title: Low-temperature (180 K) crystal structures of tetrakis-mu-(niflumato)di(aqua)dicopper(II) N,N-dimethylformamide and N,N-dimethylacetamide solvates, their EPR properties, and anticonvulsant activities of these and other ternary binuclear copper(II)niflumate complexes.
abstract: Two pseudopolymorphs, solvates, of [Cu(2)(II)(niflumate)(4)(H(2)O)(2)] of unknown structure were obtained following solution of [Cu(2)(II)(niflumate)(4)(H(2)O)(2)] in N,N-dimethylacetamide (DMA) or N,N-dimethylformamide (DMF). Low-temperature crystal structures obtained for these solvates revealed that they were ternary aqua DMA and DMF solvates: [Cu(2)(II)(niflumate)(4)(H(2)O)(2)].4DMA and [Cu(2)(II)(niflumate)(4)(H(2)O)(2)].4DMF. Intermolecular hydrogen bonding interactions account for the formation of these stable DMA and DMF solvates. These pseudopolymorphs contain a centrosymmetric binuclear center with Cu-Cu bond distances ranging from 2.6439(7) to 2.6452(9) A; the coordination sphere of Cu(II) is characterized by one long Cu-O (water) bond length of 2.128(3)-2.135(3) A and four short Cu-O (carboxylate) bonds of 1.949(3)-1.977(3) A. Crystal parameters for the DMA pseudopolymorph: a=10.372(1), b=19.625(2), c=17.967(2) A, beta=97.40(1) degrees , V=3626.8(6) A(3); monoclinic system; space group: P2(1)/a and for the DMF pseudopolymorph: a=10.125(2), b=18.647(3), c=19.616(4) A, alpha=74.38(2)(o), beta=88.18(2)(o), gamma=79.28(2)(o), V=3504(1) A(3); triclinic system; space group: P1. EPR spectra of these solids are identical and show strong antiferromagnetic coupling between the copper atoms, similar to the spectrum obtained for [Cu(2)(II)(niflumate)(4)(DMSO)(2)]. The [Cu(2)(II)(niflumate)(4)(H(2)O)(2)], [Cu(2)(II)(niflumate)(4)(H(2)O)(2)].4DMA, [Cu(2)(II)(niflumate)(4)(H(2)O)(2)].4DMF, [Cu(2)(II)(niflumate)(4)(DMF)(2)], and[Cu(2)(II)(niflumate)(4)(DMSO)(2)] evidenced protection against maximal electroshock-induced seizures and Psychomotor seizures at various times after treatment, consistent with the well known antiinflammatory activities of Cu chelates, but failed to protect against Metrazol-induced seizures while evidencing some Rotorod Toxicity consistent with a mechanism of action involving sedative activity.
authors.affiliation: Laboratoire de Chimie Générale, Faculté de Médecine et de Pharmacie, Poitiers, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Viossat
authors.forename: Frederick T
authors.initials: FT
authors.lastname: Greenaway
authors.forename: Georges
authors.initials: G
authors.lastname: Morgant
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Daran
authors.forename: Nguyen-Huy
authors.initials: NH
authors.lastname: Dung
authors.forename: John R J
authors.initials: JR
authors.lastname: Sorenson
mesh_terms: D000818:Animals; D000927:Anticonvulsants / Q000737:chemistry* / Q000494:pharmacology*; D003080:Cold Temperature; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D006860:Hydrogen Bonding; D008297:Male; D051379:Mice; D008958:Models, Molecular; D015394:Molecular Structure; D009544:Niflumic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D009942:Organometallic Compounds / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D051381:Rats
chemical_list: D000927:Anticonvulsants; D009942:Organometallic Compounds; D009544:Niflumic Acid; D003300:Copper