Heterofunctionalized phosphines derived from (2-formylphenyl)diphenylphosphine and their reactions with oxorhenium(V) complexes

Article abstract of DOI:10.1016/j.poly.2009.01.016

Reactions of [ReOCl₃(PPh₃)₂] with a potentially tridentate Schiff base derived from (2-formylphenyl)diphenylphosphine and 2-aminophenol, HL¹P, (HL¹P = Ph₂PC₆H₄-2-HC{do

Full text of DOI:10.1016/j.poly.2009.01.016

Polyhedron 28 (2009) 1155–1159
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Polyhedron
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Heterofunctionalized phosphines derived from (2-formylphenyl)diphenylphosphine
and their reactions with oxorhenium(V) complexes
*
Ali Barandov, Ulrich Abram
Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstr. 34-36, D-14195 Berlin, Germany
a r t i c l e i n f o
a b s t r a c t
Article history:
Reactions of [ReOCl3(PPh3)2] with a potentially tridentate Schiff base derived from (2-formylphe-
nyl)diphenylphosphine and 2-aminophenol, HL1P, (HL1P = Ph2PC6H4-2-HC@N(C6H4-2-OH)) result in a
rapid decomposition of the Schiff base and the formation of a large number of hitherto non-identified
metal-containing species, while from similar reactions with the analogoue phosphine oxide HL1PO,
(HL1PO = Ph2P(O)C6H4-2-HC@N(C6H4-2-OH)) products of the compositions [ReOCl2(PPh3)(L1PO)] (1)
and [Re(NC6H4-2-OH)Cl3(PPh3)2] (2) could be isolated. The structure of 2 is an experimental proof of
the preceding, metal-induced cleavage of the C–N double bond. A subsequent reaction of the released
2-aminophenol forms the final phenylimido ligand.
Received 3 January 2009
Accepted 21 January 2009
Available online 13 March 2009
Keywords:
Rhenium
Oxo complexes
Schiff base
Imido complexes
X-ray structure
Reduction of HL1P with NaBH4 gives the phosphine amine H2L2P (H2L2 = Ph2P(C6H4-2-CH2NH(C6H4-2-
OH))) in good yield. Reactions of H2L2P with common oxorhenium(V) complexes result in the formation
of the stable rhenium(V) complex [ReOCl2(HL2P)] (3) with a facially coordinated HL2PÀ ligand.
Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction
under certain conditions in vivo might be desired in order to con-
trol its biological distribution and organ clearance patterns. Thus,
Schiff bases are ligands which play an important role in the
coordination chemistry of many transition metals due to the ease
of their formation and versatility [1]. Metal complexes of Schiff
bases found use in bioinorganic chemistry as models for metal-
containing sites in metalloproteins, as catalysts for some organic
reactions, or in magneto chemistry [2–6]. They can readily be syn-
thesized by condensation of primary amines with carbonyl compo-
nents, and this general approach allows access to ligand systems of
various denticity. The introduction of additional donor atoms in-
creases the stability of the formed metal complexes and gives the
possibility to combine different ‘hard’ and ‘soft’ donor atoms in
one chelating system, which allows the formation of stable com-
plexes with various metal ions [1].
Rhenium and technetium complexes with such ligands are
well-known [7,8], and particularly complexes with tri- and tetra-
dentate Schiff bases found attention in the development of new
technetium-based radiopharmaceuticals [9,10]. Despite these
well-documented applications, often side reactions, which are
mainly related with hydrolysis/solvolysis of the imine bonds, are
observed. They frequently decrease the yields and/or result in the
formation of unexpected (and undesired) side-products.
it is necessary to characterize the decomposition products and
their influence on the course of the complex formation.
Some metal-enhanced hydrolysis has been described for lantha-
nides [11], but relatively less is known about such reactions of rhe-
nium or technetium complexes. Typically, the electropositive
imine carbon atom is the target of a nucleophilic attack by solvent
molecules, and in some rare examples metal complexes with frag-
ments of the hydrolyzed Schiff base could be isolated and structur-
ally characterized, e.g. a Re(III) complex with chelate-bonded
dehydroacetate, which was formed from a tetradentate N2O2 Schiff
base [12], or a Re(I) tricarbonyl complex with tripodal coordination
of hydroxydi(2-pyridyl)methanolate, which resulted from hydroly-
sis of a complex with dipyridylketone benzoylhydrazone [13].
Here, we describe reactions of common oxorhenium(V) com-
plexes with two Schiff bases derived from (2-formylphe-
nyl)diphenylphosphine, HL1P and HL1PO, as well as with the
corresponding phosphine amine H2L2P.
O
PPh2
N
PPh2
PPh2
Besides these doubtlessly detrimental effects in synthetic
chemistry, controlled decomposition of a potential pharmaceutical
OH
N
OH
NH OH
HL1PO
HL1P
H2L2P
* Corresponding author. Tel.: +49 30 838 54002; fax: +49 30 838 52676.
E-mail address: abram@chemie.fu-berlin.de (U. Abram).
0277-5387/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2009.01.016

1156
A. Barandov, U. Abram / Polyhedron 28 (2009) 1155–1159
mically shifted in the spectrum of the complex and appears at
2. Results and discussion
1566 cmÀ1. Single crystals of the complex were studied by X-ray
diffraction. Fig. 1 shows an ellipsoid representation of 1. Selected
bond lengths and angles are summarized in Table 1. The coordina-
tion sphere of the complex is a distorted octahedron with the Schiff
base as a singly deprotonated O,N chelate ligand binding via the
imine nitrogen and the phenolic oxygen atoms. The oxygen atom
O2 is found in trans position to the oxo ligand. Such a coordination
mode is typical for chelating ligands systems with oxygen donor
atoms [7] and goes along with a considerable transfer of electron
density from the terminal Re@O bond into the relatively short
Re-O2 bond of 1.958(6) Å. The phosphine oxide unit does not con-
tribute to the coordination of the metal atom. This results in a
bulky complex molecule, which produces relatively large voids be-
tween the molecules, which is also expressed by the relatively low
density of the rhenium complex of 1.48 g/cm3. These holes are al-
most unoccupied. The highest peaks of electron density located
there count approximately 1 eÀ/Å3. A refinement with each one
water molecule which is disordered in over four positions in such
a void improves the R value only marginally and is not justified by
other experimental data.
The formation of the green phenylimido complex 2 is an unex-
pected feature of the reaction, but confirms the decomposition of
HL1PO during the reaction with [ReOCl3(PPh3)2]. The fact that the
amount of 2 formed increases with a prolonged reaction time, also
indicates a considerable instability of 1. The presence of the metal
complex is mandatory for the observed ligand decomposition, and
all our attempts to decomposed pure HL1PO in boiling THF failed.
The compound resisted such a treatment for 5 h without degrada-
tion as has been proven by 31P NMR and TLC experiments. The re-
leased 2-aminophenol finally reacts with the oxorhenium core
under formation of a phenylimido unit. It is interesting to note that
the isolated complex 2 contains two PPh3 ligands and, conse-
quently, the triphenylphosphine released from [ReOCl3(PPh3)2] is
not oxidized immediately by a secondary reaction with the oxo
HL1P was synthesized adopting a previously published proce-
dure [14]. Some modifications in the experimental conditions,
however, increased the yield significantly. The 31P NMR spectrum
of the yellow solid shows a resonance at À12.9 ppm. A doublet at
9.1 ppm (JPH = 4.88 Hz) in the 1H NMR spectrum suggests the pres-
ence of the HC@N unit. Oxidation of HL1P with H2O2 in THF results
in the formation of HL1PO in good yields. The 31P NMR signal of the
phosphorus atom in the phosphine oxide is found at 31.6 ppm,
which corresponds to a low-field shift of 44 ppm compared to
the value for HL1P. The aminophosphine H2L2 was prepared
by the reduction of HL1P with an excess of NaBH4 in boiling EtOH.
The course of the reaction can readily be tracked by 1H NMR, where
signal of the CH@N protons disappears and a doublet of the meth-
ylene protons appears at 4.4 ppm (JHH = 5.24 Hz).
HL1P reacts with oxorhenium(V) precursors such as [Re-
OCl3(PPh3)2] or (NBu4)[ReOCl4] by almost immediate changes of
the colors of the reaction mixtures. However, all our attempts to
isolate crystalline products from such mixtures failed. 31P NMR
studies of the reaction solutions showed several new signals at
negative and positive chemical shift values for each reaction. Num-
ber and positions of the signals were strongly dependent on the
solvent and the reaction time, which indicates an ongoing decom-
position of HL1P and/or oxidation of the phosphine under formal
reduction of the metal ion. The latter type of reaction is not with-
out precedent and has frequently been observed during the inter-
action of oxorhenium(V) compounds and phosphines, and can
principally simply be initiated by released PPh3 [7]. A detailed
analysis of such oxygen transfer reactions has been carried out
by Conry and Mayer [15].
In order to simplify the reaction and to minimize the risk of the
formation of Re(III) products by a reaction of HL1P with the oxo
oxygen and subsequent formation of HL1PO in the reaction mix-
ture, we used the phosphine oxide directly. While the course of
even this reaction with (NBu4)[ReOCl4] remained unclear, HL1PO
reacted within 1 h in boiling THF with the sparingly soluble [Re-
OCl3(PPh3)2] under formation of a clear green solution. The heating
was stopped after 2 h and two crystalline products, the red [Re-
OCl2(PPh3)(L1PO–O,N)] (1) and the green [Re(NC6H4OH)Cl3(PPh3)2]
(2) could be isolated in an approximate ratio of 1:2 (Scheme 1). The
amount of compound 2 can be increased by a prolonged reaction
time.
Cl2
C7
O2
Cl1
N1
C6
O1
Re
The 31P NMR spectrum of 1 exhibits two resonances at 26.8 and
O10
29.4 ppm indicating the presence of L1POÀ and coordinated PPh3.
P1
The
m
C@N band of the uncoordinated imine compound is bathochro-
P2
O
O
Re
Ph3P
Cl
Cl
PPh3
PPh2
N
OH
Cl
Fig. 1. Ellipsoid representation [21] of [ReOCl2(PPh3)(L1PO)]. Thermal ellipsoids
represent 50% probability. H atoms have been omitted for clarity.
Table 1
O
Selected bond lengths (Å) and angles (°) in the [ReOCl2(PPh3)(L1PO)] (1).
PPh2
O
Re
Cl
N
Cl
PPh3
OH
Cl
Re–O10
Re–Cl1
Re–Cl2
Re–N1
1.657(6)
2.346(2)
2.386(2)
2.192(7)
Re–O2
Re–P2
N1–C7
N1–C11
1.958(6)
2.469(2)
1.29(1)
1.44(1)
N
Re
Ph3P
Cl
O
PPh3
Cl
O10–Re–Cl1
O10–Re–Cl2
O10–Re–P2
O10–Re–N1
102.4(2)
103.8(3)
89.7(2)
87.9(3)
O10–Re–O2
N1–Re–O2
Re–N1–C7
161.2(3)
76.3(3)
130.0(6)
(1)
(2)
Scheme 1.

A. Barandov, U. Abram / Polyhedron 28 (2009) 1155–1159
1157
Ph
Ph
O
Cl
Cl
P
PPh2
Re
THF
[ReOCl3(PPh3)2]
N
NH OH
- HCl
H
O
C31
N10
O1
H1
(3)
Cl3
Scheme 2.
P2
P1
Re
Cl2
Cl1
O10
Cl1
Cl2
Fig. 2. Ellipsoid representation [21] of [Re(NC6H4OH)Cl3(PPh3)2]. Thermal ellipsoids
represent 50% probability. H atoms (except of H1) have been omitted for clarity.
Re
P
O1
H1
N1
Table 2
C7
Selected bond lengths (Å) and angles (°) in [Re(NC6H4OH)Cl3(PPh3)2].
C6
Re–N10
Re–Cl1
Re–Cl2
Re–Cl3
1.722(6)
2.403(2)
2.425(2)
2.406(2)
Re–P1
Re–P2
N10–C31
2.501(2)
2.490(2)
1.369(9)
C11
N10–Re–Cl1
N10–Re–Cl2
N10–Re–Cl3
N10–Re–P1
173.6(2)
91.3(2)
95.8(2)
93.6(2)
N10–Re–P2
P1–Re–P2
Cl2–Re–Cl3
Re–N10–C31
92.1(2)
174.18(5)
172.92(6)
174.9(5)
Fig. 3. Ellipsoid representation [21] of fac-[ReOCl2(HL2P)]. Thermal ellipsoids
represent 50% probability. H atoms have been omitted for clarity.
Table 3
Selected bond lengths (Å) and angles (°) in fac-[ReOCl2(HL2P)] (3).
ligand as has been observed previously, but remains in the solu-
tion. This fact is supported by 31P NMR spectra of the reaction mix-
ture. Reactions of anilines with oxo complexes are common and
many phenylimido complexes have been prepared in this way,
but there are only a few structurally characterized examples of
rhenium compounds with (2-hydroxyphenylimido) ligands [16].
Fig. 2 depicts an ellipsoid representation of 2, selected bond
lengths and angles are given in Table 2. Main structural features
of the compound are similar to the corresponding ‘parent complex’
[Re(NPh)Cl3(PPh3)2] [17]. The only remarkable feature in the
molecular structure of 2 is an intramolecular hydrogen bond
(O1–H1: 0.82 Å, H1–Cl2: 2.25 Å, O1–Cl2: 3.037(7) Å, O1–H1–Cl2:
161.3°), which is established between the phenolic oxygen atom
and one of the chloro ligands.
Re–O10
Re–Cl1
Re–Cl2
Re–P
1.679(4)
2.344(1)
2.429(1)
2.414(1)
Re–N1
Re–O1
N1–C7
N1–C11
2.195(4)
1.976(3)
1.500(7)
1.469(7)
O10–Re–Cl1
O10–Re–Cl2
O10–Re–P
O10–Re–N1
O10–Re–O1
104.1(1)
95.7(1)
91.8(1)
86.4(2)
163.2(2)
P–Re–N1
91.0(1)
77.2(2)
115.0(3)
109.3(3)
112.1(4)
N1–Re–O1
Re–N1–C7
Re–N1–C11
C7–N1–C11
gand. Expectedly, the oxygen atom occupies the position trans to
the oxo ligand, and the Re–O1 bond length of 1.973(3) Å is shorter
than expected for a rhenium–oxygen single bond. More bond
lengths and angles of 3 are summarized in Table 3. The coordina-
tion sphere around the metal atom is a distorted octahedron. Main
distortions from an ideal octahedron come from the requirements
of the four- and five-membered chelate rings, as can clearly be seen
at the N1–Re–O1 angle of 77.2°. The Re–Cl2 bond is slightly longer
than the Re–Cl1 bond, which is in accord with the stronger struc-
tural trans influence of the phosphine function compared with
the amine.
Concluding it can be stated that a stable tridentate ligand is ob-
tained by the reduction of a Schiff base derived from (2-formylphe-
nyl)diphenylphosphine, while the imine itself undergoes a rapid
hydrolysis when reacted with rhenium(V) oxo complexes. This
concept can be extended to ligand systems of higher denticity
starting from the Schiff bases derived from bis(2-formylphe-
nyl)phenylphosphine or tris(2-formylphenyl)phosphine. Such
studies are currently done in our laboratory.
Cleavage of the backbone of the organic ligand is avoided, when
the Schiff base is reduced prior reaction with the metal complex.
The resulting phosphine amine H2L2P is a robust chelating system,
which readily reacts with [ReOCl3(PPh3)2] under formation of fac-
[ReOCl2(HL2P)] (3) (Scheme 2). The same product is obtained by
heating a reaction mixture of H2L2P and (NBu4)[ReOCl4] in MeOH.
The coordination of the phosphorus atom is confirmed by a single
resonance in the 31P NMR spectrum at À4.6 ppm, which corre-
sponds to a 12 ppm shift compared to the resonance of uncoordi-
nated H2L2P. The IR spectrum contains
a medium intense
absorption at 968 cmÀ1 related to the Re@O vibration. The broad
band at 3452 cmÀ1 is consistent with the stretching vibrations of
the NH unit and indicates that the amine donor function is not
deprotonated.
The conclusions of the spectroscopic studies are confirmed by
an X-ray structure determination of the compound. Fig. 3 depicts
the molecular structure of 3 with a facially coordinated HL2PÀ li-

1158
A. Barandov, U. Abram / Polyhedron 28 (2009) 1155–1159
for 2 h. The volume of the solution was reduced to 3 mL and cooled
3. Experimental
to À10 °C. Two different types of crystalline products, red 1 and
green 2, deposited and were separated mechanically. Overall yield
of both compounds: 74 mg (ca. 80%). After a reaction time of 2 h an
approximate ratio of 1:2 between the compounds 1 and 2 was ob-
tained. The relative amount of 2 increased with prolonged reaction
times.
(NBu4)[ReOCl4] [18] and [ReOCl3(PPh3)2] [19] were prepared by
literature procedures. IR spectra were measured as KBr pellets on a
Shimadzu FTIR-spectrometer 8300. FAB+ mass spectra were re-
corded with a TSQ (Finnigan) instrument using a nitrobenzyl alco-
hol matrix. Elemental analysis of carbon, hydrogen and nitrogen
were determined using a Heraeus (vario EL) elemental analyzer.
1H, 13C and 31P{1H} NMR spectra were taken with
400 MHz multinuclear spectrometer.
a JEOL
3.4.1. Data for 1
Elemental Anal. Calc. for C43H34Cl2NO3P2Re (1ÁTHF) (931.7): C,
55.43; H, 3.68; N, 1.50%. Found: C, 53.87; H, 3.66; N, 1.62%. 1H
NMR (400 MHz, DMSO-d6, ppm): d 6.85–8.04 (m, 38H, aromatic),
10.58 (s, 1H, HC@N). 31P NMR (DMSO-d6, ppm): d 26.08 (s, PPh3),
29.44 (s, OPPh3). IR (KBr, cmÀ1): 3055 (m), 2851 (w), 1697 (w),
1589 (w), 1566 (w), 1477 (m), 1431 (st), 1194 (m), 1161 (m),
1095 (m), 1068 (w), 1026 (w), 941 (w), 748 (st), 694 (st), 517
(st). MS (FAB+): m/z 896 ([MÀCl]+, 1%), 635 ([MÀC18H14PCl]+, 3%).
3.1. Synthesis of HL1P
A
mixture of (2-formylphenyl)diphenylphosphine (1.5 g,
5.2 mmol) and 2-aminophenol (0.57 g, 5.2 mmol) were suspended
in 10 mL of ethanol and heated under reflux for 1.5 h. The product
precipitated as a yellow powder, which was filtered off and washed
with cold ethanol. Yield 1.8 g (93%). Elemental Anal. Calc. for
C25H20NOP (381.13): C, 78.73; H, 5.29; N, 3.67%. Found: C, 78.92;
H, 5.29; N, 3.51%. 1H NMR (400 MHz, DMSO-d6, ppm): d 6.72–8.30
(m, 18H, aromatic), 8.78 (s, 1H, OH), 9.14 (d, 1H, HC@N, JPH = 4.88
Hz). 13C NMR (DMSO-d6, ppm): d 115–136 (aromatic), 156 (HC@N).
31P NMR (DMSO-d6, ppm): d À12.9 s. IR (KBr, cmÀ1): 3283 (st), 3043
(m), 3013 (w), 2881 (w), 1632 (st), 1581 (m), 1481 (st), 1431 (m),
1369 (w), 1281 (w), 1250 (st), 1270 (m), 1122 (w), 1026 (w), 968
(w), 883 (w), 856 (w), 744 (st), 698 (st), 602 (w), 509 (m), 482
(m). MS (EI): m/z 381 ([M]+, 83%), 304 ([MÀPh]+, 100%).
3.4.2. Data for 2 Á THF
Elemental Anal. Calc. for C42H35Cl3NOP2Re (924.2): C, 54.58; H,
3.82; N, 1.52%. Found: C, 55.18; H, 4.19; N, 1.27%. 1H NMR
(400 MHz, CDCl3, ppm): d 6.17À7.87 (m, 34H, aromatic). 13C
NMR (CDCl3, ppm): d 127.8–138.7 (aromatic). 31P NMR (CDCl3,
ppm): d À20.68 s. IR (KBr, cmÀ1): 3132 (w), 3055 (w), 2970 (w),
2851 (w), 1593 (w), 1473 (m), 1431 (m), 1342 (w), 1238 (w),
1200 (m), 1153 (w), 1092 (m), 1061 (w), 1030 (w), 999 (w), 744
(m), 694 (st), 652 (w), 517 (st).
3.5. Synthesis of fac-[ReOCl2(HL2P)] (3)
3.2. Synthesis of HL1PO
HL1P (1 g, 2.6 mmol) was dissolved in 5 mL of THF and H2O2
(0.3 mL, 30% wt.) was added. After stirring the reaction mixture
for 10 min, 10 mL brine solution was added. The organic phase
was separated and dried over MgSO4. HL1PO was isolated as an
analytically pure, yellow powder after removal of the solvent. Yield
0.98 g (95%). Elemental Anal. Calc. for C25H20NO2P (397.41): C,
75.56; H, 5.07; N, 3.52%. Found: C, 75.68; H, 5.05; N, 3.61%. 1H
NMR (400 MHz, DMSO-d6, ppm): d 6.55–8.30 (m, 18H, aromatic),
8.9 (s, 1H, HC@N), 10.05 (s, 1H, OH). 31P NMR (DMSO-d6, ppm): d
31.6 s. 13C NMR (DMSO-d6, ppm): d 164.1 (s, HC@N). IR (KBr,
cmÀ1): 3420 (w), 3058 (m), 3024 (m), 1632 (m), 1578 (m), 1485
(s), 1435 (m), 1377 (w), 1354 (w), 1292 (m), 1223 (m), 1257 (st),
1157 (m), 1130 (m), 1111 (m), 1072 (m), 1029 (w), 968 (w), 767
(m), 748 (st), 702 (s), 578 (m), 540 (st).
[ReOCl3(PPh3)2] (83 mg, 0.1 mmol) was dissolved in 20 mL of
THF and H2L2P (38 mg, 0.1 mmol) was added as solid. The mixture
was stirred under reflux for 1 h, whereupon an olive-green suspen-
sion was obtained. The solvent was removed under reduced pres-
sure and the residue was suspended in 5 mL of MeOH. The olive-
green solid was filtered through a Celite pad and washed twice
with MeOH. Recrystallization from CH2Cl2/MeOH gave green
plates. Yield: 46 mg (71%). Elemental Anal. Calc. for
C25H21NO2Cl2PRe (656.5): C, 45.74; H, 3.38; N, 2.13%. Found: C,
Table 4
X-ray structure data collection and refinement parameters.
1
2 Á THF
3 Á MeOH
Formula
Mw
Crystal system
a (Å)
b (Å)
c (Å)
C43H34Cl2NO3P2Re C46H43Cl3NO2P2Re C26H23Cl2NO3PRe
3.3. Synthesis of H2L2
931.75
monoclinic
9.5913(7)
14.0170(7)
31.379(3)
90
97.62(1)
90
4181.4(5)
P21/c
996.37
triclinic
10.874(1)
12.198(1)
16.772(1)
73.12(1)
75.09(1)
82.03(1)
2052.4(2)
P1
687.54
triclinic
9.496(1)
10.733(1)
13.209(1)
81.49(1)
78.66(1)
74.98(1)
1268.1(2)
P1
HL1P (1.4 g, 3.6 mmol) and NaBH4 (0.91 g, 24 mmol) were sus-
pended in 20 mL of EtOH and heated for 10 min. After the reaction
solution became colorless, the solvent was removed under vacuum
and the product was extracted with 15 mL of Et2O. The organic
phase was washed with water and dried over MgSO4. A colorless
solid was obtained after removing the solvent under vacuum. Yield
1.2 g (88%). Elemental Anal. Calc. for C25H22NOP (383.4): C, 78.31;
H, 5.78; N, 3.65%. Found: C, 77.05; H, 5.42; N, 3.14%. 1H NMR
(400 MHz, DMSO-d6, ppm): d 4.36 (d, 2H, CH2, JHH = 5.24 Hz), 5.4
(t, 1H, NH JHH = 5.84 Hz), 6.05–7.6 (m, 18H, aromatic), 9.2 (s, 1H,
OH). 31P NMR (DMSO-d6,, ppm): d À16.6. IR (KBr, cmÀ1): 3514
(w), 3425 (m), 3055 (m), 2866 (w), 1604 (st), 1515 (st), 1438
(m), 1242 (m), 1192 (m), 1041 (w), 737 (st), 698 (m).
a
(°)
b (°)
c
(°)
V (Å3)
Space group
Z
4
2
2
Dc (g cmÀ3
)
1.480
1.612
1.801
l
(mmÀ1
)
3.148
3.274
5.094
Absorption
correction
Tmin/Tmax
Number of
reflections
Number of
independent
Number parameters
R1/wR2
Goodness of fit
Deposit umber
(ccdc)
integration
integration
integration
0.8554/0.7745
24050
0.8172/0.6807
20987
0.5527/0.4470
14474
8732
10926
6753
3.4. Synthesis of [ReOCl(PPh3)(L1PO)] (1) and
[Re(NC6H4OH)Cl3(PPh3)2] (2)
470
543
294
0.0608/0.1200
0.919
0.0547/0.1203
1.022
0.0381/0.1951
1.053
[ReOCl3(PPh3)2] (0.17 g, 0.2 mmol) and HL1PO (79 mg,
0.2 mmol) were dissolved in 20 mL of THF and heated under reflux
715062
715063
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A. Barandov, U. Abram / Polyhedron 28 (2009) 1155–1159
1159
45.91; H, 3.34; N, 1.91%. 1H NMR (400 MHz, DMS-d6, ppm): d 5.0
References
(d, 1H, CH2, JHH = 11 Hz), 5.6 (d, 1H, CH2, JHH = 11 Hz), 6.0 (t, 1H,
NH), 6.3–7.8 (m, 18H, aromatic). 31P NMR (DMSO-d6, ppm): d
À4.6. IR (KBr, cmÀ1): 3452 (m), 3058 (m), 2943 (w), 2846 (w),
1485 (st), 1435 (m), 1257 (m), 188 (w), 1099 (w), 968 (m), 771
(m), 752 (m), 694 (m), 633 (m), 517 (m). MS (FAB+): 654.9 ([M]+,
7%), 620 ([MÀCl]+, 48%).
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Acknowledgment
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Ali Barandov gratefully acknowledges a PhD scholarship of the
German Academic Exchange Service (DAAD).
Appendix A. Supplementary data
Supplementary crystallographic data can be obtained free of
charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or
from the Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: (+44) 1223 336 033; or e-mail: de-
posit@ccdc.cam.ac.uk. Supplementary data associated with this
article can be found, in the online version, at doi:10.1016/
j.poly.2009.01.016.