Organometallics
Article
(Nujol): νmax/cm−1 3931 (vw), 3652 (w), 3483 (w), 1979 (vs), 1307
(w), 1300 (w), 1271 (s), 1230 (vw), 1192 (s), 1164 (s), 1156 (vs),
1131 (w), 1112 (w), 1099 (m), 1058 (m), 1040 (s), 1022 (m), 1007
(m), 918 (vw), 898 (w), 887 (w), 860 (vw), 847 (m), 828 (w), 816
(w), 751 (m), 742 (m), 698 (m), 694 (m), 660 (m), 637 (s), 583
(m), 542 (m), 508 (m), 489 (m), 470 (m), 444 (w). ESI+ MS: m/z
861.15 ([M + H]+). Anal. Calcd for C41H51FeO4P2RhS (860.60): C
57.22, H 5.97%. Found: C 57.35, H 6.04%.
1H NMR (400 MHz, acetone-d6): δ 1.29 (s, 2 H, nbd), 1.31 (br s,
2 H, nbd), 3.87 (br s, 2 H, nbd), 4.08 (vt, J′ = 1.9 Hz, 2 H, fc), 4.31
(vt, J′ = 1.9 Hz, 2 H, fc), 4.75 (d vt, J′ = 1.9, J = 0.7 Hz, 2 H, fc), 4.85
(br vq, J′ = 1.9 Hz, 2 H, fc), 7.43−7.54 (m, 10 H, PPh2). An
additional resonance due to the nbd ligand (2 H) is obscured by the
water signal. 31P{1H} NMR (162 MHz, acetone-d6): δ 27.4 (d, 1JRhP
=
176 Hz). Poor solubility prevented recording 13C NMR and MS
spectra. IR (Nujol): νmax/cm−1 1713 (s), 1310 (m), 1261 (s), 1195
(m), 1147 (vs), 1098 (m), 1058 (w), 1028 (m), 1002 (s), 948 (vw),
889 (vw), 847 (w), 831 (w), 800 (vw), 753 (m), 743 (m), 723 (m),
695 (m), 652 (m), 641 (s), 584 (vw), 539 (m), 522 (m), 492 (s), 473
(m), 455 (w), 445 (w). Anal. Calcd for C29H26FeN2O3PRhS·0.5H2O
(653.31): C 53.31, H 4.17%. Found: C 53.49, H 4.28%.
Synthesis of 1c. Starting with [Rh(acac)(CO)(PFur3)] (92.3 mg,
0.2 mmol) and HL (90.0 mg, 0.2 mmol), the procedure described
above for 1a afforded complex 1c as a yellow solid. Yield: 128.4 mg
(79%).
1H NMR (400 MHz, acetone-d6): δ 4.13 (vt, J′ = 2.0 Hz, 2 H, fc),
4.34 (vt, J′ = 2.0 Hz, 2 H, fc), 4.79 (d vt, J′ = 1.9, J = 0.8 Hz, 2 H, fc),
4.85 (br vq, J′ = 1.9 Hz, 2 H, fc), 6.62 (vp, J′ = 1.7 Hz, 3 H, PFur3),
7.36 (br ddd, J = 3.2, 2.1, 0.7 Hz, 3 H, PFur3), 7.49−7.58 (m, 6 H,
PPh2), 7.71−7.76 (m, 4 H, PPh2), 7.92 (br dvt, J = 0.7 Hz, J′ = 1.6
Hz, 3 H, PFur3). 31P{1H} NMR (162 MHz, acetone-d6): δ −27.1 (dd,
Synthesis of 3. [Rh(μ-Cl)(CO)2]2 (38.8 mg, 0.1 mmol) and
(Et3NH)L (220.2 mg, 0.4 mmol) were dissolved in dry acetone (5
mL), and the resulting red solution was stirred for 3 h, depositing the
product as an orange precipitate. The precipitation was completed by
storing the reaction mixture at −20 °C overnight. The separated solid
was filtered off, washed with acetone, and dried under a vacuum to
give an amorphous solid (240 mg). This solid was redissolved in
methanol (3 mL), and the solution was layered with methanol−
methyl t-butyl ether (2 mL of 1:1 mixture) and then with pure methyl
t-butyl ether (20 mL). The orange crystals which formed within 2
weeks were filtered off, washed with methyl t-butyl ether, and dried
under a vacuum to give pure 3. Yield: 220.2 mg (87%).
1
2
1
2JPP = 368, JRhP = 132 Hz, PFur3), 22.4 (dd, JPP = 368, JRhP = 135
Hz, fcPPh2). IR (Nujol): νmax/cm−1 3136 (w), 2016 (vs), 1711 (vw),
1552 (vw), 1306 (vw), 1274 (s), 1214 (w), 1196 (m), 1166 (m),
1147 (s), 1130 (w), 1101 (w), 1059 (vw), 1034 (m), 1027 (m), 1015
(w), 1008 (m), 999 (m), 908 (w), 883 (vw), 844 (vw), 830 (w), 754
(m), 744 (m), 696 (m), 643 (s), 591 (w), 581 (m), 542 (m), 531
(m), 510 (m), 500 (m), 480 (m), 471 (m), 446 (w). ESI+ MS: m/z
812.94 ([M + H]+). Anal. Calcd for C35H27FeO7P2RhS (812.35): C
51.75, H 3.35%. Found: C 51.49, H 3.47%.
1H NMR (400 MHz, CDCl3): δ 1.32 (t, 3JHH = 7.3 Hz, 9 H, NEt3),
3.10 (q, 3JHH = 7.3 Hz, 6 H, NEt3), 4.58 (vt, J′ = 1.9 Hz, 2 H, fc), 4.60
(br s, 2 H, fc), 4.67 (vt, J′ = 1.9 Hz, 2 H, fc), 4.74 (br vt, J′ = 1.9 Hz, 2
H, fc), 7.32−7.43 (m, 6 H, PPh2), 7.63−7.69 (m, 4 H, PPh2), 10.48
(br s, 1 H, HNEt3). 31P{1H} NMR (162 MHz, CDCl3): δ 21.7 (d,
1JRhP = 127 Hz). 13C{1H} NMR (101 MHz, CDCl3): δ 8.66 (s, CH3
of NEt3), 46.06 (s, CH2 of NEt3), 68.84 (s, CH of fc), 72.24 (s, CH of
fc), 75.15 (vt, JPC = 3 Hz, CH of fc), 75.25 (vt, JPC = 26 Hz, C−P of
fc), 75.87 (vt, JPC = 5 Hz, CH of fc), 94.52 (s, C−SO3), 127.82 (vt,
3JPC = 5 Hz, CHmeta of PPh2), 129.83 (s, CHpara of PPh2), 133.93 (vt,
2JPC = 6 Hz, CHortho of PPh2), 134.77 (vt, 1JPC = 23 Hz, Cipso of PPh2),
187.31 (dt, 1JRhC = 74 Hz, 2JPC = 16 Hz, CO). IR (Nujol): νmax/cm−1
2687 (br m), 2525 (m), 1960 (vs), 1307 (w), 1242 (vs), 1181 (m),
1162 (s), 1151 (s), 1095 (m), 1064 (w), 1036 (vs), 1007 (m), 893
(vw), 836 (m), 810 (vw), 756 (w), 748 (m), 698 (m), 656 (s), 651
(s), 629 (w), 576 (w), 564 (w), 540 (w), 533 (w), 504 (vs), 471 (m),
460 (w), 440 (w). ESI+ MS: m/z 1030.92 ([M − 2NEt3 − Cl]+),
1052.91 ([M − 2NEt3 − HCl + Na]+), 1074.89 ([M − 2HNEt3 − Cl
+ 2Na]+); ESI− MS: m/z 448.99 ([Ph2PfcSO3]−). Anal. Calcd for
C57H68ClFe2N2O7P2RhS2 (1269.29): C 53.94, H 5.40, N 2.21%.
Found: C 53.82, H 5.36, N 1.87%.
Synthesis of 1d. A solution of trimethyl phosphite (24.8 mg, 0.2
mmol) in acetone (0.5 mL + 1 mL for washing the vial) was added to
a suspension of [Rh(acac)(CO)2] (51.6 mg, 0.2 mmol) in the same
solvent (0.5 mL), whereupon the solid educt dissolved to give an
orange solution. This was added to an acetone suspension of HL
(90.0 mg, 0.2 mmol), and the resulting mixture was briefly sonicated
and then stirred at ambient temperature for 30 min. Then, the cloudy
reaction mixture was added to vigorously stirred, cold pentane (4 °C,
20 mL) using 1 mL of acetone to wash the reaction flask. The
suspension was aged at 4 °C for 3 h and then filtered. The precipitate
was washed pentane and dried under a vacuum to give 1d as a yellow
solid. Yield: 109.4 mg (78%).
2
1H NMR (400 MHz, acetone-d6): δ 3.94 (d, JPH = 12.3 Hz, 9 H,
OMe), 4.12 (vt, J′ = 1.9 Hz, 2 H, fc), 4.34 (vt, J′ = 1.9 Hz, 2 H, fc),
4.75−4.78 (m, 4 H, fc), 7.48−7.57 (m, 6 H, PPh2), 7.62−7.68 (m, 4
2
H, PPh2). 31P{1H} NMR (162 MHz, acetone-d6): δ 18.9 (dd, JPP
=
1
2
1
511, JRhP = 119 Hz, fcPPh2), 127.3 (dd, JPP = 511, JRhP = 210 Hz,
P(OMe)3). 13C{1H} NMR (101 MHz, acetone-d6): δ 53.14 (d, 1JPC
=
1 Hz, OMe), 70.61 (s, CH of fc), 70.75 (s, CH of fc), 73.40 (dd, 1JPC
3
Synthesis of 4·1/2H2O. Acetone (5 mL) was added to a solid
mixture of [Rh(acac)(CO)2] (51.6 mg, 0.2 mmol) and (Et3NH)L
(220.6 mg, 0.4 mmol), and the resulting mixture was stirred at room
temperature for 3 h. The solid educts rapidly dissolved with
effervescence (CO evolution) and formed a clear orange solution.
This solution was added dropwise to rapidly stirred hexane (30 mL),
and the mixture was left standing at 4 °C for 30 min. Then, the
precipitated product was filtered off, washed with hexane and pentane,
and dried under a vacuum to give 4·0.5H2O as a yellow hygroscopic
solid. Yield: 211.0 mg (92%). Crystals of dihydrate 4·2H2O were
obtained when the reaction mixture was crystallized by successive
layering with acetone−hexane (1:1) and hexane and by slow
crystallization, whereupon the initially formed oily product slowly
converted into aggregates of fine yellow needles.
= 46 Hz, JPC = 4 Hz, C−P of fc), 74.29 (d, JPC = 8 Hz, CH of fc),
78.07 (dd, JPC = 13, 2 Hz, CH of fc), 94.33 (s, C−SO3), 129.44 (d,
3JPC = 10 Hz, CHm2eta of PPh2), 131.60 (d, JPC = 2 Hz, CHpara of
4
PPh2), 134.28 (dd, JPC = 12, 2 Hz, CHortho of PPh2), 135.05 (ddd,
1JPC = 46 Hz, J = 3, 2 Hz, Cipso of PPh2). The compound is poorly
soluble, which makes the weak signal due to coordinated CO
unobservable. IR (Nujol): νmax/cm−1 2001 (vs), 1712 (m), 1307 (w),
1275 (s), 1195 (s), 1170 (m), 1150 (s), 1101 (m), 1057 (m), 1018
(s), 894 (vw), 832 (w), 809 (m), 757 (m), 702 (m), 697 (m), 657
(w), 641 (m), 580 (m), 541 (m), 518 (m), 505 (m), 494 (m), 484
(m), 472 (m), 442 (w). Anal. Calcd for C26H27FeO7P2RhS (704.25):
C 44.34, H 3.86%. Found: C 44.52, H 3.89%.
Synthesis of 2. [Rh(acac)(nbd)] (58.8 mg, 0.2 mmol) and HL
(90.1 mg, 0.2 mmol) were mixed in dry acetone (4 mL) under brief
sonication. The reaction mixture was stirred for 30 min, during which
time the starting materials dissolved and the product partly separated
as a yellow solid. The reaction mixture was poured into cold pentane
(4 °C, 20 mL) using 1 mL of acetone to wash the reaction flask. The
mixture was aged at 4 °C for 3 h and then filtered. The solid product
was washed with pentane and dried under a vacuum to give 2·1/2H2O
as a yellow solid. Yield: 110.6 mg, 86%. The mother liquor was
evaporated, and the residue crystallized from acetone−hexane (liquid-
phase diffusion), giving crystals of nonsolvated 2 suitable for structure
determination.
3
1H NMR (400 MHz, acetone-d6): δ 1.33 (t, JHH = 7.2 Hz, 9 H,
NEt3), 3.21 (q, 3JHH = 7.2 Hz, 6 H, NEt3), 4.44 (vt, J′ = 1.9 Hz, 2 H,
fc), 4.51 (vt, J′ = 1.9 Hz, 2 H, fc), 4.63 (br s, 2 H, fc), 4.75 (vt, J′ = 1.9
Hz, 2 H, fc), 7.45−7.52 (m, 6 H, PPh2), 7.73−7.79 (m, 4 H, PPh2).
The signal due to Et3NH coincides with the water resonance. 31P{1H}
1
NMR (162 MHz, acetone-d6): δ 21.3 (d, JRhP = 128 Hz). 13C{1H}
NMR (101 MHz, acetone-d6): δ 9.06 (s, CH3 of NEt3), 46.88 (s, CH2
of NEt3), 70.27 (s, CH of fc), 71.24 (s, CH of fc), 74.18 (vt, JPC = 25
Hz, C−P of fc), 75.35 (vt, JPC = 4 Hz, CH of fc), 76.77 (vt, JPC = 6
Hz, CH of fc), 96.40 (s, C−SO3), 129.13 (vt, 3JPC = 5 Hz, CHmeta of
G
Organometallics XXXX, XXX, XXX−XXX