Spin Transition and Structural Transformation in a

Transcription

1 Supporting Information for Spin Transition and Structural Transformation in a Mononuclear Cobalt(II) Complex Ying Guo, Xiu-Long Yang, Rong-Jia Wei, Lan-Sun Zheng, and Jun Tao* State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen , People s Republic of China Tel: ; Fax: taojun@xmu.edu.cn. S1

2 Contents Materials and Synthesis S3 Characterization and Methods S3 Table S1. Crystal Data and Structure Refinements for compounds 2 and 3 S6 Table S2. Selected bond lengths and bond angles for compound 2 HT S7 Table S3. Selected bond lengths and bond angles for compound 2 LT S7 Table S4. Selected bond lengths and bond angles for compound 3 S8 Table S5. Hydrogen bonds and C H π interactions for compounds 2 HT and 2 LT in the ab plane S8 Figure S1. ORTEP diagram of the structural unit of 2 HT S9 Figure S2. ORTEP diagram of the structural unit of 2 LT S9 Figure S3. ORTEP diagram of the structural unit of 3 S10 Figure S4. Intermolecular interactions of 2 HT in the ab plane S10 Figure S5. Intermolecular interactions of 2 LT in the ab plane S11 Figure S6. Intermolecular interactions of 3 in the ac plane S11 Figure S7. Intermolecular interactions of 2 HT in the bc plane S12 Figure S8. Intermolecular interactions of 2 LT in the bc plane S12 Figure S9. Magnetic properties of compound 2. Applied field: 5000 Oe, sweeping rate: 1 K min 1 S13 Figure S10. Magnetic properties of compound 3. Applied field: 5000 Oe, sweeping rate: 1 K min 1 S13 Figure S11. DSC trace for complex 2 upon cooling and warming S14 Figure S12. DSC trace for methanol upon cooling and warming S14 Figure S13. IR spectrum of compound 2 S15 Figure S14. IR spectrum of compound 3 S15 S2

3 Experimental Section Materials. CoCl 2 6H 2 O, KPF 6, 4 -(4 -pyridyl)-2,2 :6,2 -terpyridine (pyterpy), dichloromethane and methanol were purchased from commercial sources and used as received. Synthesis. Method 1) A CH 2 Cl 2 solution (5 ml) of pyterpy ( g, 0.1 mmol) was added dropwise to MeOH solution (5 ml) of CoCl 2 6H 2 O ( g, 0.05 mmol) and KPF 6 ( g, 0.1 mmol) at room temperature, the resulting red solution were sealed and left undisturbed for 5-7 days. Red block crystals of compound 2 and black block crystals of compound 3 suitable for X-ray diffraction analysis were separated and collected by hand. Method 2) A CH 2 Cl 2 solution (5 ml) of pyterpy ( g, 0.2 mmol) was added dropwise to MeOH solution (10 ml) of CoCl 2 6H 2 O ( g, 0.1 mmol) and KPF 6 ( g, 0.2 mmol) at room temperature, the resulting red solution were sealed and left undisturbed for 5-7 days. Red block crystals of compound 2 (without by-product 3) were collected by filtration. Structural transformation. During the synthesis of compounds 2 and 3 (method 1), the crystals of 2 and 3 were left undisturbed in the mother liquor for 3-4 weeks, all crystals of 2 were transformed to crystals of 3. Elemental analysis. Compounds 2 and 3 were unstable in air due to the loss of guest solvent molecules, so elemental analyses were conducted on the desolvated samples. Compounds 2 and 3 were heated at 50 C under vacuum for 48 h. Calcd (%) for the solvent-free sample of 2, C 40 H 28 N 8 P 2 F 12 Co: N, 11.56; C, 49.55; H, Found: N, 11.70; C, 49.36; H, IR (KBr pellet, cm 1 ) of 2: 3440(s, br), 1620(m), 1598(m), 1572(w), 1542(w), 1473(w), 1429(w), 1410(m), 1385(w), 1248(w), 1165(w), 1120(w), 836(vs), 793(w), 562(m). Calcd (%) for the solvent-free sample of 3, C 40 H 28 N 8 P 2 F 12 Co: N, 11.56; C, 49.55; H, Found: N, 11.62; C, 49.43; H, IR (KBr pellet, cm 1 ) of 3: 3433(s, br), 1618(m), 1598(m), S3

4 1543(w), 1469(w), 1408(w), 1376(m), 1076(w), 840(s), 793(w), 562(w). Physical techniques. Elemental analyses (C, H, N) were obtained using PerkinElmer 240Q elemental analyzer. IR spectra (KBr pellets) were recorded on a Nicolet 5DX spectrophotometer in the range of cm 1. X-ray crystallographic data collection and structure refinement. Single-crystal XRD data were recorded on Agilent SuperNova CCD diffractometer. The structures were solved by direct methods and refined on F 2 by anisotropic full-matrix least-squares methods using SHELXTL All non-hydrogen atoms were refined anisotropically, while hydrogen atoms were generated by the riding mode. (1) Sheldrick, G. M. SHELXS-97: Programs for crystal structure analysis, University of Göttingen, Göttingen (Germany), Magnetic measurements. Magnetic measurements were performed on freshly isolated samples and were carried out at a sweeping rate of 1 K min 1 on a Quantum Design SQUID XL7 magnetometer. The sample of compound 2 and a drop of methanol were sealed in a quartz tube. Magnetic susceptibilities were calibrated with the sample holder, and diamagnetic corrections were estimated from Pascal s constants. Differential Scanning Calorimetry (DSC) DSC (differential scanning calorimetry) measurement on compound 2 was performed by cooling and heating the sample (3.315mg), instilled a drop of methanol in an aluminum crucible using a NETZSCH DSC 200F3. The measurement was carried out at 10 K min 1 sweeping rate under nitrogen in the temperature range of K. We also measured a drop of methanol in an aluminum crucible under the same condition. From the Figure s11, we found an endothermic peak at 189 K during the warming process and an exothermic peak at 180 K during the cooling process. The DSC data indicated that the complex exhibited a reversible phase transition with a 9 K hysteresis. Figure s12 showed that pure methanol did not have either endothermic or exothermic S4

5 peak in the temperature range of K. It meant that methanol dropped in the sample did not affect the DSC data of the sample. Therefore, we could use the DSC data to estimate the enthalpy and entropy associated with the SCO and crystallographic phase transition upon heating, which are 4.99 kj mol 1 and J mol 1 K 1, respectively. S5

6 Tables Table S1. Crystal Data and Structure Refinements for compounds 2 and Temperature / K 250(2) 100(2) 173(2) Empirical formula C 34 H 36 CoF 12 N 8 O 2 P 2 C 34 H 36 CoF 12 N 8 O 2 P 2 C 43 H 36 Cl 4 CoF 12 N 8 OP 2 Mr / g mol Crystal system monoclinic monoclinic orthorhombic Space group C2/c P2 1 /c Pbca a / Å (10) (6) (4) b / Å (8) (9) (4) c / Å (3) (3) (5) β / (4) (3) V / Å (3) (2) 9617(3) Z D cald / g cm F(000) Index ranges 22 h h h h h h 18 9 h 9 7 h 9 32 h 33 Reflections collected Data / restraints / parameters 3165 / 0 / / 0 / / 0 / 640 Goodness-of-fit on F Final R indices [I > 2σ (I)] R indices (all data) S6

7 Table S2. Selected bond lengths and bond angles for compound 2 HT. Bond lengths of Co in 2 HT Bond angles of Co in 2 HT Co1 N (4) N1 Co1 N (2) Co1 N (6) N1 Co1 N (2) Co1 N (4) N1 Co1 N (2) Co1 N (6) N2 Co1 N (1) N2 Co1 N (0) N4 Co1 N (1) N1 Co1 N1# (1) N1 Co1 N4# 94.80(1) N4 Co1 N4# (1) #) x + 2, y, z + 3/2. Table S3. Selected bond lengths and bond angles for compound 2 LT. Bond lengths of Co in 2 LT Bond angles of Co in 2 LT Co1 N (5) N1 Co1 N (1) Co1 N (5) N1 Co1 N (1) Co1 N (5) N1 Co1 N (1) Co1 N (5) N1 Co1 N (1) Co1 N (5) N1 Co1 N (1) Co1 N (4) N2 Co1 N (1) N2 Co1 N (1) N2 Co1 N (1) N2 Co1 N (1) N3 Co1 N (1) N3 Co1 N (1) N3 Co1 N (1) N5 Co1 N (1) N6 Co1 N (1) S7

8 Table S4. Selected bond lengths and bond angles for compound 3. Bond lengths of Co in 3 Bond angles of Co in 3 Co1 N (2) N1 Co1 N (8) Co1 N (2) N1 Co1 N (7) Co1 N (2) N1 Co1 N (8) Co1 N (2) N1 Co1 N (8) Co1 N (2) N1 Co1 N (8) Co1 N (2) N2 Co1 N (8) N2 Co1 N (8) N2 Co1 N (9) N2 Co1 N (8) N3 Co1 N (8) N3 Co1 N (8) N3 Co1 N (9) N5 Co1 N (8) N6 Co1 N (8) Table S5. Hydrogen bonds and C H π interactions for compounds 2 HT and 2 LT in the ab plane. 2 HT 2 LT O1 F (1) O1 F (1) O1 F (1) O1 F (1) C F (1) O2 F (1) C F (1) O2 F (1) C H π 3.873(1) C F (1) C F (1) C F (1) C F (1) C H π 3.735(1)/ 3.742(1) S8

9 Figures Figure S1. ORTEP diagram of the structural unit of 2 HT. A) x + 2, y, z + 3/2. Figure S2. ORTEP diagram of the structural unit of 2 LT. S9

10 Figure S3. ORTEP diagram of the structural unit of 3. Figure S4. Intermolecular interactions of 2 HT in the ab plane. S10

11 Figure S5. Intermolecular interactions of 2 LT in the ab plane. Figure S6. Intermolecular interactions of 3 in the ac plane. S11

12 Figure S7. Intermolecular interactions of 2 HT in the bc plane. V) offset π π interactions: C centroid = 3.853(1) Å VI) offset π π interactions: centroid centroid = 3.572(1) Å VII) offset π π interactions: N centroid = 4.291(1) Å C centroid = 4.292(1) Å Figure S8. Intermolecular interactions of 2 LT in the bc plane. VI) offset π π interactions: C centroid = 3.812(1)/3.821(1) Å VII) offset π π interactions: centroid centroid = 3.555(1) Å VIII) offset π π interactions: N centroid = 4.213(1)/4.469(1) Å C centroid = 4.263(1)/4.388(1) Å S12

13 Figure S9. Magnetic properties of compound 2. Applied field: 5000 Oe, sweeping rate: 1 K min χ M T / cm 3 K mol complex T / K Figure S10. Magnetic properties of compound 3. Applied field: 5000 Oe, sweeping rate: 1 K min 1. Temperature sequence: K. 1.5 χ M T / cm 3 K mol K K K K T / K S13

14 Figure S11. DSC trace for compound 2 upon cooling and warming (10 K min 1 ). 0.8 Heat flow / mw heating cooling T / K Figure S12. DSC trace for methanol upon cooling and warming (10 K min 1 ) in the temperature range for compound 2 in order to rule out possible contribution from liquid methanol during spin transition and phase transition. 2 1 Heat flow / mw T / K S14

15 Figure S13. Infrared spectrum of compound Transmittance \% Complex Wavenumber / cm -1 Figure S14. Infrared spectrum of compound Transmittance / % Complex Wavenumber / cm -1 S15