Full Paper
[CpphRh(benzo[h]quinoline)Cl] (2a): 43 mg, yield 70 %; 1H NMR (s, 3H), 1.71 (s, 3H); 13C NMR (125 MHz, [D4]MeOD, 298 K): δ = 175.67
(500 MHz, CDCl3, 298 K): δ = 8.69 (d, J = 5.1 Hz, 1H), 8.14 (d, J = (JC-Rh
=
33.8 Hz), 155.81,154.29, 151.59, 142.40, 141.54,
8.0 Hz, 1H), 7.97 (d, J = 6.7 Hz, 1H), 7.79 (d, J = 8.7 Hz, 1H), 7.62–
141.21,140.40, 139.00, 135.38, 134.40, 132.16, 131.55, 130.84, 130.57,
129.97, 129.02, 128.79, 149.49, 140.54, 135.64, 133.83, 133.54,
131.99, 130.89, 129.71, 128.79, 128.05, 127.82, 127.73, 126.12,
125.13, 124.35, 124.07, 105.50, 102.72, 101.93, 98.28, 93.41, 10.57,
7.53 (m, 5H), 7.43–7.3 (m, 4H), 1.85 (s, 3H), 1.78 (s, 3H), 1.75 (s, 3H),
1.45 (s, 3H); 13C NMR (125 MHz, CDCl3, 298 K): δ = 175.18 (JC-Rh
=
33.8 Hz), 155.32, 149.49, 140.54, 135.64, 133.83, 133.54, 131.99,
130.89, 129.71, 128.79, 127.77, 127.21, 123.13, 121.53, 121.32, 107.6, 10.43, 9.02, 9.01. HR-MS (ESI): m/z calcd. for [CpbiphRh(benzo-
100.31, 95.87, 94.64, 88.79, 10.84, 10.48, 9.54, 9.22. HR-MS (ESI): m/z [h]quinoline)pyridine]+ 633.1772, found 633.1768; elemental analy-
calcd. for [CpphRh(benzo[h]quinoline)]+: 478.1037, found 478.1032;
elemental analysis calcd. (%) for C28H25ClRhN: C, 65.45; H, 4.90; N,
2.73; found C, 64.55; H, 4.86; N, 2.69.
sis calcd. (%) for C39H34RhN3O3: C, 67.34; H, 4.93; N, 6.04; found C,
67.25; H, 4.86; N, 5.95.
Methods and Instrumentation
1
[CpbiphRh(benzo[h]quinoline)Cl] (3a): 41 mg, yield 58 %; H NMR
X-ray Crystallography: Suitable crystals were selected and
mounted on a glass fibre with Fomblin oil and placed on an Xcali-
bur Gemini diffractometer with a Ruby CCD area detector. The crys-
tals were kept at 150(2) K, except crystal of complex 3a at 100(2)
K, during data collection. Using Olex2,[42] all the structures were
solved with the ShelXT[43] structure solution program using direct
methods and refined with the ShelXL[44] refinement package using
least-squares minimization.
(500 MHz, CDCl3, 298 K): δ = 8.73 (d, J = 5.1 Hz, 1H), 8.14 (d, J =
7.9 Hz, 1H), 8.00 (d, J = 6.9 Hz, 1H), 7.80 (d, J = 8.7 Hz, 1H), 7.68–
7.55 (m, 9H), 7.48 (t, J = 7.6 Hz, 2H), 7.40–7.34 (m, 2H), 1.89 (s,
3H),1.80 (s, 3H), 1.77 (s, 3H), 1.50 (s, 3H); 13C NMR (125 MHz, CDCl3,
298 K): δ = 175.14 (JC-Rh = 33.8 Hz), 155.30, 149.51, 140.59, 140.54,
140.31, 135.66, 133.83, 133.53, 131.26, 131.02, 130.20, 129.71,
129.04, 127.65, 127.36, 127.21, 127.11, 123.14, 121.59, 121.34,
107.56, 100.39, 95.44, 94.73, 88.91, 10.91, 10.53, 9.54, 9.23. HR-MS
(ESI): m/z calcd. for [CpbiphRh(benzo[h]quinoline)]+ 554.1350, found
554.1353; elemental analysis calcd. (%) for C34H29ClRhN: C, 69.22; H,
4.95; N, 2.37; found C, 69.31; H, 4.96; N, 2.17.
CCDC 1952984 (for 2a), 1952985 (for 3a), and 1952986 (for 1b·PF6)
Synthesis of [CpXRh(benzo[h]quinoline)py]NO3 (1b–3b)
NMR Spectroscopy: 1H and 13C NMR spectroscopy and 1H-1H gs
(gradient selected) COSY(correlation spectroscopy), 1H-13C HMQC
(heteronuclear multiple quantum coherence) and HMBC (hetero-
nuclear multiple bond coherence) were acquired at 298 K (unless
stated otherwise) on Bruker Advance 300 MHz, Bruker Advance III
HD 500 MHz or 600 MHz NMR spectrometers. 1H NMR chemical
shifts were internally referenced to CHCl3 (7.26 ppm) for [D]chloro-
form and (CHD2)OD (3.31 ppm) for [D4]methanol. 13C NMR chemical
shifts were internally referenced to CDCl3 (77.16 ppm) for [D]chloro-
form, and CD3OD (49.00 ppm) for [D4]methanol. The data were
processed using Mestronova and Topspin (version 2.1 Bruker UK
Ltd.).
General procedure: [CpXRh(benzo[h]quinoline)Cl] (0.05 mmol) was
stirred with silver nitrate (0.05 mmol) in 10 mL methanol for 1.5 h.
Then the solution was centrifuged and pyridine (0.5 mmol) was
added to the upper clear layer. The color changed from orange to
bright yellow, and the solution was stirred 24 h. Then the solution
was concentrated, and product recrystallized from diethyl ether giv-
ing a yellow solid which was dried under vacuum.
[Cp*Rh(benzo[h]quinoline)py]NO3 (1b): 18 mg, yield 65 %; 1H
NMR (500 MHz, [D4]MeOD, 298 K): δ = 9.44 (d, J = 5.0 Hz, 1H), 8.54
(d, J = 7.4 Hz, 1H), 8.50 (d, J = 5.6 Hz, 2H), 8.35 (d, J = 7.2 Hz, 1H),
7.91–7.81 (m, 3H), 7.75–7.71 (m, 3H), 7.26 (t, J1 = 6.8 Hz, J2 = 7.3 Hz,
2H), 1.65 (s, 15H); 13C NMR (125 MHz, [D4]MeOD, 298 K): δ = 175.14
(JC-Rh = 35.0 Hz), 155.99, 154.20, 151.45, 141.71, 140.14, 138.82,
135.17, 134.29, 131.98, 130.77,128.77, 127.51, 124.94, 124.35, 123.77,
98.62, 9.04. HR-MS (ESI): m/z calcd. for [Cp*Rh(benzo[h]quinoline)-
pyridine]+ 495.1302, found 495.1297; elemental analysis calcd. (%)
for C28H28RhN3O3: C, 60.33; H, 5.06; N, 7.54; found C, 59.65; H, 4.98;
N, 7.50.
[CpphRh(benzo[h]quinoline)py]NO3 (2b): 23 mg, yield 74 %; 1H
NMR (500 MHz, [D4]MeOD, 298 K): δ = 9.22 (d, J = 5.0 Hz, 1H), 8.53–
8.50 (m, 3H), 8.27 (d, J = 6.8 Hz, 1H), 7.91 (d, J = 8.7 Hz, 1H), 7.82–
7.74 (m, 5H), 7.30 (t, J1 = 6.7 Hz, J2 = 7.4 Hz, 2H), 7.26 (d, J = 7.5 Hz,
1H), 7.16 (t, J1 = 7.8 Hz, J2 = 7.6 Hz, 2H), 6.90 (d, J = 7.3 Hz, 2H),
1.90 (s, 3H), 1.76 (s, 3H), 1.71 (s, 3H), 1.68 (s, 3H); 13C NMR (125 MHz,
[D4]MeOD, 298 K): δ = 175.69 (JC-Rh = 33.8 Hz), 155.82, 154.29,
151.54, 141.54, 140.40, 138.98, 135.38, 134.38, 132.14,131.63,
131.02,130.85, 129.63, 129.43, 129.02, 127.72, 125.10, 124.27, 124.06,
105.56, 102.90, 102.08, 98.47, 93.07, 10.52, 10.35, 9.00. HR-MS (ESI):
m/z calcd. for [CpphRh(benzo[h]quinoline)pyridine]+ 557.1459,
found 557.1458; elemental analysis calcd. (%) for C33H30RhN3O3:
C, 63.98; H, 4.88; N, 6.78; found C, 63.91; H, 4.84; N, 6.76.
[CpbiphRh(benzo[h]quinoline)py]NO3 (3b): 22 mg, yield 63 %; 1H
NMR (500 MHz, [D4]MeOD, 298 K): δ = 9.24 (d, J = 5.1 Hz, 1H), 8.54
(d, J = 5.6 Hz, 2H), 8.51 (d, J = 8.0 Hz, 1H), 8.30 (d, J = 7.0 Hz, 1H),
7.91 (d, J = 6.7 Hz, 1H), 7.83–7.74 (m, 5H), 7.53 (d, J = 7.4 Hz, 2H),
7.43 (d, J = 8.2 Hz, 2H), 7.39 (t, J1 = 7.4 Hz, J2 = 7.7 Hz, 2H), 7.33–
7.28 (m, 3H), 6.99 (d, J = 8.2 Hz, 2H),1.93 (s, 3H), 1.77 (s, 3H), 1.73
Electrospray Mass Spectrometry: Electrospray ionization mass
spectra (ESI-MS) were obtained by injecting the samples in meth-
anol into a Bruker Esquire 2000 spectrometer. The mass spectra
were recorded with a scan range of m/z either 50–500 or 400–1000
for positive ion mode. HR-MS analysis was carried with a Bruker
MaXis plus Q-TOF mass spectrometer equipped with electrospray
ionization source. The mass spectrometer was operated in electro-
spray positive ion mode with a scan range 50–2,400 m/z.
Elemental Analysis: CHN elemental analyses were carried out on
a CE-440 elemental analyzer by Warwick Analytical (UK) Ltd.
pH Measurements: pH or pH* (pH meter reading without correc-
tion for effect of deuterium on the sensor) values of samples in H2O
or D2O were measured at ca. 298 K, using a HATCH minilab pocket
pH meter with ISFET (silicon chip) sensor, calibrated with buffer
solutions of pH 4, 7, and 10.
UV/Vis Spectroscopy: A Cary 300 UV/Vis recording spectrophotom-
eter was used with 1 cm path-length quartz cuvettes (3.0 mL) and
a PTP1 Peltier temperature controller. Experiments were carried out
at 310 K from 800 to 200 nm in 0.5 nm intervals unless stated
otherwise. Spectra were recorded using UV Winlab software and
analyzed using Origin 2018.
Reactions with NADH: The time dependence of reactions of rho-
dium complexes (0.8 μM) with NADH (75–144 μM) were studied over
24 h in 1.6 % MeOH-98.4 % phosphate buffer (5 m
M, pH 7.4) by UV/
Vis spectroscopy at 310 K. The concentration of NADH was obtained
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Eur. J. Inorg. Chem. 0000, 0–0