Exploring the Magnetic Interaction of Asymmetric Structures Based on

Article pubs.acs.org/IC

Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX

Exploring the Magnetic Interaction of Asymmetric Structures Based on Chiral VIII8 Clusters Jia-Peng Cao,† Yun-Shan Xue,† Zhao-Bo Hu,‡ Xi-Ming Luo,† Chen-Hui Cui,† You Song,*,‡ and Yan Xu*,† †

Inorg. Chem. Downloaded from pubs.acs.org by IOWA STATE UNIV on 02/07/19. For personal use only.

College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing Tech University, Nanjing, 210009, China ‡ State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China S Supporting Information *

ABSTRACT: Polyoxovanadates (III) are important class of polyoxometalates in molecular magnetism field, and particularly the systems which contain vanadium(III) centers. To date, only very few highly reduced vanadium polynuclear complexes were reported, which remains a significant challenge to synthesize novel polyoxovanadates, owing to the characteristics of easily oxidized vanadium(III). Herein, two unprecedented petaloid chiral octanuclear polyoxovanadates, L - and D -[H 2 N(CH 3 ) 2 ] 1 2 . 5 (H 3 N(CH 2 ) 2 NH 3 )(H3O)1.5(VIIIμ2-OH)8(SO4)16·2H2O (L-, D-V8), have been successfully obtained by solvothermal method without any chiral auxiliary. Both L- and D-V8 compounds contain the motif eight-membered ring (Vμ2-O)8(SO4)16 constituted of three different chiral entangled loops with the V atoms as nodes. Bond valence calculation (BVC) analysis indicates that all the V ions existed in L, D-V8 are +3 value. The magnetic behavior of compounds indicated ferromagnetic coupling between vanadium(III) ions. To our knowledge, it is the first chiral highly reduced polyoxovanadates that exhibit excellent ferromagnetism.

■

ferromagnetic coupling interactions.17−20 Therefore, it is very meaningful to explore the potential of novel highly reduced POVs with ferromagnetic interactions, providing magnetic model systems. Recently, chirality has been largely unexplored in the polyoxovanadate family due to the difficulty of synthesis and separation, but still have received long-lasting research interest because of unmatched structures and potential applications such as asymmetric catalysis.21,22 To obtain chiral POVs, two prime strategies are usually employed. The most straightforward and effective strategy is enantioselective synthesis by using chiral organic ligands or chiral precursors, which can transfer chirality to the whole POVs.23−26 In some cases, another strategy has also been confirmed to synthesis chiral POVs through symmetry breaking or spontaneous asymmetrical crystallization assembly, which produces racemic mixture of chiral crystallites.27−29 Additionally, separation is also another big problem for chiral POVs. At present, most chiral POVs have been explored by the first method. It still remains a challenge to generating chiral POVs without any chiral auxiliary, because vanadium oxide clusters usually exhibit high symmetrical architecture. Most importantly, the ferromagnetic exchange interactions are more common in

INTRODUCTION Polyoxovanadates (POVs), an important subclass of polyoxometalates (POMs), have attracted great attention as evidenced by a number of research papers published in recent years. Vanadium exists four valence states (i.e., V2+, V3+, V4+, V5+), forming different coordination geometries {VOx} (x = 4, 5, 6) which favor polymerization into diverse vanadium oxide clusters by sharing edges/corners. The molecular properties of these clusters have found wide-ranging applications in catalysis, electrochemistry, biochemistry, especially in the field of molecular magnetism.1−6 POVs are envisaged as one of the most interesting magnetic components of hybrid molecular materials, owing to their unique magnetic structures characterized by cooperativity between electron delocalization and intramolecular exchange interactions.7 Thus, far, it has been demonstrated that a majority of reported POVs presented antiferromagnetic coupling interactions,8−13 while it is rarely known about the ferromagnetic exchange interactions based on POVs.7,14−16 What’s more, the ferromagnetic exchange interactions of reported POVs are usually existed in the high value vanadium ions and to the best of our knowledge, only two cases of highly reduced POVs with ferromagnetism reported before.14,16 Besides, most of the heteropolyvanadates like phosphovanadate, polyoxovanadogermanates, polyoxovanadatoarsenates, polyoxovanadatoantimonates, etc. also have magnetic properties, which are almost presented as anti© XXXX American Chemical Society

Received: November 20, 2018

A

DOI: 10.1021/acs.inorgchem.8b03220 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry symmetric structures.16,30 To investigate the magnetic property of asymmetrical highly reduced POVs is extremely significant. With the mentioned above and through our efforts, we report two unprecedented petaloid highly reduced chiral octanuclear POVs, L - and D -[H 2 N(CH 3 ) 2 ]12.5(H 3 N(CH2)2NH3)(H3O)1.5(VIIIμ2-OH)8(SO4)16·2H2O (L-, D-V8) in this work. The polarizing microscope was used to separate the L-, D-V8, and the circular dichroism (CD) spectra faultlessly confirms that L-, D-V8 are enantiomers. The compounds contain the motif eight-membered ring (Vμ2O)8(SO4)16 constituted of three different entangled loops with the V atoms as nodes. By bond valence calculation (BVC), all the V ions existed in the L-, D-V8 are proved to be +3 value. Magnetic measurement analysis indicates that the ferromagnetic coupling between V3+ ions dominates the magnetic property of V8. Furthermore, since vanadium has empty d orbitals, electron transition is easy to occur under laser pulse, thus generating a nonlinear optical absorption response, so the third-order nonlinear optical (NLO) property of V8 was also investigated in detail. To the best of our knowledge, it is the first chiral ferromagnetic annular highly reduced octanuclear vanadium(III) compound.

Figure 1. Structures of (a) L-V8 and (b) D-V8. H atoms of C atoms and N atoms are omitted for clarity. Color code: V, green; S, yellow; C, black; O, red; N, blue.

two “V−O−V” chains, respectively, which are joined end to end to generate an eight-membered ring structure. All VO 6 and SO 4 form octahedral and tetrahedral coordination environments, respectively, which are connected by vertex-sharing O atoms (Figure 3). Additionally, one protonated dimethylamine cation is existed in the center of the ring. As shown in Figure S1, the eight VO6 octahedrons are connected via vertex-sharing μ2-O atoms to form eightmembered ring. What’s more, under the polyhedral model, the main structure of the polyanion is like petaloid as shown in Figure 3e. The octahedral V−O bond distances of L-V8 and D-V8 are in the range of 1.944−2.046 Å and 1.955−2.044 Å. The tetrahedral S−O bond distances of the L-V8 and D-V8 vary from 1.414 to 1.646 Å and from 1.34 to 1.502 Å, with the longest one involving the oxygen atom coordinated to the vanadium center. The O−V−O angles of L-V8 and D-V8 are in the range of 84.9−179.5° and 84.9−179.4°, respectively, while the O−S−O angles of both V8’s vary from 95.0 to 122.6° and from 104.9 to 120.1°, respectively. The bond lengths and bond angles are consistent with those reported in the literature.23−30 As far as we know, among the previously reported vanadium compounds, only two ring-shaped, eight-core vanadium compounds, [(n-C 4 H 9 ) 4 N] 2 [V 8 O 8 (OCH 3 ) 16 (C 2 O 4 ) and [V8(OEt)8(OH)4(O2CPh)12], have been reported.32,33 Different from V8, in the two cases, the connection is different. The [(n-C4H9)4N]2[V8O8(OCH3)16(C2O4) was linked by methanol, while the [V8(OEt)8(OH)4(O2CPh)12] was linked both by ethanol and benzoic acid. BVS calculations (V1 = 3.064, V2 = 3.145, V3 = 3.152 and V4 = 3.132 for L-V8; V1 = 3.028, V2 = 3.094, V3 = 3.035 and V4 = 3.089 for D-V8) indicate the valence state of vanadium is the +3 state. In addition, the Flack parameters of 0.027(19) and −0.004(10) for L-V8 and D-V8 indicate that the absolute configurations are correct. Although L-, D-V8 clusters are isolated, a large number of hydrogen bonds exist between V8 clusters. As shown in Figure S3, one polyanion connects six adjacent polyanions via hydrogen bonds. The range of N···O distances for L-V8 and D-V8 are 2.64−3.26 and 2.84−3.33 Å, respectively. The N− H···O angles vary from 108 to 169° and from 106 to 157°, respectively. While the range of C···O distances for L-V8 and D-V8 are 3.107−3.48 and 2.94−3.38 Å, respectively; the C− H···O angles vary from 129 to 166° and from 123 to 158°, respectively. What’s more, from the a axis, the polyanions generate a three-dimensional structure with a hydrogen bond

■

RESULTS AND DISCUSSION Synthesis. In the research of chemistry, solvothermal synthesis has recently been considered as a powerful and intriguing method in the cultivation of crystals for POVs.23,27,30 As we know, in a specific solvothermal synthesis, many factors have impact on the crystal growth of the target products, for instance, the types of the initial reactants, the kinds and amount of solvents, the reaction temperature and time and the pH values of the mixed solution. In our case, DMF, as the main solvent, plays an important role in the formation of V8, which acts as the template agent and can break down into dimethylamine balancing the skeletal charges.31 The pyridine employs as auxiliaries, which is not included in the final products, but we cannot obtain V8 without pyridine. What is more, the amount of pyridine also affects the formation of the final products. The compounds can be obtained by adding 2 mL of pyridine, while nothing can be acquired with any other amount of pyridine. Additionally, the compounds could be easily obtained under solvothermal synthesis, and they have a good repeatability. Crystal Structures of L-, D-V8. The results of singlecrystal X-ray analysis indicate that both of the L-V8 and D-V8 crystallize in the chiral orthorhombic crystal system and P21212 space group. Since, L-V8 and D-V8 are chiral enantiomers, LV8 is selected to describe the crystal structure. As shown in Figure 1, fundamental building block of compound 1 contains one eight-membered ring [(VIIIμ2-OH)8(SO4)16]16− polyanion cluster, one protonated ethanediamine molecule, 12 and a half protonated dimethylamine cations, one and a half protonated water molecules and two guest water molecules, while the structure of D-V8 is mirror symmetry with L-V8. As shown in Table 1, the Flack parameters of 0.027(19) and −0.002(10) indicate that the chiralities of both L- and D-V8 are correct. As observed in Figure 2, in the main structure of the [(VIIIμ2-OH)8(SO4)16]16− polyanion cluster, two neighboring V atoms are connected by two SO4 groups and one μ2-oxygen atom. Moreover, each V atom is in an octahedral geometrical configuration six-coordinated, connecting with six O atoms from four SO4 groups and two μ2-O atoms. Each V atom and the adjacent S and O atoms form four “V−O−S” chains and B

DOI: 10.1021/acs.inorgchem.8b03220 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry Table 1. Crystal Data and Structure Refinements for L, D-V8a compound formula formula weight T (K) wavelength (Å) cryst syst space group a (Å) b (Å) c (Å) V (Å) Z Dc (Mg/m3) μ (mm−1) F (000) θ range (deg) index ranges

no. of reflns collected no. of indep reflns R (int) data/restraints/parameters GOF final R indices [I > 2σ(I)] R indices (all data) Flack

L-V8

D-V8

C27H126.5N14.5O75.5S16V8 2783.40 296(2) 0.71073 orthorhombic P21212 18.891(2) 24.418(3) 11.8727(15) 5476.7(12) 2 1.688 1.068 2868 1.907−25.023 −22 ≤ h ≤ 22 −29 ≤ k ≤ 26 −14 ≤ l ≤ 14 38852 9658 0.0846 9658/319/697 1.050 R1 = 0.0811 wR2 = 0.2064 R1 = 0.1318 wR2 = 0.2361 0.027(19)

C27H130N14.5O75.5S16V8 2786.93 296(2) 0.71073 orthorhombic P21212 18.998(3) 24.528(4) 11.9224(18) 5555.5(14) 2 1.666 1.053 2875 1.356−25.021 −21 ≤ h ≤ 22 −29 ≤ k ≤ 29 −13 ≤ l ≤ 14 39746 9832 0.0455 9832/249/676 1.108 R1 = 0.0704 wR2 = 0.2035 R1 = 0.0820 wR2 = 0.2178 −0.004(10)

R1 = Σ||F0| − |Fc||/Σ|F0|. wR2 = Σ[w(F02 − Fc2)2]/Σ[w(F02)2]1/2.

a

interaction (Figure 4) and the corresponding three-dimensional structures (Figure S4) and one-dimensional chains (Figure 4c) of L-, D-V8 are also mirror symmetry. In order to better understand the chirality of V8, we can regard the polyanions of V8 cluster as a triple loop generated by three different loops, which consist of one sinusoid-like “V− O−S-O” ring and two cosine-like “V−O−S−O−V−O” rings (Figure S5). Interestingly, as shown in Figure 5, in the two chiral polyanion clusters, the corresponding loops are mirrorsymmetrical. CD Spectrum. Under the natural light, L-V8 and D-V8 cannot be distinguished with not only the color, but also the shape. However, under the polarized light, L-V8 and D-V8 were observed as dark and light (Figure 6(interior)), respectively, due to their chirality. In order to further demonstrate the chirality of L-V8 and DV8, the solid-state dichroism (CD) spectra was adopted with KBr pellets mixed with single crystals, respectively. As shown in Figure 6, the Cotton effects of L-V8 and D-V8 are opposite, which manifests that the L-V8 and D-V8 are chiral enantiomers. What’s more, it is noted that the CD values for the corresponding positions of L-V8 and D-V8 are not completely opposite. This is due to the difference in the quantity of L-V8 and D-V8 used in the test. Magnetic Properties. Since the valence state of V ions in the compounds are +3, we measured the magnetic properties of V8. The measurement on crystalline samples of V8 was performed on a Quantum Design MPMS-XL7 SQUID magnetometer. The molar magnetic susceptibilities are

Figure 2. Ball-and-stick models of (a) the polyanion cluster, (b) the dimer unit of V atoms, and (c) the coordination environment of the V atom. (d) Ball-and-stick of the eight-membered ring. (e) Polyhedral models of the eight-membered ring. The H atoms and terminal oxygen atoms are omitted for clarity. Color code: V, green; S, yellow; O, red. C

DOI: 10.1021/acs.inorgchem.8b03220 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry

Figure 5. (a) “Purple” and (b) “yellow”: The “V−O−S−O−V−O” rings of L-V8 and D-V8. (c) “Green”: The “V−O−S-O” rings of L-V8 and D-V8. (d) Triple helical loop of the enantiomer formed by the front three helical loops with V as the nodes. Figure 3. Polyhedral models of eight-membered rings formed by (a) the octahedra of VO6 and (b) the tetrahedra of SO4. (c) Eightmembered ring with a dimethylamine molecule in the center of the ring. (d) Three-dimensional stacked graph of polyanion clusters. (e) Petaloid structure of polyanion cluster. H atoms of C atoms and N atoms are omitted for clarity. Color code: V, green; S, yellow; C, black; O, red; N, blue.

χMT product is 8.04 cm3 K mol−1, which corresponds to the spin-only value based on eight V3+ ions (8 cm3 K mol−1 with S = 1 and g = 2). As the temperature cooling, χMT slowly increases in the range of 300 to 50 K and quickly increases below 50 K reaching a maximum of 33.7 cm3 K mol−1 at 6 K, and then sharply decreases to 29.2 cm3 K mol−1 at 1.8 K. This behavior indicates that the ferromagnetic coupling between V3+ ions dominates the magnetic properties of V8. The χMT maximum is close to the value, 36 cm3 K mol−1, based on a ground state spin S = 8, also gives an evidence of ferromagnetic coupling for all spins in V8 clusters. For further determining the coupling mode, the magnetization (M) data were collected

corrected for the diamagnetism estimated from Pascal’s tables and for sample holder by previous calibration. The variable-temperature magnetic susceptibility of V8 was measured with the powder samples in an applied field of 2 kOe as shown in Figures 7 and 8. For V8, the room-temperature

Figure 4. (a) L-Chiral three-dimensional structure connected by hydrogen bonds. (b) One-dimensional chain from part a connected via hydrogen bonds and dimethylamine. (c) L-Chiral and D-chiral one-dimensional chains, which are mirror-symmetrical. Color code: V, green; S, yellow; C, black; O, red; N, blue; H, gray. D

DOI: 10.1021/acs.inorgchem.8b03220 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry

in the field of −10 to 70 kOe at 1.8 K, as is shown in Figure S6 in Supporting Information. From 0 to 10 kOe, the magnetization rapidly increases with the external field and above 20 kOe, the increase rate slows down until a maximum value of 16.2 NμB in 70 kOe. The fast increase of magnetization in low field implies that the spins are easily magnetized, which is consistent with the ferromagnetic coupling between V3+ ions. The maximum magnetization also indicates a ferromagnetic ground state with S = 8 in V8. However, no hysteresis loop was observed in the plot of M-H. When PHI34 was used for fitting the magnetic properties in the range from 300 to 1.8 K, the best results were obtained as J1 = 8.35 cm−1, zj = 0.0035 cm−1, and TIP = 4.45 × 10−4 with g = 2.06 for V8, where J1 is the coupling constant between the neighboring V3+ ions. If the coupling interaction between the nearly molecule was not considered, the fitting results are unreasonable. It is suggested that the hydrogen bonding mediates the weak magnetic interaction between molecule. This may be the nature of vanadium-based magnetic system.13,14,35,36 Considering the ferromagnetic ground state of spin in a cluster, the AC magnetic properties of V8 were measured. However, no signal of out-of-phase susceptibility was observed above 1.8 K, as is shown in Figure S7 in the Supporting Information, so no evidence was obtained to affirm the singlemolecule magnetic properties of V8. We tried investigating the origin of the fact that the compounds do not behave as singlemolecule magnets (SMMs) by isofield variable-temperature magnetization. Seven sets of data were collected in the ranges 1−7 T and 1.8−5.0 K, and they were plotted as reduced magnetization M versus H/T in Figure 8. These data were fitted using PHI34 to give zero-field splitting parameters of D = −0.11 cm−1. Third-Order Nonlinear Optical (NLO) Properties. Since vanadium has empty d orbitals, electron transition is easy to occur under a laser pulse, thus generating a nonlinear optical absorption response. So the third-order NOL property of V8 was investigated and the third-order NLO responses, twophoton absorption (2PA) cross sections (σ) of V8, were obtained by an open-aperture Z-scan technique. Figure 9 shows the typical Z-scan measurement of V8. The nonlinear absorption coefficient β and 2PA cross section of V8 are

Figure 6. CD spectra of L-V8 (black) and D-V8 (red). Interior: Photographs of L-V8 (dark) and D-V8 (light) viewed under the polarized light with a polarized light microscope.

Figure 7. Temperature dependence of magnetic susceptibility of V8. The red lines represent the best fitting results in the range of 300 to 1.8 K.

Figure 8. Plot of reduced magnetization (M) vs H/T in the range of 1.8 to 5 K for V8. The lines represent the best fitting results by ANISOFIT.

Figure 9. Z-Scan data for the mixed compounds in aqueous solution, obtained under an open aperture configuration. The dots are the experimental data, and the solid curve is the theoretical fit. E

DOI: 10.1021/acs.inorgchem.8b03220 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry calculated as 0.008377 cm/GW and 3950 GM (1 GM = 10−50 cm4 s/photon), respectively. Physical Characterizations. We study PXRD (Figure S8), TG (Figure S9), and IR (Figure S10) properties of V8. The PXRD indicates that the experimental peaks are consistent with the simulated one, which confirms that the compounds are pure. The TG analysis manifests the process of breaking down the compound. And the IR spectrum provides the characteristic peak of the corresponding functional groups.

pounds are listed in Table 1, while bond lengths and angles and hydrogen bonds were provided in Tables S1−S6.

■

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.8b03220. Details of third-order NLO properties for V8; additional structural figures, supplementary magnetic figures, and characterizations for PXRD, TGA, and IR given in Tables S1−S7 and Figures S1−S10 (PDF)

■

CONCLUSION In this work, we have synthesized chiral enantiomeric polyoxovanadates. To the best of our knowledge, they are the first chiral ferromagnetic annular highly reduced octanuclear vanadium(III) compounds. The compounds contain the motif eight-membered ring (Vμ2-O)8(SO4)16 constituted by three different entangled loops with the V atoms as nodes. Magnetic measurement analysis indicates that the ferromagnetic coupling between V3+ ions dominates the magnetic property of V8. However, the mixed compounds do not behave as single-molecule magnets (SMMs) by isofield variable-temperature magnetization and some works are in process to design new polyoxovanadate molecules for reducing or breaking the symmetry of clusters.

■

ASSOCIATED CONTENT

S Supporting Information *

Accession Codes

CCDC 1874918−1874919 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by emailing [email protected], or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033.

■

AUTHOR INFORMATION

Corresponding Authors

*(Y.X.) E-mail: [email protected]. *(Y.S.) E-mail: [email protected]. ORCID

EXPERIMENTAL SECTION

You Song: 0000-0002-0289-7830 Yan Xu: 0000-0001-6059-075X

Methods and Materials. We use a simple and general synthetic method in the syntheses. All chemicals that we purchased were of reagent grade and used without any purification. The Nicolet Impact 410 Fourier transform infrared spectrometer was used to record the data of IR spectra with the region of 4000−450 cm−1 by using KBr pellets. We also use PerkinElmer 2400 elemental analyzer to analyze the C, H, and N elemental. Powder XRD patterns were obtained on Bruker D8X diffractometer equipped with monochromatized Cu Kα (λ = 0.15418 nm) radiation at room temperature, and the data were collected in the range of 5° ≤ 2θ ≤ 50°. What’s more, the Diamond thermogravimetric analyzer was taken to carry out the TG measurement via a flowing N2 atmosphere in the temperature range of 25 to 800 °C with a heating rate of 2 °C min−1. In addition, a JASCOJ-810 spectropolarimeter was used to record the data of circular dichroism (CD) spectra with KBr pellets. We also take single crystal X-ray and magnetic measurement to analyze the structures and magnetic properties of the compounds. Synthesis of L-V8 and D-V8. A mixture of VOSO4·xH2O (0.1145 g, 2.9950 mmol, x = 4 or 5), H2N(CH2)2NH2(0.0300 g, 0.4992 mmol), and 98% H2SO4 (0.2995 g, 2.9950 mmol) was added into 7 mL of N,N-dimethylformamide (DMF). Then 2 mL of pyridine was added into the mixed solution as auxiliaries and the final pH value was about 1−2. The mixed solution was continuously stirred for 2 h and then transferred to 25 mL of sealed Teflon-lined high pressure reactor and heated with 180 °C for 4 days. After the mixture had cooled down to room temperature and was maintained there for 1 day, green block crystals were obtained via washing with anhydrous ethanol, filtrating, and drying. Yield: 0.1075 g, 37.8% (based on V, L-V8 = 49% and D-V8 = 51%; L-V8 and D-V8 were separated by a polarizing microscope). For the mixed compounds, Anal. Calcd (%): C, 11.65; H, 4.58; N, 7.3. Found (%): C, 11.72; H, 4.53; N, 7.41. X-ray Crystallography. The single crystals of L-V8 and D-V8 were singled out by naked eye under the microscope and glued at the top of the thin glass fiber with epoxy glue. The single-crystal data were collected under a nitrogen stream at 150 K on a Bruker APEX2 CCD diffractometer with Mo Kα radiation (λ= 0.71073 Å). The structures of the L-V8 and D-V8 were determined through direct methods refined by full-matrix least-squares methods with the SHELX-97/2014 software. The vanadium atoms were located anisotropically. The CCDC numbers of L-V8 and D-V8 are 1874918 and 1874919. The final crystallographic data and structural determination for com-

Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS This work was supported by the Natural Science Foundation of China (Grant 21571103), the Major Natural Science Projects of the Jiangsu Higher Education Institution (Grant16KJA150005), and the Qing Lan Project.

■

REFERENCES

(1) Mü l ler, A.; Peters, F.; Pope, M. T.; Gatteschi, D. Polyoxometalates: very large clustersnanoscale magnets. Chem. Rev. 1998, 98, 239−271. (2) Khan, M. I.; Tabussum, S.; Marshall, C. L.; Neylon, M. K. Catalytic deNOx properties of novel vanadium oxide based openframework materials. Catal. Lett. 2006, 112, 1−12. (3) Clemente-Juan, J. M.; Coronado, E.; Gaita-Ariño, A. Magnetic polyoxometalates: from molecular magnetism to molecular spintronics and quantum computing. Chem. Soc. Rev. 2012, 41, 7464− 7478. (4) Chakrabarty, S.; Banerjee, R. Catalase-like activity of the polyoxovanadate anion [MnIVV13O38]7− a mechanistic study. Catal. Sci. Technol. 2012, 2, 2224−2226. (5) Santoni, M.-P.; La Ganga, G.; Mollica Nardo, V.; Natali, M.; Puntoriero, F.; Scandola, F.; Campagna, S. The use of a vanadium species as a catalyst in photoinduced water oxidation. J. Am. Chem. Soc. 2014, 136, 8189−8192. (6) Seliverstov, A.; Streb, C. A new class of homogeneous visiblelight photocatalysts: molecular cerium vanadium oxide clusters. Chem. - Eur. J. 2014, 20, 9733−9738. (7) Monakhov, K. Y.; Linnenberg, O.; Kozłowski, P.; van Leusen, J.; Besson, C.; Secker, T.; Ellern, A.; López, X.; Poblet, J. M.; Kögerler, P. Supramolecular recognition influences magnetism in [X@ HVIV8VV14O54]6− self-assemblies with symmetry-breaking guest anions. Chem. - Eur. J. 2015, 21, 2387−2397. (8) Laye, R. H.; Wei, Q.; Mason, P. V.; Shanmugam, M.; Teat, S. J.; Brechin, E. K.; Collison, D.; McInnes, E. J. L. A highly reduced F

DOI: 10.1021/acs.inorgchem.8b03220 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry

Na4[V4O8(rac-tart)2]·12H2O and (NEt4)4[V4O8((R,R)-tart)2]·6H2O (tart = C4H2O64−). Inorg. Chem. 2007, 46, 3971−3983. (26) Chen, Y.; Peng, J.; Yu, H.; Han, Z.; Gu, X.; Shi, Z.; Wang, E.; Hu, N. A supramolecular assembly of chiral L/D-[Cd(Cl)(H2O)(phen)2]+ and L,L/D,D-dinuclear Cd complex coordinated by phen and {V16O38(Cl)} cluster. Inorg. Chim. Acta 2005, 358, 403−408. (27) Zhou, J.; Liu, X.; Hu, F.; Chen, R.; Zou, H.; Fu, W.; Liang, G.; Chen, Y. A novel 3-D chiral polyoxovanadate architecture based on breaking high symmetry of spherical [V15O36Cl]8− cluster. CrystEngComm 2013, 15, 4593−4596. (28) Koyama, Y.; Hayashi, Y.; Isobe, K. Self-assembled all-inorganic chiral polyoxovanadate: spontaneous resolution of nitrate-incorporated octadecavanadate. Chem. Lett. 2008, 37, 578−579. (29) Khan, M. I.; Yohannes, E.; Doedens, R. J.; Golub, V. O.; O’Connor, C. J. Templated synthesis of a chiral solid: synthesis and characterization of {Co(H2N(CH2)2NH2)3}[V3O9]· H2O, containing a new type of chiral vanadium oxide chain. Inorg. Chem. Commun. 2005, 8, 841−845. (30) Marino, N.; Lloret, F.; Julve, M.; Doyle, R. P. Synthetically persistent, self assembled [VIV2VV4] polyoxovanadates: Facile synthesis, structure and magnetic analysis. Dalton Trans. 2011, 40, 12248−12256. (31) Zhou, S.; Wan, H.; Hu, G.; Zhang, Y.; Liu, Y.; Miao, H.; Zhu, D.; Xu, Y. A new vanadium sulfate with ferrimagnetic and NLO properties constructed from novel discrete umbrella-like [VV(μ3O)4VIV4O5(SO4)4(en)]5− anions. Dalton Trans. 2015, 44, 8605− 8608. (32) Chen, Q.; Liu, S.; Zubieta, J. A Cyclic Octanuclear Polyoxoalkoxyvanadate(IV) with an Oxalate-Binding Cavity, [(nC4H)4N]2[V8O8(OCH3)16(C2O4)]. Structural Comparison with the Analogous Polymolybdate(V) Complex [(nC4H9)4N]2[Mo8O16(OC2H5)8(C2O4)]. Inorg. Chem. 1989, 28, 4433−4434. (33) Laye, R. H.; Murrie, M.; Ochsenbein, S.; Bell, A. R.; Teat, S. J.; Raftery, J.; Güdel, H.-U.; McInnes, E. J. L. Solvothermal Syntheses of High-Nuclearity Vanadium(iii) Clusters. Chem. - Eur. J. 2003, 9, 6215−6220. (34) Chilton, N. F.; Anderson, R. P.; Turner, L. D.; Soncini, A.; Murray, K. S. PHI: A powerful new program for the analysis of anisotropic monomeric and exchange-coupled polynuclear d- and fblock complexes. J. Comput. Chem. 2013, 34, 1164−1175. (35) Gao, Y. Z.; Xu, Y. Q.; Huang, K. L.; Han, Z. G.; Hu, C. W. Two three-dimensional {V16Ge4}-based open frameworks stabilized by diverse types of CoII-amine bridges and magnetic properties. Dalton Trans. 2012, 41, 6122−6129. (36) Manos, M. J.; et al. A new class of ferromagnetically-coupled mixed valence vanadium(IV/V) polyoxometalates. Chem. - Eur. J. 2003, 9, 695−703.

vanadium(III/IV) polyoxovanadate comprising an octavanadyl square-prism surrounding a dimetallic vanadium(III) fragment. J. Am. Chem. Soc. 2006, 128, 9020−9021. (9) Daniel, C.; Hartl, H. A mixed-valence VIV/VV alkoxopolyoxovanadium cluster series [V6O8(OCH3)11]n± exploring the influence of a μ-Oxo ligand in a spin frustrated structure. J. Am. Chem. Soc. 2009, 131, 5101−5114. (10) Breen, J. M.; Schmitt, W. Hybrid organic−inorganic polyoxometalates: functionalization of VIV/VV nanosized clusters to produce molecular capsules. Angew. Chem., Int. Ed. 2008, 47, 6904− 6908. (11) Antonova, E.; Näther, C.; Kögerler, P.; Bensch, W. Organic functionalization of polyoxovanadates: Sb-N bonds and charge control. Angew. Chem., Int. Ed. 2011, 50, 764−767. (12) Cardona-Serra, S.; Clemente-Juan, J. M.; Coronado, E.; GaitaAriño, A.; Suaud, N.; Svoboda, O.; Bastardis, R.; Guihéry, N.; Palacios, J. J. Electrically switchable magnetic molecules: inducing a magnetic coupling by means of an external electric field in a mixedvalence polyoxovanadate cluster. Chem. - Eur. J. 2015, 21, 763−769. (13) Zhou, J.; Zhang, J.; Fang, W.-H.; Yang, G.-Y. A series of vanadogermanates from 1D chain to 3D framework built by Ge−V− O clusters and transition-metal-complex bridges. Chem. - Eur. J. 2010, 16, 13253−13261. (14) Aronica, C.; Chastanet, G.; Zueva, E.; Borshch, S. A.; Clemente-Juan, J. M.; Luneau, D. A mixed-valence polyoxovanadate(III,IV) cluster with a calixarene cap exhibiting ferromagnetic V(III)V(IV) interactions. J. Am. Chem. Soc. 2008, 130, 2365−2371. (15) Paul, G.; Choudhury, A.; Nagarajan, R.; Rao, C. N. R. Aminetemplated linear vanadium sulfates with different chain structures. Inorg. Chem. 2003, 42, 2004−2013. (16) Zhang, Y.; Wang, X.; Li, S.; Song, B.; Shao, K.; Su, Z. Liganddirected assembly of polyoxovanadate-based metal−organic polyhedra. Inorg. Chem. 2016, 55, 8770−8775. (17) Baggio, R.; Contreras, D.; Moreno, Y.; Arrue, R.; Paulus, I. E.; Pena, O.; Pivan, J. Y. Magneto-structural study and synthesis optimization of a phosphovanadate copper complex, [Cu(VO)2(PO4)2(H2O)4]n. J. Coord. Chem. 2012, 65, 2319−2331. (18) Ru, J.; Ma, X.; Cui, Y.; Guo, M.; Chen, J.; Li, X.-X. Two Vanadogermanates from 1-Dimensional Chain to 2-Dimensional Network Built from Di-Cd-Substituted Ge−V−O Clusters and Transition Metal Complex Bridges. Cryst. Growth Des. 2017, 17, 1384−1389. (19) Cui, X.-B.; Xu, J.-Q.; Meng, H.; Zheng, S.-T.; Yang, G.-Y. A Novel Chainlike As−V−O Polymer Based on a Transition Metal Complex and a Dimeric Polyoxoanion. Inorg. Chem. 2004, 43, 8005− 8009. (20) Rasmussen, M.; Näther, C.; van Leusen, J.; Kögerler, P.; Zhechkov, L.; Heine, T.; Bensch, W. Covalent Co−O−V and Sb−N Bonds Enable Polyoxovanadate Charge Control. Inorg. Chem. 2017, 56, 7120−7126. (21) Dang, D.; Wu, P.; He, C.; Xie, Z.; Duan, C. Homochiral metalorganic frameworks for heterogeneous asymmetric catalysis. J. Am. Chem. Soc. 2010, 132, 14321−14323. (22) Luo, Y.; Xie, K.-X.; Yue, D.-F.; Zhang, X.-M.; Xu, X.-Y.; Yuan, W.-C. An organocatalytic asymmetric Mannich reaction of pyrazoleamides with cyclic trifluoromethyl ketimines: enantioselective access to dihydroquinazolinone skeletons. Org. Biomol. Chem. 2018, 16, 3372−3375. (23) Cortese, A. J.; Wilkins, B.; Smith, M. D.; Yeon, J.; Morrison, G.; Tran, T. T.; Halasyamani, P. S.; zur Loye, H.-C. Crystal growth of four oxovanadium(IV) tartrates prepared via a mild two-step hydrothermal method: observation of spin-dimer behavior and second harmonic generation. Inorg. Chem. 2015, 54, 4011−4020. (24) Cao, J.; Xiong, Y.; Luo, X.; Chen, L.; Shi, J.; Zhou, M.; Xu, Y. A pair of new chiral polyoxovanadates with decent NLO properties. Dalton Trans. 2018, 47, 6054−6058. (25) Schwendt, P.; Tracey, A. S.; Tatiersky, J.; Gáliková, J.; Ž ák, Z. Vanadium(V) Tartrato Complexes: Speciation in the H3O+(OH−)/ H2VO4−/(2R3R)-tartrate system and X-ray crystal structures of G

DOI: 10.1021/acs.inorgchem.8b03220 Inorg. Chem. XXXX, XXX, XXX−XXX