Double-Helical Silver(I) Coordination Polymer Based on an Unsymmetrical Ligand

Crystal structure of a zigzag CoII coordination polymer: catena-poly[[di-chlorido-bis-(methanol-κO)cobalt(II)]-μ-bis-(pyridin-3-ylmeth-yl)sulfane-κ2N:N']

Reaction of bis-(pyridin-3-ylmeth-yl)sulfane (L) with cobalt(II) chloride in methanol led to the formation of the title coordination polymer, [CoCl2(C12H12N2S)(CH3OH)2] n , in which the CoII cation lies on a crystallographic inversion centre and the S atom of the L ligand lies on a twofold rotation axis. Each CoII ion is coordinated by two pyridine N atoms from two bridging L ligands, two O atoms from methanol mol-ecules and two chloride anions, all inversion-related. The complex unit has an elongated octa-hedral geometry, in which N2O2 donor atoms occupy the equatorial positions and two chloride anions occupy the axial positions. Each L ligand links two CoII ions, forming an infinite zigzag chain propagating along the c-axis direction and further stabilized by O-H⋯Cl hydrogen bonds between the methanol mol-ecules and the chloride anions. Adjacent chains in the structure are connected by inter-molecular C-H⋯Cl hydrogen bonds, resulting in the formation of a three-dimensional supra-molecular architecture.

Crystal structure of a looped-chain CoII coordination polymer: catena-poly[[bis-(nitrato-κO)cobalt(II)]bis-[μ-bis-(pyridin-3-ylmeth-yl)sulfane-κ2N:N']]

The asymmetric unit of the title compound, [Co(NO3)2(C12H12N2S)2] n , contains a bis-(pyridin-3-ylmeth-yl)sulfane (L) ligand, an NO3- anion and half a CoII cation, which lies on an inversion centre. The CoII cation is six-coordinated, being bound to four pyridine N atoms from four symmetry-related L ligands. The remaining coordination sites are occupied by two O atoms from two symmetry-related nitrate anions in a monodentate manner. Thus, the CoII centre adopts a distorted octa-hedral geometry. Two symmetry-related L ligands are connected by two symmetry-related CoII cations, forming a 20-membered cyclic dimer, in which the CoII atoms are separated by 10.2922 (7) Å. The cyclic dimers are connected to each other by sharing CoII atoms, giving rise to the formation of an infinite looped chain propagating along the [101] direction. Inter-molecular C-H⋯π (H⋯ring centroid = 2.89 Å) inter-actions between one pair of corresponding L ligands and C-H⋯O hydrogen bonds between the L ligands and the nitrate anions occur in the looped chain. In the crystal, adjacent looped chains are connected by inter-molecular π-π stacking inter-actions [centroid-to-centroid distance = 3.8859 (14) Å] and C-H⋯π hydrogen bonds (H⋯ring centroid = 2.65 Å), leading to the formation of layers parallel to (101). These layers are further connected through C-H⋯O hydrogen bonds between the layers, resulting in the formation of a three-dimensional supra-molecular architecture.

Crystal structure of a CoII coordination polymer with a dipyridyl ligand: catena-poly[[bis-(nitrato-κ2O,O')cobalt(II)]-μ-N-(pyridin-2-ylmeth-yl)pyridine-3-amine-κ3N,N':N'']

The asymmetric unit of the title compound, [Co(NO3)2L] n , L = N-(pyridine-2-ylmeth-yl)pyridine-3-amine (C11H11N3), contains one CoII centre, two nitrate anions and one L ligand in which the Cpy-C-N-Cpy moiety adopts a trans conformation with a torsion angle of -173.1 (3) Å. The coordination geometry of the CoII atom is a distorted penta-gonal bipyramid. One amine N atom from the L ligand and four O atoms from two η2-nitrato ligands form the basal plane and two pyridyl N atoms from two symmetry-related L ligands occupy the apical positions [N-Co-N = 171.86 (11)°]. The displacement of the central CoII atom from the basal plane (r.m.s. deviation = 0.085 Å) is 0.1491 (12) Å. Each bidentate nitrate group is bonded asymmetrically to the cobalt atom in an chelating fashion. The CoII ions are linked by the L ligands to form a zigzag chain propagating along the c-axis direction. Within the zigzag chain, C-H⋯O hydrogen bonds between the ligands and the nitrate anions are observed. Adjacent zigzag chains are connected via inter-molecular π-π stacking inter-actions [centroid-to-centroid distance = 3.844 (2) Å] between the pyridine rings together with N/C-H⋯O hydrogen bonds.

Crystal structure of a twisted-ribbon type double-stranded AgI coordination polymer: catena-poly[[silver(I)-μ3-bis-(pyridin-3-ylmeth-yl)sulfane-κ3N:N':S] nitrate]

The asymmetric unit in the title compound, {[Ag(C12H12N2S)]·NO3} n or {[AgL]·NO3} n , L = bis-(pyridin-3-ylmeth-yl)sulfane, consists of an AgI cation bound to a pyridine N atom of an L ligand and an NO3- anion that is disordered over two orientations in an 0.570 (17):0.430 (17) occupancy ratio. Each AgI cation is coordinated by two pyridine N atoms from adjacent L ligands to form an infinite zigzag chain along [110]. In addition, each AgI ion binds to an S donor from a third L ligand in an adjacent parallel chain, resulting in the formation of a twisted-ribbon type of double-stranded chain propagating along the [110] or [1-10] directions. The AgI atom is displaced out of the trigonal N2S coordination plane by 0.371 (3) Å because of inter-actions between the AgI cation and O atoms of the disordered nitrate anions. Inter-molecular π-π stacking inter-actions [centroid-to-centroid distance = 3.824 (3) Å] occur between one pair of corresponding pyridine rings in the double-stranded chain. In the crystal, the double-stranded chains are alternately stacked along the c axis with alternate stacks linked by inter-molecular π-π stacking inter-actions [centroid-to-centroid distance = 3.849 (3) Å], generating a three-dimensional supra-molecular architecture. Weak inter-molecular C-H⋯O hydrogen bonds between the polymer chains and the O atoms of the nitrate anions also occur.

Crystal structure of an AgI inter-calation compound: catena-poly[[silver(I)-μ-N-(pyridin-3-ylmeth-yl)pyridin-3-amine-κ2N:N'] hexa-fluorido-phosphate aceto-nitrile disolvate]

The asymmetric unit in the title compound, [Ag(C11H11N3)]PF6·2CH3CN or {[AgL]·PF6·2CH3CN} n , L = N-(pyridin-3-ylmeth-yl)pyridin-3-amine, comprises one AgI atom, one L ligand, two aceto-nitrile solvent mol-ecules and one PF6- anion disordered over two orientations in a 0.567 (11):0.433 (11) ratio. Each AgI atom is coordinated by two pyridine N atoms from two L ligands in a slightly distorted linear coordination geometry [N-Ag-N = 170.55 (8)°]. Each L ligand bridges two AgI ions, resulting in the formation of a zigzag chain propagating along the [101] direction. In the crystal, Ag⋯Ag contacts [3.3023 (5) Å] and inter-molecular π-π stacking inter-actions [centroid-to-centroid distance = 3.5922 (15) Å] between the pyridine rings link these chains into a corrugated layer parallel to the ([Formula: see text]01) plane. The layers are stacked with a separation of 10.4532 (5) Å, and aceto-nitrile solvent mol-ecules and PF6- anions as guests are inter-calated between the layers. The layers are connected through several N/C-H⋯F hydrogen bonds and P-F⋯π inter-actions [F⋯ring centroid = 3.241 (8) Å] between the layer and the inter-calated guests and between the inter-calated guests, forming a three-dimensional supra-molecular network.

Crystal structure of an HgII coordination polymer with an unsymmetrical dipyridyl ligand: catena-poly[[[di-chlorido-mercury(II)]-μ-N-(pyridin-4-ylmeth-yl)pyridin-3-amine-κ2N:N'] chloro-form hemisolvate]

The asymmetric unit of the title compound, {[HgLCl2]·0.5CHCl3} n (L = N-(pyridin-4-ylmeth-yl)pyridin-3-amine, C11H11N3), contains one HgII ion, one bridging L ligand, two chloride ligands and a chloro-form solvent mol-ecule with half-occupancy that is disordered about a crystallographic twofold rotation axis. Each HgII ion is coordinated by two pyridine N atoms from two symmetry-related L ligands and two chloride anions in a highly distorted tetra-hedral geometry with bond angles falling in the range 99.05 (17)-142.96 (7)°. Each L ligand bridges two HgII ions, forming polymeric zigzag chains propagating in [010]. In the crystal, the chains are linked by inter-molecular N/C-H⋯Cl hydrogen bonds together with weak C-H⋯π inter-actions, resulting in the formation of a three-dimensional supra-molecular network, which is further stabilized by C-Cl⋯π inter-actions between the solvent chloro-form mol-ecules and the pyridine rings of L [chloride-to-centroid distances = 3.442 (11) and 3.626 (13) Å]. In addition, weak Cl⋯Cl contacts [3.320 (5) Å] between the chloro-form solvent mol-ecules and the coordinating chloride anions are also observed.

Crystal structure of a helical silver(I) coordination polymer based on an unsymmetrical dipyridyl ligand: catena-poly[[silver(I)-μ-N-(pyridin-4-ylmeth-yl)pyridine-3-amine-κ (2) N:N'] tetra-fluorido-borate methanol hemisolvate]

The asymmetric unit of the title compound, {[AgL]·BF4·0.5CH3OH} n , L = N-(pyridin-4-ylmeth-yl)pyridine-3-amine, C11H11N3, contains one Ag(I) ion, one ligand L, one tetra-fluorido-borate anion disordered over two orientations in a 0.669 (13):0.331 (13) ratio and one half of a methanol solvent mol-ecule situated on an inversion center. Each Ag(I) ion is coordinated by two N atoms from two L ligands in a distorted linear geometry [N-Ag-N = 174.70 (19)°]. Each L ligand bridges two Ag(I) ions, thus forming polymeric helical chains propagating in [010]. In the crystal, Ag⋯Ag [3.3369 (10) Å] and π-π inter-actions between the aromatic rings [centroid-to-centroid distance = 3.676 (4) Å] link these chains into layers parallel to (10-1). Ag⋯F and weak N(C)-H⋯F inter-actions further consolidate the crystal packing.