title: Sensitivity of silver(I) complexes of a pyrimidine-hydrazone ligand to solvent, counteranion, and metal-to-ligand ratio changes.
abstract: Metal complexation studies were performed with AgSO(3)CF(3) and AgBF(4) and the ditopic pyrimidine-hydrazone ligand 6-(hydroxymethyl)pyridine-2-carboxaldehyde (2-methylpyrimidine-4,6-diyl)bis(1-methylhydrazone) (1) in both CH(3)CN and CH(3)NO(2) in a variety of metal-to-ligand ratios. The resulting complexes were studied in solution by NMR spectroscopy and in the solid state by X-ray crystallography. Reacting either AgSO(3)CF(3) or AgBF(4) with 1 in either CH(3)CN or CH(3)NO(2) in a 1:1 metal-to-ligand ratio produced a double helicate in solution. This double helicate could be converted into a linear complex by increasing the metal-to-ligand ratio; however, the degree of conversion depended on the solvent and counteranion used. Attempts to crystallize the linear AgSO(3)CF(3) complex resulted in crystals with the dimeric structure [Ag(2)1(CH(3)CN)(2)](2)(SO(3)CF(3))(4) (2), while attempts to crystallize the AgSO(3)CF(3) double helicate from CH(3)CN resulted in crystals of another dimeric complex, [Ag(2)1(SO(3)CF(3))(CH(3)CN)(2)](2)(SO(3)CF(3))(2)·H(2)O (3). The AgSO(3)CF(3) double helicate was successfully crystallized from a mixture of CH(3)CN and CH(3)NO(2) and had the structure [Ag(2)1(2)](SO(3)CF(3))(2)·3CH(3)NO(2) (4). The linear AgBF(4) complex could not be isolated from the double helicate in solution; however, crystals grown from a solution containing both the AgBF(4) double helicate and linear complexes in CH(3)CN had the structure [Ag(2)1(CH(3)CN)(2)](BF(4))(2) (5). The AgBF(4) double helicate could only be crystallized from CH(3)NO(2) and had the structure [Ag(2)1(2)](BF(4))(2)·2CH(3)NO(2) (6).
authors.affiliation: Department of Chemistry, University of Otago, P.O. Box 56, Dunedin, New Zealand.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Hutchinson
authors.forename: Scott A
authors.initials: SA
authors.lastname: Cameron
authors.forename: Lyall R
authors.initials: LR
authors.lastname: Hanton
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Moratti
mesh_terms: D006835:Hydrazones / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011743:Pyrimidines / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D012996:Solutions; D012997:Solvents / Q000737:chemistry*
chemical_list: D006835:Hydrazones; D008024:Ligands; D009942:Organometallic Compounds; D011743:Pyrimidines; D012996:Solutions; D012997:Solvents; D012834:Silver