Organometallics
Article
2956, 2930, 2872 (CH, alkyl); 1630, 1397, 1384 (CH, aromatic);
1585, 1571 (CH, cod); 1227, 1198 cm−1 (SO); 1432, 1335, 1031,
696, 533 (CH, bmim). Anal. Calcd for C34H40N2O3SPIr·H2O·
CHCl3 (917.84): C, 45.82; H, 4.73; N, 3.05. Found: C, 45.40; H, 4.52,
N, 3.05. MS (ESI): m/z for [M + Na+] calcd 803.200, found 803.205.
Synthesis of Na2[Ir(bmim)(η4-cod)(mtppts)] (6). This complex was
obtained by the same procedure as 5, but using 122 mg (0.21 mmol)
of mtppts-Na3 instead of mtppms-Na, as a red powder. Yield: 184 mg,
80%. The complex is soluble in water, methanol, and dimethyl
sulfoxide but insoluble in diethyl ether, hexane, acetone, chloroform,
dichloromethane, and ethanol. NMR spectra: Figures S30−S32
(Supporting Information).
19F NMR (338 MHz, CD3OD): δ/ppm −170.3 (BF4). IR (KBr): ν/
̅
cm−1 3442 (OH, water), 2933, 2871, 2828 (CH, alkyl), 1654, 1570
(CH, cod), 1294,1243, 1228, 901, 773, 533 (CH, bmim), 1198
cm−1 (BF, BF4). Anal. Calcd for C22H38N5PBF4Ir·1.5H2O (709.58): C,
37.24; H, 5.82; N, 9.87. Found: C, 36.98; H, 5.52; N, 9.52. MS (ESI):
m/z for [M − BF4]+ calcd 596.249, found 596.255.
Sample Preparation of [Ir(bmim)(η4-cod)(pta)]BF4 (8) for X-ray
Structure Determination. 4 (20 mg) was dissolved in CHCl3 (2 mL)
followed by addition of an equivalent amount of pta (5.8 mg). This
solution was stored under an acetone layer at −18 °C for 2 months.
Red crystals of [Ir(bmim)(η4-cod)(pta)]BF4·2CHCl3 separated,
suitable for X-ray analysis.
Synthesis of [IrCl(η4-cod)(emim)] (9). [Ir(OMe)(η4-cod)]2 (150
mg, 0.23 mmol) was dissolved in acetone (10 mL), and 1-ethyl-3-
methylimidazolium chloride (66 mg, 0.46 mmol) was added as a
solution in acetone (5 mL).
1H NMR (360 MHz, D2O): δ/ppm 0.83 (t, 3J(H,H) = 7.3 Hz, 3H;
NCH2CH2CH2CH3), 1.22−1.30 (m, 2H; NCH2CH2CH2CH3), 1.30−
2.00 (m, 4H; CH2,cod), 1.84−2.10 (m, 2H; NCH2CH2CH2CH3),
2.28−2.41 (m, 2H; CHcod; m, 4H; CH2,cod), 3.56 (s, 3H; CH3N),
3.49−3.51 (m, 1H; NCH2CH2CH2CH3), 4.16−4.21 (m, 1H;
NCH2CH2CH2CH3), 4.32−4.58 (m, 2H; CHcod), 6.84 (s, 1H;
NCHCHN), 6.86 (s, 1H; NCHCHN), 7.10−8.14 (m, Ar-CHphosphine).
13C NMR (90 MHz, CD3OD): δ/ppm 13.10 (s, −CH2CH3), 19.71 (s,
NCH2CH2CH2), 29.72 (s, CH2,cod), 30.36 (s, CH2,cod), 30.45 (s,
CH2,cod), 31.14 (s, CH2,cod), 31.91 (s, NCH2CH2), 36.89 (s, NCH3),
50.34 (NCH2), 79.91 (s, CHcod), 80.86 (s, CHcod), 87.44 (d, J(C,P) =
11 Hz, CHcod), 88.84 (d, J(C,P) = 11 Hz, CHcod), 121.45, 124.27 (s,
The reaction mixture was stirred for 4 h at 40 °C. No color change
was observed. The solvent was removed by vacuum, and the oily
residue was washed three times with small amounts of diethyl ether.
The orange product was dried under vacuum. Yield: 160.0 mg, 79%.
NMR spectra: Figures S37 and S38 (Supporting Information).
3
1H NMR (360 MHz, CDCl3): δ/ppm 1.47 (t, J(H,H) = 6.5 Hz,
3H; NCH2CH3), 1.57−2.98 (m, 4H; CH2,cod; m, 4H; CH2,cod; m, 2H;
CHcod), 3.96 (s, 3H; CH3N), 4.31−4.48 (m, 1H; NCH2CH3; m, 1H;
NCH2CH3; m, 2H; CHcod), 6.83 (s, 1H; NCHCHN), 6.85 (s, 1H;
NCHCHN). 13C NMR (90 MHz, CDCl3): δ/ppm 16.49 (s,
2
NCHCHN), 128.64−145.58 (m, Ar-CP), 171.96 (d, NCN, J(C,P)
= 9.9 Hz). 31P NMR (146 MHz, CD3OD): δ/ppm 20.0 ppm (s). IR
(KBr): ν/cm−1 3458 (OH, water/crystal); 2957, 2930, 2872 (CH,
−CH2CH3), 29.52 (s, CH2,cod), 29.61 (s, CH2,cod), 33.57 (s, CH2,cod
;
̅
alkyl); 1638, 1465, 1399 cm−1 (CH, aromatic); 1572 (CH, cod);
1199 (SO); 1430, 1338, 1036, 694, 535 (CH, bmim). Anal. Calcd
for C34H38N2O9S3Na2PIr·6H2O (1092.13): C, 37.24; H, 4.04; N, 2.55.
Found (%) C, 37.34; H, 4.13, N, 2.55. H2O (% w/w): calcd 9.90;
found (thermogravimetry) 5.70. MS (ESI): m/z for [M + Na+] calcd
1007.079, found 1007.080.
s, CH2,cod), 37.41 (s, NCH3), 45.21 (s, NCH2), 51.39 (s, CHcod), 51.47
(s, CHcod), 84.02 (s, CHcod), 84.25 (s, CHcod), 119.29, 121.87 (s,
NCHCHN), 179.88 ppm (s, NCN). IR (KBr): ν¯/cm−1: 3152,
3120, 3096, 3018, 2964, 2878, 2830 (CH, alkyl); 1676, 1598, 1570 (
CH, cod); 1464, 1264, 1226, 1134, 962, 754, 710 (CH, emim).
Anal. Calcd for C14H22N2ClIr (447.01): C, 37.62; H, 5.19; N, 6.27.
Found: C, 37.42; H, 5.04; N, 5.81. MS (ESI): m/z for [2M + Na]+
calcd 846.290, found 846.330.
Synthesis of [Ir(bmim)(η4-cod)(pta)]Cl (7). This complex was
obtained by the same procedure as 5, but using 33 mg (0.21 mmol) of
pta instead of mtppms-Na, as a red powder. Yield: 103 mg, 74%. The
complex is soluble in water, methanol, dimethyl sulfoxide, chloroform,
and dichloromethane but insoluble in acetone, hexane, diethyl ether,
and ethanol. NMR spectra: Figures S33−S35 (Supporting Informa-
tion).
Synthesis of Na2[IrCl(η4-cod)(emim)(mtppts)] (11). This complex
was obtained by the same procedure as for 6, but using [IrCl(η4-
cod)(emim)] (9; 95 mg, 0.21 mmol) instead of [IrCl(bmim)(η4-cod)]
(3). Red powder. Yield: 89 mg, 83%. The complex is soluble in water
and methanol and insoluble in diethyl ether, hexane, acetone, and
ethanol. NMR spectra: Figures S39−S41 (Supporting Information).
1H NMR (360 MHz, D2O): δ/ppm 1.03 (t, 3J(H,H) = 6.5 Hz, 3H;
NCH2CH3), 1.88−2.38 (m, 4H; CH2,cod; m, 4H; CH2,cod), 3.45 (s, 3H;
CH3N), 3.50−3.65 (m, 2H; CHcod), 3.81−3.88 (m, 1H; NCH2CH3)
4.12−4.22 (m, 1H; NCH2CH3), 4.40−4.65 (m, 2H; CHcod), 6.85 (s,
1H; NCHCHN), 6.93 (s, 1H; NCHCHN), 7.26−8.08 (m, Ar-
CHphosphine). 13C NMR (90 MHz, D2O): δ/ppm 14.15 (s, −CH2CH3),
29.53 (s, CH2,cod), 29.95 (s, CH2,cod), 30.53 (s, CH2,cod) 31.14 (s,
CH2,cod), 36.69 (s, NCH3), 45.19 (s, NCH2), 80.23 (s, CHcod), 80.56
(s, CHcod), 89.32 (d, J(C,P) = 11 Hz, CHcod), 90.03 (d, J(C,P) = 11
Hz, CHcod), 120.85, 124.01 (s, NCHCHN), 128.20−143.31 (m, Ar-
3
1H NMR (360 MHz, CD3OD): δ/ppm 1.02 (t, J(H,H) = 7.3 Hz,
3H; NCH2CH2CH2CH3), 1.44−1.56 (m, 2H; NCH2CH2CH2CH3),
1.72−2.35 (m, 2H; NCH2CH2CH2CH3; m, 2H; CHcod; m, 4H;
CH2,cod; m, 4H; CH2,cod), 3.82 (s, 3H; CH3N), 3.98 (s, 6H,
NCH2Ppta), 4.04−4.61 (s, 6H, NCH2Npta; m, 2H; NCH2CH2CH2CH3,
m, 2H; CHcod), 7.32 (s, 1H; NCHCHN), 7.38 (s, 1H; NCHCHN).
13C NMR (90 MHz, CD3OD): δ/ppm 14.06 (s, −CH2CH3), 19.85 (s,
NCH2CH2CH2), 29.74 (s, CH2,cod), 30.67 (s, CH2,cod), 30.95 (s,
CH2,cod), 31.94 (s, CH2,cod), 32.41 (s, NCH2CH2), 36.40 (s, NCH3),
49.94 (s, CHcod), 50.1 (s, CHcod), 50.15 (s, NCH2,bmim) 71.63 (d,
3J(C,P) = 7 Hz, PCH2,pta), 74.77 (d, 2J(C,P) = 25 Hz, NCH2,pta) 87.78
CP), 171.35 ppm (d, NCN, 2J(C,P) = 8.9 Hz). IR (KBr): ν/cm−1 3451
3
3
(d, J(C,P) = 11 Hz, CHcod), 89.20 (d, J(C,P) = 11 Hz, CHcod),
̅
2
(OH, water), 2918, 2880 (CH, alkyl), 1635 (CH, cod), 1465, 1398,
1337 (CH, aromatic), 1147, 1096 (SO), 997, 869, 797, 533 (
CH, bmim). Anal. Calcd for C32H34N2PS3O9Na2Ir·6H2O (1064.121):
C, 36.12; H, 4.36; N, 2.63. Found: C, 35.70; H, 3.98; N, 2.35. H2O (%
w/w): calcd 10.16, found (thermogravimetry) 10.58. MS (ESI): m/z
for [M + H+] calcd 957.067, found 957.670.
121.15, 123.62 (s, NCHCHN), 172.12 (d, NCN, J(C,P) = 11.4
Hz). 31P NMR (146 MHz, CD3OD): δ/ppm −64.2 ppm (s). IR
(KBr): ν/cm−1 3272, 1986 (CH, alkyl-pta); 3192, 3064, 2936, 2846,
̅
2832 (CH, alkyl); 1618 (CH, cod); 1428, 1280, 1246, 744 (CH,
bmim). Anal. Calcd for C22H38N5PClIr·1.5H2O (658.24): C, 40.14; H,
6.28; N, 10.64. Found: C, 40.24; H, 6.29; N, 10.37. H2O (% w/w):
calcd 4.11, found (thermogravimetry) 4.16. MS (ESI): m/z for [M −
Cl]+ calcd 596.249, found 596.255.
General Procedure of Hydrogenation of Unsaturated
Substrates in Water. In a Schlenk tube under an argon atmosphere,
0.005 mmol of [IrCl(bmim)(η4-cod)] (3), [IrCl(η4-cod)(emim)] (9),
or [IrCl(η4-cod)(IMes)] (10) was dissolved in 3 mL of MeOH
together with 0.005 mmol of pta or mtppts-Na3. In the case of 3 and 9
the solutions turned deep red, with both phosphines showing the
presence of Na2[Ir(bmim)(η4-cod)(mtppts)] (6) and [Ir(η4-cod)-
(bmim)(pta)]Cl (7) as well as that of Na2[Ir(η4-cod)(emim)-
(mtppts)] (11) and [Ir(η4-cod)(emim)(pta)]Cl (12; 31P NMR
Synthesis of [Ir(bmim)(η4-cod)(pta)]BF4 (8). [Ir(bmim)(η4-cod)-
(pta)]Cl (7; 60 mg, 0.095 mmol) was dissolved in acetone (5 mL)
followed by addition of AgBF4 (18.5 mg, 0.095 mmol). The solution
was stirred in the dark for 1 h. The precipitate that (AgCl) formed
during this time was filtered (using a pad of Hyflo Super Cel), and the
solvent was removed by vacuum. The oily residue was treated with
diethyl ether to yield a red solid product that was dried under vacuum.
Yield: 56 mg, 83%. In solution, the 1H, 31P, and 13C NMR parameters
of this complex are identical with those of [Ir(bmim)(η4-cod)(pta)]Cl
(7). NMR spectra: Figures S33−S36 (Supporting Information).
2
−60.64 ppm (s); 13C NMR 172.08 ppm (d, JCP = 11.4 Hz)).
Conversely, with 10 and mtppts-Na3 or pta no new resonances were
observed in the 31P and 13C NMR spectra. The solutions were stirred
I
dx.doi.org/10.1021/om5006148 | Organometallics XXXX, XXX, XXX−XXX