Modification of charge transfer in a two-dimensional donor/acceptor framework by the insertion of another donor-type molecule into electronegative interlayer pockets.

Pyrene-intercalated layered compounds, [{Ru2(O2CCF3)4}2(TCNQR(x))]·2(pyrene) (TCNQR(x) = 7,7,8,8-tetracyano-p-quinodimethane derivatives; R(x) = H4 and F4), were synthesized. Pyrene prohibits intralayer electron transfer of [Ru2(II,II)] → TCNQR(x), even in the compound with R(x) = F4, from occurring.

Cyano-bridged Mn(III)-M(III) single-chain magnets with M(III)=Co(III), Fe(III), Mn(III), and Cr(III).

A series of isostructural cyano-bridged Mn(III)(h.s.)-M(III)(l.

Pressure effect on the three-dimensional charge-transfer ferromagnet [{Ru₂(m-FPhCO₂)₄}₂(BTDA-TCNQ)].

The magnetic properties of a three-dimensional infinite network compound, [{Ru₂(m-FPhCO₂)₄}₂(BTDA-TCNQ)] (m-FPhCO₂⁻ = m-fluorobenzoate; BTDA-TCNQ = bis(1,2,5-thiadiazolo)tetracyanoquinodimethane), were investigated under hydrostatic pressures up to 12.9 kbar. The applied pressure caused the intralattice exchange couplings to weaken, inducing a decrease in the magnetic phase transition temperature from 107 K at ambient pressure to 57 K at 12.

Stepwise neutral-ionic phase transitions in a covalently bonded donor/acceptor chain compound.

Neutral (N)-ionic (I) transitions in organic donor (D)/acceptor (A) charge-transfer complexes are intriguing because a 'reservoir of functions' is available. For systematically controlling N-I transitions, tuning the ionization potential of D and the electron affinity of A is extremely important. However, the effect of Coulomb interactions, which likely causes a number of charge-gap states at once in a system bringing about stepwise transitions, is a long-standing mystery.

Tuning of the ionization potential of paddlewheel diruthenium(II, II) complexes with fluorine atoms on the benzoate ligands.

A series of paddlewheel diruthenium(ii, ii) complexes with various fluorine-substituted benzoate ligands were isolated as THF adducts and structurally characterized: [Ru(2)(F(x)PhCO(2))(4)(THF)(2)] (F(x)PhCO(2)(-) = o-fluorobenzoate, o-F; m-fluorobenzoate, m-F; p-fluorobenzoate, p-F; 2,6-difluorobenzoate, 2,6-F(2); 3,4-difluorobenzoate, 3,4-F(2); 3,5-difluorobenzoate, 3,5-F(2); 2,3,4-trifluorobenzoate, 2,3,4-F(3); 2,3,6-trifluorobenzoate, 2,3,6-F(3); 2,4,5-trifluorobenzoate, 2,4,5-F(3); 2,4,6-trifluorobenzoate, 2,4,6-F(3); 3,4,5-trifluorobenzoate, 3,4,5-F(3); 2,3,4,5-tetrafluorobenzoate, 2,3,4,5-F(4); 2,3,5,6-tetrafluorobenzoate, 2,3,5,6-F(4); pentafluorobenzoate, F(5)). By adding fluorine atoms on the benzoate ligands, it was possible to tune the redox potential (E(1/2)) for [Ru(2)(II,II)]/[Ru(2)(II,III)](+) over a wide range of potentials from -40 mV to 350 mV (vs. Ag/Ag(+) in THF).

Magnetic/conducting bifunctionality due to π/σ-conjugated functional moieties in a stacked ferrimagnetic chain.

An alternating chain of a paddlewheel [Ru(2)(II,III)(O(2)CEt)(4)](+) (EtCO(2)(-) = propionate) complex and [Pt(mnt)(2)](-) (mnt(2-) = maleonitriledithiolate) has a ferrimagnetic spin arrangement of S = 3/2 and 1/2 local spins, respectively, as well as three-dimensional antiferromagnetic ordering with a canting mode at 8.6 K. This chain is stacked at the [Pt(mnt)(2)](-) units to form a slipped column in the vertical direction against the chain, which acts as a pathway for electrical conduction.

Reversible magnetism between an antiferromagnet and a ferromagnet related to solvation/desolvation in a robust layered [Ru2]2TCNQ charge-transfer system.

The charge-transfer compound [{Ru(2)(O(2)CPh-o-Cl)(4)}(2)TCNQ(MeO)(2)] x CH(2)Cl(2) (1; o-ClPhCO(2)(-) = o-chlorobenzoate; TCNQ(MeO)(2) = 2,5-dimethoxy-7,7,8,8-tetracyanoquinodimethane) was synthesized from the reaction of the neutral precursors [Ru(2)(II,II)(O(2)CPh-o-Cl)(4)] (abbreviated as [Ru(2)(II,II)] or [Ru(2)(4+)]) and TCNQ(MeO)(2) in a CH(2)Cl(2)/nitrobenzene solution. The structure consists of two-dimensional layers consisting of an infinite array in which [Ru(2)(II,II)] units are involved in charge transfer to TCNQ(MeO)(2) to give a formal charge of [{Ru(2)(4.5+)}-TCNQ(MeO)(2)(*-)-{Ru(2)(4.

Control of charge transfer in a series of Ru2(II,II)/TCNQ two-dimensional networks by tuning the electron affinity of TCNQ units: a route to synergistic magnetic/conducting materials.

The isostructural series of two-dimensional (2-D) fishnet-type network compounds, [{Ru(2)(O(2)CCF(3))(4)}(2)(TCNQR(x))] x n(solv) (R(x) = H(4), 1; Br(2), 2; Cl(2), 3; F(2), 4; F(4), 5), has been synthesized from the reactions of a paddlewheel diruthenium(II, II) complex, [Ru(2)(II,II)(O(2)CCF(3))(4)], and neutral TCNQ derivatives (TCNQR(x) = 2,3,5,6- or 2,5-halogen-substituted 7,7,8,8-tetracyanoquinodimethane) under anaerobic conditions. Corresponding Rh compounds 1-Rh-5-Rh, which are diamagnetic and redox-inactive, were also synthesized for the purpose of comparison with 1-5. According to the electron affinity of TCNQR(x), which is related to its first reduction potential, the Ru(2) series (1-5) has the requisite driving force for charge transfer from [Ru(2)(II,II)(O(2)CCF(3))(4)] to TCNQR(x), which can lead to a mixed-valence state of [{Ru(2)(4.

A ladder based on paddlewheel diruthenium(II, II) rails connected by TCNQ rungs: a polymorph of the hexagonal 2-D network phase.

The slow diffusion reaction of [Ru(2)(O(2)CCF(3))(4)(THF)(2)] with TCNQ in CH(2)Cl(2)/4-chlorotoluene, respectively, leads to the formation of ladder chain composed of [Ru(2)] rails and TCNQ rungs in a 2 : 1 ratio.

Photoinduced spin transition for Iron(II) compounds with liquid-crystal properties.

The iron(II) compounds [Fe(3Cn-L)2(NCS)2] (n = 6 (1), n = 8 (2), n = 10 (3), n = 12 (4), n = 14 (5), n = 16 (6), n = 18 (7), n = 20 (8), and n = 22 (9)) were synthesized and their physical properties characterized by polarizing optical microscopy, differential scanning calorimetry, and powder X-ray analysis, where 3Cn-L denotes bidentate Schiff-base ligands formed from the corresponding aniline derivatives and pyridine-2-carboxyaldehyde. The iron(II) compounds 4-8 exhibited crystal to liquid-crystal transitions at 318, 334, 345, 338, and 347 K, respectively. Variable-temperature magnetic susceptibility measurements revealed that the compounds 1-9 exhibit spin-crossover behavior between the high-spin and low-spin states and a photoinduced spin transition from a low-spin state to a metastable high-spin state.