Novel One-Dimensional Polymers Generated fromp-Ferrocenylbenzoate:  Syntheses, Structures, and Magnetic Properties

Abstract

Treatment of p-ferrocenylbenzoate [p-HOOCH4C6Fc, Fc = (eta5-C5H5)Fe(eta5-C5H5)] with Mn(OAc)2 x 2H2O or Cd(OAc)2 x 2H2O afforded one-dimensional linear chain polymer [[Mn(OOCH4C6Fc)2(mu2-OH2)(H2O)2](H2O)]n (1), double-bridge polymer [Mn(mu2-OOCH4C6Fc)2(phen)]n (phen = phenanthroline) (2), and ladderlike framework [[Cd(mu2-OOCH4C6Fc)(eta2-OOCH4C6Fc)(bbp)](CH3OH)]n (bbp = 4,4'-trimethylene-dipyridine) (3). The solution-state cyclic voltammograms indicate that the half-wave potentials of the ferrocenyl moieties in these polymers are all shifted to positive potential compared to that of sodium p-ferrocenylbenzoate. Both 1 and 2 behave as 1D Heisenberg Mn(II) chains with weak intrachain antiferromagnetic interactions between the local high-spin Mn(II) ions, and the exchange coupling parameters J (-5.20 and -3.25 cm(-1) for 1 and 2, respectively) are larger than those of most of the reported di-Mn(II) complexes that contain mu2-aqua and mu2-carboxylato units and one-dimensional Mn(II) carboxylic polymers.

Versatility in the Coordination Modes of n‐Chlorobenzoato Ligands: Synthesis, Structure and Magnetic Properties of Three Types of Polynuclear MnII Compounds

“…To the best of our knowledge, there are only three 1D compounds with a similar core that have been structurally and magnetically characterized. [21,22,24] As can be seen in Table 6, the analogous compound with a bpy ligand, [Mn(bpy)(3-ClC 6 H 4 COO) 2 ] n , [21] shows similar structural parameters and J value to those of 4, which is indicative of the minor effect of the basicity of the terminal ligands. However, changing the bridging ligands from chlorobenzoato to chloroacetato as in [Mn(ClCH 2 COO) 2 -(phen)] n [22] leads to a modification of the Mn-O distances and hence the J value.…”

“…The manganese ions are bridged by two carboxylate ligands coordinated in a syn-anti mode, with a Mn···Mn distance of 4.546 Å, which is slightly longer than that reported for the analogous compound with 2,2Ј-bypiridine (4.515 Å) [21] but in the range of distances reported for other 1D compounds with a [Mn(µ 1,3 -RCOO) 2 ] n core (4.515-4.852 Å). [21,22,[24][25][26][27][28][29][30][31][32][33] There are two different Mn-O distances: the shortest distances (2.091 Å) correspond to O syn , while the largest distances (2.200 Å) correspond to O anti . The O syn atoms are trans to a N phen atom, while the O anti atoms are trans to the other O anti atoms.…”

“…The difference between these distances is smaller for the chloroacetato compound than for the chlorobenzoato compounds, and its magnetic interaction is weaker than for compound 4 and the analogous compound with bpy. [21] A larger antiferromagnetic coupling was reported for [Mn(FcC 6 H 4 COO) 2 (phen)] n , [24] in which the carboxylate -6.5 [24] [a] Abbreviations: Fc = ferrocene. bridges are coordinated in a syn-syn mode.…”

“…[19][20][21][22][23] The number of described 1D Mn II chains with two carbox-4471 -2.8, -1.8 and -3.6 cm -1 for compounds 1-5, respectively. Each type of compound may be distinguished by their characteristic EPR spectrum at 4 K. Fairly good simulations of the spectra at 4 K for the trinuclear compounds 1-3 were obtained with ground state ZFS parameters, D 5 ylate bridges is few; [21][22][24][25][26][27][28][29][30][31][32][33] not many of them are magnetically characterized, [21,22,24] and there are even fewer studied by EPR spectroscopy. [21,22] With regard to dinuclear Mn II compounds, there are not many compounds with a [Mn 2 (µ-H 2 O)(µ-RCOO) 2 ] 2+ core reported in the literature, [34][35][36][37][38][39][40][41][42][43][44] and fewer whose magnetic properties have been studied [41][42][43][44] or whose EPR spectrum have been reported.…”

Synthesis, Crystal Structure, and Magnetic Properties of Two Manganese(II) Polymers Bearing Ferrocenecarboxylato Ligands

“…[7] To the best of our knowledge, only three papers have been published on manganese complexes with ferrocene-involving carboxylate groups as ligands. [8][9][10] Among them, only the study reported by Hou, et al includes some investigation of the magnetic properties of the manganese complex with a p-ferrocenylbenzoato ligand. [9] In the other two cases, Tian, et al [8] and Kondo et al [10] described the redox properties of a dinuclear complex cation [Mn 2 (phen) 4 …”