Incorporation of MnIII and FeII Complexes into TCNQ Networks: Preparations, Crystal Structures, and Magnetic Properties of [MnIII(salen)(TCNQ)0.5][MnIII(salen)(TCNQ)0.5(CH3OH)]CH3OH·H2O and [FeII(CH3OH)4(TCNQ)2]TCNQ·2CH3CN

Abstract

Metal complexes with TCNQ as ligands, [MnIII(salen)(TCNQ)0.5][MnIII(salen)(TCNQ)0.5(CH3OH)]CH3OH·H2O (1) and [FeII(CH3OH)4(TCNQ)2]TCNQ·2CH3CN (2) (where TCNQ and H2salen represent tetracyanoquinodimethane and quadridentate schiff base N,N′-disalicylideneethylenediamine, respectively) were prepared, and crystal structures and magnetic properties were studied. Complex 1 crystallizes in the triclinic space group with cell constants a = 12.000(6), b = 19.986(7), c = 9.494(6) Å, α = 100.67(5), β = 100.01(5), γ = 81.50(4)°, V = 2188(2) Å3, and Z = 2. In 1, two distinct six-coordinate [MnIII(salen)]+ chromophores are bridged by two kinds of TCNQ2− anions (A and B) in μ2 and μ4 fashions to form a one-dimensional structure. Complex 2 crystallizes in the triclinic space group with cell constants a = 10.523(1), b = 14.008(2), c = 8.062(1) Å, α = 94.96(1), β = 111.11(1), γ = 79.96(1)°, V = 1091.3(3) Å3, and Z = 1. In 2, mono-anionic and neutral TCNQ molecules (C and D, respectively) stacks to form columns (···DCCD···), which are linked by the coordination of the nitrile group to [FeII(CH3OH)4]2+. Temperature dependent magnetic susceptibility measurements revealed that magnetic interactions between metal centers in 1 and 2 are very small.

Magnetic assemblies based on Mn(III) salen analogues

“…A peculiar 1D chain composed of [Mn(salen)] + and TCNQ was synthesized by Oshio et al: [{Mn III (salen)(TCNQ) 0.5 } {Mn III (salen)(TCNQ) 0.5 (MeOH)}]·MeOH·H 2 O [78]. This was the first [Mn III (salen)] + TCNQ assembly (a simple alternating chain was synthesized by Miyasaka et al, and this compound will be described in Section 5.2) [79].…”

Magnetic Coupling between Metal Spins through the 7,7,8,8‐Tetracyanoquinodimethane (TCNQ) Dianion

“…This series of compounds represent a third type of 3D [(M II ) 2 (TCNQ IIÀ ) 3 ] 2À coordination network that differs from the previously reported one, namely (Ph 3 PMe) 2 [Cd II 2 (TCNQ IIÀ ) 3 ] [6d] which crystallizes in the R-3 space group with one cation situated in the cavity, and the 3D [M II 2 -(TCNQ IIÀ ) 3 ] 2À (M = Mn, Zn, or Cd) coordination network with hexagonal channels. [6a] Several other compounds of the TCNQ 2À dianion have been previously reported and structurally characterized including a discrete complex with a syn-m 2 coordination binding mode to vanadocene, [11] a Mn(salen)-based 1D chain [12] and a 3D [Zn II (TCNQ IIÀ )bpy] framework. [7c] Thermogravimetric analyses indicate thermal stability up to approximately 250 8C, above which rapid decomposition occurs ( Figure S20 in the Supporting Information).…”

Structural, Spectroscopic, and Electrochemical Characterization of Semi-Conducting, Solvated [Pt(NH3)4](TCNQ)2·(DMF)2 and Non-Solvated [Pt(NH3)4](TCNQ)2

“…The most significant difference between the TCNQ and TCNQF 4 species is the shift in reversible potential for the reduction of the neutral to mono-and further to the dianionic species, DE ¼ 0.36 and 0.37 V respectively in CH 3 CN. [50,51] Thus, to probe the origin of the catalytic activity further and to assess whether the difference in the reversible potential of the TCNQ(F 4 ) 12/22 process contributed to it, several TCNQF 4based complexes were tested as catalysts for the reaction of ferricyanide and thiosulfate ions in aqueous solution. Salts of the TCNQ dianion are rare and unstable; [50,52,53] however, the TCNQF 4 22 (Pr 4 N) 2 TCNQF 4 and Li 2 TCNQF 4 both exhibited catalytic activity for the ferricyanide-thiosulfate reaction in aqueous solution (Table S1, Supplementary Material).…”

“…[50,51] Thus, to probe the origin of the catalytic activity further and to assess whether the difference in the reversible potential of the TCNQ(F 4 ) 12/22 process contributed to it, several TCNQF 4based complexes were tested as catalysts for the reaction of ferricyanide and thiosulfate ions in aqueous solution. Salts of the TCNQ dianion are rare and unstable; [50,52,53] however, the TCNQF 4 22 (Pr 4 N) 2 TCNQF 4 and Li 2 TCNQF 4 both exhibited catalytic activity for the ferricyanide-thiosulfate reaction in aqueous solution (Table S1, Supplementary Material). Furthermore, LiTCNQF 4 was catalytically active but not the TCNQ 1salts (Li þ , Bu 4 N þ ) or the neutral TCNQ and TCNQF 4 parent molecules (Table S1, Supplementary Material).…”