Ferromagnetic behavior in linear charge-transfer complexes. Structural and magnetic characterization of octamethylferrocene salts: (Fe(C sub 5 Me sub 4 H) sub 2 ) sup sm bullet + (A) sup sm bullet minus (A = TCNE, TCNQ)

Journal Article · Wed Jul 26 00:00:00 EDT 1989 · Inorganic Chemistry; (USA)

DOI:https://doi.org/10.1021/ic00314a012· OSTI ID:7003438

Miller, J S; Glatzhofer, D T; O'Hare, D M ^[1]; Reiff, W M ^[2]; Chakraborty, A; Epstein, A J ^[3]

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1. E.I. de Pont de Nemours and Co., Inc., Wilmington, DE (USA)
2. Northeastern Univ., Boston, MA (USA)
3. Ohio Sate Univ., Columbus (USA)

The reaction of Fe{sup II}({eta}{sup 5}-C{sub 5}Me{sub 4}H){sub 2} with cyano acceptors A (A = TCNE (tetracyanoethylene), TCNQ (7,7,8,8-tetracyano-p-quanodimethane), n-C{sub 4}(CN){sub 6} (n-hexacyanobutadiene), C{sub 6}(CN){sub 6} (tris(dicyanomethylene)cyclopropane), DDQ (2,3-dichloro-5,6-dicyanobenzoquinone), TCNQF{sub 4} (perfluoro-7,7,8,8-tetracyano-p-quinodimethane) results in formation of 1:1 charge-transfer salts of (Fe{sup III})(C{sub 5}Me{sub 4}H){sub 2}){sup {sm bullet}+}(A){sup {sm bullet}{minus}} composition. The TCNE and TCNQ complexes have been structurally characterized. The high-temperature magnetic susceptibility for polycrystalline samples of these complexes can be fit by the Curie-Qeiss law, {chi} = C(T-{theta}){sup {minus}1}, with {theta} = +0.5 {plus minus} 2.2 K, and {mu}{sub eff} ranges from 2.71 to 3.97 {mu}{sub B}, suggesting that the polycrystalline samples measured had varying degrees of orientation. The 7.0 K EPR spectrum of the radical cation exhibits an axially symmetric powder pattern with g{sub {parallel}} = 4.11 and g{sub {perpendicular}} = 1.42, and the EPR parameters are essentially identical with those reported for ferrocenium and decamethylferrocenium. No EPR spectrum is observed at 78 K. Akin to the (Fe(C{sub 5}Me{sub 5}){sub 2}){sup {sm bullet}+} salts, these salts have {sup 57}Fe Moessbauer spectra consistent with complete charge transfer; however, unlike the case for the former complexes, quadrupole splittings of 0.30 and 0.220 mm/s are observed at 4.8 and 298 K, respectively. The absence of strong interionic magnetic coupling for the (Fe(C{sub 5}Me{sub 4}H){sub 2}){sup {sm bullet}+} salts contrasts with the behavior of the (Fe(C{sub 5}Me{sub 5}){sub 2}){sup {sm bullet}+} salts. 26 refs., 13 figs., 8 tabs.

• OSTI ID: 7003438
• Journal Information: Inorganic Chemistry; (USA), Vol. 28:15; ISSN 0020-1669
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CYANIDES
CHEMICAL PREPARATION
ETHYLENE
IRON COMPLEXES
METHANE
CRYSTAL STRUCTURE
EXPERIMENTAL DATA
MOLECULAR STRUCTURE
ALKANES
ALKENES
COMPLEXES
DATA
HYDROCARBONS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties