Synthesis and Characterization of New Coordination Polymers Generated from Triazole-Containing Organic Ligands and Inorganic Ag(I) Salts

Abstract

The coordination chemistry of the triazole-containing rigid crooked tetradentate ligands 3,5-bis(4-pyridyl)-4-amino-1,2,4-triazole (L5) and 3,5-bis(3-pyridyl)-4-amino-1,2,4-triazole (L6) with inorganic Ag(I) salts has been investigated. Six new coordination polymers were prepared by solution reactions and fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. {[Ag 3 (L5) 2 ](NO 3 ) 3 (H 2 O) 4 } n ( 1 ) (triclinic, P 1̄; a = 6.9481(5) Å, b = 9.7267(6) Å, c = 12.8803(8) Å, α = 92.7760(10)°, β = 99.1170(10)°, γ = 104.4150(10)°, Z = 1) was obtained by the combination of L5 with AgNO 3 in a H 2 O/CH 3 OH mixed solvent system, and features a unique two-dimensional sheet, which consists of large tetrameric and small dimeric rings. The approximate dimensions of the rings are ca. 23 × 6 Å and 4 × 8 Å, respectively. {[Ag 3 (L5) 3 ](PF 6 ) 3 ·(H 2 O)·(CH 3 OH)} n ( 2 ) (monoclinic, P 2 1 /n; a = 10.4641(6) Å, b = 15.6701(8) Å, c = 31.1907(17) Å, β = 94.8840(10)°, Z = 4) was generated from the reaction of L5 with AgPF 6 in a H 2 O/CH 3 OH mixed solvent system. In 2, Ag(I) centers are interlocked together by L5 ligands through two terminal N pyridine and two N triazole donors into a novel noninterpenetrating three-dimensional framework with elliptical channels (effective cross-section of ca. 12.4 × 8.0 Å) extending along the crystallographic a axis. {[Ag(L5)](ClO 4 )·H 2 O} n ( 3 ) (triclinic, P 1̄; a = 10.3605(16) Å, b = 10.5224(16) Å, c = 15.014(2) Å, α = 89.979(2)°, β = 76.656(2)°, γ = 89.980(2)°, Z = 4) was obtained by a combination of L5 with AgClO 4 in a MeOH/H 2 O mixed solvent system. In the solid state, it forms a novel noninterpenetrating three-dimensional network with rhombic channels (effective cross-section of ca. 9.0 × 8.0 Å) along the crystallographic a axis, in which noncoordinated ClO 4 - anions and H 2 O guest molecules are located. {[Ag(L6)](ClO 4 )·CH 3 OH} n ( 4 ) (monoclinic, C 2 /c; a = 14.1747(10) Å, b = 16.2713(11) Å, c = 15.9983(11) Å, β = 114.9410(10)°, Z = 8) was obtained by the combination of L6 with AgClO 4 in a MeOH/H 2 O mixed solvent system. In the solid state, 4 features a novel noninterpenetrating three-dimensional framework with honeycomb-like and elliptical channels in two different crystallographic directions. Their dimensions are 8 × 7 and 18 × 4 Å, respectively. Uncoordinated ClO 4 - counterions and MeOH guest molecules are located in these channels. {[Ag(L6)](PF 6 )·CH 3 OH} n ( 5 ) is generated from L6 and AgPF 6 in a H 2 O/MeOH mixed solvent system and crystallizes in the space group C 2 /c, with a = 15.2035(10) Å, b = 16.5919(11) Å, c = 16.1240(10) Å, β = 116.8490(10)°, Z = 8. Compound 5 and 4 are isostructural. {[Ag 2 (C 12 H 10 N 6 ) 2 ](SiF 6 )·2H 2 O} n ( 6 ) (monoclinic, P 2 1 /c, a = 11.3839(6) Å, b = 16.5163(8) Å, c = 7.4485(4) Å, β = 95.5450(10)°, Z = 2) was obtained by the combination of L6 ligand with AgSbF 6 in a MeOH/H 2 O solvent system. In the solid state, compound 6 adopts a noninterpenetrating two-dimensional net. Uncoordinated SiF 6 2- anions and water molecules are located between the layers and further linked by extensive H-bonding systems into a three-dimensional framework. When viewed down the crystallographic [101] direction, honeycomb-like channels were found, in which SiF 6 2- counterions and water guest molecules are located.