Supporting Information For Hafnium(II) Complexes with Cyclic (Alkyl)(amino)carbene Ligation Qing Liu, Qi Chen, Xuebing Leng, Qing-Hai Deng,,* and Liang Deng, * The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, P. R. China State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, P. R. China E-mails: qinghaideng@shnu.edu.cn (Q.D.), deng@sioc.ac.cn (L.D.) s1
Table of Contents 1. Experimental Section page s3 2. Computational Details page s5 3. References page s5 4. Tables and Figures page s7 s2
1. Experimental Section General Procedures. All experiments were performed under an atmosphere of dry dinitrogen or argon with the rigid exclusion of air and moisture using standard Schlenk techniques, or in a glovebox. All organic solvents were dried with a solvent purification system (Innovative Technology) and bubbled with dry N2 gas prior to use. All other chemicals were purchased from either Strem or Alfa Aesar Chemical Co. and used as received unless otherwise noted. 1 H and 13 C NMR spectra were recorded on a Bruker 400 MHz spectrometer. Chemical shifts were reported in units with references to the residual protons of the deuterated solvents for proton chemical shifts, and the 13 C of deuterated solvents for carbon chemical shifts. Elemental analyses were performed by the Analytical Laboratory of Shanghai Institute of Organic Chemistry (CAS). Absorption spectrum was recorded with a Shimadzu UV-3600 UV vis-nir spectrophotometer. Preparation of 1. To a mixture of Me2-cAAC (1-(2,6-diisopropylphenyl)-3,3,5,5-tetramethylpyrrolidine -2-ylidene) 1 (1.63 g, 5.72 mmol), HfCl4 (0.92 g, 2.86 mmol), and KC8 (0.88 g, 6.29 mmol) was added toluene (30 ml). After stirring at -78 for 30 mins and the addition of Et2O (30 ml), the resulting brown mixture was kept stirring at -78 for 2 h, then warmed to room temperature and further stirred for 16 h. The color of the mixture turned into purple. After filtration, the filtrate was subjected to vacuum to remove the solvent. The purple residue was then extracted by Et2O (20 ml) and filtered. The filtrate was standing at room temperature to evaporate solvent, by which purple crystals of [(Me2-cAAC)2HfCl2] (1) were obtained (1.50 g, 63%). 1 H NMR(400 MHz, C6D6, 300 K): δ (ppm) 7.25-7.17 (m, 4H), 7.10-7.08 (m, 2H), 3.68 (sept, J = 8.0 Hz, 2H), 2.99 (sept, J = 8.0 Hz, 2H), 1.97 (s, 6H), 1.80 (s, 6H), 1.69 (d, J = 12.0 Hz, 2H), 1.64 (d, J = 4.0 Hz, 6H), 1.55 (d, J = 12.0 Hz, 2H), 1.51 (s, 6H), 1.46 (d, J = 8.0 Hz, 6H), 1.30 (d, J = 8.0 Hz, 6H), 1.10 (d, J = 8.0 Hz, 6H), 0.83 (s, 6H). 13 C NMR(101 MHz, C6D6, 300 K): δ (ppm) 303.56, 149.31, 147.66, 141.44, 128.52, 126.87, 124.82, 72.03, 57.52, 48.32, 40.22, 35.84, 30.93, 28.59, 27.88, 27.77, 27.57, 27.51, 26.48, s3
25.47. Anal. Calcd. for C40H62Cl2HfN2: C, 58.57; H, 7.62; N, 3.41. Found: C, 57.99; H, 3.69; N, 7.40. Absorption spectrum (toluene): λmax, nm (ε, M -1 cm -1 ) = 500 (6070), 660 (10720). Preparation of 2. At -30 o C, to a solution of 1 (320 mg, 0.39 mmol) in Et2O (20 ml) was added KCH2Ph (102 mg, 0.78 mmol). After stirring at -30 o C for 2 h, the mixture was filtered. The blue filtrate was then concentrated to ca. 5 ml. Blue crystals of 2 (180 mg, 50%) was obtained by standing the solution at room temperature overnight after solvent evaporation. 1 H NMR(400 MHz, C6D6, 295 K): δ (ppm) 7.21-7.16 (m, 2H), 7.15-7.08 (m, 4H), 7.06-6.96 (m, 4H), 6.78 (t, J = 7.1 Hz, 2H), 6.69 (d, J = 7.5 Hz, 4H), 3.81 (sept, J = 12.6, 6.1 Hz, 2H), 2.87 (sept, J = 13.0, 6.3 Hz, 2H), 2.11 (s, 6H), 1.81-1.76 (m, 8H), 1.69 (d, J = 6.4 Hz, 6H), 1.59 (s, 2H), 1.55 (s, 6H), 1.24 (d, J = 6.3 Hz, 6H), 1.13 (d, J = 6.6 Hz, 6H), 1.02 (d, J = 6.6 Hz, 6H), 0.89 (d, J = 11.6 Hz, 2H), 0.84 (s, 6H), 0.52 (d, J = 12.0 Hz, 2H). 13 C NMR(101 MHz, C6D6, 295 K): δ (ppm) 303.94, 149.75, 149.11, 147.37, 141.81, 128.12, 127.18, 126.64, 126.44, 124.40, 120.78, 101.26, 70.80, 57.60, 48.67, 40.43, 36.20, 30.27, 28.13, 27.89, 27.73, 27.59, 26.82, 25.41, 24.67. Anal. Calcd. for C40H62Cl2HfN2: C, 69.61; H, 8.22; N, 3.01. Found: C, 69.21; H, 8.23; N, 2.97. Absorption spectrum (toluene): λmax, nm (ε, M -1 cm -1 ) = 500 (3395), 650 (15370). X-Ray Structure Determination. The structures of [(Me2-cAAC)2HfCl2] (1) and [(Me2-cAAC)2Hf(CH2Ph)2] (2) were determined. The crystals were coated with Paratone-N oil and mounted on a Bruker APEX CCD-based diffractometer equipped with an Oxford low-temperature apparatus. Cell parameters were retrieved with SMART software and refined using SAINT software on all reflections. Data integration was performed with SAINT, which corrects for Lorentz polarization and decay. Absorption corrections were applied using SADABS. 2 Space groups were assigned unambiguously by analysis of symmetry and systematic absences determined by XPREP. The structure was solved and refined using SHELXTL. 3 Metal and first coordination sphere atoms s4
were located from direct-methods E-maps; other non-hydrogen atoms were found in alternating difference Fourier synthesis and least-squares refinement cycles and during final cycles were refined anisotropically. Hydrogen atoms were placed in calculated positions employing a riding model. The cif files have been deposited in The Cambridge Crystallographic Data Centre (CCDC 1868640 and 1874372). Table S2 compiles the crystal data and summary of data collection and refinement for the two complexes. 2. Computational Details To have a better understanding of the electronic structure of (Me2-cAAC)2HfCl2 (1), density functional theory (DFT) 4 study has been performed with the ORCA 3.03 program 5 using the B3LYP, 6 PBE0, 7 and TPSSh 8 methods. The SVP basis set 9 was used for the C, N, and H atoms, and the TZVP-ZORA basis set 10 was used for the Cl and Hf atoms. The RIJCOSX approximation 11 with matching auxiliary basis sets 9 was employed to accelerate the calculations. The calculation utilizes the atom-pairwise dispersion correction with the Becke-Johnson damping scheme (D3BJ) 12. The atomic coordinates of 1 used for calculation were obtained from X-ray diffraction studies, and only the positions of hydrogen atoms were optimized. The xyz file contains the Cartesian coordinates of the optimized structure. Table S1 summarizes the corresponding single point energies relative to the closed-shell state. 3. References (1) Lavallo, V.; Canac, Y.; Präsang, C.; Donnadieu, B.; Bertrand, G. Angew. Chem. Int. Ed. 2005, 44, 5705. (2) Sheldrick, G. M. SADABS: Program for Empirical Absorption Correction of Area Detector Data. University of Göttingen: Germany, 1996. (3) Sheldrick, G. M. SHELXTL 5.10 for Windows NT: Structure Determination Software Programs. Bruker Analytical X-ray systems, Inc.: Madison, Wisconsin, USA, 1997. s5
(4) (a) Hohenberg. P.; Kohn, W. Phys. Rev. 1964, 136, B864. (b) Kohn, W.; Sham, L. J. Phys. Rev. 1965, 140, A1133. (5) Neese, F., ORCA-an ab initio, Density Functional and Sem-iempirical Program Package (v. 3.0.3), Max-Planck Institute for Bioinorganic Chemistry: Mülheim an der Ruhr, Germany, 2015. (6) (a) Becke, A. D. J. Chem. Phys. 1993, 98, 5648. (b) Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. 1988, B37, 785. (7) (a) Perdew, J. P.; Ernzerhof, M.; Burke, K. J. Chem. Phys. 1996, 105, 9982. (b) Carlo, A.; Barone, V. J. Chem. Phys. 1999, 110, 6158. (8) (a) Perdew, J. P.; Kurth, S.; Zupan, A.; Blaha, P. Phys. Rev. Lett. 1999, 82, 2544. (b) Perdew, J. P.; Tao, J.; Staroverov, V. N.; Scuseria, G. E. J. Chem. Phys. 2004, 120, 6898. (9) ) (a) Schäfer, A.; Horn, H.; Ahlrichs, R. J. Chem. Phys. 1992, 97, 2571. (b) Schäfer, A.; Huber, C.; Ahlrichs, R. J. Chem. Phys. 1994, 100, 5829. (10) Pantazis, D. A.; Chen, X. Y.; Landis, C. R.; Neese, F. J. Chem. Theory Comput. 2008, 4, 908. (11) Neese, F.; Wennmohs, F.; Hansen, A.; Becker, U. Chem. Phys. 2009, 256, 98. (12)(a) Grimme, S.; Ehrlich, S.; Goerigk, L. J. Comput. Chem. 2011, 32, 1456. (b) Grimme, S.; Antony, J.; Ehrlich, S. and Krieg, H. J. Chem. Phys. 2010, 132, 154104. s6
4. Tables and Figures Table S1. Relative energies (kcal/mol) of (Me2-cAAC)2HfCl2 (1) at different states Functional rks (S = 0) uks (S = 1) uks (S = 0) B3LYP 0 13.8 0 PBE0 0 11.6 0 TPSSh 0 14.4 0 s7
Table S2. Crystal Data and Summary of Data Collection and Refinement for [(Me2-cAAC)2HfCl2] (1) and [(Me2-cAAC)2Hf(CH2Ph)2] (2) 1 (170 K) 2 (170 K) formula C40H62Cl2HfN2 C54H76HfN2 crystal size (mm 3 ) 0.03 x 0.02 x 0.01 0.1 x 0.08 x 0.06 fw 820.30 931.65 crystal system Monoclinic Triclinic space group C 2/c P-1 a, Å 34.1030(6) 13.4816(2) b, Å 10.34560(10) 18.7816(3) c, Å 22.59750(10) 19.6071(3), deg 90 74.7020(10), deg 98.2180(10) 83.3750(10), deg 90 85.6750(10) V, Å 3 7890.89(16) 4751.50(13) Z 8 4 Dcalcd, Mg/m 3 1.381 1.302 radiation ( ), Å Mo K (0.71073) Mo K (0.71073) 2 range, deg 6.876 to 109.884 5.748 to 109.912, mm -1 4.158 2.820 F(000) 3376 1944 no. of obsd reflns 7512 18069 no. of params refnd 422 1059 goodness of fit 1.035 1.071 R1 0.0340 0.0358 wr2 0.0724 0.0721 s8
Figure S1. Molecular structure of 1 showing 30% probability ellipsoids. Selected distances (Å) and angles (deg): Hf(1)-Cl(1) 2.348(1), Hf(1)-Cl(2) 2.360(1), Hf(1)-C(1) 2.177(4), Hf(1)-C(2) 2.161(3), N(1)-C(1) 1.373(4), C(2)-N(2) 1.380(4), C(1)-Hf-C(2) 98.4(1), Cl(1)-Hf-Cl(2) 113.81(4). s9
Figure S2. Molecular structure of 2 showing one of the two crystallographically independent molecules in the unit cell with 30% probability ellipsoids and a partial atom labeling scheme. Selected distances (Å) and angles (deg): Hf(1)-C(1) 2.182(3), Hf(1)-C(2) 2.211(3), Hf(1)-C(3) 2.257(3), Hf(1)-C(4) 2.250(3), N(1)-C(1) 1.397(4), C(2)-N(2) 1.385(4), C(1)-Hf-C(2) 98.0(1), C(3)-Hf-C(4) 115.2(1). Figure S3. Molecular structure of 2 showing one of the two crystallographically independent molecules in the unit cell with 30% probability ellipsoids and a partial atom labeling scheme. Selected distances (Å) and angles (deg): Hf(2)-C(5) 2.195(3), Hf(2)-C(6) 2.201(3), Hf(2)-C(7) 2.286(3), Hf(2)-C(8) 2.247(3), N(3)-C(5) 1.384(4), C(6)-N(4) 1.391(4), C(5)-Hf(2)-C(6) 95.2(1), C(7)-Hf(2)-C(8) 110.9(1). s10
Figure S4. UV-vis Spectra of [(Me2-cAAC)2HfCl2] (1) and [(Me2-cAAC)2Hf(CH2Ph)2] (2) measured at room temperature in toluene. Figure S5. Mayer bond orders for [(Me2-cAAC)2HfCl2] (1) (S = 0). s11
Figure S6. Frontier MO diagram for [(Me2-cAAC)2HfCl2] (1) (S = 0) depicted using isodensity at 0.03. au. The orbital composition was obtained from calculation using B3LYP functional. s12
Figure S7. 1 H NMR spectrum of [(Me2-cAAC)2HfCl2] (1). s13
Figure S8. 13 C NMR spectrum of [(Me2-cAAC)2HfCl2] (1). s14
Figure S9. Dept-135 NMR spectrum of [(Me2-cAAC)2HfCl2] (1). s15
Figure S10. 1 H NMR spectrum of [(Me2-cAAC)2Hf(CH2Ph)2] (2). s16
Figure S11. 13 C NMR spectrum of [(Me2-cAAC)2Hf(CH2Ph)2] (2). s17