Hydrothermal synthesis, crystal structures, and properties of two 3-D network nickel nicotinate coordination polymers: [Ni4(μ-H2O)2(nicotinate)8·2H2O] and [Ni2(H2O)2(nicotinate)4(4,4′-bpy)]

Triphenylbismuth(v) di[(iso)nicotinates] - transmetallation agents or divergent organometalloligands? First organobismuth(v)-based silver(i) coordination polymers

The reaction of Ph₃BiCl₂ with alkali salts of isonicotinic and nicotinic acids afforded Ph₃Bi[O(O)CC₅H₄N-4]₂ (1) and Ph₃Bi[O(O)CC₅H₄N-3]₂ (2), respectively, which were characterized by multinuclear NMR spectroscopy in solution, mass spectrometry and IR spectroscopy in the solid state. Their molecular structures were established by single-crystal X-ray diffraction. For both 1 and 2 the molecules contain a trigonal bipyramidal C₃BiO₂ core, with the phenyl groups in equatorial positions. The potential use of 1 and 2 as ditopic organometalloligands was investigated. The reaction of 1 or 2 with Me₃SnCl (1 : 2 molar ratio) resulted in carboxylato ligand exchange and the formation of Me₃Sn[O(O)CC₅H₄N-4] (3) and Me₃Sn[O(O)CC₅H₄N-3] (4) besides Ph₃BiCl₂. The crystals of both 3 and 4 contain 1-D coordination polymers built through intermolecular N → Sn interactions. The treatment of Ni[S₂P(OⁱPr)₂]₂ with 1 and 2, respectively, resulted, in addition to di(carboxylato)nickel(ii) derivatives, in isolation of Ph₃Bi and the disulphane [(ⁱPrO)₂P(S)S]₂. New coordination polymers were obtained by reacting 1 and 2 with various silver(i) salts: [Ag{Ph₃Bi[O(O)CC₅H₄N-4]₂}(OTf)] (5), [Ag{Ph₃Bi[O(O)CC₅H₄N-3]₂}(OTf)]·CH₂Cl₂ (6·CH₂Cl₂), [Ag{Ph₃Bi[O(O)CC₅H₄N-4]₂}](SbF₆)·2THF (7·2THF), [Ag{Ph₃Bi[O(O)CC₅H₄N-3]₂}](SbF₆)·CH₂Cl₂ (8·CH₂Cl₂) and [Ag{Ph₃Bi[O(O)CC₅H₄N-3]₂}(NO₃)]·CH₂Cl₂ (9·CH₂Cl₂). The crystal structures of 5 and 6 can be described as 1-D chains linked by triflate bridges in pairs of chains and 2-D networks, respectively. Compound 7 features a 2-D grid-like topology of the network, with tecton 1 acting as a tridentate ligand through both nitrogen and one oxygen atoms. The linker 2 molecules adopt either cis (compound 6) or trans (compounds 8 and 9) conformation. Complexes 8 and 9 are 1-D chain polymers exhibiting zig-zag and wavy motifs, respectively. The dimensionality of the structures is extended by the presence of supramolecular interactions (ππ, AgAg, AgO).

Di-μ-nicotinato-κ2N:O;κ2O:N-bis[aqua(ethylenediamine-κ2N,N′)(nicotinato-κN)cadmium(II)] dihydrate

The dinuclear mol­ecule of the title compound, [Cd₂(C₆H₄NO₂)₄(C₂H₈N₂)₂(H₂O)₂]·2H₂O, lies on an inversion centre and forms 12-membered (CdNC₃O)₂ metallacycles with the two Cd²⁺ ions bridged by two nicotinate ligands. Both Cd²⁺ ions display coordination polyhedra with a distorted octa­hedral geometry that includes two pyridine N atoms from bridging and terminal nicotinate anions, two amine N atoms from chelating ethylene­diamine ligands, carboxylate O atoms from bridging nicotinate anions and water O atoms. Inter­molecular O—H⋯O and N—H⋯O hydrogen bonds result in the formation of a three-dimensional network, and π–π stacking inter­actions are observed between symmetry-related pyridine rings of bridging as well as terminal nicotinate anions (the centroid–centroid distances are 3.59 and 3.69 Å, respectively, and the distances between parallel planes of the stacked pyridine rings are 3.53 and 3.43 Å, respectively). The two methylene groups of the ethylene­diamine ligand are disordered over two positions; the site occupancy factors are ca 0.8 and 0.2.