title: Structural variety of alkali metal compounds containing P-E-M (E = S, Se; M = Li, Na, K) units derived from nitrogen rich heterocycles.
abstract: The preparation of novel alkali metal chalcogenides supported by multidentate nitrogen rich ligands is reported. Treatment of the ligand precursors [H{(4,5-(P(E)Ph(2))(2)tz}] (E = S (1a), Se (1b)) with organolithium reagents or elemental sodium and potassium in tetrahydrofuran (THF) leads to the isolation of 2-7 in high yields. These compounds were characterized by elemental analysis, IR spectroscopy, mass spectrometry, solution and solid-state multinuclear NMR spectroscopy, and single crystal X-ray diffraction analysis. In the solid state, 2, 4, and 5 are dimers that contain bimetallic six-membered (M(2)N(4)) rings (M = Li, Na). In 3, the discrete monomer [Li{4,5-(P(Se)Ph(2))(2)tz}(thf)(2)] (tz = 1,2,3-triazole) contains a five-membered CPSeLiN ring which adopts an envelope conformation. The polymeric arrangement [K{4,5-(P(S)Ph(2))(2)}tz](infinity) in 6 displays different bonding modes based on the hapticity of the ligand upon binding to the potassium atom. In compounds 2-6, the presence of secondary bonding features the alkali metal chalcogen bonds.
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510 México D.F., Mexico.
authors.forename: Jhon A
authors.initials: JA
authors.lastname: Balanta-Díaz
authors.forename: Mónica
authors.initials: M
authors.lastname: Moya-Cabrera
authors.forename: Vojtech
authors.initials: V
authors.lastname: Jancik
authors.forename: Leslie W
authors.initials: LW
authors.lastname: Pineda-Cedeño
authors.forename: Rubén A
authors.initials: RA
authors.lastname: Toscano
authors.forename: Raymundo
authors.initials: R
authors.lastname: Cea-Olivares