# Institute of Chemistry of the Academy of Sciences of Republic of Moldova, Academiei Str. 3,

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1 Supporting Information for Vanadium(V) complexes with substituted 1,5-bis(2- hydroxybenzaldehyde)carbohydrazones and their use as catalyst precursors in oxidation of cyclohexane Diana Dragancea, # Natalia Talmaci, # Sergiu Shova, Ghenadie Novitchi, ǂ Denisa Darvasiova, Peter Rapta,*, Martin Breza, Markus Galanski, Jozef Kozisek, Nuno M. R. Martins, ǁ Luísa M. D. R. S. Martins,*,ǁ, Armando J. L. Pombeiro,*,ǁ and Vladimir B. Arion*, # Institute of Chemistry of the Academy of Sciences of Republic of Moldova, Academiei Str. 3, MD-2028 Chisinau, Moldova University of Vienna, Faculty of Chemistry, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria Petru Poni Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, Iasi, Romania ǂ Laboratoire National des Champs Magnetiques Intenses-CNRS, Universite Joseph Fourier, 25 Avenue des Martyrs, Grenoble Cedex 9, France Slovak University of Technology, Institute of Physical Chemistry and Chemical Physics, Radlinského 9, Bratislava, Slovakia ǁ Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa, Portugal Chemical Engineering Department, Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, R. Conselheiro Emídio Navarro, Lisboa, Portugal S1

2 Table of contents: Figure S1. 3D supramolecular network in the crystal structure of NH 4 [1]. Figure S2. 2D supramolecular network in the crystal structure of 4. Figure S3. stacking in octanuclear cluster in 6. Figure S4. Infinite column-like structure showing the stacking interactions in 6. Figure S5. View of the parallel packing of the infinite columns along axis c in 6. Figure S6. 1 H, 13 C HMBC NMR spectrum of NH 4 [1] in DMSO-d 6. Figure S7. Experimental (black) and theoretical (green) 1 H NMR spectra of NH 4 [1] in DMSO-d 6. Figure S8. 1 H, 1 H COSY NMR spectrum of NH 4 [1] in DMSO-d 6. Figure S9. Fragment of 1 H NMR (500 MHz) spectra a) of NH 4 [1] in DMSO-d 6 and b) of 4 in CD 3 OD at room temperature. Figure S10. Fragment of 1 H NMR (500 MHz) spectra a) of NH 4 [2] in DMSO-d 6 and b) of 5 in CD 3 OD at room temperature. Figure S11. a) COSY 1 H NMR spectra of 5 in DMSO showing correlation between CH 3 and CH 2 protons for coordinated and outer sphere ethanol b) Experimental and simulated 1 H NMR spectra of coordinated EtO. The inequivalence of CH 2 protons is obvious. Figure S12. Time dependence of 1 H NMR spectra of 5 for CH 3 regions for coordinated and outer sphere ethanol (500 MHz c=3.5 mm in DMSO-d 6 at room temperature). Figure S13. Evolution of relative population rates for A and B and their derivatives (solid lines) as a function of reaction time for 5 (500 MHz c = 3.5 mm) in DMSO-d 6 at room temperature. Figure S14. Cyclic voltammogram of 0.25 mm NH 4 [2] mm ferrocene in DMSO/nBu 4 N[PF 6 ] at Pt working electrode at scan rate of 100 mv s 1. Figure S15. Optical spectra of NH 4 [2] in 0.2 M nbu 4 N[PF 6 ]/DMSO before (green line) and after bulk electrolysis at 1.8 V vs Fc/Fc + (blue line). Figure S16. Room temperature EPR spectra measured after bulk electrolysis of NH 4 [2] in 0.2 M nbu 4 N[PF 6 ]/DMSO (blue line) and of 5 in 0.2 M LiClO 4 /EtOH (purple line) at the first reduction peak. Figure S17. Cyclic voltammograms of 5 in EtOH/LiClO 4 at glassy-carbon working electrode at scan rate of 100 mv s 1. Figure S18. In situ UV vis spectroelectrochemistry for the sample 5 in EtOH/LiClO 4 (scan rate 10 mv s 1, Pt-micro-structured honeycomb working electrode) during the second (a) and immediately afterward, the third (b) voltammetric scan. Figure S19. (a) UV vis spectra measured simultaneously during the in situ reduction of 5 in the region of the first cathodic peak; (b) UV vis spectra recorded upon reoxidation. Figure S20. (a) Calculated electronic transitions (in DMSO) for 1 [1] (green lines) and 3 [1] 3 (blue lines). (b) Calculated electronic transitions (in DMSO) for 1 [4] 0 (green lines), 2 [4] (violet lines) and 1 [4] 2 (blue lines). S2

3 Figure S21. (a) HOMO and (b) LUMO of 1 [1] in vacuum; (c) β-homo and (d) spin density of 2 [1] 2 in vacuum; (e) α-homo 1 and (f) α-lumo of 1 [1] 3 in vacuum. Orbitals are depicted at 0.05 a.u. level and spin density at 0.02 a.u. level. Figure S22. (a) HOMO and (b) LUMO of 1 [1] in DMSO; (c) β-homo and (d) spin density of 2 [1] 2 in DMSO. Orbitals are depicted at 0.05 a.u. level and spin density at 0.02 a.u. level. Figure S23. (a) HOMO and (b) LUMO of 1 [4] 0 in DMSO at 0.05 au level; (c) spin density of 2 [4] 2 in DMSO at 0.02 au level; (d) β-homo of 2 [4] in DMSO at 0.05 au level. Figure S24. B3LYP orbitals contributing dominantly to TD-B3LYP electronic transitions for 2 [4] and 1 [4] 2 in vacuum. Figure S25. Laplacian distribution L(r) 2 ρ(r) in the V1, O1, O2 plane (top left), V2, O4, O6 plane (top right), V3, O9 O8 plane (bottom left) and V4, O11, O2 plane (bottom right) in 4. Contours are drawn at , ± n, ± n, ± n (n = 3, 2 1, 0, +1, +2 +3) e Å 5, with positive contours drawn with a full blue line and negative contours with a broken red line. Table S1. Selected bond lengths (Å) and angles ( ). Table S2. Experimental 51 V NMR resonances for 2 and 5. Table S3. Calculated spin squares (<S 2 >), relative DFT (ΔE DFT ) and free energies at 298 K (ΔG 298 ) related to the most stable non-reduced system, HOMO (E HOMO ) and LUMO (E LUMO ) energies for the optimized geometries of [1] q and [4] q structures in various charge (q) and spin states in vacuum. Table S4. Calculated spin squares (<S 2 >), relative DFT (ΔE DFT ) and free energies at 298 K (ΔG 298 ) related to the most stable non-reduced system, HOMO (E HOMO ) and LUMO (E LUMO ) energies for the optimized geometries of [1] q and [4] q structures in various charge (q) and spin states in DMSO. Table S5. NBO atomic charges and d-electron populations (d x ) of vanadium atoms in the systems under study in DMSO (see Figs. 1 and 3 for atom labeling). Table S6. Charges in atomic basin for vanadium atoms in [4] 2. Table S7. Selected electron-density properties and bond critical points for [4] 2 3CH 3 OH. Table S8. Selected data for the oxidation of cyclohexane using NH 4 [1], NH 4 [2] and 4 6 as catalysts. a S3

4 Figure S1. 3D supramolecular network in the crystal of NH 4 [1]. Figure S2. 2D supramolecular network in the crystal of 4. S4

5 Figure S3. stacking in octanuclear cluster in 6. Figure S4. Infinite column-like structure showing the stacking interactions in 6. S5

6 Figure S5. View of the parallel packing of the infinite columns along axis c in 6. CH=N C H=N C D H D =N C D H D =N C H =N CH=N C=O Figure S6. 1 H, 13 C HMBC NMR spectrum of NH 4 [1] in DMSO-d 6. S6

7 theoretical experimental A A C C B (ppm) Figure S7. Experimental (black) and theoretical (green) 1 H NMR spectra of NH 4 [1] in DMSO-d 6. B,D,D Figure S8. 1 H, 1 H COSY NMR spectrum of 1 in DMSO-d 6. S7

8 b) a) Figure S9. Fragment of 1 H NMR (500 MHz) spectra a) of NH 4 [1] in DMSO-d 6 and b) of 4 in CD 3 OD at room temperature. b) a) Figure S10. Fragment of 1 H NMR (500 MHz) spectra a) of NH 4 [2] in DMSO-d 6 and b) of 5 in CD 3 OD at room temperature. S8

9 theoretical experimental 1.52 ppm J=7.0Hz 5.72 ppm J=7.0Hz J=11.4Hz 5.78 ppm a) b) (ppm) Figure S11. a) COSY 1 H NMR spectra of 5 in DMSO showing correlation between CH 3 and CH 2 protons for coordinated and outer sphere ethanol b) Experimental and simulated 1 H NMR spectra of coordinated EtO. The inequivalence of CH 2 protons is obvious. S9

10 outer sphere CH 3 CH 2 OH coordinated CH 3 CH 2 O τ Figure S12. Time dependence of 1 H NMR spectra of 5 for CH 3 protons of coordinated and outer sphere ethanol (500 MHz c = 3.5 mm in DMSO-d 6 at room temperature). S10

11 d(c i /C tot ) dt d(c i /C tot ) dt d(c i /C tot ) dt CH=N (A) CH=N (B) Série6 Série C i /C C i /C tot tot C i /C tot C i /C C i /C tot a) C i /C tot b) c) t(s) EtO (coord) 0.4 EtOH (free) Série Série t(s) NH (A) NH (B) 0.2 Série6 Série Figure S13. Evolution of relative population rates for A and B and their derivatives (solid lines) as a function of reaction time for 5 (500 MHz c = 3.5 mm) in DMSO-d 6 at room temperature. Relative population rates obtained from analysis of signals: a) CH=N(A) and CH=N(B) b) EtO(coord) and EtOH free; c) NH(A) and NH(B). t(s) S11

12 Fc/Fc I / A E vs Fc/Fc + / V Figure S14. Cyclic voltammogram of 0.25 mm NH 4 [2] mm ferrocene in DMSO/nBu 4 N[PF 6 ] at Pt working electrode at scan rate of 100 mv s 1. S12

13 A / nm Figure S15. Optical spectra of NH 4 [2] in 0.2 M nbu 4 N[PF 6 ]/DMSO before (green line) and after bulk electrolysis at 1.8 V vs Fc/Fc + (blue line). 4.0x x10 4 I EPR x B / G Figure S16. Room temperature EPR spectra measured after bulk electrolysis of NH 4 [2] in 0.2 M nbu 4 N[PF 6 ]/DMSO (blue line) and of 5 in 0.2 M LiClO 4 /EtOH (purple line) at the first reduction peak. S13

14 40 20 I / A E vs Fc/Fc + / V Figure S17. Cyclic voltammograms of 5 in EtOH/LiClO 4 at glassy-carbon working electrode at scan rate of 100 mv s 1 (black line: fist scan, red line: second scan). S14

15 (a) / nm (b) E vs Fc/Fc + / V A A / nm E vs Fc/Fc + / V Figure S18. In situ UV vis spectroelectrochemistry for the sample 5 in EtOH/LiClO 4 (scan rate 10 mv s 1, Pt-micro-structured honeycomb working electrode) during the second (a) and immediately afterward, the third (b) voltammetric scan. S15

16 (a) A (b) / nm A / nm Figure S19. (a) UV vis spectra measured simultaneously during the in situ reduction of 5 in the region of the first cathodic peak; (b) UV vis spectra recorded upon reoxidation. S16

17 (a) HOMO - LUMO f / nm (b) f / nm Figure S20. (a) Calculated electronic transitions (in DMSO) for 1 [1] (green lines) and 3 [1] 3 (blue lines). (b) Calculated electronic transitions (in DMSO) for 1 [4] 0 (green lines), 2 [4] (violet lines) and 1 [4] 2 (blue lines). S17

18 (a) (b) (c) (d) (e) (f) Figure S21. (a) HOMO and (b) LUMO of 1 [1] in vacuum; (c) β-homo and (d) spin density of 2 [1] 2 in vacuum; (e) α-homo 1 and (f) α-lumo of 1 [1] 3 in vacuum. Orbitals are depicted at 0.05 a.u. level and spin density at 0.02 a.u. level. S18

19 (a) (b) (c) (d) Figure S22. (a) HOMO and (b) LUMO of 1 [1] in DMSO; (c) β-homo and (d) spin density of 2 [1] 2 in DMSO. Orbitals are depicted at 0.05 a.u. level and spin density at 0.02 a.u. level. (a) (b) (c) (d) Figure S23. (a) HOMO and (b) LUMO of 1 [4] 0 in DMSO at 0.05 au level; (c) spin density of 2 [4] 2 in DMSO at 0.02 au level; (d) β-homo of 2 [4] in DMSO at 0.05 au level. S19

20 β-homo β-lumo transition at 467 nm (f = 0.05) for 2 [4] α-homo-2 α-lumo and β-homo-2 β-lumo transitions at 376 nm (f = 0.09) for 2 [4] β-homo 1 β-lumo transition at 413 nm (f = 0.14) for 1 [4] 2 S20

21 β-homo 2 β-lumo and α-homo-2 α-lumo transitions at 359 nm (f = 0.16) for 1 [4] 2 Figure S24. B3LYP orbitals contributing dominantly to TD-B3LYP electronic transitions for 2 [4] and 1 [4] 2 in vacuum. S21

22 Figure S25. Laplacian distribution L(r) 2 ρ(r) in the V1, O1, O2 plane (top left), V2, O4, O6 plane (top right), V3, O9 O8 plane (bottom left) and V4, O11, O2 plane (bottom right). Contours are drawn at , ± n, ± n, ± n (n = 3, 2 1, 0, +1, +2 +3) e Å 5, with positive contours drawn with a full blue line and negative contours with a broken red line. S22

23 Table S1. Selected bond lengths (Å) and angles ( ) V1-O (3) 1.626(3) 1.870(2) 1.893(3) V1-O (2) 1.609(3) 1.610(2) V1-O (3) 1.886(3) 1.656(2) V1-O (4) V1-O (3) V1-N (3) 2.149(3) 2.170(2) 2.156(4) V1-N (3) 2.063(3) 2.058(2) 2.048(4) V2-O (2) (4) V2-O (4) V2-O (3) 1.585(3) 1.828(2) 1.573(4) V2-O (2) 1.838(3) 1.989(2) 2.340(4) V2-O (3) 1.764(3) 1.584(2) 1.755(4) V2-O (2) 1.993(3) 1.768(2) V2-O (3) V2-N (3) 2.160(3) 2.152(2) 2.157(4) V3-O (3) 2.292(4) V3-O (3) 1.902(4) V3-O (3) V3-O (4) V3-O (4) V3-N (4) 2.213(5) V3-N (3) 2.093(4) V4-O (3) V4-O (4) V4-O (3) 1.856(4) V4-O (3) 2.231(4) 1 V4-O (3) V4-O (3) 1.583(4) V4-O (4) V4-N (3) 2.140(5) Cl1-C (14) Cl2-C (6) Cl3-C (8) Cl4-C (7) Cl5-C (6) Cl6-C (6) Cl7-C (7) Cl8-C (7) O1-C (4) 1.326(3) 1.310(6) O2-C (6) O3-C (5) O3-C (9) O4-C (4) 1.336(3) O5-C (4) 1.271(3) O5-C (6) O5-C (5) O6-C (5) S23

24 O6-C (7) O7-C (5) O7-C (3) O8-C (5) O8-C (4) O9-C (6) O9-C (3) O10-C (5) O10-C (6) O10-C (10) O11-C (5) O12-C (5) O13-C (5) O14-C (5) O15-C (5) 1.416(8) O16-C (5) O16-C (9) O17-C (5) O17-C (6) O18-C (9) O19-C (9) O20-C (3) O21-C (6) N1-N (4) 1.394(4) 1.383(3) 1.391(6) N1-C (4) 1.316(5) 1.299(3) 1.291(7) N2-C (4) 1.335(5) 1.344(3) 1.337(7) N3-N (4) 1.402(4) 1.397(3) 1.384(6) N3-C (5) 1.338(5) 1.336(3) 1.329(7) N4-C (5) 1.285(5) 1.291(3) 1.283(7) N5-N (4) 1.374(6) N5-C (7) N5-C (5) N6-C (7) N6-C (5) N7-N (4) 1.393(6) N7-C (7) N7-C (5) N8-C (7) N8-C (5) C1-C (5) 1.405(6) 1.422(3) 1.415(8) C1-C (5) 1.403(6) 1.402(4) 1.409(8) C2-C (5) 1.360(6) 1.386(3) 1.381(8) C3-C (5) 1.396(6) 1.406(4) 1.391(9) C4-C (5) 1.372(6) 1.378(4) 1.365(9) C4-C (3) C5-C (5) 1.383(6) 1.421(3) 1.405(8) C6-C (5) 1.434(6) 1.426(3) 1.435(8) C9-C (5) 1.435(5) 1.446(3) 1.438(6) C10-C (5) 1.411(6) 1.408(4) S24

25 C10-C (5) 1.417(6) 1.399(3) 1.439(14) C11-C (5) 1.360(6) 1.385(3) 1.369(14) C12-C (5) 1.394(6) 1.410(4) 1.407(16) C12-C (4) C13-C (5) 1.379(6) 1.387(4) 1.345(16) C14-C (5) 1.379(6) 1.416(3) 1.448(16) C14-C (3) C16-C (3) 1.405(8) C16-C (4) C16-C (4) C16-C (8) C17-C (6) 1.391(9) C17-C (6) C18-C (6) 1.389(10) C19-C (6) 1.353(9) C20-C (6) 1.532(3) 1.403(8) C20-C (3) C20-C (4) C21-C (6) 1.446(8) C22-C (6) C24-C (4) 1.427(6) C24-C (4) C24-C (4) C25-C (6) 1.409(14) C25-C C26-C (6) 1.402(16) C26-C (6) C27-C (6) 1.350(16) C28-C (6) 1.533(3) 1.347(16) C28-C (3) C28-C (4) C29-C (6) 1.395(13) C30-C (6) C32-C (4) C34-C (7) C36-C (4) C38-C (11) O1-V1-N1 82.2(1) 140.2(1) 80.26(7) 81.9(2) O1-V1-N (1) 93.0(1) (8) 151.8(2) O2-V1-O1 98.8(1) 107.9(2) 98.94(8) O2-V1-N (1) 111.1(1) (9) O2-V1-N3 93.6(1) 99.8(1) 92.20(8) O3-V1-O (1) 96.4(1) (8) O3-V1-O (1) 103.7(1) (9) O3-V1-N (1) 82.1(1) (8) O3-V1-N3 97.2(1) 150.6(1) 97.89(8) O7-V1-O (2) S25

26 O7-V1-O (2) O7-V1-N (2) O7-V1-N3 96.8(2) O8-V1-O (2) O8-V1-N (2) O8-V1-N3 91.9(2) N3-V1-N1 72.8(1) 73.0(1) 72.80(7) 73.1(2) O2-V2-O5 79.3(2) O2-V2-N4 74.4(2) O3-V2-O (2) O3-V2-N4 82.4(2) O4-V2-O2 99.2(2) O4-V2-O3 99.5(2) O4-V2-O (1) 102.8(2) (8) 173.4(2) O4-V2-N4 83.6(1) 94.3(1) 82.82(7) 94.0(2) O5-V2-N4 74.2(1) 85.0(1) 75.44(7) 79.4(2) O6-V2-O (1) 102.3(2) 99.89(9) 102.1(2) O6-V2-O5 99.6(1) 102.8(14) 94.78(8) 84.4(2) O6-V2-O (1) 91.33(1) (9) O6-V2-N4 98.4(1) 159.3(1) 97.35(8) 161.9(2) O6-V2-O2 94.6(2) O6-V2-O (2) O7-V2-O4 98.4(1) 95.1(1) (8) O7-V2-O5 92.6(1) 154.1(1) 94.96(7) O7-V2-N (1) 74.9(1) (8) O4-V2-O (7) 1 O5-V2-O (6) (2) O6-V2-O (8) 1 O7-V2-O (7) 1 N4-V2-O (7) 1 O4-V2-O (1) O5-V2-O8 81.1(1) O6-V2-O8 83.5(1) O7-V2-O8 79.1(1) N4-V2-O8 78.9(1) O8-V3-O (2) 80.4(2) O8-V3-O (1) O8-V3-N (1) O8-V3-N7 97.9(2) O9-V3-O (1) O9-V3-N (1) 83.3(2) O9-V3-N7 90.9(1) 152.1(2) O10-V3-N5 82.2(1) O10-V3-N (1) O12-V3-O (2) O12-V3-O (2) O12-V3-O (2) O12-V3-N5 91.8(2) O12-V3-N7 95.6(2) S26

27 O13-V3-O8 89.7(2) O13-V3-O (2) O13-V3-N (2) O13-V3-N7 97.5(2) N5-V3-O8 72.6(1) N7-V3-O8 78.2(2) N7-V3-N5 72.2(1) 73.4(2) O10-V4-O (2) 1 O10-V4-N8 75.1(2) O11-V4-O (1) O11-V4-O (2) O11-V4-O (1) O11-V4-O (2) O11-V4-N8 95.7(2) O11-V4-O (2) O11-V4-O (2) 1 O11-V4-N8 84.7(2) O12-V4-O2 84.9(1) O12-V4-O (1) O12-V4-O (14) O12-V4-N (2) O13-V4-O2 79.6(1) O13-V4-N8 75.4(1) O14-V4-O2 80.7(1) O14-V4-O (1) O14-V4-N8 85.5(1) O14-V4-O (2) O14-V4-O (2) O14-V4-O (2) 1 O14-V4-O (2) O14-V4-N8 94.2(2) O15-V4-O (2) O15-V4-O (2) O15-V4-O (2) 1 O15-V4-N (2) N8-V4-O2 76.9(1) N8-V4-O (2) 1 N2-N1-V (2) 115.5(3) 115.4(1) 115.5(3) C7-N1-V (3) 129.7(3) 129.1(2) 129.1(4) C7-N1-N (3) 114.8(4) 115.4(2) 115.4(4) C8-N2-N (3) 115.1(4) 114.8(2) 113.8(4) N4-N3-V (2) 130.7(3) 129.2(2) 129.2(3) C8-N3-V (3) 120.8(3) 120.8(2) 120.2(3) C8-N3-N (3) 108.5(3) 109.3(2) 109.1(4) N3-N4-V (2) 114.2(2) 113.6(1) 114.2(3) C9-N4-V (3) 126.3(3) 128.7(2) 125.7(4) C9-N4-N (3) 119.5(4) 117.7(2) 119.9(4) N6-N5-V (3) 113.9(3) C22-N5-V (4) S27

28 C22-N5-N (5) C23-N5-V (3) C23-N5-N (4) C23-N6-N (4) C24-N6-N (4) N8-N7-V (3) 131.7(3) C24-N7-V (3) C24-N7-N (4) C23-N7-V (3) C23-N7-N (4) N7-N8-V (3) 113.4(3) C25-N8-V (3) C25-N8-N (4) C24-N8-V (4) Symmetry code: 1) x, y, 1 z Table S2. Experimental 51 V NMR resonances for NH 4 [2] and 5. Compound Solvent, ppm 2 DMSO-d , CD 3 OD , DMSO-d , , CD 3 OD , Table S3. Calculated spin squares (<S 2 >), relative DFT (ΔE DFT ) and free energies at 298 K (ΔG 298 ) related to the most stable system, HOMO (E HOMO ) and LUMO (E LUMO ) energies for the optimized geometries of [1] q and [4] q structures in various charge (q) and spin states in vacuum. Charge q Spin <S 2 > ΔE DFT [ev] ΔG 298 [ev] E HOMO [ev] E LUMO [ev] multiplicity [1] q : : : s) : : : : : [4] q : : : : s) : : : : : Remarks: s) SOMO S28

29 Table S4. Calculated spin squares (<S 2 >), relative DFT (ΔE DFT ) and free energies at 298 K (ΔG 298 ) related to the most stable non-reduced system, HOMO (E HOMO ) and LUMO (E LUMO ) energies for the optimized geometries of [1] q and [4] q structures in various charge (q) and spin states in DMSO. Charge q Spin multiplicity <S 2 > ΔE DFT [ev] ΔG 298 [ev] E HOMO [ev] E LUMO [ev] [1] q : : : s) : : : : : [4] q : : : : s) : : : : : Remarks: s) SOMO Table S5. NBO atomic charges and d-electron populations (d x ) of vanadium atoms in the systems under study in DMSO solutions (see Figs. 1 and 3 for atom labeling). Compound q M s V1 V2 charge d x charge d x [1] q [4] q S29

30 Table S6. Charges in atomic basin for vanadium atoms in [4] 2. Atom V1 O1 O2 O3 N1 N3 Charge Atom V2 O4 O5 O6 O7 O8 N4 Charge Atom V3 O8 O9 O10 N5 N7 charge atom V4 O2 O11 O12 O13 O14 N8 charge Table S7. Selected electron-density ( ) properties at bond critical points (BCP) for [4] 2 3CH 3 OH. Atom A Atom B BCP [e Å 3 ] 2 BCP [e Å 5 ] d AB [Å] d A-BCP [Å] d B-BCP [Å] a BCP V1 O (162) (342) V1 O (197) (528) V1 O (96) (207) V1 N (44) 7.223(76) V1 N (52) 9.709(99) V2 O (267) (542) V2 O (102) (269) V2 O (115) (236) V2 O (83) 9.690(179) V2 O8 i 0.257(33) 3.645(54) V2 N (46) 6.201(78) V3 O (206) (595) V3 O (173) (297) V3 O ( 92) 5.268(228) V3 N ( 46) 6.636( 71) V3 N (52) 7.668( 81) V4 O (242) (502) V4 O (127) 9.180(329) V4 O (78) (143) V4 O2 i 0.253(30) 3.250(50) V4 N (39) 7.157(72) V4 O (152) (363) a denotes bond ellipticity; symmetry code: i) x, ½ y, ½ + z. S30

31 Table S8. Selected data for the oxidation of cyclohexane using NH 4 [1], NH 4 [2] and 4 6 as catalysts. a Entry 1 Catalyst amount/ mol Temperature /ºC Reaction time /h Yield (%) b TON (TOF (h -1 )) c CyOH CyO Total (44) (38) (45) (35) (23) (15) (2) (3) (6) (6) (5) 14 NH 4 [1] (5) (78) (66) (50) (37) (45) (21) (40) (18) (20) (41) (17) (14) (61) (55) (59) NH 4 [2] (41) (29) (20) (79) (63) S31

32 (54) (43) (30) (23) (2) (1) (2) (4) (4) (4) (107) (75) (62) (41) (26) (18) (47) (25) (26) (22) (16) (11) (86) (58) (40) (29) (22) (16) (76) (45) (32) (28) (31) (17) (16) (15) (13) S32

33 (11) (12) (11) (125) (79) (54) (39) (30) (23) NH 4 VO (17) 84 VO(acac) (21) 85 d e a Reaction conditions: cyclohexane (2.5 mmol), V-catalyst (1-10 mol), t-buooh (70% in H 2 O, 5 mmol), MW, h at ºC. b Moles of products [cyclohexanol (CyOH) + cyclohexanone (CyO)] per 100 mol of cyclohexane, as determined by GC after treatment with PPh 3. c Turnover number = moles of products per mol of catalyst; TOF = TON per hour (values in brackets). d In the presence of Ph 2 NH (2.5 mmol). e In the presence of CBrCl 3 (2.5 mmol). S33