Bulk Weak Ferromagnet in Ferrimagnetic Chains of Organic−Inorganic Hybrid Materials Based on BDH-TTP and Paramagnetic Thiocyanato Complex Anions: (BDH-TTP)[M(isoq)2(NCS)4], M = CrIII, FeIII

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Abstract
The preparation, X-ray crystal structures, and magnetic properties of two new isostructural charge transfer salts, (BDH-TTP)M(isoq)2(NCS)4 (M = CrIII (1), FeIII (2), BDH-TTP = 2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene, isoq = isoquinoline), are reported. Crystal data for 1: monoclinic, space group C2/c (#15), a = 16.1363(9) Å, b = 19.0874(12) Å, c = 12.5075(6) Å, β = 95.70(4)°, V = 3833.2(4) Å3, Z = 4, R = 0.0516 for 2844 reflections with I > 2σ(I); for 2: monoclinic, C2/c (#15), a = 16.1938(8) Å, b = 19.1117(11) Å, c = 12.5100(10) Å, β = 94.265(3)°, V = 3861.0(4) Å3, Z = 4, R = 0.0479 for 2969 reflections with I > 2σ(I). The crystal structure consists of zigzag mixed organic and inorganic layers, and each layer is formed by mixed columns of BDH-TTP radical cations and paramagnetic metal complex anions. Short intermolecular atomic contacts between donor and anion are observed within the column in the c-direction. The two compounds have weak room-temperature electrical conductivities. ESR measurements show a single signal without separating the donor and anion spins, suggesting a π interaction between the d and π electrons. For both compounds ferrimagnetic interactions are observed between the nonequivalent donor and anion spins. These materials exhibit bulk canted weak ferromagnetism below 7.6 K for both 1 and 2.

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