title: New BDH-TTP/[M(III)(C5O5)3]3- (M = Fe, Ga) isostructural molecular metals.
abstract: Two new isostructural molecular metals-(BDH-TTP)(6)[M(III)(C(5)O(5))(3)]·CH(2)Cl(2) (BDH-TTP = 2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene, where M = Fe (1) and Ga (2))-have been prepared and fully characterized. Compound 1 is a molecular conductor showing paramagnetic behavior, which is due to the presence of isolated [Fe(C(5)O(5))(3)](3-) complexes with high-spin S = (5)/(2) Fe(III) metal ions. The conductivity originates from the BDH-TTP organic donors arranged in a κ-type molecular packing. At 4 kbar, compound 1 behaves as a metal down to ∼100 K, showing high conductivity (∼10 S cm(-1)) at room temperature. When applying a pressure higher than 7 kbar, the metal-insulator (M-I) transition is suppressed and the compound retains the metallic state down to low temperatures (2 K). For 1, ESR signals have been interpreted as being caused by the fine structure splitting of the high-spin (S = 5/2) state of Fe(III) in the distorted octahedral crystal field from the ligands. At 4 kbar, the isostructural compound 2 behaves as a metal down to ∼100 K, although it is noteworthy that the M-I transition is not suppressed, even at pressures of 15 kbar. For 2, only the signal assigned to delocalized π-electrons has been observed in the ESR measurements.
authors.affiliation: Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, S.S. 554-Bivio per Sestu, I09042 Monserrato (Cagliari), Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Pilia
authors.forename: Elisa
authors.initials: E
authors.lastname: Sessini
authors.forename: Flavia
authors.initials: F
authors.lastname: Artizzu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamashita
authors.forename: Angela
authors.initials: A
authors.lastname: Serpe
authors.forename: Kazuya
authors.initials: K
authors.lastname: Kubo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
authors.forename: Hisaaki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Kuroda
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Yamada
authors.forename: Paola
authors.initials: P
authors.lastname: Deplano
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Gómez-García
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Mercuri
mesh_terms: D005708:Gallium / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D005708:Gallium; D007501:Iron