SUPPORTING INFORMATION Dialkylgallium complexes with alkoxide and aryloxide ligands possessing N-heterocyclic carbene functionalities synthesis and structure Paweł Horeglad, * Osman Ablialimov, Grzegorz Szczepaniak, Anna Maria Dąbrowska, Maciej Dranka and Janusz Zachara Faculty of Chemistry, University of Warsaw, świrki i Wigury 101, 02-089, Warsaw, Poland. Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland. 1) The synthesis of substrates for the synthesis of N-heterocyclic carbene salts [H 2 L]X N 1 -(2,4,6-trimethylphenyl)-N 2 -(2-hydroxybenzyl)-1,2-diaminoethane (Scheme S1): N-2,4,6- trimethylphenyl-(1,2-diaminoethane) and N-2,6-Diisopropylphenyl-(1,2-diaminoethane) were pr-pared according to Marshall's procedure. 1 In a 100 ml round-bottomed flask to a stirring solution of salicylic aldehyde (1.5 g, 12.3 mmol) in (12 ml) of MeOH and p-toluensulfonic acid cat. (PTSA) was added. Then N-2,4,6-trimethylphenyl-(1,2-diaminoethane) ( 2 g, 11.2 mmol) was added and the resulting mixture was left stirring at RT for 24 h. After that the flask was placed in an ice-cooling bath and MeOH (20 ml) was added. Then, NaBH 4 (2.12 g, 56.1mmol) was added portion-wise over period of 10 minutes during 1 h. Then the reaction was allowed to stir for additional 1 h at RT. After that the reaction mixture was concentrated and the saturated NaHCO 3(aq.) (50 ml) was added. The product was extracted with EtOAc and washed with brine (50 ml). The organic phase was dried over MgSO 4, filtered and concentrated. The resulting orange coloured oil was purified by silica-gel chromatography (c-hex:etoac, 4:1) yielded the product N 1 -(2,4,6-trimethylphenyl)-N 2 -(2-hydroxybenzyl)- 1,2-diaminoethane as yellow coloured oil which was dried in vacuo (2.1 g, 66 % over two steps);
1 H NMR (400 MHz, CDCl 3 ): δ = 7.23-7.17 (m, 1H, Ar-H), 7.03 (d, 1H, J = 8, 1, Ar-H), 6.91-6.78 (m, 3H, Ar-H), 4.07 (s, 2H, CH 2 ), 3.15-3.07 (m, 2H, Imd-CH 2 ), 2.93-2.86 (m, 2H, Imd-CH 2 ), 2.28(s, 6H, Mes-CH 3 ), 2.25 (s, 3H, Mes-CH 3 ); 13 C NMR (100 MHz, CDCl 3 ): δ = 158.3, 142.9, 132.1, 130.4, 129.6, 128.9, 128.5, 122.4, 119.2, 116.5, 52.8, 49.4, 47.8, 20.7, 18.4; mp = 60-62 C; MS (ESI): m/ɀ 285.2 [M+H] + ; HRMS calcd 285.1967, found 285.1976 Scheme S1. The synthesis of N 1 -(2,4,6-trimethylphenyl)-N 2 -(2-hydroxybenzyl)-1,2-diaminoethane Figure S1. 1 H NMR (400 MHz, CDCl 3 ) spectrum of N 1 -(2,4,6-trimethylphenyl)-N 2 -(2-hydroxybenzyl)-1,2-diaminoethane
Figure S2. 13 C NMR (400 MHz, CDCl 3 ) spectrum of N 1 -(2,4,6-trimethylphenyl)-N 2 -(2-hydroxybenzyl)-1,2-diaminoethane N 1 -(2,6-Diisopropylphenyl)-N 2 -(2-hydroxybenzyl)-1,2-diaminoethane (Scheme S2): In a (100 ml) round-bottomed flask to a stirring solution of salicylic aldehyde (2.09 g, 17.2 mmol) in (15 ml) of MeOH and p-toluensulfonic acid cat. (PTSA) was added. Then N-2,6-Diisopropylphenyl-(1,2diaminoethane) ( 3.6 g, 16.3 mmol) was added and the resulting mixture was left stirring at RT for 24 h. After that the flask was placed in an ice-cooling bath and MeOH (20 ml) was added. Then NaBH 4 (2.47 g, 65.3 mmol) was added portion-wise over period of 10 minutes during 1 h. Then the reaction was allowed to stir for additional 1 h at RT. After that the reaction mixture was concentrated and the saturated NaHCO 3(aq.) (50 ml) was added. The product was extracted with EtOAc and washed with brine (50 ml). The organic phase was dried over MgSO 4, filtered and concentrated. The resulting orange coloured oil was purified by silica-gel chromatography (c-hex:etoac, 9:1) yielded the product N 1 -(2,6-Diisopropylphenyl)-N 2 -(2-hydroxybenzyl)-1,2-diaminoethane as white powder which was
dried in vacuo (4.88 g, 92% over two steps); 1 H NMR (400 MHz, CDCl 3 ): δ = 7.24-7.17 (m, 1H, Ar-H), 7.16-7.08 (m, 3H, 1, Ar-H), 7.07-7.01 (m, 1H, 1, Ar-H), 6.92-6.87 (m, 1H, Ar-H), 6.85-6.79 (m, 1H, Ar-H), 6.10-4.90 (br, 1H, OH), 4.10 (s, 2H, CH 2 ), 3.35-3.20 (m, 1H, i Pr-CH), 3.13-3.03 (m, 2H, Imd-CH 2 ), 3.01-2.92 (m, 2H, Imd-CH 2 ), 1.26 (d, 12H, J = 8, i Pr-CH 3 ); 13 C NMR (100 MHz, CDCl 3 ): δ = 158.3, 143.0, 142.7, 129.0, 128.6, 124.4, 123.7, 122.4, 119.2, 116.6, 52.8, 51.0, 49.4, 27.8, 24.4; mp = 75-76 C; MS (ESI): m/ɀ 327.2 [M+Na] + ; HRMS calcd 327.2437, found 327.2424 Scheme S2. The synthesis of N 1 -(2,6-Diisopropylphenyl)-N 2 -(2-hydroxybenzyl)-1,2-diaminoethane Figure S3. 1 H NMR (400 MHz, CDCl 3 ) spectrum of N 1 -(2,6-Diisopropylphenyl)-N 2 -(2-hydroxybenzyl)-1,2-diaminoethane
Figure S4. 13 C NMR (400 MHz, CDCl 3 ) spectrum of N 1 -(2,6-Diisopropylphenyl)-N 2 -(2-hydroxybenzyl)-1,2-diaminoethane 2-(2,6-diisopropylphenylamino)ethanol (Scheme S3): 2,6-Diisopropylaniline (49.8 g, 0.253 mol), bromoethanol (15.8 g, 0.126 mol) and toluene (70 ml) were charged into 250 ml flask and left stirring at 90 C for 48 h under Ar atmosphere. Progress of the reaction was monitored by TLC control (c-hex:etoac, 1:1). After the reaction was complete the resulting mixture was cooled down and KOH (aq.) 50% was added until the resulting mixture became basic. Organic phase was separated and the aqueous was extracted with EtOAc (2x50 ml). The combined organic phases were dried over anhydrous MgSO4, filtered and concentrated. The resulting brown-colored oil was purified by silica-gel chromatography (c-hex:etoac, 3:2) yielded the product orange colored oil which was dissolved in hot n-hexane. The resulting solution was left standing overnight at RT. Next day the white crystals of 2-(2,6-diisopropylphenylamino)ethanol were formed which were filtered, washed with cold n-hexane
and dried in vacuo (22.6 g, 81 %). Spectral data for 2-(2,6-diisopropylphenylamino)ethanol in agreement with those reported in the literature. 2 Scheme S3. The synthesis of 2-(2,6-diisopropylphenylamino)ethanol N-(2-bromoethyl)-2,6-diisopropylaniline (Scheme S4): 2-(2,6-diisopropylphenylamino)ethanol (4g, 18.1 mmol), carbon tetrabromide (7.64 g, 22.6mmol) were dissolved in (30 ml) of DCM (czda) and the resulting mixture was submerged into an ice-salt bath and cooled to -10 C. Then triphenylphosphine (5.93 g, 22.6 mmol) was added portionally in 6 steps with 7 minutes interval. The resulting mixture was left stirring allowing the bath to warm up to RT for 2 h. Progrees of the reaction was monitored by TLC control (c-hex:etoac, 95:5). The resulting brown coloured mixture was purified by silica-gel chromatography (c-hex:etoac, 19:1) yielded the product N-(2-bromoethyl)-2,6- diisopropylaniline, as a yellow coloured oil which was dried in vacuo (4.94 g, 96%); 1 H NMR (400 MHz, CDCl 3 ): δ = 7.24-7.12 (m, 3H, Ar-H), 3.80-3.60 (m, 2H, i Pr-CH), 3.47-3.35 (m, 3H, Imd-CH 2 ), 3.22 (s, 1H, Imd-CH 2 ), 1.28 (d, 12H, J = 4 Hz, i Pr-CH 3 ); 13 C NMR (100 MHz, CDCl 3 ): δ = 149.2, 146.6, 143.1, 126.6, 124.1, 53.0, 52.4, 28.1, 24.6; MS (ESI): m/ɀ 284.1 [M] + ; HRMS calcd 284.1014, found 284.1008 Scheme S4. The synthesis of N-(2-bromoethyl)-2,6-diisopropylaniline
Figure S5. 1 H NMR (400 MHz, CDCl 3 ) spectrum of N-(2-bromoethyl)-2,6-diisopropylaniline Figure S6. 13 C NMR (400 MHz, CDCl 3 ) spectrum of N-(2-bromoethyl)-2,6-diisopropylaniline
N 1 -(2,6-diisopropylphenyl)-N 2 -(2-methoxyphenyl)ethane-1,2-diamine (Scheme S5): o-anisidine (3.95 g, 31.9 mmol), N-(2-bromoethyl)-2,6-diisopropylaniline (4.54 g, 16 mmol), MeCN (20 ml) were placed in (50 ml) flask and left stirring for 12 h at 70 C. Progress of the reaction was monitored by TLC control c-hex:etoac (1:1). Then the reaction mixture was cooled down to RT, concentrated and the brownish-precipitate was dissolved in CH 2 Cl 2 (40 ml) and washed with NaHCO 3 saturated solution (2x40 ml). Then the aqueous layer was washed with CH 2 Cl 2 (2x50 ml). The combined organic phases were dried over anhydrous MgSO 4, filtered and concentrated. Purification of the crude mixture by silica-gel chromatography (c-hex:etoac, 9:1) yielded the product N 1 -(2,6-diisopropylphenyl)-N 2 - (2-methoxyphenyl)ethane-1,2-diamine as a brown oil which was dried in vacuo (4.76 g, 91 %). 1 H NMR (400 MHz, CDCl 3 ): δ = 7.16-7.08 (m, 3H, Ar-H), 6.90 (td, 1H, J = 9.2, 1.6, Ar-H), 6.82 (dd, 1H, J = 8, 1.2 Hz, Ar-H), 6.75-6.66 (m, 2H, Ar-H), 3.88 (s, 3H, OMe), 3.48 (t, 2H, J = 12, 6, Imd-CH 2 ), 3.34-3.24 (m, 2H, i Pr-CH), 3.19 (t, 2H, J = 12,6, Imd-CH 2 ), 1.22 (d, 12H, J = 7, i Pr-CH 3 ); 13 C NMR (100 MHz, CDCl 3 ): δ = 147.2, 142.9, 142.6, 138.0, 124.4, 123.7, 121.4, 117.0, 110.2, 109.6, 55.5, 50.7, 44.0, 27.8, 24.4; MS (ESI): m/ɀ 349.2 [M+Na]+; HRMS calcd 349.2256, found 349.2256. Scheme S5.The synthesis of N 1 -(2,6-diisopropylphenyl)-N 2 -(2-methoxyphenyl)ethane-1,2-diamine
Figure S7. 1 H NMR (400 MHz, CDCl 3 ) spectrum of N 1 -(2,6-diisopropylphenyl)-N 2 -(2-methoxyphenyl)ethane-1,2-diamine
Figure S8. 13 C NMR (400 MHz, CDCl 3 ) spectrum of N 1 -(2,6-diisopropylphenyl)-N 2 -(2-methoxyphenyl)ethane-1,2-diamine 2) 1 H and 13 C NMR data of [H 2 L]X, [HL], [(Me 2 Ga(HL))X] and Me 3 Ga(SIMes) Figure S9. 1 H NMR (400 MHz, CDCl 3 ) spectrum of 3-(2-hydroxyethyl)-1-mesityl-4,5-dihydro-1Himidazolinium iodide [H 2 L 1 ]I
Figure S10. 13 C NMR (400 MHz, CDCl 3 ) spectrum of 3-(3-hydroxypropyl)-1-mesityl-4,5-dihydro- 1H-imidazolinium iodide [H 2 L 2 ]I
Figure S11. 1 H NMR (400 MHz, CDCl 3 ) spectrum of [H 2 L 2 ]I
Figure S12. 13 C NMR (400 MHz, CDCl 3 ) spectrum of [H 2 L 2 ]I Figure S13. 1 H NMR (400 MHz, DMSO-d 6 ) spectrum of [H 2 L 3 ]Cl
Figure S14. 13 C NMR (400 MHz, DMSO-d 6 ) spectrum of [H 2 L 3 ]Cl Figure S15. 1 H NMR (400 MHz, DMSO-d 6 ) spectrum of [H 2 L 4 ]Cl
Figure S16. 13 C NMR (400 MHz, DMSO-d 6 ) spectrum of [H 2 L 4 ]Cl Figure S17. 1 H NMR (200 MHz, CD 2 Cl 2 ) spectrum of [HL 2 ] Figure S18. 1 H NMR (400 MHz, CD 2 Cl 2 ) spectrum of [HL 3 ]
Figure S19. 13 C NMR (400 MHz, CD 2 Cl 2 ) spectrum of [HL 3 ] Figure S20. 1 H NMR (400 MHz, CD 2 Cl 2 ) spectrum of [HL 4 ] Figure S21. 13 C NMR (400 MHz, CD 2 Cl 2 ) spectrum of [HL 4 ]
Figure S22. 1 H NMR (400 MHz, CD 2 Cl 2 ) spectrum of [(Me 2 Ga(HL 2 ))I)] Figure S23. 13 C NMR (400 MHz, CD 2 Cl 2 ) spectrum of [(Me 2 Ga(HL 2 ))I)] Figure S24. 1 H NMR (400 MHz, CD 2 Cl 2 ) spectrum of [(Me 2 Ga(HL 3 ))Cl)]
Figure S25. 13 C NMR (400 MHz, CD 2 Cl 2 ) spectrum of [(Me 2 Ga(HL 3 ))Cl)] Figure S26. 1 H NMR (400 MHz, CD 2 Cl 2 ) spectrum of [(Me 2 Ga(HL 4 ))Cl)] Figure S27. 13 C NMR (400 MHz, CD 2 Cl 2 ) spectrum of [(Me 2 Ga(HL 4 ))Cl)]
Figure S28. 1 H NMR (400 MHz, CD 2 Cl 2 ) spectrum of [(Me 2 Ga(HL 5 ))Cl)] Figure S29. 13 C NMR (400 MHz, CD 2 Cl 2 ) spectrum of [(Me 2 Ga(HL 5 ))Cl)] Figure S30. 1 H NMR (400 MHz, toluene-d 8 ) spectrum of Me 3 Ga(SIMes)
Figure S31. 13 C NMR (400 MHz, toluene-d 8 ) spectrum of Me 3 Ga(SIMes) Figure S32. 1 H NMR of the crude product of the reaction of [HL 3 ] with Me 3 Ga 3) Calculations of bond valence vectors for gallium centers Bond valences were calculated using the most widely used equation describing the relationship between the bond length (d ij ) between the i-th and j-th atoms, and the valence of this bond (s ij ) 3 ( ) sij = exp rij dij / b (S1) where r ij and b are empirically determined constants for the given i-j bond. The r ij is equal to the length of a conceptual bond of a unit valence, while the parameter b is generally treated as a 'universal' constant, often taken to be 0.37 Å.3,4 To determine the appropriate r GaX bond valence parameters, the high accuracy structural data of gallium complexes comprising GaO 6, GaO 4 and GaC 4 central skeletons
were retrieved from CSD (ver. 5.28, R 0.05, σ(c C) 0.005 Å, no errors, no disorder). The resulting data-sets comprised 18(19), 7(7), and 18(20) fragments(entries) for GaO 6, GaO 4, and GaC 4 moieties, respectively. Then, the r GaO and r GaC values which minimized the sum of the squares of the difference between the expected valence of gallium (3) and the valence calculated from the bond-valence sum were evaluated. The resulting r GaO and r GaC bond-valence parameters are equal to 1.708 and 1.931 Å, respectively. Bond valences for all Ga-X bonds were calculated using eq (S1) with a common constant b = 0.37 Å. According to the bond valence vector model 5 the bond between the coordination center i and the more electronegative ligating atom j of s ij valence can be represented by the bond-valence vector v ij directed from i to j with a length defined by the equation: sij v ij = sij 1 (S2) Qi where Q i is the charge of the core of the central i-th atom. Accordingly, the bond-valence vectors v GaO, v GaC and the resultant vector v Ga were calculated for all analyzed complexes by setting the gallium core charge Q Ga = 3. In order to show the spatial orientation, the resultant bond valence vector v Ga has been projected on the direction of each of the four Ga X bonds. In consequence for each molecular GaOC 3 fragment one obtains four residual vectors δv GaX. The results are presented in Table S1. Table S1. Calculated bond valences (s GaX ), lengths of residual (δv GaX ) and resultant ( v Ga ) bond valence vectors for gallium centers in compounds 1-6 and XALTAH 6 (Me 2 GaOMe(SIMes) 7 ) (in v.u.). Comp Atom s GaO s GaC1 s GaC2 s GaC3 δv GaO δv GaC1 δv GaC2 δv GaC3 v Ga 1 Ga(1) 0.604 0.671 0.878 0.878 0.053 0.053 0.045 0.032 0.077 2 Ga(1) 0.532 0.657 0.901 0.889 0.014 0.029 0.030 0.000 0.036 2 Ga(2) 0.454 0.842 0.876 0.852 0.023 0.016 0.032 0.001 0.038 3 Ga(1) 0.574 0.668 0.885 0.894 0.061 0.001 0.001 0.040 0.066
4 Ga(1) 0.588 0.694 0.879 0.900 0.016 0.015 0.017 0.038 0.039 5 Ga(1) 0.562 0.714 0.926 0.863 0.079 0.076 0.062 0.043 0.108 6 Ga(1) 0.501 0.687 0.907 0.915 0.018 0.045 0.026 0.046 0.059 6 Ga(2) 0.378 0.867 0.871 0.869 0.047 0.009 0.015 0.005 0.049 6 Ga(3) 0.497 0.672 0.907 0.937 0.013 0.012 0.034 0.032 0.040 6 Ga(4) 0.384 0.893 0.878 0.876 0.055 0.030 0.005 0.001 0.058 XALTAH 0.632 0.632 0.867 0.876 0.016 0.023 0.041 0.006 0.043 1 Marshall, C.; Ward, M. F.; Skakle, J. M. S. Synthesis 2006, 6, 1040-1044. 2 Prasad, B.; Gilbertson, S. Org. Lett. 2009, 11, 3710-3713. 3 Brown, I. D.; Altermatt, D. Acta Crystallogr., Sect. B 1985, B41, 244-247. 4 Brese, N. E.; O Keeffe, M. Acta Crystallogr., Sect. B 1991, B47, 192-197. 5 Zachara, J. Inorg. Chem. 2007, 46, 9760-9767. 6 CCDC 241085 7 Horeglad, P.; Szczepaniak, G.; Dranka, M.; Zachara, J. Chem. Commun. 2012, 48, 1171.