Spin Canting and Topological Ferrimagnetism in Two Manganese(II) Coordination Polymers Generated by In Situ Solvothermal Ligand Reactions

Abstract

Two manganese(II) coordination polymers, [Mn 2 (bpt)(pa) 2 -(N 3 )] n [1; Hpa = picolinic acid, Hbpt = 3,5-bis(2-pyridyl)-4H-1,2,4-triazole] and [Mn 3 (ina) 2 (pa) 2 (N 3 ) 2 ] n (2; Hina = isonicotinic acid), have been synthesized by solvothermal treatment, in which the ligands bpt and pa were generated in situ by cyclocondensation and hydrolysis of 2-pyridylamidrazone, respectively. In 1, each binuclear subunit [Mn 2 (bpt)(N 3 )] bridged by bpt and N 3 -ligands is interlinked to four adjacent subunits via four tridentate pa ligands into a diamondoid 3D network, which shows spin-canting magnetism arising from

Spin canting and metamagnetism in the two azido-bridged 1D complexes [Ni(3,5-dmpy)2(N3)2]n and [Co1.5(3,5-dmpy)3(N3)3]n

“…The ZFCM and FCM show a divergence below 31 K, suggesting the irreversible transition of the weak ferromagnetism. 17 The x M T maximum is suppressed by the applied fields (see the curves at 0.2 T, 0.5 T and 1.5 T in Fig. 3), characteristic of field-induced metamagnets.…”

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

“…The spin canting angle estimated to be about α = 0.30°, based on the equation sin(α) = MR/MS (MR = 0.026 obtained by extrapolating the high-field linear part of the magnetization curve at 1.8 zero field, and MS = 5.0 Nβ) [42][43][44][45]. Generally speaking, spin canting can arise from two contributions: (i) the presen an antisymmetric exchange Dzyaloshinsky−Moriya interaction [46] and (ii) the exist of single-ion magnetic anisotropy [47][48][49][50][51][52]. The presence of an inversion center betw adjacent spin centers can result in the disappearance of the antisymmetric excha Hence, the lack of antisymmetric exchange in compound 1 would be expected, due to existence of a crystallographic inversion center between the Mn(II) ions (see symm codes in caption of Figure 2).…”

“…The presence of an inversion center betw adjacent spin centers can result in the disappearance of the antisymmetric excha Hence, the lack of antisymmetric exchange in compound 1 would be expected, due to existence of a crystallographic inversion center between the Mn(II) ions (see symm codes in caption of Figure 2). However, the Mn1 center in 1 displays a distorted octahe Generally speaking, spin canting can arise from two contributions: (i) the presence of an antisymmetric exchange Dzyaloshinsky−Moriya interaction [46] and (ii) the existence of single-ion magnetic anisotropy [47][48][49][50][51][52]. The presence of an inversion center between adjacent spin centers can result in the disappearance of the antisymmetric exchange.…”

A 2D rhomboidal system of manganese(ii) [Mn(3-MeC6H4COO)2(H2O)2]n with spin canting: rationalization of the magnetic exchange

“…There are several examples of systems with an antiferromagnetic interaction between similar spins that show weak ferromagnetism at low temperature, due to the nonperfect alignment of the antiferromagnetically coupled spins (spin canting). [18][19][20][21] In this work we report the synthesis, crystal structure and magnetic properties of a new 2D magnetic system with the chemical formula [Mn(3-MeC6H4COO)2(H2O)2]n and a syn-anti conformation of the carboxylate ligand. The analysis of the experimental magnetic data has been carried out by a fitting procedure using the expansion series for a weakly anisotropic quadratic-layer antiferromagnet reported by Lines.22 This methodology provides the value for the exchange coupling constant J between the neighboring Mn(II) ions.…”