The first 1,3,2-diazaphospha-[3]ferrocenophanes

Article abstract of DOI:10.1016/j.inoche.2004.04.026

1,1^′-Diaminoferrocene 1 reacts with tert-butyl-(2a) and phenylphosphorus dichloride (2b) in the presence of triethylamine to afford the respective 1,3,2-diazaphospha-[3]ferrocenophanes 3a and 3b, of which 3a could be isolated in good yield and

Full text of DOI:10.1016/j.inoche.2004.04.026

Inorganic Chemistry Communications 7 (2004) 884–888
www.elsevier.com/locate/inoche
The first 1,3,2-diazaphospha-[3]ferrocenophanes
*
Bernd Wrackmeyer , Elena V. Klimkina, Wolfgang Milius
Laboratorium fur Anorganische Chemie II, Universit€at Bayreuth, D-95440 Bayreuth, Germany
Received 12 March 2004; accepted 23 April 2004
Available online 8 June 2004
Abstract
1,10-Diaminoferrocene 1 reacts with tert-butyl-(2a) and phenylphosphorus dichloride (2b) in the presence of triethylamine to
afford the respective 1,3,2-diazaphospha-[3]ferrocenophanes 3a and 3b, of which 3a could be isolated in good yield and high purity.
The phosphane 3a reacts with bis(trimethylsilyl)peroxide to give the oxide 5a, and with sulfur and selenium to the sulfide (6a) and
the selenide (7a), respectively. The molecular structures of 3a and 7a, as determined by X-ray analysis, show that the tert-butyl group
is in cis-position relative to the N–H bond vectors. NMR spectra prove that prominent structural features are retained in solution.
Ó 2004 Elsevier B.V. All rights reserved.
Keywords: Aminophosphanes; [3]Ferrocenophanes; NMR; X-ray
Aminophosphanes are of considerable interest in
synthesis, as ligands in transition metal complexes, and
the nature of the P–N bond, depending on the substit-
uents at phosphorus and nitrogen, is still a fascinating
topic [1–4]. Considering the bulkiness and rigid nature
of the ferrocene unit in [3]ferrocenophanes, such com-
plexes containing a N–P–N bridge could be of interest
for further transformations, in particular as ligands in
transition metal complexes. The steric requirements to-
gether with the redox behaviour of the ferrocene-derived
unit should provide attractive ligand properties of 1,3,2-
diazaphospha-[4]ferrocenophanes. Since 1,10-diamino-
ferrocene 1 [5] is now available by more convenient
methods [6], the synthesis of 1,n-diaza-[n]ferroceno-
phanes containing various heteroatoms in the bridge has
become an attractive goal [7–10]. In this work, we have
studied the reaction of 1 with RPCl2 2a (R ¼ tBu) and 2b
(R ¼ Ph).
both nitrogen atoms either prior to ring closure or fol-
lowing ring closure. The most likely structure [11,12] of
the major side products (4b,4b0) is given in Fig. 1 to-
gether with the 31P NMR spectrum of the reaction
mixture. The side products could not be separated from
3b.
However, the tert-butyl derivative 3a was isolated in
pure state as a yellow-orange crystalline solid, and its
molecular structure was determined by X-ray analysis
(Fig. 2). Oxidation of 3a to 5a proceeds readily under
mild conditions by the reaction of 3a with bis(trimeth-
ylsilyl)peroxide [13,14]. The reaction of 3a with ele-
mental sulfur or selenium leads to the sulfide 6a and the
selenide 7a, respectively (Scheme 1). All three complexes
5a, 6a and 7a are yellow-to-orange crystalline solids, and
the molecular structure of 7a was determined by X-ray
analysis (Fig. 3). The mixture containing 3b was treated
with elemental sulfur in the hope to precipitate side
products of higher molecular weight as less soluble
sulfides. Although the sulfide 6b could be identified by
NMR spectroscopy in the reaction mixture, it could not
be completely separated from other sulfides neither by
fractional crystallisation nor by chromatography.
For both complexes 3a and 7a, the crystal structure
determinations show that intermolecular interactions
are negligible. The cyclopentadienyl rings in 3a and 7a
are in eclipsed positions. The C5 planes are slightly tilted
The reaction (Scheme 1) of 1,10-diaminoferrocene 1
with 2a in the presence of triethylamine gives mainly the
1,3,2-diazaphospha-[3]ferrocenophane 3a, whereas the
analogous reaction of 1 with 2b affords the [3]ferroce-
nophane 3b in low yield along with various other
products which arise from further substitution at one or
* Corresponding author. Fax: +49-921-553157.
E-mail address: b.wrack@uni-bayreuth.de (B. Wrackmeyer).
1387-7003/$ - see front matter Ó 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.inoche.2004.04.026

B. Wrackmeyer et al. / Inorganic Chemistry Communications 7 (2004) 884–888
885
NH2
NH
NH
P(E)
NH
+ Me3SiOOSiMe3
+ 2 NEt3
P
R
R
RPCl2
+
Fe
Fe
Fe
or
+ E
Et2O
2
NH2
NH
- 2 [Et3NH]Cl
5 a 6a 6b 7a
tBu tBu Ph tBu
3
a
b
1
R
tBu Ph
R
E
O
S
S
Se
Scheme 1.
Fig. 1. 101.4 MHz 31P{1H} NMR spectrum of a reaction mixture containing 3b, and the diastereomers 4b and 4b0 (in D8-toluene at 23 °C); the
doublets according to 2J(31P, 31P) for 4b (256.9 Hz) are marked by asterisks; and for 4b0 (221.3 Hz) are marked by filled circles (assignment of the
doublets was confirmed by a 202.4 MHz 31P{1H} NMR spectrum).
Fig. 2. ORTEP plot (50 % probability; hydrogen atoms, except of NH,
are omitted for clarity) of the molecular structure of the 1,3,2-diaza-
phospha-[4]ferrocenophane 3a. Selected bond lengths and distances
[pm], and angles [°]: N(1)–P 172.1(5), N(2)–P 174.4(4), P–C(11)
185.9(6), C(1)–N(1) 142.7(7), C(6)–N(2) 143.1(6), N(1)ꢀ ꢀ ꢀN(2) 274.3,
Fig. 3. Ball and stick model (hydrogen atoms, except of NH, are
omitted for clarity) of the molecular structure of the 1,3,2-diaza-
N(2)PC(11) 101.4(2), C(1)N(1)P 115.0(4), C(6)N(2)P 113.4(4). C5/C5
C(1)ꢀ ꢀ ꢀC(6) 312.3; N(1)PN(2) 104.7(2), N(1)PC(11) 101.8(2),
selenophosphoryl-[3]ferrocenophane 7b. Selected bond lengths and
distances [pm], and angles [°]: N(1)–P 161.5(18), N(2)–P 164.8(16),
C5 (twist) (sÞ 0.
(aÞ 8.9, C5/N(1) (b1) 5.5, C5/N(2) (b2) 1.8, C5–Fe(1)–C5 (cÞ 171.9, C5/
P–C(11) 184(2), P–Se 211.9(5), C(1)–N(1) 141(2), C(6)–N(2) 144(2),
N(1)ꢀ ꢀ ꢀN(2) 260.0, C(1)ꢀ ꢀ ꢀC(6) 308.3; N(1)PN(2) 105.7(9), N(1)PC(11)
towards each other, forming an angle a ¼ 8:9° (3a) or
107.7(10), N(2)PC(11) 103.7(8), N(1)PSe 112.6(8), N(2)PSe 112.2(6),
C(11)Pxe 114.2(7), C(1)N(1)P 128.5(15), C(6)N(2)P 123.5(12). C5/C5
10.4° (7a). The C–N bond vectors differ slightly from the
C5 planes by 5.5° (N(1)), 1.8° (N(2)) in 3a, and by 5.4°
(N(1)) and 4.7° (N(2)) in 7a. The tert-butyl group in 3a is
(a) 10.4, C5/N(1) (b1) 5.4, C5/N(2) (b2) 4.7, C5–Fe(1)–C5 (cÞ 173.1,
C5/C5 (twist) (sÞ 0.

886
B. Wrackmeyer et al. / Inorganic Chemistry Communications 7 (2004) 884–888
in cis-position with respect to the N–H bond vectors
which minimizes steric repulsion with the ferrocenylene
moiety. The addition of selenium in 7a does not change
the configuration at the phosphorus atom as to be ex-
pected. Typical for the P(V) atom in 7a, the P–N and P–
C distances become shorter than in 3a.
(CHCl3/CDCl3) ¼ 7.24; (CDHCl2) ¼ 5.33; (CD3(CD2H)-
SO) ¼ 2.50; d13C (CDCl3) ¼ 77.0; (CD2Cl2) ¼ 53.8,
((CD3)2SO) ¼ 39.4]; external aqueous H3PO4 (85%) with
d31P ¼ 0 for N(31P) ¼ 40.480747 MHz. IR spectra: Per-
kin–Elmer Spectrum 2000 FTIR. EI–MS spectra: Finn-
igan MAT 8500 spectrometer (ionisation energy 70 eV)
The prominent structural features of 3a and 7a are
retained in solution as shown by the NMR data in Table
1. The inversion at the phosphorus atom in 3a is slow on
the NMR time scale, as usual for phosphanes, which
gives rise to four different 1H and 13C resonances for the
CH units of the cyclopentadienyl rings. The magnitude
of 2J(31P,1HNH) is small (9.0 Hz) which can be related to
the orientation of the NH bond vectors with respect to
the lone pair of electrons at phosphorus [15]. In the case
of 3b, the magnitude of 2J(31P,1HNH) is much larger
(25.8 Hz) which points towards a different configuration
at the phosphorus atom in 3b when compared with 3a.
with direct inlet; the m=z data refer to the isotopes 1H, 12
C
14N, 56Fe, 16O, 32S and 80Se. The melting points (uncor-
€
rected) were determined using a Buchi 510 or a Stuart
Scientific smp 3 melting point apparatus.
2-tert-Butyl-1,3,2-diazaphospha-[3]ferrocenophane 3a.
A suspension of 1,10-diaminoferrocene 1 (325 mg, 1.5
mmol) in Et2O (45 mL) together with triethylamine (0.5
mL, 3.59 mmol) was prepared. The suspension was
t
cooled to 0 °C, and BuPCl2 (239 mg, 1.5 mmol) dis-
solved in Et2O (5 mL) was added dropwise. The reaction
mixture was stirred at 0 °C for 2 h; then it was allowed
to reach ambient temperature and kept stirring for 20 h.
Insoluble materials were filtered off, and volatile mate-
rials were removed from the filtrate in vacuo. The re-
maining yellow solid was dissolved in Et2O (30 mL) and
the solution was filtrated. After removing of the solvent
in vacuo 3a (424 mg; 93%) was left as yellow-orange
solid. Crystallisation from CH2Cl2, after 2 weeks at )20
°C, gave red-orange crystals of 3a (m.p. 194–196 °C).
1H NMR (CD2Cl2, 23 °C): d ¼ 1:20 (d, 9H, MeC,
3J(1H,31P) ¼ 11.7 Hz), 1.80 (br d, 2H, NH, 2J(1H,
31P) ¼0 9.0 Hz), 3.75, 3.84 and 3.99 (all m, 2H, 4H, 2H,
1
In the case of 7a, a complete assignment of all H (see
Fig. 4) and 13C resonances has been carried out, and the
data were found to be in full agreement with predictions
on the basis of the solid-state molecular structure.
All syntheses and the handling of the samples was
carried out observing necessary precautions to exclude
traces of air and moisture. Carefully dried solvents and
oven-dried glassware were used throughout. 1,10-Dia-
minoferrocene 1 was prepared according to the pub-
lished procedure [6]. NMR measurements in solution (5
0
mm o.d. tubes): Bruker ARX 250: 1H (250.1 MHz), 13
C
H2–5;2 –5 ). H NMR (D8-toluene, 23 °C): d ¼ 0:96 (d,
1
(62.9 MHz), 31P (101.3 MHz) and 77Se NMR (47.7
9H, MeC, J(1H,31P) ¼ 11.6 Hz), 1.37 (br d, 2H, NH,
3
1
MHz); Bruker DRX 500: H (500.1 MHz), 31P (202.4
2J(1H,31P) ¼ 9.4 Hz), 3.57, 3.83, 3.91 and 3.97 (all m,
0
0
MHz); chemical shifts are given relative to Me4Si [d1H
8H, H2–5;2 –5 ). EI–MS (70 eV) for C14H19N2PFe
Table 1
13C, 31P, 77Se and 1H NMR dataa of the 2-R-1,3-diaza-2-phospha-[3]ferrocenophanes
Compound PR
3a P–tBu
5a P(O)tBu
6a P(S)tBu
7ac P(Se)tBu
3b P–Ph
6b P(S)Ph
d
31P
103.8
51.5 (DMSO)
50.3 (CD2Cl2)
102.9
101.6
106.9
79.4
[792.5] 1J(31P,77Se)
(68.4) 1J(31P,13CCP
(9.0) 2J(31P,13C)
25.5 (1.2) Me
)
d
13C(PR)
25.7 (13.8) Me
29.9 (9.3) P–C
25.4 (<0.5) Me
30.5 (107.0) P–C
25.6 (<0.5) Me
35.2 (79.5) P–C
128.4 Cm
128.9 Cp
130.6 Co
141.0
129.1 (14.3) Cm
131.8 (11.6) Co
132.4 (3.2) Cp
n.o. Ci
36.8 (68.4) P–C
d
d
d
d
d
13C(fc-C1)
13C(fc-C2)
13C(fc-C3)
13C(fc-C4)
13C(fc-C5)
98.4 (3.3)
60.0 (7.0)
64.7 (1.2)
67.1 (<0.5)b
66.7 (<0.5)b
1.80 {9.0}
93.1 (7.4)
68.1 (3.4)
63.5 (<0.5)
66.8 (<0.5)
65.1 (<0.5)
4.83
92.0 (8.8)
68.0 (3.9)
66.0 (0.7)
68.1 (<0.5)b
66.7 (<0.5)b
3.14 {8.4}
91.9 (9.0)
68.3 (3.7)
66.3 (0.9)
68.2 (<0.5)b
67.1 (<0.5)b
3.23 {8.3}
98.5 (7.2)
62.4 (<0.5)
65.4 (<0.5)
67.3 (<0.5)
68.2 (<0.5)
3.03 {25.8}
93.2 (10.2)
70.3 (2.8)
62.5 (<0.5)
68.6 (<0.5)
66.9 (0.9)
d1H(NH)
3.78 {5.3}
{11.8}(DMSO)
2.94
{11.2}(CD2Cl2)
a Measured in CD2Cl2 (3a,3b,6b), CDCl3 (6a,7a), (CD3)2SO (5a); coupling constants nJ (31P,13C) (ꢁ0.5 Hz) are given in parentheses; coupling
constants 2J(31P,1H) are given in braces; coupling constants 1J(77Se,31P) are given in brackets; n.o. ¼ not observed.
b Assignment might be reversed.
c d77Se )250.9 [792.5].

B. Wrackmeyer et al. / Inorganic Chemistry Communications 7 (2004) 884–888
887
Fig. 4. 500 MHz 1H{1H] NOE difference spectra (gradient enhanced [16]) of 7a (2% in CDCl3 at 23 °C; relaxation delay 1 s; mixing time 0.8 s; 4 min
0
0
of spectrometer time). The NH-resonance was irradiated and response is shown for the 1H resonances of H2;2 , H5;5 and the tert-butyl group, as
expected from the results of the crystal structure determination. The complete assignment of the NMR signals is based on 2D 1H/1H NOESY, 2D
1H/1H COSY and 2D 13C/1H HETCOR experiments.
(302.06): m=z (%) ¼ 302 (50) [Mþ], 245 [Mþ–C4H9]
(100), 200 (10); 166 (9), 139 (6).
C14H19N2PSFe (334.04): m=z (%) ¼ 334 (100) [Mþ], 278
[Mþ–C4H8] (40), 245 (8), 199 (60); 135 (5).
2-tert-Butyl-1,3.2-diaza-phosphoryl-[3]ferrocenophane
5a. Bis(trimethylsilyl)peroxide (328 mg, 1.84 mmol) was
added to a solution of 3a (138 mg, 0.46 mmol) in Et2O
(30 mL) at 0 °C. After standing for 20 h at room tem-
perature, a precipitate was formed, and filtered off from
the reaction solution. This solid was dried under vacuum
to give 5a as a yellow powder (135 mg, 93%; m.p. 299–
The selenide 7a was prepared in the same way, using
toluene as a solvent. The selenide was obtained in 94%
yield as a yellow solid. Crystallisation from CHCl3, after
2 weeks at )20 °C, gave yellow-orange crystals of 4, m.p.
1
200–230 °C (decomposition). H NMR (CDCl3, 23 °C):
d ¼ 1:42 (d, 9H, MeC, 3J(1H,31P) ¼ 17.4 Hz), 3.23 (br d,
0
2
2H, NH, J(10H,31P) ¼ 8.3 Hz), 3.99 (m, 2H, H3;3 ), 4.03
0
1
301 °C). H NMR (CD2Cl2, 23 °C): d ¼ 1:34 (d, 9H,
(m, 02H, H2;2 ), 4.10 (m, 2H, H4;4 ) and 4.82 (m, 2H,
MeC, 3J(1H,31P) ¼ 15.1 Hz), 2.94 (br d, 2H, NH,
H5;5 ). H NMR (D8)-toluene, 23 °C): d ¼ 1:03 (d, 9H,
1
2J(1H,31P)0¼0 11.2 Hz), 3.95, 4.00, 4.05 (all m, 2H, 2H,
MeC, 3J(1H,31P) ¼ 17.0 Hz), 2.64 (br d, 2H, NH,
0
0
1
2H, H2–4;2 –4 ) and 4.17 (m, 2H, H5;5 ). H NMR (D6-
2J(1H,31P) ¼ 8.9 Hz), 3.69 (m, 2H, H3;3 ), 3.80 (m, 2H,
0
0
0
3
DMSO, 23 °C): ¼ 1.24 (d, 9H, MeC, J(1H,31P) ¼ 14.1
H2;2 ), 3.92 (m, 2H, H4;4 ) and 4.99 (m, 2H, H5;5 ). EI–
MS (70 eV) for C14H19N2PSeFe (381.98): m=z (%) ¼ 382
(100) [Mþ], 326 [Mþ–C4H8] (30), 324 (15), 247 (55), 245
(72), 167 (10); 139 (7).
0
0
Hz), 3.83, 3.93 and 3.99 (all m, 4H, 2H, 2H, H2–5;2 –5 ),
2
4.83 (br d, 2H, NH, J(1H,31P) ¼ 11.8 Hz). EI–MS (70
eV) for C14H19N2OPFe (318.06): m=z (%) ¼ 318 (85)
[Mþ], 262 [Mþ–C4H8] (100), 182 (73), 135 (12). IR
(CHCl3) m[cmꢂ1] ¼ 3386 (N–H).
2-Phenyl-1,3,2-diazaphospha-[3]ferrocenophane 3b
and the sulfide 6b. A suspension of 1,10-diaminoferro-
cene 1 (280 mg, 1.3 mmol) in Et2O (30 mL) together with
triethylamine (0.43 mL, 3.1 mmol) was prepared and
cooled to 0 °C before PhPCl2 (232 mg, 1.3 mmol) dis-
solved in Et2O (5 mL) was added dropwise. The reaction
mixture was stirred at 0 °C for 2 h, then allowed to reach
ambient temperature and kept stirring for 20 h. Insoluble
materials were filtered off, and volatile materials were
removed from the filtrate in vacuo. The yellow, oily-
residue was dissolved in Et2O (10 mL), filtrated, and then
the solvent was removed in vacuo to give 216 mg of a
mixture containing 3b (ca. 50%) and 4b,4b0, together with
some starting material 1 as a yellow, oily-material.
2-tert-Butyl-1,3-2-diaza-thiophosphoryl-[3]ferroceno-
phane 6a and the selenophosphoryl derivative 7a. A
solution of 3a (100 mg, 0.33 mmol) in CH2Cl2 (5 mL)
was added at room temperature to an excess of pure,
degassed elemental sulfur (32 mg). The solution was
stirred for 1 day and then filtered to remove most of the
unreacted sulfur. The solvent was removed in vacuo to
give 105 mg (95%) of 6b as a yellow-green solid. 1H
NMR (CDCl3, 23 °C): d ¼ 1:43 (d, 9H, MeC,
3J(1H,31P) ¼ 16.7 Hz), 3.14 (br d, 2H, NH,
2J(1H,31P) ¼ 8.4 Hz), 3.98, 4.00, 4.09 (all m, 2H, 2H, 2H,
0
0
0
H2–4;2 –4 ) and 4.67 (m, 2H, H5;5 ). EI–MS (70 eV) for

888
B. Wrackmeyer et al. / Inorganic Chemistry Communications 7 (2004) 884–888
Table 2
Crystallographic data of the [3]ferrocenophanes 3a and 7a
nat.): +44 (0)1223/336033; e-mail: deposit@ccdc.cam.
ac.uk].
3a
7a
Formula
Crystal
C14H19FeN2P
Red-orange
prism
C14H19FeN2PSe
Yellow-orange
platelet
Acknowledgements
Dimensions (mm)
Crystal system
0.25 ꢃ 0.16 ꢃ 0.14 0.25 ꢃ 0.22 ꢃ 0.08
This work was supported by the Deutsche Fors-
chungsgemeinschaft.
Monoclinic
Cc
Monoclinic
P21=c
Space group
Lattice parameters (pm, °)
a
b
c
b
1705.9(3)
860.51(17)
1056.0(2)
118.39(3)
4
2009.4(4)
1292.3(3)
1166.2(2)
94.04(3)
8
References
[1] (a) H.R.G. Bender, E. Niecke, M. Nieger, H. Westermann, Z.
Anorg. Allg. Chem. 620 (1994) 1194;
Z
Absorption coefficient
l (mmꢂ1
Diffractometer
1.206
3.502
€
(b) B. Eichhorn, H. Noth, T. Seifert, Eur. J. Inorg. Chem. (1999)
2355;
)
STOE IPDS I (Mo Ka, k ¼ 71; 073
(c) B. Wrackmeyer, C. Kohler, W. Milius, J.M. Grevy, Z. Garcia-
Hernandez, R. Contreras, Heteroatom Chem. 13 (2002) 667.
[2] (a) Z. Fei, R. Scopelliti, P.J. Dyson, J. Chem. Soc., Dalton Trans.
(2003) 2772;
pm), graphite monochromator
Measuring range (#, °)
Reflections collected
Independent reflections
(I > 2rðIÞ)
2.7–26
2036
1708
2.4–28
13272
6983
(b) P. Wimmer, M. Widhalm, Tetrahedron: Asymmetry 6 (1995)
657.
Absorption correctiona
Refined parameters
WR2/R1 (I > 2rðIÞ)
None
163
0.104/0.043
None
343
[3] (a) J.D. Woollins, J. Chem. Soc., Dalton Trans. (1996) 2893;
(b) T. Chivers, R.W. Hilts, Coord. Chem. Rev. 137 (1994) 201;
(c) P. Wisian-Neilson, K.-T. Nguyen, S. Rippstein, C. Claypool,
F.J. Garcia-Alonso, Phosphorus, Sulfur Silicon 87 (1994)
277–285.
0.381/0.130
2.321/)0.912
Max./min. residual electron 0.407/)0.322
density (e pmꢂ3 10ꢂ6
)
a Absorption corrections did not improve the parameter set.
[4] (a) S. Priya, M.S. Balakrishna, J.T. Mague, J. Organomet. Chem.
679 (2003) 116;
(b) T.Q. Ly, A.M.Z. Slawin, J.D. Woollins, J. Chem. Soc., Dalton
Trans. (1997) 1611;
The mixture containing 3b and 4b,4b0, dissolved in
toluene (5 mL), was added at room temperature to ele-
mental sulfur. This mixture was stirred for 4 h, and then
insoluble materials were filtered off. The solvent was
removed in vacuo to give of mixture containing 6b (ca.
50%) together with the sulfides of 4b/4b0 as a yellow
solid. Several circles of dissolving and filtration led to
(c) S. Doherty, M. Waugh, T.H. Scanlan, M.R.J. Elsegood, W.
Clegg, Organometallics 18 (1999) 679.
[5] (a) G.R. Knox, Proc. Chem. Soc. London (1959) 56;
(b) G.R. Knox, P.L. Pauson, J. Chem. Soc. (1961) 4615;
(c) A.N. Nesmeyanov, V.N. Drozd, V.A. Sazonova, Dokl. Akad.
Nauk. SSSR 150 (1963) 321.
[6] A. Shafir, M.P. Power, G.D. Whitener, J. Arnold, Organometal-
lics 19 (2000) 3978.
1
samples enriched in 6b; 6b: H NMR (CDCl3, 23 °C):
[7] A. Shafir, M.P. Power, G.D. Whitener, J. Arnold, Organometal-
lics 20 (2001) 1365.
d ¼ 3:78 (br d, 2H, NH, 2J(1H,31P) ¼ 5.3 Hz), 03.20, 3.92,
0
4.00 and 4.21 (all m, 2H, 2H, 2H, 2H, H2–5;2 –5 ), 7.10–
[8] (a) B. Wrackmeyer, E.V. Klimkina, H.E. Maisel, W. Milius, M.
Herberhold, Inorg. Chim. Acta 357 (2004) 1703;
(b) B. Wrackmeyer, E.V. Klimkina, W. Milius, Inorg. Chem.
Commun. 7 (2004) 412.
7.30 (m, 3H Ph), 7.50–7.65 (m, 3H, Ph), 7.90–8.05 (m,
2H, Ph).
Crystal structure determinations of the [3]ferroceno-
phane 3a and its selenide 7a. Details pertinent to the
crystal structure determinations are listed in Table 2.
Crystals of appropriate size were sealed under argon in a
Lindemann capillary, and the data collections were
carried out at 20 °C.
[9] (a) B. Wrackmeyer, W. Milius, H.E. Maisel, H. Vollrath, M.
Herberhold, Z. Anorg. Allg. Chem. 629 (2003) 1169;
(b) B. Wrackmeyer, H.E. Maisel, W. Milius, M. Herberhold, J.
Organomet. Chem. 680 (2003) 271.
[10] A. Shafir, J. Arnold, J. Am. Chem. Soc. 123 (2001) 9212.
[11] S.A. Katz, V.S. Allured, A.D. Norman, Inorg. Chem. 33 (1994)
1762.
[12] (a) O.J. Scherer, G. Schnabl, Angew. Chem. 88 (1976) 845;
(b) O.J. Scherer, G. Schnabl, Angew. Chem. Int. Ed. 15 (1976)
772.
Supplementary information
[13] (a) D. Brandes, A. Blaschette, J. Organomet. Chem. 73 (1974) 217;
(b) L. Wozniak, J. Kowalski, J. Chojnowski, Tetrahedron Lett. 26
(1985) 4965.
Crystallographic data (excluding structure factors)
for the structures reported in this paper have been de-
posited with the Cambridge Crystallographic Data
Centre as supplementary publication Nos. CCDC
234160 (3a) and CCDC 234161 (7a). Copies of the data
can be obtained free of charge on application to CCDC,
12 Union Road, Cambridge CB2 1EZ, UK [fax (inter-
[14] (a) J. Breker, R. Schmutzler, Chem. Ber. 123 (1990) 1307;
(b) X. Liu, P. Ilankumaran, I.A. Guzei, J.G. Verkade, J. Org.
Chem. 65 (2000) 701.
[15] V.M.S. Gil, W. von Philipsborn, Magn. Reson. Chem. 27 (1989)
409.
[16] K. Stott, J. Keeler, Q.N. Van, A.J. Shaka, J. Magn. Reson. 125
(1997) 302.