Electronic Supplementary information for 'A plutonium-based single-molecule magnet'

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1 Eletroni upplementary Material (EI) for ChemComm. This journal is The Royal oiety of Chemistry 2014 Eletroni upplementary information for 'A plutonium-based single-moleule magnet' N. Magnani, E. Colineau, J.-C. Griveau, C. Apostolidis, O. Walter, R. Caiuffo European Commission, Joint Researh Centre, Institute for Transuranium Elements, Postfah 2340, Karlsruhe, Germany 1. ynthesis The solvents were purhased from Aldrih in their anhydrous form onditioned under argon. The potassium salt of the ligand (KTp) was prepared as previously desribed. [1] The roomtemperature reation of 1 equiv. of PuCl 3 with 3.05 equivalents of KTp in water leads to the preipitation of PuTp 3. Purifiation proeeds via washing with water, ethanol, and diethylether and drying of the residue. Extration with benzene yields in 90 % of single rystalline material. Elemental analysis (%) alulated for 239 PuTp 3 (B 3 C 27 H 30 N 18 Pu; g/mol) C 36.97; H 3.45; N 28.74; Pu Found Pu petrosopi data FTIR and olid state UV-NIR spetra were reorded respetively on a Perkin-Elmer 2000 IRspetrometer and on a Perkin-Elmer Lambda 9 spetrometer. The observed transitions are listed in the following. IR (KBr; m -1 ): 3142(m), 3119(w), 3112(w), 2453(sh), 2442(s), 2405(m), 2374(w), 1505(s), 1431(m), 1423(m), 1406(s), 1381(s), 1301(vs), 1293(vs), 1226(m), 1212(vs), 1197(m), 1185(m), 1129(m), 1121(vs), 1085(w), 1061(m), 1048(vs), 974(vs), 924(w), 920(w), 899(w), 878(w), 804(w), 777(m), 769(vs), 750(vs), 739(m), 725(vs), 670(m), 625(m), 620(m) FIR (Polyethylen; m -1 ): 338(m), 332(m), 319(m), 260(w), 182(m), 161(m), 136(vs) (w = weak, m = medium, s = strong, vs = very strong) olid state UV-NIR spetrum taken on a Perkin-Elmer Lambda 9 spetrometer. NIR/VI (KBr; nm): 1556, 1413, 1189, 1147, 1100, 1049, 1023, 928, 912, 822, 814, 805, 796, 774, 768, 669, 605, 565,

2 3. X-Ray Crystallography Diffration data were measured at 100 K on a Bruker APEX II Quazar diffratometer (Mo-Kα radiation, graphite monohromator, λ = Å) in the Ω-range from 1.48 to frames were olleted with an irradiation time of 3 s per frame obtained from eight runs performed with - or -sans with = = 0.5. The data were integrated with AINT [2] and orreted to Lorentz and polarisation effets; absorption effets were orreted with ADAB. [3] The struture was solved by diret methods and refined to an optimum R 1 value with HELXL [4] Visual evaluation was performed with XPMA. [5] Refinement of F 2 proeeded against all refletions. Data have been deposited at the CCDC with the referene number , and are available on request from Table 1. Crystallographi data. Empirial formula B 3 C 27 H 30 N 18 Pu Formula weight Temperature 100(2) K Wavelength Å Crystal system Hexagonal pae group P 63/m Unit ell dimensions a = (5) Å = (8) Å Volume (17) Å 3 Z 2 Density (alulated) Mg/m 3 Absorption oeffiient mm -1 F(000) 854 Crystal size x x mm 3 Ω range for data olletion to Index ranges -15 h 15, -15 k 15, -18 l 17 Refletions olleted Independent refletions 1381 [R(int) = ] Completeness to theta = % Absorption orretion multi-san Max. and min. transmission and Refinement method Full-matrix least-squares on F 2 Data / restraints / parameters 1381 / 0 / 108 Goodness-of-fit on F Final R indies [I>2sigma(I)] R 1 = , wr 2 = R indies (all data) R 1 = , wr 2 = Largest diff. peak and hole and eå -3 2

3 Table 2. Bond lengths [Å] and angles [ ]. * Pu(1)-N(1) (15) Pu(1)-N(3) 2.762(2) N(1)-C(1) 1.336(2) N(1)-N(2) 1.373(2) N(2)-C(3) 1.351(2) N(2)-B(1) 1.544(2) N(3)-C(4) 1.338(3) N(3)-N(4) 1.369(3) N(4)-C(6) 1.342(3) N(4)-B(1) 1.530(4) C(1)-C(2) 1.389(3) C(2)-C(3) 1.372(3) C(4)-C(5) 1.400(4) C(5)-C(6) 1.370(4) B(1)-N(2)# (2) N(1)#1-Pu(1)-N(1)# (5) N(1)#1-Pu(1)-N(1)# (2) N(1)#2-Pu(1)-N(1)# (7) N(1)#1-Pu(1)-N(3)# (4) N(1)#2-Pu(1)-N(3)# (3) N(1)#4-Pu(1)-N(3)# (4) N(3)#4-Pu(1)-N(3) C(1)-N(1)-N(2) (15) C(1)-N(1)-Pu(1) (12) N(2)-N(1)-Pu(1) (11) C(3)-N(2)-N(1) (15) C(3)-N(2)-B(1) (17) N(1)-N(2)-B(1) (16) C(4)-N(3)-N(4) 105.1(2) C(4)-N(3)-Pu(1) (17) N(4)-N(3)-Pu(1) (15) C(6)-N(4)-N(3) 110.7(2) C(6)-N(4)-B(1) 128.4(2) N(3)-N(4)-B(1) 120.8(2) N(1)-C(1)-C(2) (17) C(3)-C(2)-C(1) (17) N(2)-C(3)-C(2) (17) N(3)-C(4)-C(5) 111.1(2) C(6)-C(5)-C(4) 104.7(2) N(4)-C(6)-C(5) 108.3(2) N(4)-B(1)-N(2) (14) N(2)#1-B(1)-N(2) 112.5(2) * ymmetry transformations used to generate equivalent atoms: #1 x,y,-z+3/2 ; #2 -y+1,x-y+1,-z+3/2 ; #3 -y+1,x-y+1,z; #4 -x+y,-x+1,z Unlisted distanes or angles are idential to ones already present in the table. 3

4 Figure 1. Cell paking along the axis of PuTp 3. Plutonium atoms are shown in blue, nitrogen in violet, and boron ions are shown in pink. 4. Magneti haraterization The temperature-dependent d magneti suseptibility has been measured in the temperature range from 1.9 to 300 K with a Quantum Design MPM-7T uperonduting Quantum Interferene Devies (QUID). useptibility data have been olleted with applied magneti fields µ 0 H ranging from 0.05 to 7 T on a sample of mg using ompressed powder in a uprasil-quartz sample holder. The sample was restrained to prevent grain torqueing using a fitted quartz stopper, and was sealed under argon before measurement. The ontribution to the signal of the empty sample holder was measured before the enapsulation and subtrated from the total signal. The suseptibility has been obtained as the ratio between the longitudinal magnetization and the applied magneti field. The resulting data were orreted for the diamagneti ontribution using tabulated Pasal s onstants. Magneti alibration was done with a ylindrial palladium standard having approximately the same geometry of the measured samples. The real and imaginary parts of the a magneti suseptibility were measured as a funtion of temperature on the same sample using a Quantum Design PPM-14T platform; data for this experiment were olleted on warming from 1.9 to 40 K, after zero-field ooling of the sample. For eah run of measurements, the exitation a.. field was applied with a fixed amplitude of µ 0 H a = 10 G and fixed frequenies f, ranging from 18 to 9987 Hz. The temperature of the samples was ontrolled with an auray of about 0.1 K. 4

5 Figure 2. Frequeny dependene of the a.. magneti suseptibility measured for PuTp 3 at various temperature and field values (see text for details). Isotherms of the frequeny dependent a.. magneti suseptibility have also been measured at several temperatures from 1.9 to 12 K in the frequeny range from 18 Hz to about 10 khz, both with and without a superimposed field ( 0 H d = 0, 100 Oe, 2000 Oe), generated by a superonduting d.. magnet. The results obtained with field 0 H d = 100 Oe have been fitted to a modified Debye relaxation law valid in the low frequeny range and allowing for a ontinuous distribution of the relaxation time 6] a T 1 1 i Where T is the isothermal suseptibility in the limit << 1, = a () is the adiabati suseptibility, = 2f is the angular frequeny and is the average relaxation time. The 1 5

6 parameter determines the width of the time relaxation distribution funtion g(ln). Equation 1 an be separated into real and imaginary omponents orresponding to the in-phase and out-of-phase suseptibilities and a a sinh 1ln 1ln sin / 2 T 1 2 osh os / 2 1ln sin / 2. T 2 osh 2 3 Table 3. Parameters obtained by fitting Cole-Cole plots to the modified Debye relaxation model. T (K) (10-3 emu/mol) T (10-3 emu/mol) (s) The parameters obtained from the fits are reported in Table 3, and the orresponding distribution funtion for the relaxation times on a logarithmi sale is given by g ln 1 2 osh sin 1 ln / os. As an example, the g(ln) distribution obtained at 1.9 and 12 K are shown in the inset of Fig. 4. The parameter inreases with inreasing temperature, thus the distribution funtion g(ln) beomes progressively broader. 4 6

7 5. Additional referenes [1] a). Trofimenko, J. Am. Chem. o. 1967, 89, 3165; b). Trofimenko, Inorg. ynth. 1970, 12, 99. [2] AINT: Bruker 2007, Bruker AX In., Madison, Wisonsin, UA. [3] ADAB: Bruker 2007, Bruker AX In., Madison, Wisonsin, UA. [4] HELXL-2013: G. M. heldrik, 2013, University of Göttingen, Germany. [5] XPMA: L. Zsolnai, 1997, University of Heidelberg, Germany. [6] a) D. Huser, A. J. Vanduyneveldt, G. J. Nieuwenhuys, J. A. Mydosh, J. Phys. C: olid tate Phys. 1986, 19, 3697; b) U. T. Hohli, Phys. Rev. Lett. 1982, 48,