Synthesis, structure and reactions of 1-(p-chlorophenyl)-3-(2,4,6-tri-t-butylphenyl)-1-aza-3-phospha-allene

Article abstract of DOI:10.1016/S0022-328X(00)00281-3

A new phosphaazaallene Mes*P=C=NAr (Mes* = 2,4,6-^tBu₃C₆H₂, Ar = p-ClC₆H₄) (1) has been synthesized. Complex 1 reacts with Mes*PHSiMe^t₂Bu to form the phosphaazaallene i

Full text of DOI:10.1016/S0022-328X(00)00281-3

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 604 (2000) 260–266
Synthesis, structure and reactions of
1-(p-chlorophenyl)-3-(2,4,6-tri-t-butylphenyl)-1-aza-3-phospha-allene
Xi-Geng Zhou a,*, Li-Bei Zhang a, Rui-Fang Cai a, Qiang-Jin Wu b, Lin-Hong Weng c,
Zu-En Huang a
a Department of Chemistry, Fudan Uni6ersity, Shanghai 200433, People’s Republic of China
b The State Key Laboratory of Structural Chemistry, Fuzhou 350002, People’s Republic of China
c The State Key Laboratory of Elemental Organic Chemistry, Tianjin 300071, People’s Republic of China
Received 10 February 2000; received in revised form 14 April 2000; accepted 25 April 2000
Abstract
A new phosphaazaallene Mes*PꢀCꢀNAr (Mes*=2,4,6-tBu3C6H2, Ar=p-ClC6H4) (1) has been synthesized. Complex 1 reacts
with Mes*PHSiMet2Bu to form the phosphaazaallene insertion product Mes*PꢀC(PHMes*)NAr(SiMet2Bu) (2). The treatment of
1 with an excess amount of YCl3 in THF leads to the isolation of the symmetrical dimer Mes*P(m-CNAr)2PMes* (3), indicating
both of the PꢀC and CꢀN bonds of 1 are reactive sites. X-ray structure analysis of 1 indicates that the distance of the PꢀC bond,
,
,
1.642(5) A, is markedly shorter than those of isolated PꢀC bonds (1.66–1.72 A), and the NꢀCꢀP unit slightly deviates from
linearity with the PꢀCꢀN angle of 170.8(4)°. The structure determination of 2 revealed the molecule adopts a planar conformation
about PꢀC bond and the mutual orientation of two bulky Mes* moieties is almost orthogonal (92.8°). Complex 3 is a symmetrical
four-membered ring structure in which the Mes* rings lie nearly perpendicular to the planes of the Ar ring and the P2C2 ring (84.8
and 75.6°, respectively), while the Ar ring is almost parallel to the plane of the P2C2 ring (25.2°). © 2000 Elsevier Science S.A.
All rights reserved.
Keywords: Phosphorus; Yttrium trichlorides; Phosphaazaallene; Crystal structure; Insertion
1. Introduction
tions have been described so far [8,10,15,16], it is still
uncertain whether the phosphaazaallenes can become
excellent building blocks in organic and organometallic
synthesis as imines, phosphaalkenes or carbodiimides
featuring. On the other hand, since p bonding is gener-
ally weakened with increasing atomic number, for
phosphaazaallene-type compounds most of reactions
reported occur at the site of PꢀC double bond to date
[3–8], their reactivities at the CꢀN bond are relatively
unexplored [9,10]. In order to explore the cooperative
reactivity of different polar cumulative double bond
units, we report here the synthesis and reactivities of a
new phosphacumulene Mes*PꢀCꢀNAr.
There has been much recent interest in phosphacu-
mulenes because of their moiety of ambident reactivies
as well as their unique bonding situation [1–10]. The
heteropolar addition of an organometallic reagent to
the double bond of unsaturated molecules is the sim-
plest manifestation pattern. Varieties of insertion reac-
tions for other heterocumulenes such as carbon dioxide,
carbodiimides, isocyanates, isothiocyanates, carbon
disulfide, etc. have been known [11–14]. In contrast,
although isoelectronic phosphacumulenes are thought
desirable to possess some reactivities similar to their
nitrogen analogues, their reactivities have been studied
to a lesser extent due to the starting late and the
difficulty of preparation. Only a few examples of inser-
2. Results and discussion
2.1. Synthesis of Mes*PꢀCꢀNAr (1)
* Corresponding author. Tel.: +86-21-65643885; fax: +86-21-
65641740.
We have synthesized the new phosphaazaallene
Mes*PꢀCꢀNAr (1) by a slightly modified literature
E-mail address: xgzhou@fudan.edu.cn (X.-G. Zhou).
0022-328X/00/$ - see front matter © 2000 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(00)00281-3

X.-G. Zhou et al. / Journal of Organometallic Chemistry 604 (2000) 260–266
261
2.2. Crystal structure of Mes*PꢀCꢀNAr (1)
method for reactivity studies [3,17]. There have been
several reports on the preparation of phosphaazaal-
lenes, in which all the products were column chro-
matographed over silica gel. However, compound 1
decomposes very easily in the same conditions of the
column chromatography due to more highly reactive
and sensitive to moisture. Therefore, for the purifica-
tion of 1 the recrystallization is a preferable method to
the column chromatography. It needs to point out
that when 1 is purified by the extraction and recrystal-
lization with n-hexane, the stoichiometric reactions
must be strictly controlled and the THF solvent must
be completely removed from the residue, if not, 1 will
be very difficult to isolate.
The X-ray structure of 1 is shown in Fig. 1, with
selected bond lengths and angles in the caption. The
P, C, N and C(11) atoms are coplanar within 0.03 A.
,
The interplanar angle between this plane[P, C, N and
C(11)] with the Ar ring is 16.4°, which is remarkably
smaller than that found in Mes*PꢀCꢀNPh, 22.7°.
The change of the orientation of the Ar ring relative
to the PꢀCꢀNꢁC(11) plane suggests that some far
conjugation may be taking place between the cumu-
lene chain and the chlorine atom of the Ar group
[18]. The C(1), P, C and N atoms are also coplanar
,
within 0.02 A. This plane[C(1), P, C, N] makes an
Compound 1 was characterized by IR, 1H-NMR,
UV, and mass spectroscopies. The IR spectrum of 1
shows the characteristic absorption of the asymmetric
stretching vibration of the PꢀCꢀN moiety at 1831
cm−1 is lower, by about 15 cm−1, than the corre-
sponding absorption of Mes*PꢀCꢀNPh due to the far
conjugation of the chlorine atom. The molecular ion
and main fragments are clearly observed in the mass
spectra, indicating 1 to be monomeric structure.
angle of 77.2° with the plane of P, C, N and C(11)
atoms, and makes an angle of 85.4° with the Mes*
ring. These values are respectively similar to the cor-
responding dihedral angles in Mes*PꢀCꢀNPh, 75.8
,
and 87.4°. The PꢀC distance of 1.642(5) A in 1 is
comparable to the values found in other phosphacu-
,
mulenes, such as Mes*PꢀCꢀNPh, 1.651 A [19] and
,
Mes*PꢀCꢀPMes*, 1.635(8) A [20], but is markedly
shorter than isolated PꢀC bond distances with an sp2-
,
hybridized C atom (1.66–1.72 A) [21,22]. This short-
ening presumably results from the special electronic
characteristics of heteroallene system and the smaller
bond radius of the sp-hybridized C atom. The CꢀN
,
distance [1.214(6) A] is in the normal range observed
for carbodiimide systems [18], and is similar to that
,
observed in Mes*PꢀCꢀNPh (1.209 A) [19]. The ring
plane of Mes* group is almost perpendicular to that
of the Ar group, probably due to the steric repulsion
of the Ar group and the ortho-t-butyl groups of the
Mes* group.
The PꢀCꢀN angle of 170.8° in 1 is smaller than the
value expected for linear allene molecule which is
probably due to packing forces as commonly found in
cumulenes. The C(1)ꢁPꢁC angle of 99.8° is similar to
those in Mes*PꢀCPh2 [22] and 1,3-diphosphaallene
[20]. The smaller angle at the central P atom parallels
also those found in dipnictene compounds, such as
diphosphenes, diarsene, distibene and dibismuthene.
As a result it has been proposed that since the s-or-
bital character of the lone pairs increases with increas-
ing atomic number, the pnictogen atom trends toward
bonding to substituent via one non-hybridization p-or-
bital, thus the angle at the pnictogen atom decreases
sequentially from phosphorus to bismuth [23–27]. In-
terestingly, it is contrasted with the main trend of
decrease observed in the heavier pntictogen congeners,
the CꢁNꢁC(11) angle (128.3°) is significantly larger
than that in PhNꢀNPh (NꢁNꢁC=113.6°) [28], and is
even wider than that expected for the sp2 hybridization
angle. This is probably a result of the greater steric
Fig. 1. Molecular structure of Mes*PꢀCꢀNAr (1). Selected bond
lengths (A) and angles (°): PꢁC 1.642(5), PꢁC(1) 1.860(4), NꢁC
1.214(6), NꢁC(11) 1.423(6), ClꢁC(14) 1.732(5); CꢁPꢁC(1) 99.8(2),
CꢁNꢁC(11) 128.3(4), NꢁCꢁP 170.8(4).
,

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X.-G. Zhou et al. / Journal of Organometallic Chemistry 604 (2000) 260–266
congestion as well as the lone pair in the p-orbital for
the smaller, lighter nitrogen atom.
bond instead of the high reactive phosphaalkene one.
Because the two bulky ortho-t-butyl groups cause the
very large steric hindrance around the PꢀC and PꢁSi
units, this is unfavorable to their mutual action. As a
result, it provides a competitive chance for the smaller
steric hindrance CꢀN bond to react with
Mes*PHSiMet2Bu. Although the insertions of other cu-
mulenes (e.g. RNꢀCꢀNR%, CS2, PhNꢀCꢀO, etc.) into
PꢁSi bond have been known for long time, few inser-
tions of phosphaazaallenes into PꢁSi are reported [10].
This may give a new insight into the reactivity of
phosphacumulenes. Thus, further studies on other in-
sertions of phosphacumulenes are currently under way.
2.3. Studies on reacti6ity of Mes*PꢀCꢀNAr (1)
Compound 1 reacts with Mes*PHSiMet2Bu to form
the phosphaazaallene insertion product Mes*Pꢀ
C(PHMes*)NAr(SiMet2Bu) (2) with migration of phos-
phinyl onto the central carbon atom of phosphaazaal-
lene to form phosphaalkene (Eq. (1)). In contrast to the
results of the unsymmetrical dimerization of
Mes*PꢀCꢀNPh, catalyzed by Pd(0) complexes [9], YCl3
catalyzes dimerization of 1 to yield the symmetrical
dimer Mes*P(m-CNAr)2PMes* (3) (Eq. (2)). This reac-
tion proceeds smoothly regardless of the polarity of
solvents at room temperature, and is irreversible under
the mild reaction conditions. Related dimerization has
been previously observed [9,29], and has been at-
tributed to [2+2]-cycloaddition at the PꢀC double
bond. Two bands of strong to medium intensity in the
range of 1521–1591 cm−1 are attributed to the sym-
metric and antisymmetric CꢀN stretches of the 2,4-
diimino-1,3-diphosphetanes.
2.4. Description and discussion of crystal structure of 2
The crystal structure of 2 (Fig. 2) shows that the
molecule adopts a planar conformation about PꢀC
bond containing the atoms C(2), P(1), C(1), N and P(2),
and the N atom is in a sp2 hybridization state with
ꢀN=360°. But the P(2) center has quite pyramidal
coordination, ꢀP=290.5°, suggesting little delocaliza-
tion of the P(2) lone pair, at least in the ground state
[32,33]. To release the steric congestion between two
extremely bulky 2,4,6-tBu3C6H2 moieties, their mutual
orientation is almost orthogonal (92.8°). In addition,
the plane comprising from P(1), C(1), P(2) and N also
lies nearly perpendicular to three aromatic ring planes,
and made dihedral angles with planes of C(2)ꢁC(7)
ring, 77.8; C(20)ꢁC(25) ring, 90.7 and C(44)ꢁC(49) ring,
84.6°, respectively. The C(1)ꢁPꢁC(2) angle [112.6(2)°] is
significantly wider than that in 1, 99.8°. This is proba-
bly a result of the greater steric crowding arising from
the additional bulky Mes*PH and SiMet2Bu sub-
stituents compared with 1. The P(1)ꢁC(1) distance of
Mes*PCNAr+Mes*PHSiMet2Bu
“Mes*PC(PHMes*)N(Ar)SiMet2Bu
Mes*PꢀCꢀNArY“Cl3Mes*P(m-CNAr)2PMes*
(1)
(2)
Since insertion of a small molecule or an organic
functional group into a metalꢁcarbon bond represents a
fundamental step for any metal-promoted functional-
ization of a hydrocarbon residue, there is currently
considerable interest in studying the reactivities of the
LnꢁC bonds of organolanthanide complexes. Varieties
of the LnꢁC bond insertion reactions for other isoelec-
tronic heterocumulenes such as carbon dioxide, iso-
cyanates, carbon disulfide, etc. have been known
[30,31]. However, no insertion of phosphacumulenes
into the LnꢁC bond has been described up to now. To
further understand if Mes*PꢀCꢀNAr is capable of un-
dergoing the same insertion reaction, we studied the
reaction of 1 and (C5H4Me)2Dy(CMe3), but the result
indicates that 1 can not be inserted into the DyꢁC bond
at room temperature. This may be due to that the steric
factor of (C5H4Me)2Dy(CMe3) is unfavorable to the
bulky 1 to attack at the DyꢁC bond.
,
1.701(4)A is in normal range observed for isolated PꢀC
double bond distances [21,22]. Comparison of PꢁC
distances in 1 and 2, it is found that the PꢁC distance
changes with the difference of the carbon hybridization
states, but hardly changes with the difference of the
phosphorus ones. The coordination environment about
the silicon atom is approximately tetrahedral.
2.5. Description of crystal structure of 3
The formations of 2 and 3 indicate that both the PꢀC
and CꢀN bonds of 1 are reactive sites, and the reaction
selectivity depends to a large extent on the steric factors
and the electronic effects. Many previous investigation
results indicate that the PꢀC site is more reactive than
the CꢀN one in the phosphaazaallene molecules, and
the polarity of the PꢀC bond might be the phosphorus
atom as the more positive partner. It is probably the
steric hindrance that makes the most important contri-
bution to the low reactive imine insertion into the PꢁSi
The structure of 3 is similar to those of RP(m-
CꢀNPh)2PR [R=CH2CH3, CH2Ph, 2,4,6-(tBu)3C6H2]
[9,29]. The four-membered ring P2C2 is a planar and
has a rhombic geometry with the PꢁC bond distances
,
[1.813(2) and 1.829(2) A] and the PꢁCꢁP and CꢁPꢁC
bond angles [94.5(1) and 85.5(1)°, respectively]. The
Mes* rings lie nearly perpendicular to the planes of the
Ar ring and the P2C2 ring (84.8 and 75.6°, respectively),
while the Ar ring is almost parallel to the plane of the
P2C2 ring (25.2°). The average PꢁC bond distance of

X.-G. Zhou et al. / Journal of Organometallic Chemistry 604 (2000) 260–266
263
t
,
Fig. 2. Molecular structure of Mes*PꢀC(PHMes*)NAr(SiMe2Bu) (2). Selected bond lengths (A) and angles (°): P(1)ꢁC(1) 1.701(4), P(1)ꢁC(2)
1.872(4), P(2)ꢁC(1) 1.868(4), P(2)ꢁC(20) 1.856(4), NꢁC(1) 1.432(4), NꢁC(44) 1.444(4), SiꢁN 1.783(3), SiꢁC(38) 1.860(5), SiꢁC(39) 1.842(5), SiꢁC(40)
1.901(5), C(1)ꢁP(1)ꢁC(2) 112.6(2), C(1)ꢁP(2)ꢁC(20) 104.8(2), P(1)ꢁC(1)ꢁP(2) 115.1(2), P(1)ꢁC(1)ꢁN 133.5(3), P(2)ꢁC(1)ꢁN 111.4(2), C(1)ꢁNꢁC(44)
115.0(3), C(1)ꢁNꢁSi 128.4(2), C(44)ꢁNꢁSi 116.6(2).
,
1.821(2) A in the ring is comparable to the exocyclic
hexane were refluxed and distilled over sodium ben-
zophenone ketyl immediately before use. 2,4,6-Tri-t-
butylphenylphosphine (Mes*PH2) was prepared by the
published procedure [34]. t-Butylchlorodimethysilane
(Aldrich) was purified by sublimation prior to use.
The Mes*PHSiMet2Bu was prepared by reaction of
equiv of Mes*PH2 and BuLi in THF, followed silyla-
tion with Met2BuSiCl. Elemental analyses for C, H and
N were carried out on a Perkin–Elmer 240C analyzer.
Infrared spectra were obtained on a Nicolet FT-IR
360 spectrometer. A Nujol mull of the compound was
pressed between KBr pellets. Mass spectra were
recorded on a HP 5989A instrument operating in EI
mode. Samples were introduced by direct probe inlet
without any heating. The ion source temperature was
200°C. UV–visible spectra were recorded on a HP
8452A UV–vis absorption spectrophotometer. 1H-
NMR data were obtained on a Bruker MSL-300
NMR spectrometer.
,
PꢁC bond distance of 1.845(2) A. The CꢀN bond
,
distance of 1.282(3) A is similar to the values observed
previously. The steric constraints imposed by the Mes*
groups require them to be trans each other and the Ar
groups to adopt the Z-configuration. The endocyclic
angle of 85.5° at phosphorus atom is markedly
widened as compared to the corresponding angles in
[CH3CH2P(m-CNPh)]2 and [PhCH2P(m-CNPh)]2 [81
and 82°, respectively], but the endocyclic angle at car-
bon atom is smaller than the values observed in the
above compounds, 99 and 98°. This is presumably due
to the increased steric demand of the supermesityl
group as compared to CH3CH2- and PhCH2-groups.
3. Experimental
All the manipulations were carried out under
purified argon using Schlenk technique. THF and n-

264
X.-G. Zhou et al. / Journal of Organometallic Chemistry 604 (2000) 260–266
3.1. Preparation of 1-(p-chlorophenyl)-3-(2,4,6-tri-t-
butylphenyl)-1-aza-3-phospha-allene (1)
[M+−tBu, 46], 276 [Mes*P+, 31], 261 [Mes*P+ꢁCH3,
45], 220 [Mes*PH+ꢁtBu, 100], 57 [tBu+, 78].
Addition of butyllithium (1.80 M, in cyclohexane,
3.2. Insertion of 1 into PꢁSi bond of Mes*PHSiMet2Bu
1.80 ml) to
a
stirred solution of 2,4,6-tri-t-
butylphenylphosphine (0.900 g, 3.24 mmol) in 60 ml
of THF at −50°C caused an red solution under
argon. After 3 h, to the reaction solution t-butyl-
chlorodimethylsilane (0.490 g, 3.25 mmol) was added at
−15°C. The clear red solution became immediately
pale. Then, butyllithium was added to the mixture (3.25
mol) at −10°C. After being stirred overnight at ambi-
ent temperature, the reaction mixture was cooled at
−50°C and was slowly added to a cooled (−50°C)
solution of 4-chlorophenyl isocyanate (0.50 g, 3.26
mmol) in THF (20 ml) to give a red solution. After
being stirred for 3 h at −50°C, the reaction mixture
was warmed up to ambient temperature. The solvent
was evaporated under vacuum, and the yellow solid
was extracted with 100 ml of hexane. The red extract
solution was concentrated and cooled at −30°C to give
an orange–yellow powder. Recrystallization of the or-
ange–yellow powder from hexane gave 1 as orange
crystals (0.325 g, 24%). M.p. 148–149°C. 1H-NMR
(CDCl3): l=7.43 (d, 4JPH=2.3 Hz, 2H, m-Mes*),
7.09–7.28 (m, 4H, Ar), 1.66 (s, 18H, o-tBu), 1.30 (s,
9H, p-tBu). IR (KBr, cm−1): 3395 w, 2960 s, 2862 s,
1831 m, 1700 w, 1593 w, 1585 w, 1572 w, 1482 s, 1467
s, 1377 m, 1240 w, 1204 w, 1091 m, 1012 m, 878 m,
832 s, 742 m. UV (hexane): umax 220 (m 18 100),
268 (23 900), 296 (sh 8180), 420 nm (430). MS (EI):
m/z (fragment, relative intensity)=413 [M+, 65], 356
To a solution of 1 (0.12 g, 0.29 mmol) in 20 ml of
hexane was added Mes*PHSiMet2Bu (0.118 g, 0.30
mmol) in THF (20 ml). The mixture became slowly
yellow–green and was stirred at room temperature (r.t.)
for 36 h. The solvent was removed in vacuum, and the
residue was extracted with 40 ml of n-hexane to give
0.10 g of green crystals (2) in 43% yield. Elemental
Anal. Found: C, 72.63; H, 9.82; N, 1.76.
C49H78NP2ClSi, Calc.: C, 72.95; H, 9.75; N, 1.74%. IR:
3393 m, 2974 s, 2874 m, 1657 w, 1509w, 1460 s, 1361 w,
1260 s, 1177 m, 1069 s, 911 s, 808 m, 662 m. MS (EI):
m/z (fragment, relative intensity)=806 [M+, 2], 749
[M+−tBu, 15], 691 [M+−SiMet2Bu, 5], 528 [M+−
Mes*H2, 2], 472 [M+−Mes*PHꢁtBu, 22], 277
[Mes*PH+, 26], 220 [Mes*PH+ꢁtBu, 14], 115
[SiMet2Bu+, 4], 73 [Me2SiꢀNH+, 100], 57 [tBu+, 59].
UV (hexane): umax 222 (m 63 900), 232 (61 540), 286
(32 920), 334 nm (sh 18 600).
3.3. Dimerization of 1
To a solution of Mes*PꢀCꢀNAr (1) (0.12 g, 0.29
mmol) in THF (25 ml) was added anhydrous YCl3
(0.10 g, 0.51 mmol). The mixture became brown imme-
diately and was stirred at r.t. over night. The solvent
was removed in vacuum, and 3 was extracted from the
resulting residue with n-hexane. Cooling of the concen-
trated n-hexane solution to −20°C gave 3 as yellow
crystals (0.050 g, yield 42%). M.P. 238–240°C. Elemen-
tal Anal. Found: C, 72.12; H, 7.98; N, 3.41. Calc. for
C50H66N2P2Cl2: C, 72.53; H, 8.03; N, 3.38%. IR (KBr):
3442 m, 2963 s, 2868 m, 1591 m, 1521 s, 1480 s, 1393
m, 1362 m, 1120 w, 1089 w, 1006 m, 829 m, 612 m, 540
w, 498 w, 464 w, 428 w cm−1. MS (EI): m/z (fragment,
relative intensity)=715 [M+−Ar, 1.5], 630 [M+−
NArꢁtBuꢁCH3+1, 3.4], 586 [M+−2ArꢁCH4, 2.0], 494
[M+−Mes*ꢁtBuꢁ2CH3, 1.2], 413 [(M/2)+, 32.5], 357
[(M/2)+ꢁtBu+1, 35.8], 276 [Mes*P+, 13.5], 261
[Mes*P+ꢁCH3, 30.2], 220 [Mes*PH+ꢁtBu, 52.1], 111
[Ar+, 14.6], 86 [C2P2+, 1.2], 57 [tBu+, 100]. UV (hex-
ane): umax 218 (m 11 300), 234 (4 630), 242 nm (4630).
3.4. X-ray crystal structure determination of 1
Fig. 3. Molecular structure of Mes*P(m-CNPh)2PMes*. Selected bond
A suitable single crystal was sealed under argon in a
thin-walled glass capillary and mounted on an Enraf–
Nonius CAD-4 diffractometer. Lattice patameters were
determined from the angular settings of 25 reflections
with 13.93BqB14.81°. Crystal and data collection
parameters are given in Table 1. The intensities were
,
lengths (A) and angles (°): P(1)ꢁC(1) 1.829(2), P(1)ꢁC(1A) 1.813(2),
P(1)ꢁC(31) 1.845(2), P(1)ꢁP(1A) 2.674(1), Cl(1)ꢁC(24) 1.741(3),
N(1)ꢁC(1) 1.282(3), N(1)ꢁC(21) 1.405(3), C(1)ꢁPꢁC(1A) 85.5(1),
C(1)ꢁPꢁC(31) 122.2(1), C(1A)ꢁPꢁC(31) 121.9(1), C(1)ꢁN(1)ꢁC(21)
124.8(2), N(1)ꢁC(1)ꢁP(1) 139.3(2), N(1)ꢁC(1)ꢁP(1A) 125.8(2),
P(1)ꢁC(1)ꢁP(1A) 94.5(1).

X.-G. Zhou et al. / Journal of Organometallic Chemistry 604 (2000) 260–266
265
Table 1
Crystal and data collection parameters of 2, 5, and 7
Compound
1
2
3
Formula
Molecular weight
Size (mm)
Crystal color
Crystal system
Space group
Lattice parameters
C25H33NPCl
413.97
0.75×0.35×0.20
Red–orange
Monoclinic
P21/n
C
806.65
0.30×0.20×0.20
Green
Monoclinic
P21/n
49H78NP2ClSi
C50H66N2P2Cl2
827.94
0.45×0.35×0.20
Yellow
Triclinic
(
P1
,
a (A)
15.200(6)
9.982(6)
15.868(6)
10.319(3)
23.309(5)
21.41(1)
9.5349(7)
10.3912(8)
13.5741(10)
69.453(1)
75.242(1)
70.892(1)
1175.0(2)
1
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
99.47(3)
99.64(5)
3
,
V (A )
2375(3)
4
5078(3)
4
Z
Diffractometer
Enraf–Nonius CAD4
Rigaku AFC7R
Bruker Smart 1000
,
Radiation Mo–Ka (u, A)
(0.71069)
2.35
(0.71073)
1.92
(0.71069)
2.41
v (cm−1
)
Temperature (K)
Type of scan
2qmax (°)
296
ꢀ–2q
52
293
ꢀ–2q
50.0
296
ꢀ–2q
50.0
Reflections measured
Unique reflections observed
Reflections observed
Number of variables
Refinement
5339
4977
2692 [I\3|(I)]
253
F
7867
7326(Rint=0.021)
4359 [I\2.5|(I)]
487
4807
4045 (Rint=0.0141)
3550 [I\2|(I)]
253
F
F2
R
Rw
w
0.072
0.083
1/|2(F)
0.06
0.049
0.056
1/|2(F)
0.024
0.282
0.053
0.060
1/[|2(F2o)+(0.0972P)2+0.6790P] P=(Fo2+2F2c)/3
(D/|)max
Dzmax (e A
0.015
0.495
−3
,
)
0.32
corrected for Lorentz, polarization and absorption ef-
fects. The structure was solved by the direct methods
The structure was solved by direct methods [36] and
expanded using Fourier techniques [37]. The nonhydro-
gen atoms were refined anisotropically. Hydrogen
atoms were included but not refined. The positional
parameters for the most reasonable model were fixed
for the final least-squares cycles and the isotropic tem-
perature factors allowed to vary. The final cycle of
full-matrix least-squares refinement was based on 4359
observed reflections [I\2.50 |(I)] and 487 variable
parameters and converged to the final values of R=
0.057 and Rw=0.070. All calculations were performed
using the TEXSAN crystallographic software package of
Molecular Structure Corporation [38].
(MITHRIL) [35] and refined by full-matrix least squares
on F. The H-atoms were included in calculated posi-
tions with isotropic thermal parameters related to those
of the supporting carbon atoms, but were not included
in the refinement. All calculations were performed on a
Micro VAX 3100 computer.
3.5. X-ray crystal structure determination of 2
A suitable single crystal of 2 was sealed under N2 in
a thin-walled glass capillary. Final lattice parameters
were determined from a least-squares refinement using
the setting angles of 20 carefully centered reflections in
the range 13.48B2qB21.44°. Data were collected on a
Rigaku AFC7R diffractometer using the ꢀ–2q scan
technique to a maximum 2q value of 50.0°. Relevant
crystal and data collection parameters are given in
Table 1. During the data collection, the intensities of
three standard reflections measured every 200 reflec-
tions showed linear decay of −1.20%. A linear correc-
tion factor was applied. The intensities were corrected
for Lorentz, polarization and absorption effects.
3.6. X-ray crystal structure determination of 3
A yellow crystal of 3 was handled as described above
for 1. Data were collected on a Bruker Smart 1000
diffractometer using the ꢀ–2q scan technique to a
maximum 2q value of 50.0°. Relevant crystal and data
collection parameters are given in Table 1. The intensi-
ties were corrected for Lorentz, polarization and ab-
sorption effects.

266
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Crystallographic data for the structural analysis has
been deposited with the Cambridge Crystallographic
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compounds 1, 2 and 3. Copies of this information may
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12 Union Road, Cambridge, CB2 1EZ, UK (fax:
+44-1223-336033; e-mail: deposit@ccdc.cam.ac.uk or
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This work is supported by the National Natural
Science Foundation of China and the Shuguang Foun-
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thank the Open Laboratory of Organometallic Chem-
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