This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
Article pubs.acs.org/IC
Two Cyanide-Bridged MnII−NbIV Coordination Chain Ferrimagnets Promoted by Interchain Ferromagnetic Interactions Michał Magott,† Hanna Tomkowiak,‡ Andrzej Katrusiak,‡ Wojciech Nitek,† Barbara Sieklucka,† and Dawid Pinkowicz*,† †
Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland
‡
S Supporting Information *
ABSTRACT: Two new coordination chain compounds based on octacyanoniobate(IV) are reported: {[MnII(bpy)(H2O)2]2[NbIV(CN)8]·5H2O}n (1) and {[MnII(bpy)(H2O)2][MnII(bpy)2][NbIV(CN)8]·5H2O}n (2) (bpy = 2,2′-bipyridine). Both have the topology of vertex-sharing CN-bridged squares. The Mn2Nb2 units are mutually parallel in 1 and perpendicular in 2. The antiferromagnetic intrachain interactions between the MnII and NbIV centers in 1 and 2, typical for MnII-[NbIV(CN)8] family of compounds, lead to ferrimagnetic ground state of each single chain. Both compounds show bulk ferrimagnetic ordering below their critical temperatures (Tc) of 6.4 K in 1 and 4.7 K in 2. Such a behavior is due to the ferromagnetic interchain interactions, assured by the π−π contacts between the 2,2′-bipyridine rings and by the hydrogen bonds between the terminal cyanide ligands of the [NbIV(CN)8]-building blocks and coordination/crystallization water molecules. 1 and 2 are rare examples of ferrimagnets promoted by interchain ferromagnetic exchange, and the Tc of 1 is one of the highest among similar 1-D coordination polymers.
■
INTRODUCTION Synthesis and characterization of one-dimensional (1-D) molecular assemblies, such as magnetic chains, recently received considerable attention due to the intrinsic structural anisotropy of such assemblies resulting in the anisotropy of their physical properties. Magnetic chains, for instance, can exhibit slow magnetic relaxation or the so-called single-chain magnet (SCM)1−3 behavior with potential applications in the information storage and quantum computing.4 It is worth mentioning that the first reported molecular magnet was [FeIII(Cp*)2]+[TCNE]− (Cp* = pentamethylcyclopentadienyl) with a chain-like alternating arrangement of cations and anions that below 4.8 K became a 3-D bulk ferromagnet.5 Octacyanoniobate(IV) anion [NbIV(CN)8]4− has been proved to be an efficient building block in the construction of discrete zero-dimensional (0-D)6,7 and extended two- (2D)8,9 and three-dimensional (3-D)10−12 coordination frameworks that show many different functionalities.13−15 However, only two 1-D coordination architectures have been constructed with the use of this building block:16,17 an SCM {[(H2O)FeII(L)][NbIV(CN)8][FeII(L)]·4.5H2O}n16 (L = pentadentate macrocycle) and its Mn II analogue {[(H 2 O)Mn II (L)][NbIV(CN)8][MnII(L)]·5H2O}n17a simple paramagnet with a possible magnetic ordering around 2 K. We find the lack of 1D coordination systems based on octacyanoniobate(IV) quite surprising, taking into account a variety of 1-D structures based on its diamagnetic analogues: octacyanomolybdate(IV)18,19 and octacyanotungstate(IV),20,21 which should encourage the preparation of the niobium(IV) congeners. Therefore, we © XXXX American Chemical Society
decided to focus our attention on new 1-D coordination assemblies of manganese(II) and octacyanoniobate(IV) by using 2,2′-bipyridine (bpy) as a blocking ligand. Bpy was used before, in the synthesis of Mn4Nb2 hexanuclear molecules,6 and we decided to alter the MnII:bpy stoichiometry during the selfassembly process of the building blocks in order to “unfold” the discrete “cluster” topology into a coordination chain structure. Here we report the results of such an approach: the successful isolation and magneto-structural characterization of two 1-D ferromagnetic coordination chains: {[Mn I I (bpy)(H2O)2]2[NbIV(CN)8]·5H2O}n (1) and {[MnII(bpy)(H2O)2][MnII(bpy)2][NbIV(CN)8]·5H2O}n (2).
■
EXPERIMENTAL SECTION
Syntheses. K4[Nb(CN)8]·2H2O was prepared according to the published procedure.22 All other reagents and solvents of analytical grade were used as supplied. {[MnII(bpy)(H2O)2]2[NbIV(CN)8]·5H2O}n (1). MnCl2·4H2O (0.050 mmol, 10.0 mg) together with 2,2′-bipyridine (Mn:bpy ≈ 1:1) (0.055 mmol, 8.6 mg) were dissolved in 50 mL of water by sonification (10 min.). The resulting colorless solution was slowly poured into the solution of 0.025 mmol (12.5 mg) of K4[Nb(CN)8]·2H2O in 50 mL of water with gentle stirring. The reaction mixture was kept in the dark at room temperature. After ca. 5 days yellow crystals were collected by decantation (yield: 3.4 mg; 15%), filtered, and dried. The structure was determined by X-ray diffraction measurement, and the identity of the bulk sample was confirmed by powder X-ray diffraction (PXRD; Received: February 1, 2016
A
DOI: 10.1021/acs.inorgchem.6b00269 Inorg. Chem. XXXX, XXX, XXX−XXX
Article
Inorganic Chemistry
1061m, 1043w, 1019m, 817w, 770s, 736m, 650m, 627w, 451m(br) (Figure S1). {[MnII(bpy)(H2O)2][MnII(bpy)2][NbIV(CN)8]·5H2O}n (2). MnCl2·4H2O (0.10 mmol, 20 mg) together with 2,2′-bipyridine (Mn:bpy ≈ 1:1.5) (0.15 mmol, 24 mg) were dissolved in 100 mL of water by sonification (10 min.). The resulting colorless solution was slowly poured into the solution of 0.05 mmol (25 mg) of K4[Nb(CN)8]·2H2O in 100 mL of water with simultaneous stirring. The reaction mixture was kept in the dark at room temperature. After approximately 24 h yellow prisms were collected by decantation (yield: 13 mg; 25%), filtered, and dried shortly in air. Their structure was determined by X-ray diffraction measurement, and the identity of the sample was confirmed by elemental analysis and PXRD. Found: C, 44.95; H, 3.878; N, 19.38; calculated for {[Mn II (bpy)(H 2 O) 2 ][Mn II (bpy) 2 ][Nb IV (CN) 8 ]· 5H2O}n: C, 45.39; H, 3.81; N, 19.50. The slight differences in the experimental and calculated elemental composition are probably due to the slight contamination with 1 and Mn4Nb2 molecules described in ref 6. Such a contamination is unavoidable in a synthesis where so many byproducts are possible. The PXRD pattern of 2 was found to be fully consistent with that simulated from the single-crystal structural model, confirming the identity and purity of the compound within the acceptable limits (Figure 1b). IR (KBr, cm−1): 3407s(br), 2141s, 2117m, 1635m(br), 1603s, 1596s, 1576m, 1567m, 1491m, 1474s, 1440vs(sh), 1385w, 1316m, 1283w, 1260w, 1247m, 1222m(br), 1175m, 1157m, 1114m, 1102m, 1062m, 1044w, 1014vs, 1006m, 917w, 897w, 8139w, 769vs, 739s(sh), 652m, 646m, 626m, 554w, 463s, 456s, 424w (Figure S1). Structure Determination. The single-crystal diffraction data for 1 were collected on Nonius-Bruker Kappa CCD diffractometer (Mo Kα, graphite monochromator) and the data for 2 were collected on Bruker D8 Quest Eco Photon50 CMOS (Mo Kα, graphite monochromator) at 100 K and on SuperNova (Cu Kα, graphite monochromator) at 200 K (see Table 1 and Table S1 for details). Data reduction and cell refinements were performed using DENZO and HKL SCALEPACK, SAINT and SADABS, or Crysalis, respectively. Intensities of reflections were corrected for the sample absorption using multiscan
Figure 1. Experimental (red lines) and simulated from single crystal structural models (black lines) powder X-ray diffraction patterns for 1 (a) and 2 (b).
Figure 1a) and elemental analysis. Found: C, 38.00; H, 3.73; N, 18.63; calculated for {[MnII(bpy)(H2O)2]2[NbIV(CN)8]·5H2O}n: C, 37.98; H, 3.87; N, 18.98. IR (KBr, cm−1): 3424s(br), 2924m, 2854m, 2360w, 2340w, 2157m, 2140s, 2127s, 2113m, 1742w, 1726w, 1708w, 1660m, 1641m, 1598s, 1575m, 1552w, 1533w, 1514w, 1491m, 1474m, 1440s, 1314m, 1286w, 1247m, 1220w, 1177m, 1158m, 1118w, 1102w,
Table 1. Selected Crystallographic Parameters for 1 and 2
formula FW/g·mol−1 temp/K crystal system space group a/Å b/Å c/Å β/° V/Å3 Z ρ/g·cm−3 abs. coeff./mm−1 F(000) crystal/mm θ range/° refl. collected Rint indep. refl. refl. I > 2σ(I) parameters GOF on F2 R1 (refl. I > 2σ(I)) wR2 (all refl.) completeness largest diff. peak/hole/e·Å−3
1
2
C28H23Mn2N12NbO9 874.37 293(2) monoclinic P21/c 10.530(5) 16.296(5) 23.221(5) 109.700(14) 3751(2) 4 1.548 1.027 1752 0.12 × 0.07 × 0.02 2.50−27.52 27976 0.1106 8601 4670 473 0.972 0.0537 0.1470 0.995 1.293/−0.627
C152H96Mn8N56Nb4O28 3966.00 100(2) monoclinic P21/n 16.944(2) 54.523(7) 19.801(3) 109.553(2) 17289(4) 4 1.524 0.90 7952 0.32 × 0.27 × 0.16 3.18−24.62 130556 0.1046 28576 18096 2261 1.04 0.0882 0.2110 0.972 2.406/−2.416
B
DOI: 10.1021/acs.inorgchem.6b00269 Inorg. Chem. XXXX, XXX, XXX−XXX
Article
Inorganic Chemistry
Figure 2. Structural diagrams of 1 viewed perpendicular (a) and along (b) the chain. Crystallization water molecules and hydrogen atoms have been omitted for clarity. Nb: cyan, Mn: magenta, C: gray, N: blue, O: red. method. All structures were solved using direct methods and refined anisotropically using weighted full-matrix least-squares on F2.23,24 Details of the diffraction experiments and crystal data for 1 and 2 are given in Table 1. The crystals of 2 are pseudosymmetric (approximate space group C2/c), but the true unit cell is two times longer along [010] and the space group is P21/n (Table 1). According to the structural determination the compound is a pentahydrate {[MnII(bpy)(H2O)2][MnII(bpy)2][NbIV(CN)8]·5H2O}n. Twenty independent water molecules, not involved in coordination bonds to Mn2+ cations, exhibit a considerable disorder. This disorder has a strong static contribution, as evidenced by hardly reduced temperature factors (U) at 100 K. The disorder is without doubt connected to the loss of crystallization water. Hydrogen atoms of the H2O molecules could not be located from the difference density map. Therefore, the H atoms were located at the idealized calculated positions and excluded from the refinements, but included in the structure factors. Physical Measurements and Magnetic Fitting. Infrared spectra were measured in KBr pellets between 4000 and 400 cm−1 using a Bruker EQUINOX 55 FTIR spectrometer. Elemental analyses were performed using the ELEMENTAR Vario Micro Cube CHNS analyzer. Magnetic susceptibility measurements were performed using a Quantum Design MPMS-3 Evercool magnetometer. Magnetic susceptibility data collected at 1000 Oe were fitted using PHI program developed by Chilton et al.25 PXRD experiments were performed using graphite monochromated Cu Kα radiation (PANalytical X’Pert Pro MPD) for wet samples loaded into glass capillaries (0.5 mm in diameter for 1 and 0.7 mm in diameter for 2). The Continuous Shape Measure analysis for the coordination spheres of eight-coordinated NbIV centers was performed using SHAPE software ver. 2.1.26
Such a topology was reported previously for the diamagnetic octacyanotungstate(IV) and octacyanomolybdate(IV) analogues,18,20,21 but was not observed for octacyanoniobate(IV). In the structure of 1, of monoclinic space group P21/c, the asymmetric unit contains two MnII and one NbIV. The coordination sphere of NbIV resembles best a triangular dodecahedron according to the Continuous Shape Measure Analsysis27 (Table S2). Each NbIV center forms four cyanide bridges toward four neighboring MnII centers. The remaining four CN ligands are terminal. The Mn−N bond lengths within the NbIV−CN−MnII structural motifs range from 2.172(4) to 2.188(4) Å. The CN bridges are significantly bent at Mncenters with Mn−N−C angles in the 151.5(5)−174.2(4)° range. The MnII centers are coordinated in a distorted octahedral geometry by one 2,2′-bipyridine, two H2O molecules in cis configuration, and two N atoms of the bridging CN− groups. The chain structure is stabilized by three types of hydrogen bonds: interchain ones connecting manganese-coordinated water molecules with the terminal CN− ligands of the octacyanoniobate(IV) moiety of the neighboring chain through two additional crystallization water molecules (Figure S2), intrachain hydrogen bonds between the terminal cyanides and water molecules coordinated to MnII centers (Figure S3), and crystallization water-mediated H-bonds. There are also numerous hydrogen bonds binding the crystallization water molecules into layers between the chains (Figure S4). Furthermore, the hydrogen-bonding network is additionally supported by an extended π−π stacking of bipyridyl rings along the b axis (the chain direction), with the closest distances between the planes of the rings being 3.58 and 3.63 Å (Figure S5). The structural analysis of the octacyanotungstate(IV) analog20 gives the corresponding π−π distances equal to 3.61 and 3.98 Å, which leads to a conclusion that incorporation of the larger tungsten(IV) cation with a geometry of a square antiprism instead of the dodecahedral niobium(IV) causes uneven distortion of the π−π interactions in the WIV analog. Compound 2 crystallizes in monoclinic space group P21/n. The crystals of 2 exhibit a pseudosymmetry along direction [010], in the reciprocal space the reflections with odd k indices are much weaker than those with k even, and the structure could also be reasonably refined in pseudo space group C2/c. However, the reflections with k odd are clearly present, and the b parameter is equal to over 54.5 Å and the actual space group is P21/n (Table 1). In the crystal structure of 2 there are 4 independent Mn2Nb formula units, each containing 5
■
RESULTS AND DISCUSSION Synthetic Strategy. Both compounds were obtained in one-pot reactions between the in situ prepared [Mn(bpy)n]2+ (n = 1 for 1 and n = 2 for 2) cationic complexes and the [NbIV(CN)8]4− anions using the self-assembly approach. The use of the aforementioned cations led to four or two labile coordination sites at the MnII centers, respectively, which increased the probability of obtaining the chain topology. The one-pot reactions facilitated the control of concentration of possible manganese(II) complexes, reduced the risk of byproduct formation, such as Mn4Nb2 hexanuclear clusters,6 and enabled the isolation of compounds 1 and 2 pure enough for a reliable physical characterization. Slow diffusion methods were avoided in contrast to the previously reported syntheses of MnII−[M(CN)8] compounds with 2,2′-bipyridine.17,20 Crystal Structures. The structure of 1 built of 1-D CNbridged ribbon-like coordination chains of Nb-vertex-sharing Mn2Nb2 squares is shown in Figure 2. C
DOI: 10.1021/acs.inorgchem.6b00269 Inorg. Chem. XXXX, XXX, XXX−XXX
Article
Inorganic Chemistry
Figure 3. Structural diagrams of 2 viewed perpendicular (a) and along (b) the chain. Crystallization water molecules and hydrogen atoms have been omitted for clarity. Nb: cyan, Mn: magenta, C: gray, N: blue, O: red.
crystallization water molecules. There are 20 crystallization water molecules in the asymmetric unit in total, in accordance with the elemental analysis. Several of the water molecules are strongly disordered, even at 100 K, and one of the water molecules resides in two sites, with the O-sites about 1.6 Å apart. Compound 2 is the first example of a new 1-D coordination topology of a chain with perpendicular Mn2Nb2 rhombus units, in contrast to 1 where such motifs are coplanar (Figure 3; see also Figure S6 for the autostereographic projection of the crystal structure of 228). This interesting topology results from the presence of two types of MnII sites within the chain structure of 2one type is coordinated by two 2,2′-bipyridine molecules and the other one by a single 2,2′-bipyridine molecule and two water molecules in trans geometry. The coordination spheres of each MnII center is completed by two nitrogen atoms of the cyanide ligands of the octacyanoniobate(IV) moieties. This results in two almost perpendicular Mn2Nb2 rhombus-motifs with each type of MnII located in different rhombi (Figure 3). The octacyanoniobate(IV) in 2 adopts a square antiprism geometry (Table S2). The Mn−N bond lengths within the NbIV−CN−MnII structural motifs ranging from 2.163(9) to 2.230(6) Å are similar to those in 1, though some bonds are distinctly longer. The CN bridges are bent at MnII centers with Mn−N−C angles in the 150.9(9)−174.2(8)° range which is also similar to 1. The chain structure of 2 is stabilized by an extensive network of hydrogen bonds. Crystallization water molecules O15 and O18 form dimeric units with four hydrogen bonds toward manganese-coordinated water molecules and terminal cyanides of the octacyanoniobate(IV) moieties resulting in an H-shaped pattern (Figure S7). There are also interchain hydrogen bonds connecting octacyanoniobiate(IV) with manganese-coordinated water molecules through only one additional crystallization H2O (Figure S8) and numerous hydrogen bonds between crystallization water molecules. Similarly to 1, there are two types of π−π contacts in 2. However, they are much longer (interplanar distance in the 3.70−3.90 Å range) and only local, which means that there are no extended stacks of aromatic rings along the chain or in any other direction (Figure S9). Noteworthy, the crystal of 2 exhibits a very rare effect of negative area thermal expansion: with the increase of temperature from 100 to 200 K only parameter c becomes longer, by 0.217 Å, while parameters a and b shrink slightly by −0.043 and −0.013 Å, respectively (Table S1). The volume
shows only minimal positive thermal expansion and becomes larger by 79(5) Å3 (0.4%).
Figure 4. Magnetic properties of compounds 1 (black) and 2 (red): χMT(T) at 1000 Oe in the 35−300 K range (main plot; solid lines represent the best fit to the model described in the text) and M(H) at 1.8 K (inset).
Magnetic Properties. The temperature dependences of the χMT(T) at 1000 Oe for 1 and 2 are shown in Figure 4. Both compounds show similar experimental χMT values at 300 K (9.0 and 9.3 cm3 K/mol for 1 and 2, respectively), which are close to 9.125 cm3 K/mol, expected for two high-spin MnII (S = 5/2) and one NbIV (S = 1/2) ions assuming an average g = 2.0. Both compounds show also a significant increase of the χMT(T) dependence with decreasing temperature below 100 K, indicating the presence of significant magnetic interactions between the CN-bridged MnII and NbIV ions. Around 10 K the χMT for both compounds increases abruptly suggesting the presence of long-range magnetic ordering. In order to confirm this, the zero field-cooled (ZFC) and field-cooled (FC) magnetization measurements were performed at small DC magnetic fields (Figure 5). For both 1 and 2 a sharp increase of the magnetization could be observed at 6.4 and 4.7 K, respectively, which is typical for long-range ferromagnetic/ ferrimagnetic ordering below these temperatures. The M(H) dependencies for both compounds measured at 1.8 K (much below the Curie temperatures) are presented in the inset of Figure 4. The magnetization reaches 90% of the saturation value Msat of 9.1 μB for 1 and 8.8 μB for 2 at the magnetic field as low as 0.25 T, which supports the long-range ferrimagnetic order at 1.8 K. Both Msat values are close to 9 Nβ D
DOI: 10.1021/acs.inorgchem.6b00269 Inorg. Chem. XXXX, XXX, XXX−XXX
Article
Inorganic Chemistry
MnII and NbIV were fixed at 2.0. Moreover, the weak interchain interactions zj were fit within the frame of mean field theory: χzj =
(2)
We would like to stress that this approximation is rough and valid only at higher temperatures (in our case above 50 K). The χMT(T) dependencies were fitted in the 50−300 K range (solid lines in Figure 4 and Figure S12). The following best fit parameters have been obtained: J1 = −12(1) cm−1 and zj1 = +0.1(1) cm−1 for 1, and J2 = −7(1) cm−1 and zj2 = +0.2(1) cm−1 for 2. The intrachain interactions in both cases are antiferromagnetic and their values are comparable with those reported in the literature.6,38 The interchain interactions, on the other hand, are ferromagnetic, which is in line with the observed long-range ferromagnetic ordering for both compounds. Noteworthy, the obtained intrachain magnetic interaction is stronger in 1 than in 2, which is in line with the higher magnetic ordering temperature observed for 1. Careful analysis of the magnetic data for both compounds suggests that the ferrimagnetic chains, with the underlying intrachain antiferromagnetic interactions between the SNb = 1/2 and SMn = 5/2, are coupled ferromagnetically through the extensive interchain hydrogen bonding and π−π contacts. The intrinsically antiferromagnetic “through space” interchain dipolar interactions are insignificant in both cases. Each single chain in 1 and 2 is ferrimagnetic and the overall magnetic ordering in both compounds has a ferrimagnetic character. This is because the long-range magnetic order is controlled by ferromagnetic interactions between the chains through supramolecular contacts. Both the hydrogen bonds and π−π contacts were proposed previously as efficient ferromagnetic interaction pathways leading to the supramolecular ferromagnetic behavior. However, only a handful of 1-D systems with a coordination chain topology have been reported to show long-range ferro- or ferrimagnetic ordering, so far all are based on the following bridging groups: azide,30,32 amido,31 oxalate,33 thiocyanate,34 cyanide,29,35 and chloride36 (Table 2).
Figure 5. ZFC-FC curves for 1 (black, left scale; HDC = 4.9 Oe) and 2 (red, right scale; HDC = 10.0 Oe).
expected for the antiparallel alignment of the magnetic moments of the NbIV and MnII ions caused by the intrachain antiferromagnetic interactions transmitted via the CN-bridges. AC susceptibility measurements in the 1.8−10 K range (Figures S10 and S11) confirm the presence of the long-range magnetic ordering. AC signals do not show significant frequency dependence at the Curie temperatures of both compounds, clearly indicating that they are not SCMs or spinglasses. Attempts to fit the χMT(T) dependencies using the Curie− Weiss law were unreliable for both compounds (Figure S12). The results varied depending on the temperature range and the fit parameters were unsatisfactory, i.e., for the fit in the 200− 300 K range the Curie constant values were C1 = 8.5 cm3 K mol−1 and C2 8.8 cm3 K mol−1 for 1 and 2, respectively, which is much lower than the room temperature χMT products and the expected spin-only value of 9.125 cm3 K mol−1. The values of the Weiss constants were positive for both fits suggesting ferromagnetic interactions between MnII and NbIV, which is in direct opposition to the observed magnetization saturation values discussed previously. In order to estimate more reliably the intra- and interchain magnetic−exchange interactions in 1 and 2, another approach has been taken in which the behavior of an infinite −Mn2− Nb− magnetic chain was approximated by a −Mn2−Nb− Mn2−Nb− molecule closed in a loop37 (Figure S12) using the following Hamiltonian: H = −2JMnNb SMnS Nb + μB μ0 HZg (2SMn + S Nb)
χ ⎛⎜ zj ⎞⎟ 1− χ ⎝ NAμB2 ⎠
■
CONCLUSIONS We have designed, synthesized, and successfully characterized two new coordination chains based on manganese(II) and octacyanoniobate(IV): {[MnII(bpy)(H2O)2]2[NbIV(CN)8]· 5H 2 O} n (1) and {[Mn I I (bpy)(H 2 O) 2 ][Mn I I (bpy) 2 ][NbIV(CN)8]·5H2O}n (2). Both coordination chains were obtained by the rational modification of the self-assembly approach that led previously to discrete MnII4NbIV2 molecular
(1)
Only one type of intrachain magnetic interaction between the MnII and NbIV centers JMnNb was assumed. The g factors of both
Table 2. Compounds with Coordination Chain Topology Showing Ferromagnetic/Ferrimagnetic Behavior formula
bridge
TC /K
ref
{[NiII(en)2]3[FeIII(CN)6]2·2H2O}n {CuII(4-fluorobenzoate)(N3)(C2H5OH)}n {LMnIII(CH3OH)}n {[MnII(bpy)(H2O)2]2[NbIV(CN)8]·5H2O}n {MnIII(Etphox)2(N3)}n {[Mn(bpy)(H2O)2][Mn(bpy)2][Nb(CN)8]·5H2O}n {[K(18-crown-6)][MnII(H2O)2][CrIII(ox)3]}n {CoII(NCS)2(4-(3-phenylpropyl)pyridine)2}n {NiIICl2(CH3OH)2(1,4-dioxane)0.5}n [NEt4]2[MnIII(acacen)][FeIII(CN)6]
CN− N3− Schiff base CN− N3− CN− ox− NCS− Cl− CN−
18.6 7.0 ∼7 6.4 5.6 4.7 3.5 3.3 3.1 2.5
29 30 31 this work 32 this work 33 34 35 36
E
DOI: 10.1021/acs.inorgchem.6b00269 Inorg. Chem. XXXX, XXX, XXX−XXX
Article
Inorganic Chemistry clusters.6 Significantly, despite the extreme structural similarity and similar preparation procedures, both compounds were isolated from one-pot reaction mixtures as pure phases thanks to the rigorous control of the MnII:bpy stoichiometry. They show long-range ferrimagnetic ordering at 6.4 and 4.7 K for 1 and 2, respectively. We have demonstrated that weak supramolecular contacts are able to effectively couple large magnetic objects, such as the reported ferrimagnetic coordination chains, and can lead to the bulk nonantiferromagnetic orderinga rare phenomenon among low-dimensional molecular magnets.
■
(12) Pinkowicz, D.; Podgajny, R.; Nitek, W.; Makarewicz, M.; Czapla, M.; Mihalik, M.; Bałanda, M.; Sieklucka, B. Inorg. Chim. Acta 2008, 361 (14−15), 3957−3962. (13) Pinkowicz, D.; Rams, M.; Mišek, M.; Kamenev, K. V.; Tomkowiak, H.; Katrusiak, A.; Sieklucka, B. J. Am. Chem. Soc. 2015, 137 (27), 8795−8802. (14) Ohkoshi, S.-i.; Imoto, K.; Tsunobuchi, Y.; Takano, S.; Tokoro, H. Nat. Chem. 2011, 3 (7), 564−569. (15) Ohkoshi, S.-i.; Takano, S.; Imoto, K.; Yoshikiyo, M.; Namai, A.; Tokoro, H. Nat. Photonics 2013, 8 (1), 65−71. (16) Venkatakrishnan, T. S.; Sahoo, S.; Bréfuel, N.; Duhayon, C.; Paulsen, C.; Barra, A.-L.; Ramasesha, S.; Sutter, J.-P. J. Am. Chem. Soc. 2010, 132 (17), 6047−6056. (17) Pradhan, R.; Desplanches, C.; Guionneau, P.; Sutter, J.-P. Inorg. Chem. 2003, 42 (21), 6607−6609. (18) Ma, S.-L.; Ma, Y.; Ren, S.; Yan, S.-P.; Liao, D.-Z. Struct. Chem. 2008, 19 (2), 329−338. (19) Stefanczyk, O.; Majcher, A. M.; Rams, M.; Nitek, W.; Mathoniere, C.; Sieklucka, B. J. Mater. Chem. C 2015, 3 (33), 8712−8719. (20) Ozaki, N.; Yamada, R.; Nakabayashi, K.; Ohkoshi, S.-i. Acta Crystallogr., Sect. E: Struct. Rep. Online 2011, 67 (6), m702−m703. (21) Zhao, H.; Shatruk, M.; Prosvirin, A. V.; Dunbar, K. R. Chem. Eur. J. 2007, 13 (23), 6573−6589. (22) Kiernan, P. M.; Griffith, W. P. J. Chem. Soc., Dalton Trans. 1975, 23, 2489−2494. (23) Sheldrick, G. Acta Crystallogr., Sect. A: Found. Crystallogr. 2008, 64 (1), 112−122. (24) Sheldrick, G. Acta Crystallogr., Sect. C: Struct. Chem. 2015, 71 (1), 3−8. (25) Chilton, N. F.; Anderson, R. P.; Turner, L. D.; Soncini, A.; Murray, K. S. J. Comput. Chem. 2013, 34 (13), 1164−1175. (26) Llunell, M.; Casanova, D.; Cirera, J.; Alemany, P.; Alvarez, S. SHAPE 2.1; University of Barcelona: Barcelona, Spain, 2013. (27) Casanova, D.; Llunell, M.; Alemany, P.; Alvarez, S. Chem. - Eur. J. 2005, 11 (5), 1479−1494. (28) Katrusiak, A. J. Mol. Graphics Modell. 2001, 19 (3−4), 363−367. (29) Ohba, M.; Maruono, N.; Okawa, H.; Enoki, T.; Latour, J.-M. J. Am. Chem. Soc. 1994, 116 (25), 11566−11567. (30) Liu, X.; Chen, S.; Grancha, T.; Pardo, E.; Ke, H.; Yin, B.; Wei, Q.; Xie, G.; Gao, S. Dalton Trans. 2014, 43 (41), 15359−15366. (31) Costes, J.-P.; Dahan, F.; Donnadieu, B.; Rodriguez Douton, M.J.; Fernandez Garcia, M.-I.; Bousseksou, A.; Tuchagues, J.-P. Inorg. Chem. 2004, 43 (8), 2736−2744. (32) Zhang, Y.; Wang, X.-T.; Zhang, X.-M.; Liu, T.-F.; Xu, W.-G.; Gao, S. Inorg. Chem. 2010, 49 (13), 5868−5875. (33) Coronado, E.; Galán-Mascarós, J. R.; Gómez-García, C. J.; Martí-Gastaldo, C. Inorg. Chem. 2005, 44 (18), 6197−6202. (34) Werner, J.; Rams, M.; Tomkowicz, Z.; Nather, C. Dalton Trans. 2014, 43 (46), 17333−17342. (35) Re, N.; Gallo, E.; Floriani, C.; Miyasaka, H.; Matsumoto, N. Inorg. Chem. 1996, 35 (21), 6004−6008. (36) Zhang, B.; Zhang, Y.; Wang, D.; Zhu, D. Polyhedron 2011, 30 (18), 3145−3150. (37) Kahn, O. Molecular Magnetism; VCH Publishers: Weinheim, 1993. (38) Pinkowicz, D.; Podgajny, R.; Nitek, W.; Rams, M.; Majcher, A. M.; Nuida, T.; Ohkoshi, S. I.; Sieklucka, B. Chem. Mater. 2011, 23 (1), 21−31.
ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.6b00269. Additional structural diagrams and tables, magnetic data, and IR spectra (PDF) X-ray crystallographic data for 1 (CIF) X-ray crystallographic data for 2 (CIF) X-ray crystallographic data for 2 at 200 K (CIF)
■
AUTHOR INFORMATION
Corresponding Author
*Email:
[email protected],
[email protected]. pl. Notes
The authors declare no competing financial interest.
■
ACKNOWLEDGMENTS This work was supported by the Polish National Science Centre within the Opus 8 research grant (decision no. DEC2014/15/B/ST5/04465). Magnetic measurements were performed using the equipment purchased from the “Large Research Infrastructure Fund” of the Polish Ministry of Science and Higher Education (contract no. CRZP/UJ/254/2013).
■
REFERENCES
(1) Caneschi, A.; Gatteschi, D.; Lalioti, N.; Sangregorio, C.; Sessoli, R.; Venturi, G.; Vindigni, A.; Rettori, A.; Pini, M. G.; Novak, M. A. Angew. Chem., Int. Ed. 2001, 40 (9), 1760−1763. (2) Clérac, R.; Miyasaka, H.; Yamashita, M.; Coulon, C. J. Am. Chem. Soc. 2002, 124 (43), 12837−12844. (3) Hoshino, N.; Iijima, F.; Newton, G. N.; Yoshida, N.; Shiga, T.; Nojiri, H.; Nakao, A.; Kumai, R.; Murakami, Y.; Oshio, H. Nat. Chem. 2012, 4 (11), 921−926. (4) Gatteschi, D.; Sessoli, R. S.; Villain, J. Molecular Nanomagnets; Oxford University Press: Oxford, 2006. (5) Miller, J. S.; Epstein, A. J.; Reiff, W. M. Science 1988, 240 (4848), 40−47. (6) Venkatakrishnan, T. S.; Rajamani, R.; Ramasesha, S.; Sutter, J.-P. Inorg. Chem. 2007, 46 (23), 9569−9574. (7) Pinkowicz, D.; Podgajny, R.; Nowicka, B.; Chorazy, S.; Reczynski, M.; Sieklucka, B. Inorg. Chem. Front. 2015, 2 (1), 10−27. (8) Korzeniak, T.; Pinkowicz, D.; Nitek, W.; Balanda, M.; Fitta, M.; Sieklucka, B. Dalton Trans. 2011, 40 (45), 12350−12357. (9) Pinkowicz, D.; Rams, M.; Nitek, W.; Czarnecki, B.; Sieklucka, B. Chem. Commun. 2012, 48 (67), 8323−8325. (10) Nakagawa, K.; Imoto, K.; Miyahara, H.; Ohkoshi, S.-i. Polyhedron 2013, 52, 424−428. (11) Pinkowicz, D.; Kurpiewska, K.; Lewinski, K.; Balanda, M.; Mihalik, M.; Zentkova, M.; Sieklucka, B. CrystEngComm 2012, 14 (16), 5224−5229. F
DOI: 10.1021/acs.inorgchem.6b00269 Inorg. Chem. XXXX, XXX, XXX−XXX
