3552 Organometallics, Vol. 17, No. 16, 1998
Duffey et al.
Ta ble 3. X-r a y P a r a m eter s for
cis-Mo(CO)4{1,2-(P h 2P (CH2CH2O)2)2C6H4-P ,P ′}, 7
NMR (chloroform-d), δ: 6.91 (phenylene, broad singlet, 4); 4.40
(methylene, multiplet, 4); 4.14 (methylene, multiplet, 4); 3.87
(two methylenes, multiplets, 8); 3.06 (methyl, sharp singlet,
6).
empirical formula
cryst size
C42H40MoO8P2
0.30 × 0.30 × 0.10 mm
cryst syst,
monoclinic, P21/c
(ii) P r ep a r a tion of 1,2-(P h 2P (CH2CH2O)2)2C6H4 (6). A
solution of 50 mL of THF and 9.3 g (0.021 mol) of 1,2-(MsO-
(CH2CH2O)2)2C6H4 in a 200 mL Schlenk flask was cooled to
-78 °C in dry ice/acetone and then titrated to a persistent rose
color with a 0.5 M solution of potassium diphenylphosphide
in THF. After the addition was completed, the reaction
mixture was stirred for 2 h and then allowed to warm to room
temperature. Water (15 mL) was then added to neutralize the
residual potassium diphenylphosphide, causing the solution
to turn yellow. The solution was evaporated to dryness using
a rotary evaporator, and the residue was extracted with four
50-mL portions of dichloromethane. The extracts were com-
bined and evaporated to dryness first on a rotary evaporator
and then under high vacuum to yield 10.6 g (81.0%) of the
product as a clear, pale yellow oil. The ligand was character-
ized by its 1H NMR spectrum and its successful use in the
synthesis of the metallacrown ether complexes. 1H NMR
(chloroform-d), δ: 7.40 (phenyl, multiplet, 20); 7.27 (phenylene,
singlet, 4); 4.07 (methylene, multiplet, 4); 3.71 (methylene,
multiplet, 4); 3.64 (methylene, multiplet, 4); 2.39 (methylene,
multiplet, 4).
space group
unit cell dimens
a ) 18.7844(33), b ) 18.0198(33),
c ) 23.6283(24) Å;
â ) 90.086(13)°
77998(4) Å3
V
Z
fw
8
830.6
d (calcd)
abs coeff
F(000)
1.380 Mg/m3
0.459 mm-1
3424
298 K
T
monochromator
index ranges
highly oriented graphite crystal
-24 < h < 24, -23 < k < 0,
-30 < l < 0
no. of reflns collected
no. of indep reflns
obsd reflns
18 789
18 340 (Rint ) 2.92%)
6911 (F g 6.0σ(F)), 8173
(F g 3.0 σ(F))
semiempirical
0.7027/0.8014
abs cor
min/max transm
system used
solution/refinement
method
quantity minimized
hydrogen atoms
weighting scheme
no. of params refined
final R indices
(6σ data/3σ data)
Siemens SHELXTL PLUS (PC version)
Patterson methods/full-matrix
least-squares
cis-Mo(CO)4{1,2-(P h 2P (CH2CH2O)2)2C6H4-P ,P ′} (7). So-
lutions of 0.579 g (1.93 mmol) of cis-Mo(CO)4(nbd) in 200 mL
of dichloromethane and of 1.20 g (1.93 mmol) of 6 in 200 mL
of dichloromethane were added simultaneously and dropwise
to 500 mL of dichloromethane over a period of 3 h. This
mixture was stirred for 18 h, and then its volume was reduced
to 50 mL by rotary evaporation. The dark brown concentrate
was filtered through 10 g of silica gel, and the light golden
filtrate was evaporated to dryness on a rotary evaporator. This
gave 1.27 g (78.6% yield) of the product as an off-white solid.
Analytically pure product was obtained by preparative chro-
matography on silica gel plates using a 2:5 ethyl acetate:
hexanes solvent system. Anal. Calcd for C42H40O8MoP2‚
H2O: C, 59.06; H, 4.78. Found: C, 59.44; H, 4.95. IR
(chloroform solution): ν(CO) 2021 (m), 1922 (s, br), 1904 (s,
∑w(Fo - Fc)2
riding model, fixed isotropic U
w-1 ) σ2(F) + 0.0021F2
956
R ) 6.01%, Rw
)
6.45%/R ) 7.01%,
Rw ) 8.70%
goodness-of-fit
largest and mean ∆/σ 0.001, 0.000
largest diff peak/hole
1.01
0.71/-0.54 e Å-3
cis and trans peaks was used as a direct indication of the
degree of isomerization. Several additional 31P NMR spectra
were taken at longer times after mixing, but no further change
in the ratio of the isomers was observed.
cis,cis,tr a n s-R u Cl2(CO)2{1,2-(P h 2P (CH 2CH 2O)2)2C6H 4-
P ,P ′} (9). Solutions of 0.164 g (0.498 mmol) of fac-RuCl2(CO)3-
(THF) in 200 mL of dichloromethane and of 0.310 g (0.248
mmol) of 6 in 200 mL of dichloromethane were added simul-
taneously and dropwise to 500 mL of dichloromethane over a
period of 2 h. This reaction mixture was stirred for 18 h, and
then the yellow solution was evaporated to dryness to yield
0.43 g (100% yield) of 9 as a pale yellow solid. Anal. Calcd
for C42H40O6Cl2RuP2: C, 56.60; H, 4.82. Found: C, 56.48; H,
br), 1880 (s, br) cm-1
.
tr a n s-Mo(CO)4{1,2-(P h 2P (CH2CH2O)2)2C6H4-P ,P ′} (8). (i)
P r ep a r a tion Usin g UV Ir r a d ia tion . A solution of 0.14 g
(1.1 mmol) of 7 in 150 mL of THF was irradiated in an Ace
concentric photochemical reactor with a 350-W mercury vapor
lamp for 5 min. During this time, water was circulated in a
jacket located between the lamp and solution chambers to cool
the solution. The murky, dark golden reaction mixture was
then evaporated to dryness. The residue was dissolved in
dichloromethane, and this solution was filtered through silica
gel. The filtrate was reduced in volume to 10 mL using a
rotary evaporator and then streaked onto a preparative TLC
plate. A 2:5 ethyl acetate:hexanes solvent system was used
to develop the plate. Bands for both 7 and 8 were observed
and were scraped off the plate. The metallacrown ethers were
eluted from the silica gel with methanol, and the methanol
solutions were evaporated to dryness on a rotary evaporator.
The solid residues were dried for 2 h under high vacuum to
yield 0.011 g (8% recovery) of 7 and 0.005 g (4%) of 8 as an
off-white solid. Anal. Calcd for C42H40O8MoP2‚H2O: C, 59.06;
H, 4.78. Found: C, 59.12; H, 4.88.
(ii) 31P NMR Stu d y of th e Isom er iza tion of 7 to 8
Ca ta lyzed by HgCl2. A solution of 0.090 g (0.11 mmol) of 7
in 0.51 mL of chloroform-d was prepared in a 5 mm screw-top
NMR tube. The headspace of the tube was flushed with
nitrogen, and then the tube was carefully sealed with a septum
cap. Both 13C and 31P NMR spectra of this solution were
recorded. Then 6.7 µL (0.11 µmol) of an aqueous 45 mg/mL
solution of HgCl2 was injected under the surface of the
chloroform-d solution. After vigorous shaking, a quantitative
31P NMR spectrum was acquired, and the integration of the
4.74. IR (chloroform): ν(CO) 2058 (s), 1994 (s) cm-1
.
X-Ra y Str u ctu r a l An a lysis for cis-Mo(CO)4{1,2-(P h 2P -
(CH2CH2O)2)2C6H4-P ,P ′}. A crystal with dimensions 0.35 ×
0.30 × 0.10 mm was mounted upon a glass fiber under aerobic
conditions. It was then mounted and aligned upon an Enraf-
Nonius CAD4 single-crystal diffractometer. Details of the data
collection are collected in Table 3.
The unit cell parameters suggest that the crystal belongs
to the orthorhombic crystal system (a * b * c, R ) â ) γ )
90°), but upon examination of equivalent reflections, it is clear
that the crystal belongs to the monoclinic crystal system
(+h,+k,+l ) +h,-k,+l ) -h,-k,-l ) -h,+k,-l * -h,+k,+l
) +h,-k,-l ) -h,-k,+l ) +h,+k,-l). This was confirmed
by analyzing the merging statistics (monoclinic Rint ) 2.92%
vs orthorhombic Rint ) 54.9%). Upon correct assignment of
the crystal system, the space group was determined unequivo-
cally by the systematic absences, h0l for l ) 2n + 1 and 0k0
for k ) 2n + 1, to be the centrosymmetric space group P21/c.
All crystallographic calculations were accomplished with the
Siemens SHELXTL-PC program package.13 The analytical
(13) Siemens SHELXTL-PC Manual, Release 4.1; Siemens Analyti-
cal Instruments: Madison, WI, 1990.
Duffey, Christina H.
