Inorganic Chemistry
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in toluene (5 mL) was added to a suspension of RuHCl(PPh3)3 (7)
(100 mg, 0.100 mmol) in toluene (5 mL) and heated at 80 °C for 1 h,
changing the color from dark purple to yellow. After this time, the
mixture was cooled to room temperature, and the solvent was
removed. The resulting pale yellow solid was washed with pentane
(3 × 3 mL) and dried in vacuo. Yield: 70 mg (83%). Anal. Calcd for
C45H56ClOP3Ru: C, 64.46; H, 6.70. Found: C, 64.34; H, 6.56. HRMS
(electrospray, m/z): calcd for C45H56OP3Ru [M − Cl]+, 807.2594;
found, 807.2580. IR (cm−1): ν(Ru−H) 2045(w), ν(O−C) 1086 (s).
1H NMR (300 MHz, CD2Cl2, 293 K): δ 8.18 (m, 6H, CHarom),
7.47 (m, 2H, CHarom), 7.46 (d, JH−H = 7.5, 2H, CHarom), 7.33 (m, 9H,
CHarom), 7.15 (t, JH−H = 7.5, 2H, CHarom), 2.30 (m, 4H, PCH(CH3)2),
1.65, 1.33 (both s, 3H, CH3), 0.99 (dvt, JH−H = 7.2, N = 14.6, 18H,
PCH(CH3)2), 0.74 (dvt, JH−H = 7.2, N = 15.9, 6H, PCH(CH3)2),
−17.48 (dt, JH−P = 27.9, JH−P = 24.0, 1H, RuH). 13C{1H}-APT plus
HSQC and HMBC NMR (75.47 MHz, CD2Cl2, 293 K): δ 155.9 (vt,
N = 14.3, Carom), 140.0 (d, JC−P = 42.3, Carom), 135.9 (d, JC−P = 10.2,
CHarom), 131.7 (s, Carom), 130.0 and 129.2 (both s, CHarom), 127.0 (d,
JC−P = 8.8, CHarom), 126.8 (s, CHarom), 126.6 (vt, N = 20.4, Cipso),
124.3 (s, CHarom), 35.1 (s, C(CH3)2), 34.4 (s, C(CH3)2), 28.9 (vt, N =
28.5, PCH(CH3)2), 27.6 (s, C(CH3)2), 26.6 (vt, N = 11.6,
PCH(CH3)2), 20.9, 19.3, and 18.8 (all s, PCH(CH3)2). 31P{1H}
NMR (121.5 MHz, CD2Cl2, 293 K): δ 76.4 (t, JP−P = 31.2, PPh3), 51.8
(d, JP−P = 31.2, xant(PiPr2)2).
HRMS (electrospray, m/z): calcd for C42H51Cl2OP2Ru [M + H]+,
805.1836; found, 805.1870. IR (cm−1): ν(CCC) 1889 (s),
1
ν(O−C) 1187 (s). H NMR (300 MHz, C6D6, 293 K): δ 8.25−7.01
(m, 16H, CHarom), 3.12 (m, 4H, PCH(CH3)2), 1.58 (dvt, JH−H = 6.0,
N = 15.0, 12H, PCH(CH3)2), 1.47 (dvt, JH−H = 9.0, N = 15.0, 12H,
PCH(CH3)2), 1.40 (s, 6H, CH3). 13C{1H}-APT plus HSQC and
HMBC NMR (75.47 MHz, C6D6, 293 K): δ 308.8 (t, JC−P = 12.8,
RuC), 253.5 (s, C), 154.8 (vt, N = 14.3, Carom-xant(PiPr2)2),
147.3 (s, CPh2), 145.8 (s, Cipso), 133.9 (s, CHarom-xant(PiPr2)2),
132.1 (vt, N = 5.3, Carom-xant(PiPr2)2), 129.7 and 129.1 (both s,
CHarom), 129.0 (s, CHarom-xant(PiPr2)2), 126.6 (s, CHarom), 124.5 (vt,
N = 24.9, Cipso-xant(PiPr2)2), 124.0 (vt, N = 4.5, CHarom-xant(PiPr2)2),
34.4 (s, C(CH3)2), 33.5 (s, C(CH3)2), 25.0 (vt, N = 22.6,
PCH(CH3)2), 22.1, 19.6 (both s, PCH(CH3)2). 31P{1H} NMR
(121.5 MHz, C6D6, 293 K): δ 46.9 (s).
Spectroscopic Detection of RuCl2(CCH−CHPh2){xant-
(PiPr2)2 (11). A solution of RuCl2(CCCPh2){xant(PiPr2)2}
(10) (100 mg, 0.124 mmol) in toluene (10 mL) was treated with
ammonia borane (11.5 mg, 0.373 mmol). After stirring the mixture at
room temperature for 24 h, it was dried in vacuo and dissolved in
1
benzene-d6. H and 31P{1H} NMR spectroscopies show a 1:3 mixture
of complexes 10 and 11. Spectroscopic data for 11: 1H NMR
(300 MHz, C6D6, 293 K): δ 8.14−6.84 (16H, CHarom), 5.60 (d, JH−H
=
10.5, 1H, −CHPh2), 4.68 (dt, JH−H = 10.5, JH−P = 3.0, 1H, CH−),
3.02 (m, 4H, PCH(CH3)2), 1.49 (dvt, JH−H = 7.5, N = 16.5, 12H,
PCH(CH3)2), 1.39 (dvt, JH−H = 6.0, N = 15.0, 12H, PCH(CH3)2),
1.20 (s, 6H, CH3). 13C{1H}-APT NMR plus HSQC and
HMBC (75.47 MHz, C6D6, 293 K): δ 346.4 (t, JC−P = 12.8, Ru
C), 153.9 (vt, N = 12.8, Carom-xant(PiPr2)2), 146.6 (s, Cipso), 133.7 (s,
CHarom-xant(PiPr2)2), 131.6 (vt, N = 5.3, Carom-xant(PiPr2)2), 129.4 (s,
CHarom-xant(PiPr2)2), 128.4 and 128.2 (both s, CHarom), 124.3 (vt, N =
Synthesis of RuH2(η2-H2){xant(PiPr2)2} (8). Method a: In a
Fisher−Porter bottle, a solution of xant(PiPr2)2 (140 mg, 0.316 mmol)
in pentane (5 mL) was added to a solution of Ru(COD)(COT) (9)
(100 mg, 0.317 mmol) in pentane (5 mL). The bottle was pressurized
to 3 atm of H2, and the mixture was stirred at room temperature for
24 h. During that time, the color of the mixture changed from bright
yellow to light brown. Cooling the solution at −70 °C with a iPrOH/
dry ice bath afforded the formation of a pale yellow precipitate that
was washed with pentane (2 × 2 mL) and dried by passing through a
stream of hydrogen gas. The complex is moderately stable under a
hydrogen atmosphere. Yield: 62 mg (36%). Note that residual free
xant(PiPr2)2 was always observed. Method b: A Schlenk flask equipped
with a Teflon stopcock was charged with RuH(η2-H2BH2){xant-
(PiPr2)2} (12) (50 mg, 0.089 mmol) and 2-propanol (3 mL). The
argon atmosphere was replaced by a hydrogen atmosphere, and the
mixture was stirred at 80 °C for 24 h. During that time, the color of
the mixture changed from yellow to light brown. The solvent was
evaporated passing a stream of hydrogen gas, and a light brown oil was
thus obtained. Yield: 48 mg (94%). 1H NMR (400 MHz, C7D8,
293 K): δ 7.21 (dd, JH−H = 8.0, JH−H = 2.0, 2H, CHarom), 7.12
(m, 2H, CHarom), 6.92 (t, JH−H = 6.0, 2H, CHarom), 2.10 (m, 4H,
PCH(CH3)2), 1.33 (dvt, JH−H = 6.0, N = 18.0, 12H, PCH(CH3)2),
1.19 (s, 6H, CH3), 1.00 (dvt, JH−H = 6.0, N = 14.0, 12H, PCH(CH3)2),
−9.18 (t, JH−P = 14.0, 4H, RuH). 13C{1H}-APT NMR (75.47 MHz,
C6D6, 293 K): δ 157.5 (vt, N = 15.1, Carom), 132.1 (vt, N = 5.3, Carom),
128.5 (s, CHarom), 126.2 (s, CHarom), 128.2 (this resonance is masked
by the resonance of C6D6, Cipso), 124.4 (vt, N = 3.8, CHarom), 31.0
(s, C(CH3)2), 30.9 (s, C(CH3)2), 28.9 (vt, N = 22.6, PCH(CH3)2),
21.4 (vt, N = 12.8, PCH(CH3)2), 19.9 (vt, N = 3.8, PCH(CH3)2).
31P{1H} NMR (121.5 MHz, C6D6, 293 K): δ 92.1 (s). t1(min) (ms,
RuH, 400 MHz, C7D8, 233 K): 44 3 (−8.97 ppm).
24.2, Cipso-xant(PiPr2)2), 125.9 (s, CHarom), 123.7 (vt, N = 5.3, CHarom
-
xant(PiPr2)2), 106.9 (t, JC−P = 3.0, CH−), 41.7 (s, −CHPh2), 34.0
(s, C(CH3)2), 32.9 (s, C(CH3)2), 25.7 (vt, N = 21.9, PCH(CH3)2),
22.2 and 19.7 (both s, PCH(CH3)2). 31P{1H} NMR (121.5 MHz,
C6D6, 293 K): δ 37.3 (s).
Synthesis of RuH(η2-H2BH2){xant(PiPr2)2} (12). A solution of
RuCl2(CCCPh2){xant(PiPr2)2} (10) (100 mg, 0.124 mmol) in
toluene (12 mL) was treated with ammonia borane (46 mg, 1.491
mmol). The mixture was stirred at room temperature for 48 h, and the
color of the mixture changed from purple to yellow. After this time, it
was filtered through Celite, and the yellow solution obtained was dried
in vacuo. Pentane (10 mL) was added to afford a yellow solid that was
washed with pentane and dried in vacuo. Yield: 52 mg (75%). Anal.
Calcd for C27H45BOP2Ru: C, 57.96; H, 8.11. Found: C, 58.16; H, 8.17.
HRMS (electrospray, m/z): calcd for C27H40OP2Ru [M − H2BH2 −
H]+, 543.1522; found, 543.1512. IR (cm−1): ν(B−H) 2389, 2321,
1
ν(Ru−H) 1945 (m), ν(O−C) 1180 (s). H NMR (400 MHz, C7D8,
293 K): δ 7.26−6.82 (m, 6H, CHarom), 2.80 (m, 2H, PCH(CH3)2),
2.45 (m, 2H, PCH(CH3)2), 1.36 (dvt, JH−H = 8.0, N = 16.0, 6H,
PCH(CH3)2), 1.32 (s, 3H, CH3), 1.28 (dvt, JH−H = 6.0, N = 14.0, 6H,
PCH(CH3)2), 1.20 (dvt, JH−H = 8.0, N = 12.0, 6H, PCH(CH3)2), 1.15
(dvt, JH−H = 6.0, N = 14.0, 6H, PCH(CH3)2), 0.94 (s, 3H, CH3),
−4.86 (br, 1H, Ru−Ha-B), −15.41 (td, JH−P = 20.0, JH−H = 8.0, 1H,
1
RuH), −24.08 (br, 1H, Ru−Hb-B). H NMR (400 MHz, C7D8, 243
K): δ 7.15−6.85 (6H, CHarom), 6.08 (br, 2H, H2−B-H2), 2.82 (m, 2H,
PCH(CH3)2), 2.41 (m, 2H, PCH(CH3)2), 1.36 (dvt, JH−H = 10.0, N =
16.0, 6H, PCH(CH3)2), 1.27 (dvt, JH−H = 8.0, N = 16.0, 6H,
PCH(CH3)2), 1.21 (s, 3H, CH3), 1.17 and 1.14 (both dvt, overlapped,
12H, PCH(CH3)2), 0.88 (s, 3H, CH3), −4.77 (br, 1H, Ru−Ha−B),
−15.35 (td, JH−P = 20.0, JH−H = 8.0, 1H, RuH), −23.92 (br, 1H, Ru−
Determination of the JH−D Value for Complex 8. Under a H2
atmosphere, an NMR tube was charged with 8 (20 mg, 0.038 mmol),
1
and 0.5 mL of benzene-d6 was added. After 10 min, the H NMR
spectrum of this solution exhibits a multiplet with a JH‑D (average) = 4.5 Hz
in the hydride region.
Synthesis of RuCl2(CCCPh2){xant(PiPr2)2} (10). A sol-
ution of RuCl2{xant(PiPr2)2}(κ-S-DMSO) (2) (400 mg, 0.577 mmol)
in toluene (15 mL) was treated with 1,1-diphenyl-2-propyn-1-ol
(361 mg, 1.732 mmol). The mixture was stirred under reflux
overnight. During this time, the color of the mixture changed from
yellow to purple. After the mixture was cooled to room temperature,
the solvent was evaporated, and the addition of diethyl ether (6 mL)
afforded a purple solid that was washed with diethyl ether (2 × 3 mL)
and dried in vacuo. Yield: 428 mg (92%). Anal. Calcd for
C42H50Cl2OP2Ru: C, 62.68; H, 6.26. Found: C, 62.36; H, 6.24.
1
Hb−B). H{31P} NMR (400 MHz, C7D8, 293 K, high-field region): δ
−4.85 (br, 1H, Ru−Ha−B), −15.41 (d, JH−H = 8.0, 1H, RuH), −24.07
(br, 1H, Ru−Hb−B). 13C{1H}-APT NMR (75.47 MHz, C6D6, 293 K):
δ 158.5 (vt, N = 13.6, Carom), 132.7 (vt, N = 6.0, Carom), 129.7 (s,
CHarom), 128.1 (this resonance is masked by the resonance of C6D6,
Cipso), 125.5 (s, CHarom), 124.8 (vt, N = 3.8, CHarom), 34.9 (s,
C(CH3)2), 34.5 (s, C(CH3)2), 26.1 (vt, N = 16.6, PCH(CH3)2), 24.0
(s, C(CH3)2), 23.9 (vt, N = 25.7, PCH(CH3)2), 20.1 (vt, N = 3.8,
PCH(CH3)2), 19.6 and 19.5 (both vt, overlapped, PCH(CH3)2),
1205
dx.doi.org/10.1021/ic402795g | Inorg. Chem. 2014, 53, 1195−1209