Synthesis and crystal structure of three mixed-ligand silver(I) complexes constructed from 1,2-Di(4-pyridyl)ethylene and different organic carboxylate anions

Abstract

The reaction of AgNO3 with 1,2-di(4-pyridyl)ethylene (Dpe) and 2,3-pyrazinedicarboxylic acid (H2Pzdc) or 2,2′-bipyridyl-4,4′-dicarboxylic acid (H2Bpdc) or salicylic acid (HSa) in alcohol aqueous solution produces block-like crystals of [Ag2(Dpe)2]Ppzdc) · 6H2O (I), [Ag3(Dpe)3](Bpdc)(NO3) · 4H2O (II), and [Ag2(Dpe)2](Sa)(NO3) · 3H2O (III) at room temperature. Crystal I is monoclinic: space group P21/m, a = 7.5370(7), b = 17.2309(16), c = 12.5131(11) A, β = 98.3780(10)°, V = 1607.7(3) A3, Z = 2. Crystal II is triclinic: space group $P\bar 1$ , a = 8.8260(8), b = 11.1149(11), c = 13.3751(14) A, α = 102.0140(10)°, β = 105.696(2)°, γ = 99.5940(10)°, V = 1200.4(2) A3, Z = 1. Crystal III is triclinic: space group $P\bar 1$ , a = 7.3600(6), b = 2.7549(11), c = 18.2241(16) A, α = 106.225(2)°, β = 98.0150(10)°, γ = 99.5400(10)°, V = 1588.5(2) A3, Z = 2. All the three complexes contain sandwich-like crystal structures, in which anionic sheets built up from different anions (Pzdc2−, Bpdc2−, Sa−) and lattice water molecules via rich hydrogen-bonding interactions are inserted between the cationic silver complexes layers. The lattice water molecules are situated among the framework of the crystal structure and stabilized by rich hydrogen-bonding interactions, and lattice water molecules may play a role in the orientation of the organic anions in the crystal packing.