New Mononuclear Mn(III) Complexes with Hydroxyl-Substituted Hexadentate Schiff Base Ligands

Xu, Peng-Yu; Wang, Yu-Ting; Yu, Zong-Mei; Li, Yong-Hua; Wang, Shi

doi:10.3390/magnetochemistry7010012

Open AccessArticle

New Mononuclear Mn(III) Complexes with Hydroxyl-Substituted Hexadentate Schiff Base Ligands

Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China

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Magnetochemistry 2021, 7(1), 12; https://0-doi-org.brum.beds.ac.uk/10.3390/magnetochemistry7010012

Submission received: 10 December 2020 / Revised: 29 December 2020 / Accepted: 11 January 2021 / Published: 13 January 2021

(This article belongs to the Special Issue Molecular Magnetism 2021: Paradigmatic Landmarks and Horizons)

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Abstract

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This paper reports the syntheses, crystal structures and magnetic properties of Mn(III) hexadentate Schiff base complexes [Mn(4-OH-sal-N-1,5,8,12)]NO₃ (1) and [Mn(4-OH-sal-N-1,5,8,12)]ClO₄ (2), where (4-OH-sal-N-1,5,8,12)²⁻ (4,4′-((1E,13E)-2,6,9,13-tetraazatetradeca-1,13-diene-1,14-diyl)bis(3-methoxyphenol) is a new hydroxyl-substituted hexadentate Schiff base ligand. The introduction of the (4-OH-sal-N-1,5,8,12)²⁻ ligand induces more hydrogen bonding interactions, in addition to promoting the formation of intermolecular interactions among the cations. However, the close-packing structures of both complexes lead to their stabilization in the high-spin state in the temperature range of 2−300 K.

Keywords:

spin crossover; manganese(III); hydrogen bonding; crystal structure

1. Introduction

Spin crossover (SCO), which is a hot topic in modern materials science [1,2,3,4,5,6], occurs in octahedral transition metal complexes with electron configurations of 3d⁴−3d⁷. The phenomenon between a low-spin (LS) and a high-spin (HS) state may be triggered by the use of external stimuli, such as light, heat, magnetic field, and pressure [7,8,9,10,11].

Schiff bases are used widely because they are readily derivatized and generally easy to prepare. As versatile ligands, they can stabilize a wide range of geometries and oxidation states in transition metal complexes. This great diversity may permit the design of Schiff bases with a suitable ligand field strength to obtain Mn(III) SCO complexes. Notably, the first SCO d⁴ system [Mn(pyrol)₃tren] with a hexadentate N₆ Schiff base ligand was designed in 1981 by Sinn and Sim [12], breaking the conventional wisdom that it was too difficult to generate an amenable ligand-field strength to stabilize an LS state in Mn(III) complexes. Later, the prototypic gradual SCO phenomenon of a Mn(III) hexadentate N₄O₂ Schiff base complex was reported in 2006 by Morgan et al. [13] Subsequently, another ligand system, a tridentate Schiff base N₂O ligand provided the third example of Mn(III) SCO compounds [14].

Mn(III) hexadentate Schiff base compounds with N₄O₂ donor sets are extensively studied [13,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30] from various aspects such as ligand substitution [31], the nature of counter anions [32,33,34], and the cocrystallized solvent molecules [35,36,37,38]. The chemical influences affect intermolecular interactions like crystal packing and hydrogen bonding, which offer more possibilities for cooperative SCO behaviors. In previous reports, we reported a series of Mn(III) hexadentate Schiff base compounds [Mn(sal-N-1,5,8,12)]Y (Y = Cl⁻, PF₆⁻, AsF₆⁻, SbF₆⁻, and NO₃⁻) [25] to confirm that the counter anion effects are clearly related to the SCO behavior. Moreover, cocrystallized solvent molecules affect the SCO profoundly. For instance, the complexes [Mn(3,5-diBr-sal-N-1,5,8,12)]ClO₄·C₂H₅OH and [Mn(3,5-diBr-sal-N-1,5,8,12)] ClO₄·0.5CH₃CN show different SCO behaviors [19]. The ethanol solvate has a more complete SCO while the latter persists in the LS state over a considerable temperature range. Besides, the analysis of Mn(III) complexes with various hexadentate Schiff base ligands, such as (3-OMe-sal-N-1,5,8,12)²⁻ [22], (5-OMe-sal-N-1,5,8,12)²⁻ [24,30], (5-Br-sal-N-1,5,8,12)²⁻ [18] and (naphth-sal-N-1,5,8,12)²⁻ [29], has emphasized the impact of the substituent effects.

In addition, the report on the 4-position of salicylaldehyde of hexadentate Schiff base ligands is rare; however, a series of Mn(III) SCO compounds [Mn(4-R-sal-N-1,5,8,12)]Y (R = OC₆H₁₃, OC₁₂H₂₅, OC₁₈H₃₇) with gradual and uncompleted SCO behavior were reported by Albrecht and his co-workers [16]. Under this circumstance, we study to obtain complexes that can provide strong cooperation interactions and more complete SCO behaviors. Therefore, the complexes [Mn(4-OH-sal-N-1,5,8,12)]Y (Y = NO₃⁻ and ClO₄⁻) (Scheme 1) were selected with the following main goals: increase the number of hydrogen bonds through the hydroxyl group, in order to strengthen the connection between anions and cations and improve the cooperativity of the system.

Herein, we report the synthesis, X-ray crystal structures, and magnetic properties of two isostructural compounds with the general formula [Mn(4-OH-sal-N-1,5,8,12)]Y (Y = NO₃⁻ and ClO₄⁻). Correlations between properties and structures are discussed with respect to the alteration of the geometry and hydrogen-bonding acceptor of the anions.

2. Experimental Section

All of the reagents and chemicals were analytically pure, purchased from commercial sources, and were used without further purification. Although we experienced no problems with the compounds reported in this work, the manganese perchlorate salt with the organic ligand is potentially explosive and should be handled with great care and used in small amounts. Elemental analyses of C, H, and N were performed on a Vario EL III elemental analyzer. IR spectra of the solid samples (KBr tablets) in the range 400−4000 cm⁻¹ were recorded by an FT-IR Perkin Elmer spectrometer. The properties of the Hirshfeld surface for complexes 1 and 2 were generated using a CrystalExplorer 17.5. The Hirshfeld surface was generated using a high resolution and mapped with the d_norm and shape-indexed functions. 2D fingerprint plots were prepared using the same software. Magnetic susceptibility was measured in a sweep mode upon cooling from 300 to 2 K under a 0.1 T applied magnetic field by the use of a Quantum Design MPMS SQUID VSM magnetometer. A freshly prepared crystalline sample was placed in a gelatin capsule holder. Magnetic data were calibrated with the sample holder and diamagnetic corrections were estimated from Pascal’s constants. Magnetic behavior was primarily analyzed by using variable-temperature magnetic susceptibility measurements.

[Mn(4-OH-sal-N-1,5,8,12)]NO₃ (1) 2,4-dihydroxybenzaldehyde (31.4 mg, 0.228 mmol) and N,N-bis(3-aminopropyl)ethylenediamine (21.4 mg, 0.114 mmol) dissolved in methanol (6 mL), and then solid manganese(II) nitrate tetrahydrate (33.4 mg, 0.114 mmol) was added. The resulting dark brown solution was stirred for half an hour and then filtered. Black crystals formed upon evaporation of the solvent (56.9%). Anal. calcd for C₂₂H₂₈MnN₅O₇: C, 49.91; H, 5.33; N, 13.23. Found: C, 49.86; H, 5.35; N, 13.16. IR (cm⁻¹): 3550 (m, sh), 1613 (m, sh), 1338 (m, sh).

[Mn(4-OH-sal-N-1,5,8,12)]ClO₄ (2) 2,4-dihydroxybenzaldehyde (45.8 mg, 0.332 mmol) and N,N-bis(3-aminopropyl)ethylenediamine (28.9 mg,0.166 mmol) dissolved in methanol (6 mL), and then solid manganese(II) perchlorate hexahydrate (41.9 mg, 0.166 mmol) was added_. The resulting dark brown solution was stirred for half an hour and then filtered_. Black crystals formed upon evaporation of the solvent (63.8%)_. Anal_. calcd for C₂₂H₂₈ClMnN₄O₈: C, 46.61; H, 4.98; N, 9.88. Found: C, 46.66; H, 4.94; N, 9.83. IR (cm⁻¹): 3552 (m, sh), 1618 (m, sh), 1076 (st,sh), 619 (m, b).

3. Results and Discussion

3.1. Crystallographic Studies

Single-crystal X-ray diffraction data for the compounds [Mn(4-OH-sal-N-1,5,8,12)]NO₃ (1) and [Mn(4-OH-sal-N-1,5,8,12)]ClO₄ (2) were collected at 100 and 298 K, respectively. Table 1 presents the most relevant parameters for single-crystal determination.

At both temperatures (100 and 298 K), the two isomorphic complexes crystallized in the triclinic

P \bar{1}

space group. The asymmetric unit of 1 contained one [Mn(4-OH-sal-N-1,5,8,12)]⁺ cation and one NO₃⁻ counter anion (Figure 1), while one [Mn(4-OH-sal-N-1,5,8,12)]⁺ cation and one ClO₄⁻ anion were observed in the structure of 2 (Figure 2). In these compounds, the Mn³⁺ ion was coordinated pseudo-octahedrally by trans-O (O1 and O2) donors in the axial position and pairs of cis-imine (N1 and N4) and cis-amine (N2 and N3) in the equatorial plane. The Mn-N_imine (N1 and N4) (2.075–2.135 Å), Mn-N_amine (N2 and N3) (2.233–2.291 Å), and Mn-O (1.864–1.880 Å) bond lengths at 100 K were in greatagreement with those observed in other HS Mn(III) hexadentate Schiff base complexes. Moreover, the bond lengths of the complexes at 298 K had no significant change compared with those at 100 K (Table 2).

The octahedral distortion parameters Σ and θ can intuitively reflect the changes of the Mn(III) coordination sphere. For complex 1, θ was from 292.38° at 100 K to 291.98° at 298 K, while the change in Σ was small, with values of 79.59° and 79.41°, respectively. Both parameters, with a little change, further demonstrate that there was no SCO behavior in complex 1. The central Mn³⁺ ion of compound 2, which is similar to complex 1, was furnishing a distorted octahedral geometry (θ = 289.93° and Σ = 77.66° at 100 K; θ = 294.06° and Σ = 78.90° at 298 K).

In Figure 3, a pair of [Mn(4-OH-sal-N-1,5,8,12)]⁺ cations form a centrosymmetric dimer through the N–H···O hydrogen bonds between the amino nitrogen atoms and peripheral hydroxy oxygen atoms. Moreover, weak edge-to-edge π···π contacts exist between the two sets of C(1)–C(2) atoms (Figure 4), and stabilize the dimer structure.

The anions connected cationic dimers located in chains via the O–H···O hydrogen bonds (Figure 3). The supramolecular chains were relatively independent and extended infinitely in the bc-plane. With the increase of the temperature, there was no significant change in the strength of the hydrogen bonds (Table 3). The intrachain Mn-Mn separation was 8.337 Å at 100 K and 8.349 Å at 298 K. However, the formation of dimers resulted in the short interchain Mn···Mn distance, which was 6.709 Å at 100 K and 6.749 Å at 298 K, respectively. The close Mn–Mn distance gave the [Mn(4-OH-sal-N-1,5,8,12)]⁺ cation less space to change the coordination geometry.

As for complex 2, increasing the size of the anion from planar NO₃⁻ to tetrahedral ClO₄⁻ resulted in more intricate interconnections, but there was no change in crystal packing. Moreover, the formations of supramolecular dimers indicate the close contacts between the [Mn(4-OH-sal-N-1,5,8,12)]⁺ cations. The existence of O(2)–H(2)···O(7), O(7)–H(27)···O(3) and O(6)–H(27)···O(3) hydrogen bonds contributed to the close stacking between the anions and cations, which hindered the flexibility of the whole ligand and prevented the distortion of the Mn(III) coordination geometry (Figure 5). In addition, the interchain Mn-Mn separation changed from 6.841 at 298 K to 6.740 Å at 100 K because of its bigger anion size. However, this did not give the Mn(III) cation enough space to change its conformation to meet the structural requirements of SCO.

3.2. Hirshfeld Surface Analysis

To gain deeper insight into the supramolecular contacts in 1 and 2, we undertook Hirshfeld surface analysis using CrystalExplorer 17.5. The Hirshfeld surfaces for the cations of complexes 1 and 2 were mapped with the d_norm function [39,40], which shows several red spots. For 1, the four strongest red spots were due to N–H···O and O–H···O hydrogen bonding interactions, and the weak red spots were due to C–H···O interactions (Figure 6a). The hydrogen bond was one of the major interactions here, contributing to 17% of all interactions in Figure 6c.

For complex 2, owing to the change in anions, the hydrogen bond contributed to 24.8% of all interactions (Figure 6d). This supports the discussion above and suggests that the OH group in the (4-OH-sal-N-1,5,8,12)²⁻ ligand is critical in linking the [Mn(4-OH-sal-N-1,5,8,12)]⁺ cations together in these structures.

In order to more intuitively study the influence of hydroxyl on the hydrogen bond interaction, we introduced Hirshfeld surface analysis on the complex [Mn(4-OC₆H₁₃-sal-N-1,5,8,12)]NO₃·H₂O [16] (Figure 7). Though it crystallizes as an H₂O solvate, the hydrogen bond contributed to only 9.6% of all interactions. All in all, the OH group played a significant role in non-covalent interactions.

From the Hirshfeld analysis, it was very clear that the hydroxyl group effectively enhanced the hydrogen bonding interactions in both complexes. However, these non-covalent intermolecular forces were insufficient to result in a cooperative SCO. The cation structures were tightly packed, hindering the distortion required to undergo SCO.

3.3. Magnetic Characterization

The temperature dependence of the product χ_MT (χ_M is the molar paramagnetic susceptibility) versus T plots for the crystalline samples of complexes 1 and 2 is shown in Figure 8 and Figure 9, respectively.

At room temperature, the χ_MT value of 1 was about 2.79 cm³ K mol⁻¹, which is typical of an HS Mn³⁺ center (S = 2) with a g value of 2.0 (Figure 7). As the temperature went down, the χ_MT value was constant until 20 K, when it decreased rapidly because of the ZFS (zero field split) effects of HS Mn³⁺ ions. However, within the temperature range, the χ_MT value did not drop to 1.0 cm³ K mol⁻¹. The temperature dependence of the χ_M⁻¹ of complex 1 is shown in Figure 7. It is linear between 2 and 300 K and a linear least-squares fit yields a Curie constant of 2.84 emu K mol⁻¹, a Weiss temperature θ of −1.67 K, while the Curie constant and θ value of compound 2 was 2.95 emu K mol⁻¹ and −1.51 K (Figure 8).

The magnetic characterization of [Mn(4-OH-sal-N-1,5,8,12)]ClO₄ was similar to that of complex 1, and increasing the size of the anion from NO₃⁻ from ClO₄⁻ seems to have had no effect on the magnetic behavior.

4. Conclusions

In an effort to synthesize new Mn(III) SCO complexes, we have described two new isomorphic [Mn(4-OH-sal-N-1,5,8,12)]Y (Y = NO₃⁻ and ClO₄⁻) complexes. The crystal structure of these compounds is rich in non-covalent contacts (hydrogen bonding and π···π interactions) between the mononuclear cations and anions. Whereas, compared with other Mn(III) hexadentate Schiff base SCO complexes, such as [Mn(5-OMe-sal-N-1,5,8,12)]Cl and [Mn(sal-N-1,5,8,12)]NO₃, the introduction of hydroxyl groups makes the Mn(III) cations dimerized and weakens the interactions between anions and cations. Besides, the Mn···Mn separations are short and the connections between Mn³⁺ centers are extremely close. They may limit the Mn³⁺ cations to change their coordination geometry.

Author Contributions

Methodology, Z.-M.Y.; formal analysis, Y.-T.W. and P.-Y.X.; investigation, Y.-T.W. and P.-Y.X.; resources, Y.-H.L.; project administration, S.W.; All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

The data presented in this study are available in this article.

Acknowledgments

We gratefully acknowledge financial support from the Natural Science Foundations of China (grant no. 21771110) and from the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions (grant no. YX03002).

Conflicts of Interest

There is no conflict to declare.

References

Vogelsberg, C.S.; Garcia-Garibay, M.A. Crystalline molecular machines: Function, phase order, dimensionality, and composition. Chem. Soc. Rev. 2012, 41, 1892–1910. [Google Scholar] [CrossRef] [PubMed]
Ohkoshi, S.; Tokoro, H. Photomagnetism in Cyano-Bridged Bimetal Assemblies. Acc. Chem. Res. 2012, 45, 1749–1758. [Google Scholar] [CrossRef] [PubMed]
Koumousi, E.S.; Jeon, I.-R.; Gao, Q.; Dechambenoit, P.; Woodruff, D.N.; Merzeau, P.; Buisson, L.; Jia, X.; Lionel, B.; Volatron, F.; et al. Metal-to-Metal Electron Transfer in Co/Fe Prussian Blue Molecular Analogues: The Ultimate Miniaturization. J. Am. Chem. Soc. 2014, 136, 15461–15464. [Google Scholar] [CrossRef] [PubMed]
Irie, M.; Fukaminato, T.; Matsuda, K.; Kobatake, S. Photochromism of Diarylethene Molecules and Crystals: Memories, Switches, and Actuators. Chem. Rev. 2014, 114, 12174–12277. [Google Scholar] [CrossRef] [PubMed]
Zhang, J.L.; Zhong, J.-Q.; Lin, J.D.; Hu, W.P.; Wu, K.; Xu, G.Q.; Wee, A.T.S.; Chen, W. Towards single molecule switches. Chem. Soc. Rev. 2015, 44, 2998–3022. [Google Scholar] [CrossRef] [PubMed] [Green Version]
Gerhard, L.; Edelmann, K.; Homberg, J.; Valasek, M.; Bahoosh, S.G.; Lukas, M.; Pauly, F.; Mayor, M.; Wulfhekel, W. An electronically actuated molecular toggle switch. Nat. Commun. 2017, 8, 14672. [Google Scholar] [CrossRef] [Green Version]
Kahn, O.; Martinez, C.J. Spin-transition Polymers: From Molecular Materials Toward Memory Devices. Science 1998, 279, 44–48. [Google Scholar] [CrossRef]
Southon, P.D.; Liu, L.; Fellows, E.A.; Price, D.J.; Halder, G.J.; Chapman, K.W.; Moubaraki, B.; Murray, K.S.; Létard, J.-F.; Kepert, C.J. Dynamic Interplay between Spin-Crossover and Host−Guest Function in a Nanoporous Metal−Organic Framework Material. J. Am. Chem. Soc. 2009, 131, 10998–11009. [Google Scholar] [CrossRef]
Bousseksou, A.; Molnár, G.; Salmon, L.; Nicolazzi, W. Molecular spin crossover phenomenon: Recent achievements and prospects. Chem. Soc. Rev. 2011, 40, 3313–3335. [Google Scholar] [CrossRef]
Linares, J.; Codjovi, E.; Garcia, Y. Pressure and Temperature Spin Crossover Sensors with Optical Detection. Sensors 2012, 12, 4479–4492. [Google Scholar] [CrossRef]
Gao, D.; Liu, Y.; Miao, B.; Wei, C.; Ma, J.-G.; Cheng, P.; Yang, G.-M. Pressure Sensor with a Color Change at Room Temperature Based on Spin-Crossover Behavior. Inorg. Chem. 2018, 57, 12475–12479. [Google Scholar] [CrossRef] [PubMed]
Sim, P.G.; Sinn, E. First manganese(III) spin crossover and first d4 crossover: Comment on cytochrome-oxidase. J. Am. Chem. Soc. 1981, 103, 241–243. [Google Scholar] [CrossRef]
Morgan, G.G.; Murnaghan, K.D.; Müller-Bunz, H.; McKee, V.; Harding, C.J. A Manganese(III) Complex That Exhibits Spin Crossover Triggered by Geometric Tuning. Angew. Chem. Int. Ed. 2006, 45, 7192–7195. [Google Scholar] [CrossRef] [PubMed]
Ossinger, S.; Naggert, H.; Kipgen, L.; Jasper-Toennies, T.; Rai, A.; Rudnik, J.; Nickel, F.; Arruda, L.M.; Bernien, M.; Kuch, W.; et al. Vacuum-Evaporable Spin-Crossover Complexes in Direct Contact with a Solid Surface: Bismuth versus Gold. J. Phys. Chem. C 2017, 121, 1210–1219. [Google Scholar] [CrossRef]
Wang, S.; Ferbinteanu, M.; Marinescu, C.; Dobrinescu, A.; Ling, Q.-D.; Huang, W. Case Study on a Rare Effect: The Experimental and Theoretical Analysis of a Manganese(III) Spin-Crossover System. Inorg. Chem. 2010, 49, 9839–9851. [Google Scholar] [CrossRef] [PubMed]
Gandolfi, C.; Cotting, T.; Martinho, P.N.; Sereda, O.; Neels, A.; Morgan, G.G.; Albrecht, M. Synthesis and self-assembly of spin-labile and redox-active manganese(iii) complexes. Dalton Trans. 2010, 40, 1855–1865. [Google Scholar] [CrossRef] [PubMed] [Green Version]
Martinho, P.N.; Gildea, B.; Harris, M.M.; Lemma, T.; Naik, A.D.; Müller-Bunz, H.; Keyes, T.E.; Garcia, Y.; Morgan, G.G. Cooperative Spin Transition in a Mononuclear Manganese(III) Complex. Angew. Chem. Int. Ed. 2012, 51, 12597–12601. [Google Scholar] [CrossRef]
Gildea, B.; Gavin, L.C.; Murray, C.A.; Müller-Bunz, H.; Harding, C.J.; Morgan, G.G. Supramolecular modulation of spin crossover profile in manganese(III). Supramol. Chem. 2012, 24, 641–653. [Google Scholar] [CrossRef]
Pandurangan, K.; Gildea, B.; Murray, C.; Harding, C.J.; Müller-Bunz, H.; Morgan, G.G. Lattice Effects on the Spin-Crossover Profile of a Mononuclear Manganese(III) Cation. Chem. A Eur. J. 2012, 18, 2021–2029. [Google Scholar] [CrossRef]
Wang, S.; He, W.-R.; Ferbinteanu, M.; Li, Y.-H.; Huang, W. Tetragonally compressed high-spin Mn(III) Schiff base complex: Synthesis, crystal structure, magnetic properties and theoretical calculations. Polyhedron 2013, 52, 1199–1205. [Google Scholar] [CrossRef]
Chen, Y.; Gao, F.; Wei, R.-M.; Zhang, Y.; Zhang, Y.-Q.; Song, Y. Spin-crossover phenomena of the mononuclear MnIII complex tuned by metal dithiolene counteranions. Dalton Trans. 2014, 43, 3783–3791. [Google Scholar] [CrossRef] [PubMed]
Gildea, B.; Harris, M.M.; Gavin, L.C.; Murray, C.A.; Ortin, Y.; Müller-Bunz, H.; Harding, C.J.; Lan, Y.; Powell, A.K.; Morgan, G.G. Substituent Effects on Spin State in a Series of Mononuclear Manganese(III) Complexes with Hexadentate Schiff-Base Ligands. Inorg. Chem. 2014, 53, 6022–6033. [Google Scholar] [CrossRef] [PubMed]
Morgan, G.G.; Fitzpatrick, A.J.; Trzop, E.; Müller-Bunz, H.; Dîrtu, M.M.; Garcia, Y.; Collet, E. Electronic vs. structural ordering in a manganese(III) spin crossover complex. Chem. Commun. 2015, 51, 17540–17543. [Google Scholar]
Wang, S.; Li, Y.-H.; Huang, W. Effects of Big Planar Anions on the Spin Transition of a Mononuclear Manganese(III) Complex with a Hexadentate Schiff-Base Ligand. Eur. J. Inorg. Chem. 2015, 2015, 2237–2244. [Google Scholar] [CrossRef]
Wang, S.; Xu, W.-T.; He, W.-R.; Takaishi, S.; Li, Y.-H.; Yamashita, M.; Huang, W. Structural insights into the counterion effects on the manganese(iii) spin crossover system with hexadentate Schiff-base ligands. Dalton Trans. 2016, 45, 5676–5688. [Google Scholar] [CrossRef]
Wang, S.; Li, Y.-J.; Ju, F.-F.; Xu, W.-T.; Kagesawa, K.; Li, Y.-H.; Yamashita, M.; Huang, W. The molecular and supramolecular aspects in mononuclear manganese(iii) Schiff-base spin crossover complexes. Dalton Trans. 2017, 46, 11063–11077. [Google Scholar] [CrossRef]
Barker, A.; Kelly, C.T.; Kühne, I.A.; Hill, S.; Krzystek, J.; Wix, P.; Esien, K.; Felton, S.; Müller-Bunza, H.; Morgan, G.G. Spin state solvomorphism in a series of rare S = 1 manganese(III) complexes. Dalton Trans. 2019, 48, 15560–15566. [Google Scholar] [CrossRef] [PubMed]
Kazakova, A.V.; Tiunova, A.V.; Korchagin, D.V.; Shilov, G.V.; Yagubskii, E.B.; Zverev, V.N.; Yang, S.C.; Lin, J.; Lee, J.; Maximova, O.V.; et al. The First Conducting Spin-Crossover Compound Combining a Mn III Cation Complex with Electroactive TCNQ Demonstrating an Abrupt Spin Transition with a Hysteresis of 50 K. Chem. A Eur. J. 2019, 25, 10204–10213. [Google Scholar] [CrossRef]
Zhao, S.-Z.; Qin, C.-Y.; Wang, S.; Yamashita, M.; Li, Y.-H.; Huang, W. Structure function correlations in mononuclear manganese(III) spin crossover systems with a big conjugated hexadentate Schiff-base ligand. Dalton Trans. 2020, 49, 4293–4305. [Google Scholar] [CrossRef]
Villaman, D.; McMonagle, C.J.; Probert, M.R.; Peña, O.; Moreno, Y.; Fuentealba, M. Structural studies of a manganese(iii) complex with spin-crossover and thermochromic properties. CrystEngComm 2020, 22, 3221–3233. [Google Scholar] [CrossRef]
Krüger, C.; Augustín, P.; Dlháň, L.; Pavlik, J.; Moncol’, J.; Nemec, I.; Boča, R.; Renz, F. Iron(III) complexes with pentadentate Schiff-base ligands: Influence of crystal packing change and pseudohalido coligand variations on spin crossover. Polyhedron 2015, 87, 194–201. [Google Scholar] [CrossRef]
Yamada, M.; Hagiwara, H.; Torigoe, H.; Matsumoto, N.; Kojima, M.; Dahan, F.; Tuchagues, J.P.; Re, N.; Iijima, S. A variety of spin-crossover behaviors depending on the counter anion: Two-dimensional complexes constructed by NH Cl hydrogen bonds, [FeIIH3LMe]Cl·X (X=PF6, AsF6, SbF6, CF3SO3; H3LMe=Tris[2-{[(2-methylimidazol-4-yl) methylidene]amino}ethyl]amine). Chem. Eur. J. 2006, 12, 4536–4549. [Google Scholar] [CrossRef] [PubMed]
Ni, Z.; McDaniel, A.M.; Shores, M.P. Ambient temperature anion-dependent spin state switching observed in “mostly low spin” heteroleptic iron(ii) diimine complexes. Chem. Sci. 2010, 1, 615–621. [Google Scholar] [CrossRef]
Nemec, I.; Herchel, R.; Šalitroš, I.; Trávníček, Z.; Moncoľ, J.; Fuess, H.; Ruben, M.; Linert, W. Anion driven modulation of magnetic intermolecular interactions and spin crossover properties in an isomorphous series of mononuclear iron(iii) complexes with a hexadentate Schiff base ligand. CrystEngComm 2012, 14, 7015. [Google Scholar] [CrossRef]
Li, B.; Wei, R.-J.; Tao, J.; Huang, R.-B.; Zheng, L.-S.; Zheng, Z. Solvent-Induced Transformation of Single Crystals of a Spin-Crossover (SCO) Compound to Single Crystals with Two Distinct SCO Centers. J. Am. Chem. Soc. 2010, 132, 1558–1566. [Google Scholar] [CrossRef] [PubMed]
Wei, R.-J.; Tao, J.; Huang, R.-B.; Zheng, L.-S. Reversible and Irreversible Vapor-Induced Guest Molecule Exchange in Spin-Crossover Compounds. Inorg. Chem. 2011, 50, 8553–8564. [Google Scholar] [CrossRef]
Costa, J.S.; Rodríguez-Jiménez, S.; Craig, G.A.; Barth, B.; Beavers, C.M.; Teat, S.J.; Aromí, G. Three-way crystal-tocrystal reversible transformation and controlled spin switching by a nonporous molecular material. J. Am. Chem. Soc. 2014, 136, 3869–3874. [Google Scholar] [CrossRef]
Wannarit, N.; Nassirinia, N.; Amani, S.; Masciocchi, N.; Youngme, S.; Roubeau, O.; Teat, S.J.; Gamez, P. Drastic Effect of Lattice Propionitrile Molecules on the Spin-Transition Temperature of a 2,2′-Dipyridylamino/s-triazine-Based Iron(II) Complex. Inorg. Chem. 2014, 53, 9827–9836. [Google Scholar] [CrossRef]
Spackman, M.A.; Jayatilaka, D. Hirshfeld surface analysis. CrystEngComm. 2009, 11, 19–32. [Google Scholar] [CrossRef]
Hassan, N.H.H.; Abdullah, A.A.; Arshad, S.; Khalib, N.C.; Razak, I.A. Crystal structure and Hirshfeld surface analysis of (E)-3-(2-chloro-6-fluorophenyl)-1-(3-fluoro-4-methoxyphenyl)prop-2-en-1-one. Acta Cryst. Sec. E 2016, 72, 716–719. [Google Scholar] [CrossRef]

Scheme 1. Structural unit of the cation [Mn(4-OH-sal-N-1,5,8,12)]⁺.

Figure 1. The structure of [Mn(4-OH-sal-N-1,5,8,12)]NO₃ at T = 100 K. Ellipsoids are drawn at the 50% probability level. Hydrogen atoms were omitted for clarity.

Figure 2. The structure of [Mn(4-OH-sal-N-1,5,8,12)]ClO₄ at T = 100 K. Ellipsoids are drawn at the 50% probability level. Hydrogen atoms were omitted for clarity.

Figure 3. Crystal packing of complex 1 at 100 K, viewed along the a-axis. The cation–anion O–H···O hydrogen bonds are shown with cyan blue dash lines and the cation–cation N–H···O hydrogen bonds are shown with black lines. Most of the hydrogen atoms were omitted for clarity, except for those involved in hydrogen bonds.

Figure 4. The details of π···π stacking interactions between phenolate rings of complex 1 at 100 K. Hydrogen atoms were omitted for clarity.

Figure 5. Crystal packing of complex 2 at 100 K, viewed along the a-axis. The cation–anion O–H···O hydrogen bonds are shown with cyan blue dash lines and the cation–cation N–H···O hydrogen bonds are shown with black lines. Most of the hydrogen atoms were omitted for clarity, except for those involved in hydrogen bonds.

Figure 6. The N–H···O and O–H···O hydrogen bonding interactions in 1 (a) and 2 (b) through Hirshfeld surface mapping by d_norm function. 2D fingerprint plots of all contacts: H···O for 1 (c) and 2 (d) at 298 K.

Figure 7. Hirshfeld surface mapped with d_norm (a); 2D fingerprint plots of H···O for [Mn(4-OC₆H₁₃-sal-N-1,5,8,12)]NO₃·H₂O (b).

Figure 8. Temperature dependence of the χ_MT of [Mn(4-OH-sal-N-1,5,8,12)]NO₃ between 2 and 300 K.

Figure 9. Temperature dependence of the χ_MT of [Mn(4-OH-sal-N-1,5,8,12)]ClO₄ between 2 and 300 K.

Table 1. Selected crystallographic data for complexes 1 and 2.

Formula	1		2
Formula	C₂₂H₂₈MnN₅O₇		C₂₂H₂₈ClMnN₄O₈
CCDC	2,043,724	2,043,725	2,043,722	2,043,723
T, K	100 K	298 K	100 K	298 K
Crystal system	triclinic	triclinic	triclinic	triclinic
Space group	$P \bar{1}$	$P \bar{1}$	$P \bar{1}$	$P \bar{1}$
Z	2	2	2	2
a, Å	9.4195(19)	9.4904(10)	9.6692(14)	9.883(7)
b, Å	10.455(2)	10.4832(10)	10.5597(15)	10.741(7)
c, Å	12.733(3)	12.8865(13)	12.8271(18)	13.204(10)
α, deg	93.434(5)	93.556(2)	93.505(3)	94.021(15)
β, deg	106.356(4)	106.793(2)	107.134(3)	108.463(17)
γ, deg	107.143(5)	106.914(2)	105.371(3)	104.578(16)
V, Å³	1135.7(4)	1159.3(2)	1192.9(3)	1269.4(15)
D_calc, g cm⁻³	1.548	1.517	1.578	1.483
µ, mm⁻¹	0.637	0.624	0.722	0.679
F(000)	552	552	588	588
hkl range	−11 ≤ h ≤ 11	−8 ≤ h ≤ 11	−12 ≤ h ≤ 10	−11 ≤ h ≤ 9
	−8 ≤ k ≤ 12	−12 ≤ k ≤ 11	−14 ≤ k ≤ 13	−12 ≤ k ≤ 12
	−15 ≤ l ≤ 15	−15 ≤ l ≤ 15	−16 ≤ l ≤ 17	−14 ≤ l ≤ 15
Collected	7306	7846	10719	7399
Parameters	333	333	336	339
Goodness-of-fit	1.033	1.075	1.022	1.081
R₁[I>2σ(I)]	0.0525	0.0310	0.0291	0.1847
wR₂[I>2σ(I)]	0.1328	0.0917	0.0722	0.0614
max./min. [e Å⁻³]	0.99/−0.91	0.63/−0.51	0.38/−0.44	0.56/−0.91

Table 2. Selected bond distances (Å), angles (°), and octahedral distortion parameters (°) for complexes 1 and 2.

	1		2
T, K	100 K	298 K	100 K	298 K
Bond distances
Mn1-N1	2.121(3)	2.1194(16)	2.0839(13)	2.148(3)
Mn1-N2	2.233(3)	2.2375(17)	2.2912(13)	2.267(3)
Mn1-N3	2.273(3)	2.2747(18)	2.2369(13)	2.310(3)
Mn1-N4	2.075(3)	2.0852(16)	2.1346(13)	2.116(3)
Mn1-Nav	2.1755	2.1792	2.18665	2.210
Mn1-O1	1.864(2)	1.8688(12)	1.8797(11)	1.894(3)
Mn1-O4	1.872(2)	1.8748(13)	1.8742(11)	1.903(3)
Mn1-Oav	1.868	1.8718	1.87695	1.8985
Bond angles
O4-Mn1-N1	92.22(10)	92.31(6)	91.53(5)	91.79(13)
O1-Mn1-N1	86.86(10)	86.84(6)	88.35(5)	86.85(13)
O4-Mn1-N4	87.88(10)	87.91(6)	86.93(5)	88.51(13)
O1-Mn1-N4	91.43(10)	91.29(6)	91.42(5)	91.17(13)
N1-Mn1-N4	116.80(10)	116.81(6)	116.38(5)	116.84(13)
O4-Mn1-N3	95.42(10)	94.46(6)	93.77(5)	96.33(13)
O1-Mn1-N3	85.86(9)	85.79(6)	86.95(5)	85.30(13)
N4-Mn1-N3	83.15(10)	83.17(7)	82.65(5)	83.18(15)
O4-Mn1-N2	86.35(10)	86.53(6)	85.33(5)	86.68(12)
O1-Mn1-N2	94.76(10)	94.67(6)	96.54(5)	94.16(13)
N1-Mn1-N2	82.87(10)	82.88(7)	83.60(5)	82.33(13)
N3-Mn1-N2	78.07(10)	78.01(7)	78.18(5)	78.48(15)
O4-Mn1-O1	178.46(9)	178.42(5)	178.10(4)	178.29(10)
N1-Mn1-N3	158.93(10)	158.85(7)	160.52(5)	158.64(14)
N4-Mn1-N2	159.72(10)	159.75(7)	158.77(5)	160.39(13)
Mn-Mn distance
interchain	6.709(1)	6.749(6)	6.740(8)	6.841(4)
intrachain	8.337(1)	8.349(7)	8.335(9)	8.431(4)
Octahedral distortion parameters
θ	292.38	291.98	289.93	294.06
Σ	79.59	79.41	77.66	78.90

Table 3. Hydrogen bond distances and parameters for the complexes of 1 and 2 (Å, °).

1
100 K					298 K
D-H···A	D-H	H···A	D···A	angle	D-H···A	D-H	H···A	D···A	angle
N2-H12···O2 ⁱ	0.78(5)	2.32(5)	3.091(4)	170(4)	N2-H12···O2 ^iv	0.87(2)	2.25(3)	3.108(3)	171(2)
O2-H2···O7 ⁱⁱ	0.72(5)	1.96(5)	2.677(4)	175(4)	O2-H2···O5 ^v	0.71(4)	2.01(4)	2.711(3)	177(3)
O3-H27···O6 ⁱⁱⁱ	0.80(4)	2.04(5)	2.796(4)	158(4)	O3-H27···O6 ^vi	0.79(3)	2.06(3)	2.807(3)	158(3)
2
100 K					298 K
D-H···A	D-H	H···A	D···A	angle	D-H···A	D-H	H···A	D···A	angle
N3-H17···O3 ⁱ	0.88(2)	2.34(2)	3.1779(19)	159.2(18)	N2-H12···O2 ^vii	0.89(6)	2.34(6)	3.206(6)	165(5)
O2-H2···O7 ^vi	0.84	2.03	2.8420(18)	163	O2-H2···O5 ⁱⁱ	0.82	2.11	2.922(8)	171
O3-H27···O6	0.84	1.95	2.784(2)	174	O3-H27···O8 ^viii	0.71(5)	2.18(5)	2.861(8)	163(6)
O3-H27···O7	0.84	2.674	3.248(2)	126.79	O2-H2···O8	0.821	2.658	3.272(9)	132.9

Symmetry codes: ⁱ 1-x,1-y,1-z; ⁱⁱ 1+x,y,z; ⁱⁱⁱ -1-x,1-y,-z; ^iv 2-x,2-y,1-z; ^v 1+x,1+y,z; ^vi -x,1-y,-z; ^vii 1-x,1-y,2-z; ^viii -1-x,1-y,1-z.

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Xu, P.-Y.; Wang, Y.-T.; Yu, Z.-M.; Li, Y.-H.; Wang, S. New Mononuclear Mn(III) Complexes with Hydroxyl-Substituted Hexadentate Schiff Base Ligands. Magnetochemistry 2021, 7, 12. https://0-doi-org.brum.beds.ac.uk/10.3390/magnetochemistry7010012

AMA Style

Xu P-Y, Wang Y-T, Yu Z-M, Li Y-H, Wang S. New Mononuclear Mn(III) Complexes with Hydroxyl-Substituted Hexadentate Schiff Base Ligands. Magnetochemistry. 2021; 7(1):12. https://0-doi-org.brum.beds.ac.uk/10.3390/magnetochemistry7010012

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Xu, Peng-Yu, Yu-Ting Wang, Zong-Mei Yu, Yong-Hua Li, and Shi Wang. 2021. "New Mononuclear Mn(III) Complexes with Hydroxyl-Substituted Hexadentate Schiff Base Ligands" Magnetochemistry 7, no. 1: 12. https://0-doi-org.brum.beds.ac.uk/10.3390/magnetochemistry7010012

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New Mononuclear Mn(III) Complexes with Hydroxyl-Substituted Hexadentate Schiff Base Ligands

Abstract

1. Introduction

2. Experimental Section

3. Results and Discussion

3.1. Crystallographic Studies

3.2. Hirshfeld Surface Analysis

3.3. Magnetic Characterization

4. Conclusions

Author Contributions

Funding

Data Availability Statement

Acknowledgments

Conflicts of Interest

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