2p-3d-4f Heterotrispin Chains and Ring–Chains Bridged by a Nitronyl


May 1, 2019 - Compounds 1–3 display one-dimensional (1D) chain structure with NIT-4PyPh radical ligand bridging LnIII and CuII ions in “head-to-he...
0 downloads 0 Views 749KB Size


Subscriber access provided by FONDREN LIBRARY, RICE UNIVERSITY

Article

2p-3d-4f Hetero-tri-spin Chains and Ring-chains Bridged by a Nitronyl Nitroxide Ligand: Structure and Magnetic Properties Juan Sun, Kang Wang, Pei Jing, Jiao Lu, and Licun Li Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.9b00489 • Publication Date (Web): 01 May 2019 Downloaded from http://pubs.acs.org on May 7, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

2p-3d-4f Hetero-tri-spin Chains and Ring-chains Bridged by a Nitronyl Nitroxide Ligand: Structure and Magnetic Properties Juan Sun, Kang Wang, Pei Jing, Jiao Lu, Licun Li* Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China

ABSTRACT Two types of the radical-3d-4f chains {[Cu(hfac)2][(NIT-4PyPh)]2[Ln(hfac)3]}n (Ln = Gd 1, Tb 2, Dy 3) and {[Cu(hfac)2(NIT-4PyPh)]2Ln(hfac)3}n (Ln = Gd 4, Tb 5, Dy

6;

NIT-4PyPh

=

2-[4-(4-pyridinylmethoxy)phenyl]-4,4,5,5-tetramethyl-

imidazoline-1-oxyl-3-oxide; hfac = hexafluoroacetylacetonate) have been successfully achieved upon adjusting the experimental conditions. Compounds 1-3 display 1D chain structure with NIT-4PyPh radical ligand bridging LnIII and CuII ions in “headto-head” mode through pyridine-N atom and nitroxide unit of the radical. Complexes 4-6 possess an interesting 1D topological structure consisting of cyclic [Cu-Radical]2 dimers connected by Ln ions. Magnetic investigations indicate that ferromagnetic the copper(II)/lanthanide(III)-NO exchange occurs in two series of compounds. Furthermore, complexes 3 and 5 were found to exhibit frequency dependence of ac susceptibilities, evidencing slow magnetic relaxation.

INTRODUCTION Combined 3d-4f heteronuclear compounds are well known for representing a promising way in the design of molecular nanomagnets.1-6 The first example of 3d-4f heterometallic SMM was obtained in 2004.7 Since then, the investigation of 3d-4f heterometallic complexes e.g. Mn-Ln,8-11 Fe-Ln,12-14 Co-Ln,15-18 Ni-Ln19-21 and CuLn22-25 have been spurred. A typical example, [Mn18Dy], which has been proven successful in enhancing the magnetic anisotropy through introducing the strong anisotropic dysprosium(III) ion into a Mn19 complex, and displays slow magnetic relaxation behavior.26,27 Recently, MII2DyIII (M=FeII, ZnII, CoII) system reported by Tong et al., achieves a record anisotropy barrier of 600 K (M =CoII) among all 3d-4f 1

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

complexes.28-30 In spite of these achievements, it is still a challenging task to enhance the JM-Ln of 3d-4f complexes.31,32 In view of this, the introduction of paramagnetic radical ligands would be an appealing strategy for 3d-4f heterometallic complexes. According to “hard and soft” concept, the functionalized nitronyl nitroxide radical containing N group is an excellent candidate to combine 4f and 3d ions for constructing 3d-4f system. However, the N-O groups of nitronyl nitroxide radicals have poor ability to coordinate, thus they only ligate to metal centers with electronwith-drawing groups such as hexafluoroacetylacetonate (hfac). To date, few 3d-4f multinuclear compounds involving nitronyl nitroxide radical ligands have been obtained by using hfac as coligand.33-36 More recently, we concentrate our study on hetero-tri-spin (Ln-radical-M) 1D systems using functionalized nitronyl nitroxide radicals, and a few d-f complexes linked by nitronyl nitroxides (i.e. hetero-tri-spin) with interesting topology structures or magnetic behaviors were obatined.37-39 In the present work, using nitronyl nitroxide radical ligand NIT-4PyPh ( NIT4PyPh=2-[4-(4-pyridinylmethoxy)phenyl]-4,4,5,5-tetramethylimidazoline-1-oxyl-3oxide), we successfully prepared two types of hetero-tri-spin complexes. One is a family of the radical ligand bridging Ln and Cu centers (2p-3d-4f) chains by “head and head” mode, namely, {[Cu(hfac)2][(NIT-4PyPh)]2[Ln(hfac)3]}n (Ln = Gd 1, Tb 2, Dy 3). Changing the experimental conditions, the other series of interesting radical bridged Ln-Cu ring-chains {[Cu(hfac)2(NIT-4PyPh)]2Ln(hfac)3}n (Ln = Gd 4, Tb 5, Dy 6) were achieved, in which [Cu(hfac)2(NIT-4PyPh)]2 cyclic dimers are bridged by the LnIII ions. Ferromagnetic copper(II)/lanthanide(III)-NO interactions are active in these 1D chains. Slow magnetic relaxation behaviors are found in complexes 3 and 5.

EXPERIMENTAL SECTION Materials NIT-4PyPh radical was prepared according to the previous report.40 The used other chemicals including organic solvents were bought from Aldrich and Alfa Aesar and directly used. Physical measurements Chemical analyses including carbon hydrogen and nitrogen were tested with a Perkin−Elmer 240 elemental analyzer. PXRD data were collected with a Rigaku Ultima IV diffractometer for all six compounds. IR spectra (KBr pellets) were implemented on a Bruker Tensor 27 Spectrometer. Dc and ac magnetic data were 2

ACS Paragon Plus Environment

Page 2 of 20

Page 3 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

collected on a Quantum Design SQUID-VSM magnetometer. Pascal’s constants41 were used for diamagnetic corrections. Synthesis of {[Cu(hfac)2][(NIT-4PyPh)]2[Ln(hfac)3]}n (Ln= Gd 1; Tb 2; Dy 3 ) 0.01 mmol Ln(hfac)32H2O in 15 mL C7H16 was under reflux for three hours. Cool the mixture to 80°C, 5 mL of CH2Cl2 solution containing NIT-4PyPh radical (0.0068g, 0.02 mmol) was introduced. The reaction was maintained at 80°C for 30 minutes under stirring, then 0.0048g (0.01 mmol) of solid Cu(hfac)2 was introduced. The blue block-shaped crystals were obtained after one day by evaporating the filtrate at room temperature. For 1, yield: 43% (based on Gd ion). Chemical analysis (%) found(calcd): C, 38.98(39.07); H, 2.68(2.55); N, 4.31(4.34). IR (KBr): 2360(m), 1655(s), 1504(m), 1259(s), 1205(s), 1148(s), 800(m), 665(m) cm−1. For 2, yield: 47% (based on Tb ion). Chemical analysis (%) found(calcd): C, 38.93(39.03); H, 2.72(2.55); N, 4.43(4.34). IR (KBr): 2360(m), 1654(s), 1504(m), 1260(s), 1205(s), 1148(s), 800(m), 665(m) cm−1. For 3, yield: 52% (based on Dy ion). Chemical analysis (%) found(calcd): C, 38.86(38.96); H, 2.74(2.54); N, 4.26(4.33). IR (KBr): 2360(m), 1655(s), 1506(m), 1259(s), 1205(s), 1149(s), 801(m), 665(m) cm−1. Synthesis of {[Cu(hfac)2(NIT-4PyPh)]2Ln(hfac)3}n (Ln = Gd, 4; Tb, 5; Dy, 6 ) A heptane solution (15 mL) containing 0.0096g (0.02 mmol) of Cu(hfac)2 and 0.01 mmol Ln(hfac)32H2O was stired under reflux for three hours, then 5 mL CH2Cl2 containing 0.0068g NIT-4PyPh radical (0.02 mmol) was added. After refluxing for 30 minutes, the reaction solution was cooled to RT. The blue filtrate was left at RT for one day, yielding blue rhombus crystals. For 4, yield: 51% (based on Gd ion). Chemical analysis (%) found(calcd): C, 36.23(36.31); H, 2.39(2.13); N, 3.48(3.48). IR (KBr): 2360(m), 1655(s), 1350(m), 1255(s), 1208(s), 1145(s), 802(m), 668(m), 586(m) cm−1. For 5, yield: 58% (based on Tb ion). Chemical analysis (%) found(calcd): C, 36.33(36.29); H, 2.32(2.13); N, 3.53(3.48). IR (KBr): 2361(m), 1656(s), 1350(m), 1254(s), 1214(s), 1148(s), 802(m), 669(m), 587(m) cm−1. For 6, yield: 63% (based on Dy ion). Chemical analysis (%) found(calcd): C, 36.39(36.23); H, 2.27(2.12); N, 3.59(3.47). IR (KBr): 2361(m), 1652(s), 1349(m), 1258(s), 1207(s), 1145(s), 802(m), 669(m), 587(m) cm−1. 3

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 20

X-Ray Crystallography Crystallographic data of all six compounds were acquired on a Rigaku Saturn diffractometer using graphite-monochromated Mo K radiation ( = 0.71073 Å) at 113 K. Direct methods were employed to solve the structures using SHELXS-201442 and the refinements on full-matrix least-squares based on F2 were implemented using SHELXL-2014 programs.43 For non-H atoms, the anisotropic thermal parameters were empolyed. The H atoms of the liangds were positioned geometrically. Crystallographic refinement details for 1-6 are provided in Table 1. Significant bond parameters for all compounds are given in Tables S7-S8. Table 1. Crystallographic data for 1-6. 1 Formula Formula weight Crystal system Space group T, K a /Å b /Å c /Å , deg , deg , deg V /Å3 Z Dcalcd /g cm-3 F(000) min, max deg Reflections collected Unique reflns/ Rint GOF (F2) R1/wR2 [I > 2σ(I)]a R1/wR2 (all

data)a

2 3 C63H49CuF30LnN6O16 1936.89 1938.57 1942.14 Monoclinic Monoclinic Monoclinic P21/c P21/n P21/n 113 113 113 20.134(18) 20.106(2) 20.0670(15) 16.550(15) 16.5242(16) 16.5312(12) 28.159(17) 24.609(3) 24.6290(18) 90 90 90 121.48(4) 102.757(3) 102.688(2) 90 90 90 8002(12) 7974.2(15) 7970.7(10) 4 4 4 1.608 1.615 1.618 3840 3844 3848 2.990/25.010 3.043/27.475 1.712/27.908

4

5 6 C73H51Cu2F42LnN6O20 2414.55 2416.23 2419.80 Monoclinic Monoclinic Monoclinic C2/c C2/c C2/c 113 113 113 37.300(2) 37.287(4) 37.188(14) 12.3530(5) 12.3718(11) 12.339(4) 20.2349(12) 20.263(2) 20.224(7) 90 90 90 105.858(2) 105.705(4) 105.824(2) 90 90 90 8970.3(8) 8991.7(15) 8934(5) 4 4 4 1.788 1.785 1.799 4764 4768 4772 3.201/27.520 1.746/28.742 3.202/28.319

49660

78969

103278

41972

56418

42818

13973/0.1881 1.052

17937/0.0743 0.978

18908/0.0706 1.016

11076/0.0366 1.053

10307/0.0167 1.049

11384/0.0417 1.030

0.1189/0.2844

0.0574/0.1393

0.0531/0.1253

0.0357/0.0774

0.0265/0.0683

0.0355/0.0802

0.1821/0.3523

0.1019/0.1624

0.0899/0.1425

0.0447/0.0834

0.0285/0.0696

0.0472/0.0863

RESULTS AND DISCUSSION Synthesis To achieve 2p-3d-4f complexes, the nitronyl nitroxide radical with additional N atom was used. Based on the soft-hard rule, the NO unit of NIT-4PyPh can coordinate to the Ln(III) ions while the ring with N donor could ligate to the transition metal ion. Using the ratio of 1:2:1 of CuII/NIT-4PyPh/LnIII, one series of 1D chains have been 4

ACS Paragon Plus Environment

Page 5 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

synthesized, where the LnIII and CuII centers are linked by the nitroxides unit and pyridyl N atoms of NIT-4PyPh radicals. Varying the ratio of CuII/NIT-4PyPh/LnIII as 2:2:1, the other series of radical bridged Ln-Cu compounds exhibiting interesting chain of ring structure have been obtained, where [Cu-radical]2 cyclic dimers are connected by LnIII ions. It is the molar ratio of CuII, LnIII and the NIT-4PyPh radical that determines the structure of the product. Description of the crystal structure

Figure 1. (left) 1D chain of 2. (right) The ligation environment of Tb(III) ion. {[Cu(hfac)2][(NIT-4PyPh)]2[Ln(hfac)3]}n (Ln = Gd, 1; Tb, 2; Dy, 3 ). Complexes 1-3 are isostructural and display one-dimensional structure. Compound 1 belongs to the monoclinic P21/c space group, whereas complexes 2 and 3 crystallize in the monoclinic P21/n space group. The 1D chain structure is formed by the NIT-4PyPh radical ligands bridging CuII and LnIII ions via their nitroxides and pyridyl-N atoms (Figures 1, S1 and S2). The Ln ion is eight-coordinated by tri-hfac O-donor anions (Ln-Ohfac: 2.352(10)-2.415(9) Å for 1, 2.338(4)-2.398(4) Å for 2 and 2.330(3)-2.386(3) Å for 3) and two nitroxides of two NIT-4PyPh radicals (Ln-Orad: 2.365(9) and 2.388(9) Å for 1, 2.352(4) and 2.369(4) Å for 2, 2.335(3) and 2.357(3) Å for 3). SHAPE analysis44,45 reveals that all of the LnIII centers are located in triangular dodecahedron (D2d) coordination geometries (Table S9). The angle formed by two N-O units and the Ln(III) (Orad−Ln−Orad) is 137.3(3)° for 1, 137.51(13)° for 2 and 137.59(11)° for 3. The copper(II) center is defined by two nitrogen atoms and four oxygen atoms coming from pyridine rings of radicals and β-diketonate coligands, respectively. The equatorial Cu-Ohfac/N bond lengths are 1.958(13)-2.013(13) Å for 1, 1.985(5)2.004(4) Å for 2 and 1.981(4)-2.014(4) Å for 3. The apical sites are filled with two O atom of two β-diketonate coligands (Cu-Ohfac bond distances: 2.273(14) and 2.328(13) Å for 1, 2.261(5) and 2.325(5) Å for 2, 2.269(4) and 2.329(4) Å for 3). The greater 5

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

axial bond distances may be attributed to the effect of Jahn-Teller.46-48 In the chain, the Ln⋯Cu distances are 12.2785(94) Å for 1, 12.2750(17) Å for 2 and 12.5059(13) Å for 3. Chains packing of 1-3 is given in Figures S5-S7, the nearest interchain Ln⋯Ln and Ln⋯Cu and Cu⋯Cu contacts are 10.7564(67) Å and 9.0281(60) Å and 10.5628(72) Å for 1, 10.7383(10) Å and 9.0356(11) Å and 10.5472(14) Å for 2, 10.7433(8) Å and 9.0305(9) Å and 10.5541(11) Å for 3.

Figure 2. (left)Ring-chain structure of 5. (right) The ligation polyhedron of Tb(III) ion. {[Cu(hfac)2(NIT-4PyPh)]2Ln(hfac)3}n (Ln = Gd, 4; Tb, 5; Dy, 6). Complexes 4-6 belong to the monoclinic system and crystallize in space group C2/c. Complexes 4-6 are isomorphic and consist of 1D chain structure assembled by LnIII ions and cyclic [Cu-radical]2 moieties (Figures 2, S3 and S4). In three ring-chains, every NIT-4PyPh ligand serves as a bridge to connect two CuII centers via its one nitroxide and one pyridine ring to form centro-symmetric dimeric cycle [Cu-(NIT-4PyPh)]2. Dimers are linked by Ln centers via the uncoordinated N-O groups, thus developing a 1D ringchain structure. The copper atom possesses a octahedral ligation environment with equatorial one pyridyl N atom and three Ohfac atoms (Cu-Ohfac: 1.9577(19)-1.9651(18) Å for 4, 1.9616(15)-1.9686(15) Å for 5 and 1.957(2)-1.9668(19) Å for 6; Cu-N: 1.998(2) Å for 4, 2.0007(16) Å for 5 and 1.998(2) Å for 6). The apical sites are held by one nitroxide group from the other NIT-4PyPh and one O atom of hfac anion (CuOhfac: 2.2085(19) Å for 4, 2.2109(15) Å for 5 and 2.203(2) Å for 6; Cu-Orad: 2.5266(22) Å for 4, 2.5295(18) Å for 5 and 2.5200(23) Å for 6). The Ln center is ligated by two nitroxide units of the NIT-4PyPh radicals (Ln-Orad: 2.3606(18) Å for 4, 2.3553(14) Å for 5 and 2.3353(19) Å for 6) and three hfac anions (Ln-Ohfac: 2.3570(18)-2.3890(18) Å for 4, 2.3494(14)-2.3712(14) Å for 5 and 2.3323(19)2.3557(19) Å for 6). All eight-coordinate LnIII ions are located in triangular dodecahedron (D2d) coordination spheres (Table S9, SHAPE analysis: CShM =0.2526

ACS Paragon Plus Environment

Page 6 of 20

Page 7 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

0.258).44,45 The O(nitroxide)−Ln−O(nitroxide) angles are 137.49(9)° for 4, 137.06(7)° for 5 and 137.16(9)° for 6. For the dimeric rings, the Cu⋯Cu separations are 13.1141(10) Å for 4, 13.1306(14) Å for 5 and 13.1125(46) Å for 6. The Ln⋯Cu distances bridged by the NIT moieties are 8.8760(8) Å for 4, 8.8735(11) Å for 5 and 8.8450(29) Å for 6. Chains packing of 4-6 are presented in Figures S8-S10, the closest interchain Ln⋯Ln and Ln⋯Cu and Cu⋯Cu contacts are 12.3530(6) Å and 11.1453(6) Å and 7.2391(6) Å for 4, 12.3718(12) Å and 11.1527(8) Å and 7.2487(7) Å for 5, 12.339(4) Å and 11.1443(24) Å and 7.2338(19) Å for 6. Magnetic properties

Figure 3. Temperature-dependent MT plots for 1 and 3 (left), 2 (right). The red line is theoretical curve based on the magnetic model for 1. The dc magnetic data of all six complexes over the 2-300 K were collected under 1000 Oe external field (Figures 3 and 4). The phase purity of 1-6 has been checked using PXRD patterns which well match with the simulated ones (Figures S11 and S12). As illustrated in Figure 3, the MT products at 300K are 9.84 cm3Kmol1 for 1, 13.75 cm3Kmol1 for 2 and 15.95 cm3Kmol1 for 3, close to the anticipated values (9.01 cm3Kmol1 for 1, 12.95 cm3K mol1 for 2 and 15.30 cm3Kmol1 for 3) for one uncoupled system including two S = 1/2 radicals, one CuII ion (S=1/2) and one lanthanide ion. For complex 1, as temperature is decreased, the χMT values gradually increase to a maximum of 11.02 cm3Kmol−1 at 4 K. Below this temperature the values of χMT decrease to 10.90 cm3K mol−1 at 2 K. This observed magnetic profile means the ferromagnetic Gd-nitroxide exchange.49 Based on the crystal structure of 1, these species of magnetic exchange couplings should be taken place: (i) the Gd-NO interaction (J1); (ii) the NO-ON magnetic 7

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 20

exchange through the Gd(III) center (J2); (iii) the copper−nitroxide interaction via the benzene and pyridine rings (J3), which should be very weak and can be ignored. Hence, the magnetic data of 1 may be modeled as a tri-spin unit of NIT-Gd-NIT plus one independent Cu(II) ion; the spin Hamiltonian of the tri-spin NIT-Gd-NIT





unit can be described as H  2 J1 SˆGd SˆRad 1  SˆGd SˆRad 2  2 J 2 SˆRad 1SˆRad 2 . Other possible weak interactions between the NIT-Gd-NIT moiety and independent CuII are included by using the molecular mean-field approximation ( zJ) (eq 2). M  

Ng 2  2 165  84 exp(9 J1 / kT )  84 exp[(7 J1  2 J 2 ) / kT ]  35exp(16 J1 / kT ) { } 4kT 5  4 exp(9 J1 / kT )  4 exp[(7 J1  2 J 2 ) / kT ]  3exp(16 J1 / kT ) (1)

Ng 2  2 SCu ( SCu  1) 3kT

 total   M 1   zJ '  M Ng 2  2  

(2)

The simulation of experimental data produced the following magnetic parameters: g = 2.08, J1 = 1.02cm-1, J2 = -3.43 cm-1 and zJ '= -0.02 cm-1. The determined values of J1 and J2 match well with those of previous reports.50,51 For 2, the MT value steadily decreases from 300 to 36 K to attain a value of 13.35 cm3Kmol−1 and then lifts to 13.51 cm3Kmol−1 at 3 K and then declines to 13.46 cm3Kmol−1 at 2.0 K. While the MT product declines continuously to the value of 12.30 cm3Kmol−1 at 2 K for complexes 3,. The observed behaviors of 2 and 3 might be attributed to Tb/Dy-radical interactions as well as the effects of crystal-field of the DyIII or TbIII ions.

Figure 4. Thermal dependences of MT for 4-6. The red line is the curve calculated using Magpack program for 4. 8

ACS Paragon Plus Environment

Page 9 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

The room temperature MT values are 10.23 cm3Kmol1 for 4, 13.90 cm3Kmol1 for 5 and 16.53 cm3Kmol1 for 6 (Figure 4), which are close to the anticipated values (9.38 cm3Kmol1 for 4, 13.32 cm3K mol1 for 5 and 15.67 cm3Kmol1 for 6) for noninteracting rare earth ion, the radicals and copper(II) ions. For compounds 4 and 5, a continuous increase of the MT value with reducing the temperature is found and the maximums of 18.24 cm3Kmol-1 and 22.31 cm3Kmol-1 are obtained at 2 K, suggesting the dominant ferromagnetic couplings in the system. For compound 6, the MT value maintains almost unchanged until 40 K, then reduces to 14.14 cm3Kmol-1 at 2 K. For compound 4, the possible magnetic exchanges are as follows: (i) the copper(II)-nitroxide magnetic coupling through the whole radical ligand, that can be neglected due to the long distance; (ii) the copper(II)-nitroxide direct exchange (J1); (iii) the NO-ON coupling through the GdIII ion (J2); (iv) the Gd-nitroxide interaction (J3). Thus, the magnetic behavior of 4 could be modeled using the linear [Cu-NIT-GdNIT-Cu] motif (Scheme 1). To reproduce the magnetic data, MAGPACK software52 with the following spin Hamiltonian was employed.







H  2 J1 SˆCu1SˆRad 1  SˆRad 2 SˆCu 2  2 J 2 SˆRad 1SˆRad 2  2 J 3 SˆRad 1SˆGd  SˆGd SˆRad 2



Scheme 1. The scheme of magnetic exchanges in 4. J2 J1 Cu1

J3 NIT1

J3 Gd

J1 NIT2

Cu2

The fit to the magnetic data yields: g = 2.07, J1 = 23.92 cm−1, J2 = -6.98 cm−1 and J3 = 2.83 cm−1. The positive J1 demonstrates the ferromagnetic copper(II)nitroxide (axial) exchange, attributing to the orthogonal magnetic orbitals (the * (radical unit) and the dx2−y2 (Cu(II) ion) orbitals).46,53 The magnitude of the J1 is well compared with the exchange interactions found in other CuII-NIT complexes.54-56 The negative J2 and positive J3 are consistent with the antiferromagnetic radicalradical coupling via through the gadolinium(III) ion and the weak ferromagnetic gadolinium(III)-nitroxide interaction, respectively, as found in other reported Gd-NIT complexes.50,51

9

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Figure 5. Field-dependent magnetization curve for 1 (2 K). The blue line is the theoretical behavior described in text. At 2.0K, the M vs. H curves of all six complexes were determined from 0 to 7 T (Figures 5, 6 and S13-S16). For complex 1, as the magnetic field strengthens, the M value attains 10.57 N at 7T, corresponding to the anticipated saturation value (10N) (Figure 5). In addition, the experimental M value is above corresponding theoretical data obtained from Brillouin equation for the system composed of independent three S=1/2 and one S=7/2 spins using T = 2.0K and g =2.0, clearly supporting ferromagnetic GdIII-nitroxide coupling. For 2 and 3, the M values reach 8.39 and 7.27 N at 70 kOe (Figures S13 and S14) and no saturations are observed because of the magnetic anisotropy originating from the 4f ions.

Figure 6. Field-dependent magnetization curve for 4 (2 K). The blue line is the theoretical behavior described in text. For 4, at low fields, the curve of M vs H displays a sharp rise and attains 11.43 Nβ at 7 KOe, reaching to the theoretical saturation value (11 Nβ) (Figure 6). The 10

ACS Paragon Plus Environment

Page 10 of 20

Page 11 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

experimental M values are higher than those calculated by the Brillouin equation for the isolated spins (four S = 1/2 and one S = 7/2) using g = 2.0 and T = 2.0 K, further demonstrating the presence of ferromagnetic exchanges in 4. The M values exhibit a rapid increase with the magnetic field and attain 9.92 Nβ for 5 and 9.81 Nβ for 6 at 70 kOe (Figure S15 and S16). It can be noticed that M value does not reach saturation for 5 and 6, owing to the anisotropic 4f ions.

Figure 7. Thermal dependence of ac signals under zero (left) and 3000 Oe (right) dc field for 5.

Figure 8. Thermal-dependent ac signals for 3 in 3000 Oe dc field. To explore spin dynamic behaviors of Tb and Dy compounds, the ac susceptibilities were measured utilizing an oscillating 3.0 Oe field from 2K to 10 K at different frequencies. 5 exhibits clear frequency-dependent ′′ signals in zero dc field, which could be due to slow magnetic relaxation behavior (Figure 7). However, no 11

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

peak maxima of  was observed in the available window above 2 K for 5. For 2, 3 and 6, no non-zero  ac susceptibility was found in zero dc field (Figures S17-S19). Then the ac data were collected in 3 kOe dc field for all compounds to reduce or suppress the possible quantum tunneling process (QTM). 3 and 5 displayed frequency-dependent peaks in  susceptibility curves, yet no visible  peaks (Figures 7 and 8). Thus, the activation barrier (Ueff) and relaxation time (0) can't be obtained from the fit of Arrhenius law. If there is only one relaxation process in 3 and 5, the equation ln(/) = ln(0) + Ea/kBT could be used to roughly estimate the Ueff and 0 values.57,58 The best fitting ac data of 3 and 5 yield the energy barrier (Ea/kB) 8.86 K and 8.85 K with the relaxation time (0) 2.9210-7 s and 1.410-6 s, respectively (Figure 9). For 2 and 6, no χ″ components were observed even in a 3000 Oe dc field (Figures S20-S21).

Figure 9. Natural logarithm of / vs 1/T plots for 3 (left) and 5 (right), the lines are the linear fit to the equation given in the text.

CONCLUSIONS Two types of 2p-3d-4f chains bridged by the NIT-4PyPh radicals have been successfully achieved via varying the molar ratio of the starting materials. Complexes 1-3 display 1D chain structure with radical ligand bridging Ln and Cu ions via “head and head or tail and tail” mode. Complexes 3-6 exhibit interesting spin topologies assembled by LnIII units and [Cu-Radical]2 cyclic dimers. Magnetic investigations indicate that 3 and 5 exhibit frequency-dependencent χ″ signals, suggesting the slow magnetic dynamics. The present work not only demonstrates that functionalized nitronyl nitroxides are appealing blocks for constructing f-d heterometallic compounds exhibiting fascinating magnetic behaviors, but also provides the important information for the rational design of heterometallic chains by using paramagnetic 12

ACS Paragon Plus Environment

Page 12 of 20

Page 13 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

nitronyl nitroxides. ASSOCIATED CONTENT Supporting Information Significant bond parameters, analysis of rare earth geometry, packing diagrams, PXRD patterns and ac and dc data. The CIF files of six complexes with CCDC 1892090-1892095 can be achieved from Cambridge Crystallographic Data Centre. AUTHOR INFORMATION Corresponding Author *E-mail: [email protected] ORCID Licun Li: 0000-0001-8380-2946 Notes The authors declare no competing financial interest. ACKNOWLEDGMENT This work was found by NSFC (Nos. 21773122 and 21471083). REFERENCES (1) Mori, F.; Nyui, T.; Ishida, T.; Nogami, T.; Choi, K.-Y.; Nojiri, H. Oximatebridged trinuclear Dy-Cu-Dy complex behaving as a single-molecule magnet and its mechanistic investigation. J. Am. Chem. Soc. 2006, 128, 1440-1441. (2) Novitchi, G.; Wernsdorfer, W.; Chibotaru, L. F.; Costes, J. P.; Anson, C. E.; Powell, A. K. Supramolecular “Double-Propeller” Dimers of Hexanuclear CuII/LnIII Complexes: A {Cu3Dy3}2 Single-Molecule Magnet. Angew. Chem., Int. Ed. 2009, 48, 1614-1619. (3) Huang, Y. G.; Jiang, F. L.; Hong, M. C. Magnetic lanthanide–transitionmetal organic-inorganic hybrid materials: From discrete clusters to extended frameworks. Coord. Chem. Rev. 2009, 253, 2814-2834. (4) Rinck, J.; Novitchi, G.; Van den Heuvel, W.; Ungur, L.; Lan, Y.; Wernsdorfer, W.; Anson, C. E.; Chibotaru, L. F.; Powell, A. K. An Octanuclear

13

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

[CrIII4DyIII4] 3d-4f Single-Molecule Magnet. Angew. Chem., Int. Ed. 2010, 49, 75837587. (5) Sharples, J. W.; Collison, D. The coordination chemistry and magnetism of some 3d-4f and 4f amino-polyalcohol compounds. Coord. Chem. Rev. 2014, 260, 120. (6) Liu, K.; Shi, W.; Cheng, P. Toward heterometallic single-molecule magnets: Synthetic strategy, structures and properties of 3d-4f discrete complexes. Coord. Chem. Rev. 2015, 289, 74-122. (7) Osa, S.; Kido, T.; Matsumoto, N.; Re, N.; Pochaba, A.; Mrozinski, J. A tetranuclear 3d-4f single molecule magnet:[CuIILTbIII(hfac)2]2. J. Am. Chem. Soc. 2004, 126, 420-421. (8) Zaleski, C. M.; Depperman, E. C.; Kampf, J. W.; Kirk, M. L.; Pecoraro, V. L. Synthesis, structure, and magnetic properties of a large lanthanide-transition-metal single-molecule magnet. Angew. Chem., Int. Ed. 2004, 43, 3912-3914. (9) Mishra, A.; Wernsdorfer, W.; Abboud, K. A.; Christou, G. Initial observation of magnetization hysteresis and quantum tunneling in mixed manganese-lanthanide single-molecule magnets. J. Am. Chem. Soc., 2004, 126, 15648-15649. (10) Karotsis, G.; Kennedy, S.; Teat, S. J.; Beavers, C. M.; Fowler, D. A.; Morales, J. J.; Evangelisti, M.; Dalgarno, S. J.; Brechin, E. K. [MnIII4LnIII4] calix[4] arene clusters as enhanced magnetic coolers and molecular magnets. J. Am. Chem. Soc. 2010, 132, 12983-12990. (11) Alaimo, A. A.; Worrell, A.; Das Gupta, S.; Abboud, K. A.; Lampropoulos, C.; Christou, G.; Stamatatos, Th. C. Structural and Magnetic Variations in a Family of Isoskeletal, Oximate-Bridged {MnIV2MIII} Complexes (MIII=Mn, Gd, Dy). Chem. Eur. J. 2018, 24, 2588-2592. (12) Ferbinteanu, M.; Kajiwara, T.; Choi, K.-Y.; Nojiri, H.; Nakamoto, A.; Kojima, N.; Cimpoesu, F.; Fujimura, Y.; Takaishi, S.; Yamashita, M. A binuclear Fe(III)Dy(III) single molecule magnet. Quantum effects and models. J. Am. Chem. Soc. 2006, 128, 9008-9009. (13) Zeng, Y. F.; Xu, G. C.; Hu, X.; Chen, Z.; Bu, X. H.; Gao, S.; Sañudo, E. C. Single-molecule-magnet behavior in a Fe12Sm4 cluster. Inorg. Chem. 2010, 49, 97349736. (14) Xu, G. F.; Gamez, P.; Tang, J.; Clérac, R.; Guo, Y. N.; Guo, Y. MIIIDyIII3 14

ACS Paragon Plus Environment

Page 14 of 20

Page 15 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

(M= FeIII, CoIII) Complexes: Three-Blade Propellers Exhibiting Slow Relaxation of Magnetization. Inorg. Chem. 2012, 51,5693-5698. (15) Mondal, K. C.; Sundt, A.; Lan, Y.; Kostakis, G. E.; Waldmann, O.; Ungur, L.; Chibotaru, L. F.; Anson, C. E.; Powell, A. K. Coexistence of Distinct Single-Ion and Exchange-Based Mechanisms for Blocking of Magnetization in a CoII2DyIII2 Single-Molecule Magnet. Angew. Chem., Int. Ed. 2012, 51, 7550-7554. (16) Zou, L. F.; Zhao, L.; Guo, Y. N.; Yu, G. M.; Guo, Y.; Tang, J.; Li, Y. H. A dodecanuclear heterometallic dysprosium-cobalt wheel exhibiting single-molecule magnet behaviour. Chem. Commun. 2011, 47, 8659-8661. (17) Langley, S. K.; Chilton, N. F.; Ungur, L.; Moubaraki, B.; Chibotaru, L. F.; Murray, K. S. Heterometallic tetranuclear [LnIII2CoIII2] complexes including suppression of quantum tunneling of magnetization in the [DyIII2CoIII2] single molecule magnet. Inorg. Chem. 2012, 51,11873-11881. (18) Vignesh, K. R.; Langley, S. K.; Murray, K. S.; Rajaraman, G. Quenching the

Quantum

Tunneling

of

Magnetization

in

Heterometallic

Octanuclear

{TMIII4DyIII4}(TM= Co and Cr) Single-Molecule Magnets by Modification of the Bridging Ligands and Enhancing the Magnetic Exchange Coupling. Chem. - Eur. J. 2017, 23, 1654-1666. (19) Colacio, E.; Ruiz-Sanchez, J.; White, F. J.; Brechin, E. K. Strategy for the rational design of asymmetric triply bridged dinuclear 3d-4f single-molecule magnets. Inorg. Chem. 2011, 50, 7268-7273. (20) Zhao, L.; Wu, J.; Ke, H.; Tang, J. Family of Defect-Dicubane Ni4Ln2 (Ln= Gd, Tb, Dy, Ho) and Ni4Y2 Complexes: Rare Tb (III) and Ho (III) Examples Showing SMM Behavior. Inorg. Chem. 2014, 53, 3519-3525. (21) Wen, H. R.; Dong, P. P.; Liu, S. J.; Liao, J. S.; Liang, F. Y.; Liu, C. M. 3d4f heterometallic trinuclear complexes derived from amine-phenol tripodal ligands exhibiting magnetic and luminescent properties. Dalton Trans. 2017, 46, 1153-1162. (22) Aronica, C.; Pilet, G.; Chastanet, G.; Wernsdorfer, W.; Jacquot, J. F.; Luneau, D. A Nonanuclear Dysprosium (III)-Copper (II) Complex Exhibiting SingleMolecule Magnet Behavior with Very Slow Zero-Field Relaxation. Angew. Chem., Int. Ed. 2006, 45, 4659-4662. (23) Langley, S. K.; Ungur, L.; Chilton, N. F.; Moubaraki, B.; Chibotaru, L. F.; Murray, K. S. Structure, Magnetism and Theory of a Family of Nonanuclear 15

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

CuII5LnIII4-Triethanolamine Clusters Displaying Single-Molecule Magnet Behaviour. Chem. - Eur. J. 2011, 17, 9209-9218. (24) Ojea, M J. H.; Milway, V. A.; Velmurugan, G.; Thomas, L. H.; Coles, S. J.; Wilson, C.; Wernsdorfer, W.; Rajaraman, G.; Murrie, M. Enhancement of TbIII-CuII Single-Molecule Magnet Performance through Structural Modification. Chem. - Eur. J. 2016, 22, 12839-12848. (25) Dey, A.; Das, S.; Kundu, S.; Mondal, A.; Rouzieres, M.; Mathonière, C.; Clérac, R.; Suriya Narayanan, R.; Chandrasekhar, V. Heterometallic Heptanuclear [Cu5Ln2] (Ln = Tb, Dy, and Ho) Single-Molecule Magnets Organized in OneDimensional Coordination Polymeric Network. Inorg. Chem. 2017, 56, 14612-14623. (26) Ako, A. M.; Hewitt, I. J.; Mereacre, V.; Clérac, R.; Wernsdorfer, W.; Anson, C. E.; Powell, A. K. A ferromagnetically coupled Mn19 aggregate with a record S= 83/2 ground spin state. Angew. Chem., Int. Ed. 2006, 118, 5048-5051. (27) Ako, A. M.; Mereacre, V.; Clérac, R.; Wernsdorfer, W.; Hewitt, I. J.; Anson, C. E.; Powell, A. K. A [Mn18Dy] SMM resulting from the targeted replacement of the central MnII in the S= 83/2 [Mn19]-aggregate with DyIII. Chem. Commun. 2009, 544546. (28) Liu, J.-L.; Chen, Y.-C.; Zheng, Y.-Z.; Lin, W.-Q.; Ungur, L.; Wernsdorfer, W.; Chibotaru, L. F.; Tong, M.-L. Switching the anisotropy barrier of a single-ion magnet by symmetry change from quasi-D5h to quasi-Oh. Chem. Sci. 2013, 4, 33103316. (29) Liu, J.-L.; Wu, J.-Y.; Chen, Y.-C.; Mereacre, V.; Powell, A. K.; Ungur, L.; Chibotaru, L. F.; Chen, X.-M.; Tong, M.-L. A Heterometallic FeII-DyIII SingleMolecule Magnet with a Record Anisotropy Barrier. Angew. Chem., Int. Ed. 2014, 53, 12966-12970. (30) Liu, J.-L.; Wu, J.-Y.; Huang, G.-Z.; Chen, Y.-C.; Jia, J.-H.; Ungur, L.; Chibotaru, L. F.; Chen, X.-M.; Tong, M.-L. Desolvation-driven 100-fold slow-down of tunneling relaxation rate in Co(II)-Dy(III) single-molecule magnets through a single-crystal-to-single-crystal Process. Sci. Rep. 2015, 5, 16621. (31) Kajiwara, T.; Nakano, M.; Takahashi, K.; Takaishi, S.; Yamashita, M. Structural Design of Easy-Axis Magnetic Anisotropy and Determination of Anisotropic Parameters of LnIIICuII Single-Molecule Magnets. Chem. - Eur. J. 2011, 17, 196-205. 16

ACS Paragon Plus Environment

Page 16 of 20

Page 17 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

(32) Colacio, E.; Ruiz, J.; Mota, A. J.; Palacios, M. A.; Cremades, E.; Ruiz, E.; White, F. J.; Brechin, E. K. Family of Carboxylate- and Nitratediphenoxo Triply Bridged Dinuclear NiIILnIII Complexes (Ln = Eu, Gd, Tb, Ho, Er, Y): Synthesis, experimental and theoretical magnetostructural studies, and single-molecule magnet mehavior. Inorg. Chem. 2012, 51, 5857-5868. (33) Escobar, L. B. L.; Guedes, G. P.; Soriano, S.; Speziali, N. L.; Jordão, A. K.; Cunha, A. C.; Ferreira, V. F.; Maxim, C.; Novak, M. A.; Andruh, M.; Vaz, M. G. F. New Families of Hetero-tri-spin 2p-3d-4f Complexes: Synthesis, Crystal Structures, and Magnetic Properties. Inorg. Chem. 2014, 53, 7508−7517. (34)

Li,

C.;

Li,

H.;

Xie,

J.;

Yang,

M.;

Wang,

X.;

Li,

L.

{[Ln(hfac)3]2[Cu(hfac)2]3(NIT-Pyrim)2(H2O)2}(LnIII= Gd, Ho, Er): Unique Nitronyl Nitroxide Bridged 3d–4f Heterometallic Clusters. Eur. J. Inorg. Chem. 2018, 525–530. (35) Patrascu, A. A.; Calancea, S.; Briganti, M.; Soriano, S.; Madalan, A. M.; Cassaro, R. A. A. Caneschi, A.; Totti, F.; M. Vaz, G. F.; Andruh, M. A chimeric design of heterospin 2p-3d, 2p-4f, and 2p-3d-4f complexes using a novel family of paramagnetic dissymmetric compartmental ligands. Chem. Commun. 2017, 53, 65046507. (36) Wang, X. F.; Hu, P.; Li, Y. G.; Li, L. C. Construction of Nitronyl NitroxideBased 3d-4f Clusters: Structure and Magnetism. Chem. - Asian J. 2015, 10, 325-328. (37) Wang, X.; Hu, P.; Li, L.; Sutter, J. P. [(Cu-Radical)2-Ln]: Structure and Magnetic Properties of a Hetero-tri-spin Chain of Rings (Ln= YIII, GdIII, TbIII, DyIII). Inorg. Chem. 2015, 54, 9664-9669. (38) Zhu, M.; Li, C.; Wang, X.; Li, L.; Sutter, J. P. Thermal Magnetic Hysteresis in a Copper-Gadolinium-Radical Chain Compound. Inorg. Chem. 2016, 55, 26762678. (39) Yang, M.; Xie, J.; Sun, Z.; Li, L.; Sutter, J. P. Slow Magnetic Relaxation in Ladder-Type and Single-Strand 2p-3d-4f Heterotrispin Chains. Inorg. Chem. 2017, 56, 13482-13490. (40) Ullman, E. F.; Call, L.; Osiecki, J. H.. Stable free radicals. VIII. New imino, amidino, and carbamoyl nitroxides. J. Org. Chem. 1970, 35, 3623-3631. (41) Kahn, O. Molecular Magnetism; VCH: Weinheim, 1993. (42) Sheldrick, G. M. SHELXS-2014, Program for structure solution; Universität Göttingen: Göttingen, Germany, 2014. 17

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 20

(43) Sheldrick, G. M. SHELXL-2014, Program for structure refinement; Universität Göttingen, Göttingen, Germany, 2014. (44) Casanova, D.; Llunell, M.; Alemany P.; Alvarez, S. The Rich Stereochemistry of Eight-Vertex Polyhedra: A Continuous Shape Measures Study. Chem. Eur. J. 2005, 11, 1479-1494. (45) Llunell, M.; Casanova, D.; Cirera, J.; Alemany, P.; Alvarez, S. SHAPE 2.1; University of Barcelona, Barcelona, 2013. (46) Gatteschi, D.; Laugier, J.; Rey, P.; Zanchini, C. Crystal and molecular structure

and

magnetic

hexafluoroacetylacetonate

properties

with

the

of

nitroxide

the ligand

adducts

of

2-phenyl-4,

copper(II) 4,

5,

5-

tetramethylimidazoline-1-oxyl 3-oxide. Inorg. Chem. 1987, 26, 938-943. (47) Lanfranc de Panthou, F.; Belorizky, E.; Calemzuk, R.; Luneau, D.; Marcenat, C.; Ressouche, E.; Turek, P.; Rey, P. A New Type of Thermally Induced Spin Transition Associated with an Equatorial. dblarw. Axial Conversion in a Copper (II)-Nitroxide Cluster. J. Am. Chem. Soc. 1995, 117, 11247-11253. (48) Ishimaru, Y.; Kitano, M.; Kumada, H.; Koga, N.; Iwamura, H. Regiospecificity in the exchange coupling of the spins of copper(II) ion coordinated with the ring nitrogen atoms and N-tert-butylaminoxyl radical attached as a substituent on the pyridine and N-phenylimidazole rings. Inorg. Chem. 1998, 37, 2273−2280. (49) Benelli, C.; Caneschi, A.; Gatteschi, D.; Pardi, L. Gadolinium (III) complexes with pyridine-substituted nitronyl nitroxide radicals. Inorg.Chem., 1992, 31, 741-746. (50) Sutter, J. P.; Kahn, M. L.; Golhen, S.; Ouahab, L.; Kahn, O. Synthesis and Magnetic Behavior of Rare-Earth Complexes with N, O-Chelating Nitronyl Nitroxide Triazole Ligands: Example of a [GdIII{Organic Radical}2] Compound with an S= 9/2 Ground State. Chem. Eur. J. 1998, 4, 571-576. (51) Benelli, C.; Caneschi, A.; Gatteschi, D.; Pardi, L.; Rey, P.; Shum, D. P.; Carlin, R. L. Magnetic properties of lanthanide complexes with nitronyl nitroxides. Inorg. Chem. 1989, 28, 272-275. (52) Borrás-Almenar, J. J.; Clemente-Juan, J. M.; Coronado, E.; Tsukerblat, B. S. MAGPACK A package to calculate the energy levels, bulk magnetic properties, and inelastic neutron scattering spectra of high nuclearity spin clusters. J. Comput. Chem. 18

ACS Paragon Plus Environment

Page 19 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

2001, 22, 985−991. (53) Cabello, C. I.; Caneschi, A.; Carlin, R. L.; Gatteschi, D.; Rey, P.; Sessoli, R. Structure and magnetic properties of ferromagnetic alternating spin chains. Inorg. Chem. 1990, 29, 2582-2587. (54) Caneschi, A.; Gatteschi, D.; Laugier, J.; Rey, P. Ferromagnetic alternating spin chains. J. Am. Chem. Soc. 1987, 109, 2191-2192. (55) Caneschi, A.; Gatteschi, D.; Grand, A.; Laugier, J.; Pardi, L.; Rey, P. Moderate ferromagnetic exchange between copper(II) and a nitronyl nitroxide in a square-pyramidal adduct. MO interpretation of the mechanism of exchange in copper(II)-nitroxide complexes. Inorg. Chem. 1988, 27, 1031-1035. (56) Yao, B.; Guo, Z.; Zhang, X.; Ma, Y.; Yang, Z.; Wang, Q.; Li, L.; Cheng, P. A New Nitronyl Nitroxide Radical as Building Blocks for a Rare S = 13/2 High Spin Ground State 2p-3d Complex and a 2p-3d-4f Chain. Cryst. Growth Des. 2017, 17, 9599. (57) Luis, F.; Bartolomé, J.; Fernández, J. F.; Tejada, J.; Hernández, J. M.; Zhang, X. X.; Ziolo, R. Thermally activated and field-tuned tunneling in Mn12Ac studied by ac magnetic susceptibility. Phys. Rev. B. 1997, 55, 11448. (58) Bartolomé, J.; Filoti, G.; Kuncser, V.; Schinteie, G.; Mereacre, V.; Anson, C. E.; Powell, A. K.; Prodius, D.; Turta, C. Magnetostructural correlations in the tetranuclear series of {Fe3LnO2} butterfly core clusters: Magnetic and Mössbauer spectroscopic study. Phys. Rev. B. 2009, 80, 014430.

19

ACS Paragon Plus Environment

Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

For Table of Contents Use Only

2p-3d-4f Hetero-tri-spin Chains and Ring-chains Bridged by a Nitronyl Nitroxide Ligand: Structure and Magnetic Properties Juan Sun, Kang Wang, Pei Jing, Jiao Lu, Licun Li*

Synopsis: Two series of new 2p-3d-4f hetero-tri-spin compounds have been achieved via changing the experimental conditions. One is 2p-3d-4f 1D chain while the other possesses the interesting 1D ring-chain topological structure. Furthermore, Dy (chain) and Tb (ring-chain) derivatives exhibit slow relaxation of the magnetization.

20

ACS Paragon Plus Environment

Page 20 of 20