Poly[[[μ3-(E)-N-(pyridin-4-ylmethylidene)hydroxylaminato-κ3 O:N:N′][μ2-(E)-N-(pyridin-4-ylmethylidene)hydroxylamine-κ2 N:N′][(E)-N-(pyridin-4-ylmethylidene-κN)hydroxylamine]disilver(I)] nitrate]

The title coordination polymer, {[Ag2(C6H5N2O)(C6H6N2O)2]NO3}n, features a deprotonated N-(pyridin-4-ylmethylidene)hydroxylaminate anion and two neutral N-(pyridin-4-ylmethylidene)hydroxylamine molecules in the asymmetric unit. The anion connects three AgI atoms through its O and two N-donor atoms. One neutral ligand functions in a monodentate mode; the other functions in a bridging mode, binding though its two N atoms. The coordination geometry of the two independent metal atoms is T-shaped; the manner of bridging gives rise to a layer motif parallel to (100). In the crystal, the nitrate ion is disordered over two positions in a 1:1 ratio, and is sandwiched between adjacent layers. O—H⋯O hydrogen bonding is present between nitrate ions and layers, and also between adjacent layers.

The title coordination polymer, {[Ag 2 (C 6 H 5 N 2 O)(C 6 H 6 -N 2 O) 2 ]NO 3 } n , features a deprotonated N-(pyridin-4-ylmethylidene)hydroxylaminate anion and two neutral N-(pyridin-4ylmethylidene)hydroxylamine molecules in the asymmetric unit. The anion connects three Ag I atoms through its O and two N-donor atoms. One neutral ligand functions in a monodentate mode; the other functions in a bridging mode, binding though its two N atoms. The coordination geometry of the two independent metal atoms is T-shaped; the manner of bridging gives rise to a layer motif parallel to (100). In the crystal, the nitrate ion is disordered over two positions in a 1:1 ratio, and is sandwiched between adjacent layers. O-HÁ Á ÁO hydrogen bonding is present between nitrate ions and layers, and also between adjacent layers.
When some ammonium hydroxide was added to the reaction, the acid hydrogen of the isonicotinylaldehyde oxide is partially removed so that the product consists of a cation having two AgI atoms, one deprotonated ligand and two neutral ligands. The charge is balanced by a nitrate anion. The dinuclear cations are linked by coordination bonds into a polycation (Scheme I). The coordination polymer features a deprotonated N-(pyridin-4-ylmethylidene)hydroxylamine and two neutral N-(pyridin-4-ylmethylidene)hydroxylamine molecules. The anion connects three Ag I atoms through its O and two N donor-atoms. One neutral ligand functions in a monodentate mode; the other functions in a bridging mode, binding though its two N atoms. The geometry of the two independent metal atoms is T-shaped (Fig. 1); the manner of bridge gives rise to a layer motif. The anion is sandwiched between adjacent layers (Fig. 2).

Experimental
Isonicotinaldehyde oxime was synthesized from the reaction of isonicotinaldehyde and hydroxylamine. Silver nitrate (1 mmol) dissolved in water (5 ml) was added to picolinaldehyde oxime (1 mmol) dissolved in ethanol (5 ml). Several drops of ammonium hydroxide were added. The solution was filtered and set aside, away from light, for the growth of colorless crystals.

Refinement
Carbon-and oxygen-bound H-atoms were placed in calculated positions (C-H 0.93 Å, O-H 0.84 Å) and were included in the refinement in the riding model approximation, with U(H) set to 1.2-1.5U(C,O).
The nitrate ion is disordered over two positions in a 1:1 ratio. Nitrogen-oxygen distances were restrained to 1.24±0.01 A and oxygen···oxygen contacts to 2.15±0.01 Å. For each component, the temperature factors of the O atoms were made identical. The temperature factors of the N atoms of the two components were made identical too. The isotropic temperature factors were tightly restrained.