Spin-canting in a 1D chain Mn(II) complex with alternating double end-on and double end-to-end azido bridging ligands

Coexistence of Spin Canting and Metamagnetism in a One-Dimensional Mn(II) Compound Bridged by Alternating Double End-to-End and Double End-On Azido Ligands and the Analog Co(II) Compound

“…Although the spincanted antiferromagnetism might seem incompatible with the crystal structure of 2, because of the presence of an inversion center between the bridged Mn(II) centers, the observation of the spin canting in 2 should be attributed to a structural phase transition, or a distortion in the crystal at low temperature, thereby removing the inversion center. Such types of distortions have been reported before [34,58]. The weak interchain interactions present in both compounds are ascribed to the π-π stacking interactions between the dmbpy rings.…”

“…The ferromagnetic interaction decreases with the increasing Mn-N azide -Mn angle, while the antferromagnetic couplings via double EE-N 3 bridges were dependent on the δ angle, the dihedral angle between the N azide -Mn-N azide plane and the plane defined by the two azido bridges, the magnetic coupling decreases with the increasing δ angles [13]. The obtained magnetic coupling of two Mn(II) ions is ferromagnetic for a double EO-N 3 bridging with a small Mn-N azide -Mn angle of 100.92(12) • , and is antiferromagnetic for a double EE-N 3 bridging with a small δ angle, 9.69(3) • , which are consistent with the reported results for related compounds [13,22,23,[33][34][35][36][37][38]. In Table S1, a detailed overview of the literature is given with structural details and J values for a variety of Mn compounds, including the present two new compounds.…”

“…Therefore, it is assumed that the spin-canted antiferromagnetism in 1 can be attributed to weak single-ion magnetic anisotropy by a distorted metal coordination environment at low temperature. Similar spin canting behavior has been observed in a few other Mn(II) compounds containing chains of alternating double EO and double EE bridging modes of azides [34,58].…”

“…Therefore, it is assumed that the spincanted antiferromagnetism in 1 can be attributed to weak single-ion magnetic anisotropy by a distorted metal coordination environment at low temperature. Similar spin canting behavior has been observed in a few other Mn(II) compounds containing chains of alternating double EO and double EE bridging modes of azides [34,58]. The field-induced magnetic phase transition for compound 1 was further investigated by the measurements of various fields of the FC magnetic susceptibilities, χM(T), and the field dependence of the magnetizations, M(H), at different temperatures.…”

“…Furthermore, the temperature dependences of χ M T for compound 1 under 100 Oe were also collected (see Figure S4), showing similar behavior to that under 1000 Oe except for that in the low-temperature range, in which the χ M T value slightly increases with decreasing temperature below 6.0 K to a maximum of 0.381 cm 3 mol −1 K at 4.5 K and then sharply decreases to 0.076 cm 3 mol −1 K at 2.0 K. This suggests that a possible mechanism involving weak ferromagnetic correlations is operative within compound 1 below 6.0 K and the final decrease may be due to antiferromagnetic interactions between the chains and/or saturation effects. These weak ferromagnetic correlations can be attributed to spin canting, i.e., the antiferromagnetically coupled local spins within the -Mn-(EE-N 3 ) 2 -Mn-EO-N 3 ) 2 -chains are not perfectly antiparallel, but are canted with respect to each other, resulting in uncompensated residual spins [13,22,23,[33][34][35][36][37].…”