spectrometer. All reactions were carried out in Schlenk tubes
under atmospheres of dry oxygen-free nitrogen, using freshly
distilled and degassed solvents. Column chromatography was
performed using BDH alumina, Brockman activity II as solid
support.
(Found: C, 57.0; H, 6.2. C33H26BrRe requires C, 57.5; H, 6.6%).
1
NMR (CD2Cl2): H, δ 7.24–7.16 (m, 20 H, Ph), 5.17 (s, 5 H,
C5H5) and Ϫ12.15 (s, 1 H, ReH); 13C-{1H}, δ 133.6, 131.4,
128.1, 127.7 (Ph), 89.9 (C5H5) and 67.1 (CPh). FAB mass
spectrum: m/z 688 (Mϩ) and 608 ([M Ϫ Br]ϩ).
Preparations
Reaction of complex 2 with lithium triethylhydroborate. A
solution of Li[BHEt3] (160 µl, 1 solution in thf, 0.16 mmol)
was added with stirring to a cooled (Ϫ78 ЊC) solution of com-
plex 2 (0.16 g, 0.15 mmol) in thf (20 cm3). On warming to room
temperature the solution changed from orange to black. After
2 h the reaction mixture was filtered through a plug of silica
gel. The volatiles were removed in vacuo and the orange residue
crystallised (Ϫ10 ЊC) from thf–diethyl ether (1:1) to afford a
mixture (20:1) of 5 and [ReH(PPh3)(η4-C4Ph4)(η-C5H5)]Br 6
[ReBr2(ç4-C4Ph4)(ç-C5H5)] 1. A solution of a mixture of cis-
and trans-[ReBr2(CO)2(η-C5H5)]27 (2.00 g, 4.28 mmol) and an
excess of diphenylacetylene (7.63 g, 42.8 mmol) in toluene (100
cm3) was heated under reflux for 24 h. The reaction mixture was
allowed to cool and the volatile material removed in vacuo. The
residue was dissolved in the minimum volume of dichloro-
methane and chromatographed on alumina (30 × 3 cm
column). Elution with hexane gave a trace of unchanged start-
ing materials, and further elution with CH2Cl2–hexane (1:5)
gave a single red band. This was collected and recrystallised
from CH2Cl2–hexane to give deep red air stable crystals of
complex 1 (2.23 g, 68%) (Found: C, 51.5; H, 3.3. C33H25Br2Re
requires C, 51.6; H, 3.3%). NMR (CD2Cl2): 1H, δ 7.75–6.35 (m,
20 H, Ph) and 5.68 (s, 5 H, C5H5); 13C-{1H}, δ 136.0–122.0
(C6H5) and 96.1 (C5H5).
1
(0.06 g, 40%). NMR (CD2Cl2): H, δ 7.48–7.14 (m, 35 H, Ph),
5.19 (s, 5 H, C5H5, major), 5.07 [d, 5 H, C5H5, minor J(HP) 1.4],
Ϫ11.81 [d, 1 H, ReH, minor, J(HP) 25.2 Hz] and Ϫ12.14 (s, 1 H,
ReH, major); 13C-{1H}, δ 134.1–127.7 (Ph) and 89.9 (C5H5,
major); 31P-{1H}, δ 27.3 (s, PPh3, minor).
Reaction of complex 4 with trifluoroacetic acid. An excess of
CF3CO2H (84 µl, 1.09 mmol) was added at Ϫ78 ЊC to a yellow
solution of complex 4 (0.22 g, 0.36 mmol) in CH2Cl2 (20 cm3).
After 12 h at room temperature the volatiles were removed in
vacuo and the resulting dark orange solid was chromatographed
on alumina. Elution with CH2Cl2 gave a single orange band,
which was collected and recrystallised (0 ЊC) from toluene–
hexane to give orange crystals of [ReH{OC(O)CF3}{η4-
[ReBr(PPh3)(ç4-C4Ph4)(ç-C5H5)][BF4] 2. Addition of tri-
phenylphosphine (0.36 g, 1.38 mmol) and silver tetrafluoro-
borate (0.35 g, 1.8 mmol) to a stirred (room temperature)
solution of complex 1 (1.05 g, 1.38 mmol) in dichloromethane
(20 cm3) resulted in the rapid formation of a precipitate of
AgBr. After 12 h the reaction mixture was filtered through
Celite and the solvent removed in vacuo. Recrystallisation of
the solid residue from CH2Cl2–Et2O afforded orange crystals of
2 (0.62 g, 70%) (Found: C, 59.2; H, 4.0. C51H40BBrF4PRe
requires C. 59.1; H, 3.9%). NMR (CD2Cl2): 1H, δ 7.55–6.25 (m,
35 H, Ph) and 5.89 (s, 5 H, C5H5); 13C-{1H}, δ 133.9–125.8 (Ph)
and 96.0 (C5H5); 19F, δ Ϫ154.0 (s, BF4Ϫ); 31P-{1H}, δ 15.0 (s,
PPh3).
PhCH᎐C(Ph)C(Ph)᎐C(Ph)H}(η-C H )] 7 (0.22 g, 85%) (Found:
᎐
᎐
5
5
C, 58.2; H, 4.0. C35H28F3O2Re requires C, 58.1; H 3.9%). NMR
1
(CD2Cl2): H, δ 8.42–6.74 (m, 20 H, Ph), 4.52 (s, 5 H, C5H5),
4.04 [d, 1 H, Hc, J(HcHa) 3.0], 3.40 [d, 1 H, Hb, J(HaHb) 5.6] and
Ϫ7.87 [dd, 1 H, ReHa, J(HaHc) 3.0, J(HaHb) 5.6]; 13C-{1H}, δ
165.0 [q, CCF3, J(CF) 36], 143.1–126.5 (Ph), 113.1 (C2 or C3),
112.3 [q, CF3, J(CF) 291 Hz], 88.7 (C5H5), 61.5 (CH, C4 or C1)
and 57.8 (CH, C1 or C4); 19F, δ Ϫ74.9 (CF3). FAB mass spec-
trum: m/z 723 (Mϩ) and 610 (M Ϫ CF3Cl2]ϩ).
[ReBr(PMe3)(ç4-C4Ph4)(ç-C5H5)][BF4] 3. A similar reaction
between complex 1 (0.14 g, 0.184 mmol), PMe3 (0.014 g, 0.184
mmol) and silver tetrafluoroborate (0.036 g, 0.184 mmol) in
dichloromethane (20 cm3) gave orange crystals of 3 (0.06 g,
35%) (Found: C, 50.3; H, 3.4. C36H34BBrF4PRe requires C,
50.8; H, 4.0%). NMR (CD2Cl2): 1H, δ 7.60–7.00 (m, 20 H, Ph),
5.69 [d, 5 H, C5H5, J(HP) 1.0] and 1.11 [d, 9 H, PMe, J(HP)
14.0]; 13C-{1H}, δ 133.0–122.5 (Ph), 94.4 (C5H5) and 16.5 [d,
PMe, J(CP) 39.0 Hz]; 31P-{1H}, δ 55.3 (s, PMe3).
[Re{᎐C(Ph)-ç3-C(Me)CHCHC H PPh -o}(ç-C H )][BF ] 8.
᎐
6
4
2
5
5
4
Silver tetrafluoroborate (0.21 g, 1.1 mmol) was added to a solu-
tion (thf, 20 cm3) of o-diphenylphosphinostyrene (0.16 g, 0.55
mmol) and [ReBr2{η2(4e)-MeC2Ph}(η-C5H5)] (0.294 g, 0.54
mmol). After stirring at room temperature for 4 h, the solvent
was removed in vacuo and the product extracted into CH2Cl2
and filtered through Celite. Removal of the solvent followed by
recrystallisation from CH2Cl2–Et2O gave green crystals of
complex 8 (0.36 g, 93%) (Found: C, 55.1; H, 3.8. C34H29BF4PRe
requires C, 55.1; H, 3.9%). NMR (CD2Cl2): 1H, δ 7.65–6.46 (m,
19 H, Ph), 6.59–6.55 [AB spectrum, 2 H, Ha and Hb, J(HaHb)
8.0], 5.46 [d, 5 H, C5H5, J(HP) 1.65] and 2.17 (s, 3 H, Me);
[ReH2(ç4-C4Ph4)(ç-C5H5)] 4. Addition (Ϫ78 ЊC) of an excess
of lithium aluminium hydride (4.20 cm3 of a 1 solution in
tetrahydrofuran) to a stirred solution of complex 1 (1.23 g, 1.61
mmol) in thf (20 cm3) resulted in a change from red to yellow on
warming to room temperature. The volatiles were removed in
vacuo and the yellow residue chromatographed. Elution with
thf afforded a yellow band, which on recrystallisation (Ϫ20 ЊC)
from CH2Cl2–hexane gave yellow crystals of 4 (0.79 g, 80%)
(Found: C, 64.9; H, 4.4. C33H27Re requires C, 65.0; H, 4.5%).
13C-{1H}, δ 257.7 [d, Re᎐C, J(CP) 16.3 Hz], 152.0–126.7 (Ph),
᎐
88.1 (C5H5), 78.3 (C3 or C4), 69.2 (C2), 57.3 (C3 or C4) and 17.0
(Me); 31P-{1H}, δ 41.0. FAB mass spectrum: m/z 655 (Mϩ).
[Re{᎐C(Ph)-ç3-C(Ph)CHCHC H PPh -o}(ç-C H )][BF ] 9.
᎐
6
4
2
5
5
4
Similarly, reaction of [ReBr2{η2(4e)-PhC2Ph}(η-C5H5)] (0.25 g,
0.42 mmol) with dpps (0.127 g, 0.4 mmol) and AgBF4 (0.166 g,
0.85 mmol) in thf (20 cm3) gave a green product, which on
recrystallisation (CH2Cl2–Et2O) afforded green crystals of 9
(0.30 g, 90%) (Found: C, 58.3; H, 3.9. C39H31BF4PRe requires
1
NMR (CD2Cl2): H, δ 7.36–7.14 (m, 20 H, Ph), 4.85 (s, 5 H,
C5H5), Ϫ13.07 (s, 2 H, ReH); 13C-{1H}, δ 136.6, 130.6, 128.0,
126.4 (Ph), 89.3 (C5H5) and 66.9 (CPh).
1
[ReH(Br)(ç4-C4Ph4)(ç-C5H5)] 5. Dropwise addition (Ϫ78 ЊC)
of Li[AlH4] in thf (1.6 cm3 of a 1 solution in thf) to a stirred
solution of complex 1 (1.23 g, 1.61 mmol) in thf (20 cm3)
resulted in a change in colour on warming to room temperature.
The volatiles were removed in vacuo and the residue chromato-
graphed. Elution with pentane gave a trace of the yellow com-
plex 4. Further elution with CH2Cl2–pentane (1:5) gave an
orange band which was collected and recrystallised (Ϫ10 ЊC)
from CH2Cl2–pentane to give orange crystals of 5 (0.22 g, 20%)
C, 58.3; H, 3.9%). NMR (CD2Cl2): H, δ 7.70–6.51 (m, 24 H,
Ph), 6.81–6.69 [AB spectrum, 2 H, Ha and Hb, J(HaHb) 8.3] and
5.42 [d, 5 H, C5H5, J(HP) 1.65]; 13C-{1H}, δ 252.9 [d, Re᎐C,
᎐
J(CP) 14.9 Hz], 151.5, 125.8 (Ph), 89.3 (C5H5), 73.5 (C3 or C4),
71.3 (C2) and 57.7 (C3 or C4); 31P-{1H}, δ 39.9. FAB mass
spectrum: m/z 717 (Mϩ).
Reaction of complex 9 with K[BHBus3]. A solution of K[BH-
Bus3] (0.38 cm3, 1 thf solution, 0.38 mmol) was added
J. Chem. Soc., Dalton Trans., 1997, Pages 3671–3682
3679
Dossett, Stephen J.
