, space group <i>P</i>2₁/<i>a</i>, with <i>a</i> = 10.029(7) Å, <i>b</i> = 20.291(12) Å, <i>c</i> = 13.907(6) Å, <i>β</i> = 95.38(5)°, and <i>Z</i> = 4. For Ag₂(3-amp)₃(PF₆)₂ (<b>4</b>):  triclinic, space group <i>P</i>1̄, with <i>a</i> = 10.4482(7) Å, <i>b</i> = 11.1468(9) Å, <i>c</i> = 12.2720(11) Å, <i>α</i> = 81.018(7)°, <i>β</i> = 80.668(6)°, <i>γ</i> = 80.977(6)°, and <i>Z</i> = 2. For Ag(4-amp)BF₄·0.75CH₃CN (<b>5</b>):  orthorhombic, space group <i>C</i>222₁, with <i>a</i> = 9.272(2) Å, <i>b</i> = 16.164(12) Å, <i>c</i> = 27.851(2) Å, and <i>Z</i> = 8. For Ag(4-amp)PF₆ (<b>6</b>):  monoclinic, space group <i>P</i>2₁/<i>m</i>, with <i>a</i> = 5.2089(7) Å, <i>b</i> = 14.3950(17) Å, <i>c</i> = 7.0149(14) Å, <i>β</i> = 96.538(14)°, and <i>Z</i> = 2. While Ag(I) is 2-coordinate in <b>1</b>, <b>5</b> and <b>6</b>, it shows 3-coordination in <b>2</b> and <b>4</b>. Compound <b>1</b> consists of a 1-D polymeric cation chain with interchain Ag···Ag contacts and the anions sitting on the edges of the chains. The dication in <b>2</b> is held in the form of a circular helicate by closed shell Ag···Ag interactions. Compound <b>4</b> generates a 2-D network with channels big enough to accommodate the anions. Compound <b>5</b> is a 2-D chiral network of chains connected by Ag···Ag contacts. Compound <b>6</b> shows a simple 1-D chain structure with an alternating arrangement of cationic chains and anions.