Structure and Properties of Titanium-Including Complex, Tris(tetramethyltetrathiafulvalene) Di-μ-fluoro-bis[tetrafluorotitanate(IV)], (TMTTF)3Ti2F10

Abstract

A novel molecular complex of tetramethyltetrathiafulvalene (TMTTF) was prepared by the treatment with TiF4. The X-ray analysis reveals the exsistence of a trimer of TMTTF’s and a Ti2F102− anion in a triclinic unit cell of the dimension; a = 10.934(3), b = 12.798(2), c = 8.000(1) Å, α = 103.86(1), β = 107.08(2), γ = 75.02(2)°. All the molecular planes of TMTTF are nearly parallel. The trimers stack parallel to the a axis, and the intertrimer interaction is estimated to be weak. A semiconductive behavior with a relatively large Seebeck coefficient was observed (ρ = 3 × 102 Ω cm, Ea = 0.26 eV, and S = −0.41 mV K−1 along the a axis). Weak electron spin resonance (ESR) absorption was observed to be characteristic of low-dimensional diffusive spin systems.

Structures, Multicenter π-Bonding, and Spin Equilibria in the Mixed-Valence Trimers of Tetramethyltetrathiafulvalene Cation-Radicals

“…It should also be mentioned that the earlier reported examples of dicationic (TMTTF) 3 2+ trimers showed either rotated arrangements of TMTTF moieties or shifted moieties (analogous to that with (TMTTF) 3 +• ). ,, The structural features of the former indicate that the larger fractions of charge are residing on the side moieties (similar to that observed in the current work), while structural and FT-IR characterizations of the latter revealed that the charge is located mostly on the central moiety. , To rationalize charge distributions in the mono- and dicationic trimers, we first considered a simplified molecular-orbital (MO) diagram of these associations. The MO LCAO model of the π-stacked trimers suggests that the interaction of (occupied or semioccupied) frontier orbitals of three TMTTF monomers results in the formation of bonding (B), nonbonding (NB), and antibonding (AB) orbitals of the complex.…”

“…The (TMTTF) 3 2+ associations are capped on both sides with Br 6 CAR – anions, which provide clear separation between trimeric units with no close intertrimer contacts between TMTTF moieties (in contrast to the published structures in which (TMTTF) 3 2+ units represented more or less distinct parts of the infinite TMTTF stacks ,− ). The stoichiometry of the salt indicates a 2+ charge for each TMTTF trimer.…”

Increasing Structural Dimensionality of Alkali Metal Fluoridotitanates(IV)

“…The ([Ti 6 F 27 ] 3– ) ∞ anion represents the first example of a 3-D framework built of TiF 6 octahedra. To date only examples of 0-D ([Ti 2 F 10 ] 2– , , [Ti 2 F 11 ] 3– , − [Ti 4 F 18 ] 2– , − [Ti 4 F 19 ] 3– , [Ti 4 F 20 ] 4– , [Ti 5 F 23 ] 3– , [Ti 8 F 36 ] 4– , and [Ti 10 F 45 ] 5– ), 1-D {([TiF 5 ] − ) ∞ , − ([Ti 2 F 9 ] − ) ∞ , , ([Ti 3 F 13 ] − ) ∞ , ([Ti 7 F 30 ] 2– ) ∞ , and ([Ti 9 F 38 ] 2– ) ∞ }, and 2-D {([Ti 8 F 33 ] − ) ∞ } , geometries have been known.…”

“… , Almost three-quarters of the characterized compounds are hexafluoridotitanate­(IV) ([TiF 6 ] 2– ) salts. Other oligomeric fluoridotitanate­(IV) anions with 0-D geometry are presented by [Ti 2 F 10 ] 2– , , [Ti 2 F 11 ] 3– , − [Ti 4 F 18 ] 2– , − [Ti 4 F 19 ] 3– , [Ti 4 F 20 ] 4– , [Ti 5 F 23 ] 3– , [Ti 8 F 36 ] 4– , and [Ti 10 F 45 ] 5– . Known polymeric fluoridotitanate­(IV) anions include five 1-D examples {([TiF 5 ] − ) ∞ , − ([Ti 2 F 9 ] − ) ∞ , , ([Ti 3 F 13 ] − ) ∞ , ([Ti 7 F 30 ] 2– ) ∞ , and ([Ti 9 F 38 ] 2– ) ∞ } and two 2-D examples {two modifications of ([Ti 8 F 33 ] − ) ∞ anion , }.…”

Guanidinium Perfluoridotitanate(IV) Compounds: Structural Determination of an Oligomeric [Ti6F27]3– Anion, and an Example of a Mixed‐Anion Salt Containing Two Different Fluoridotitanate(IV) Anions

“…In the solid state these units can remain isolated, leading to trivial hexafluoridotitanate(IV) salts, or they can be linked by sharing fluorine ions, yielding larger oligomeric (0‐D geometry) or polymeric (1‐D, 2‐D and 3‐D) anions. So far, there are 18 structurally characterized fluoridotitanate(IV) anions: oligomeric [TiF 6 ] 2– , [Ti 2 F 10 ] 2– ,, [Ti 2 F 11 ] 3– , [Ti 4 F 18 ] 2– , [Ti 4 F 19 ] 3– , [Ti 4 F 20 ] 4– , [Ti 5 F 23 ] 3– , [Ti 8 F 36 ] 4– , [Ti 10 F 45 ] 5– , and polymeric ([TiF 5 ] – ) ∞ , ([Ti 2 F 9 ] – ) ∞ ,, , ([Ti 3 F 13 ] – ) ∞ , ([Ti 4 F 19 ] 3– ) ∞ , ([Ti 6 F 27 ] 3– ) ∞ , ([Ti 7 F 30 ] 2– ) ∞ , ([Ti 9 F 38 ] 2– ) ∞ , and two modifications of the ([Ti 8 F 33 ] – ) ∞ anion , . The geometries of the various anions were determined with X‐ray experiments on single crystals of pure inorganic and/or hybrid compounds.…”